Student Assignments for CL-1919-06_053327 Part 5-6 — Student Experiments and Advanced Assignments Ohm’s Law and DC Circuits Trainer 95-CL-1919-06_Part5-6_REVA © ConsuLab Educatech Inc, 2023. Tous droits réservés. 95-CL-1919-06 Table of Contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 2 Table of Contents Trainer Layout and Familiarization 4 Front Panel Component Identification 5 Electrical Component Identification 6 Electrical Accessories 7 Trainer Use and Operation 8 Warnings and Cautions 9 Student Learning Modules 10 MODULE 5 Student Experiments Student Assignment Guidelines 12 SA-16 — Light Bulb with Diode 13 SA-16 — Light Bulb with Diode - Student Answer Sheet 15 SA-17 — Light Bulb Circuits 16 SA-17 — Light Bulb Circuits - Student Answer Sheet 18 SA-18 — Light Bulb Circuits with Resistances 19 SA-18 — Light Bulb Circuits with Resistances - Student Answer Sheet 23 SA-19 — Light Bulb Circuits with Problems 24 SA-19 — Light Bulb Circuits with Problems - Student Answer Sheet 27 SA-20 — Relay Circuits 28 SA-20 — Relay Circuits - Student Answer Sheet 30 SA-21 — Flasher Controlled Circuit 31 SA-21 — Flasher Controlled Circuit - Student Answer Sheet 33 SA-22 — PWM Circuit with Motor 34 SA-22 — PWM Circuit with Motor - Student Answer Sheet 37 SA-23 — Transistor Controlled Circuits 38 SA-23 — Transistor Controlled Circuits - Student Answer Sheet 44 MODULE 6 Advanced Student Circuit Assignments SA-24 — Using M1 as a Generator 47 SA-24 — Using M1 as a Generator - Student Answer Sheet 49 SA-25 — Alarm System — Option 1 50 SA-25 — Alarm System — Option 1 - Student Answer Sheet 51 95-CL-1919-06 Table of Contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 3 SA-26 — Alarm System — Option 2 52 SA-26 — Alarm System — Option 2 - Student Answer Sheet 53 SA-27 — Light Bulb Dimming 54 SA-27 — Light Bulb Dimming - Student Answer Sheet 55 SA-28 — Horn Circuit with Relay 56 SA-28 — Horn Circuit with Relay - Student Answer Sheet 57 SA-29 — Alternately Flashing Lights 58 SA-29 — Alternately Flashing Lights - Student Answer Sheet 59 SA-30 — Throttle Position Sensor Circuit 60 SA-30 — Throttle Position Sensor Circuit - Student Answer Sheet 63 SA-31 — PWM Controlled NPN Transistor Circuit 65 SA-31 — PWM Controlled NPN Transistor Circuit - Student Answer Sheet 68 SA-32 — PWM Controlled PNP Transistor Circuit 69 SA-32 — PWM Controlled PNP Transistor Circuit - Student Answer Sheet 72 SA-33 — Flashing Lights Transistor Controlled Circuit 73 SA-33 — Flashing Lights Transistor Controlled Circuit - Student Answer Sheet 76 4 95-CL-1919-06 Introduction consulab.com info@consulab.com Trainer Layout and Familiarization The CL-1919-06_053052 Ohm’s Law and DC Circuits Trainer contains electrical and electronic components mounted on a panel containing electrical connection receptacles where students complete the wiring of circuits. The trainer is designed to provide learning assistance in the understanding of basic Ohm’s Law concepts and also provides learning activities for student learning of basic circuit components and operation. A built-in 120VAC to 14VDC (4 A max) power supply is internally protected and is adjustable from 2-14 VDC. The front panel contains a digital display indicating the DC voltage supply available to the trainer. The CL-1919-06_053052 trainer meets CSA/UL safety requirements. The CL-1919-06 also contains a surface mounted digital multi-meter (DMM) that is powered with two AAA replaceable batteries. NOTE : Because the trainer’s power supply output is limited to 4 A, the meter’s internal 10A ammeter fuse should never need replacement. The meter is used throughout the student activities and circuit construction for electrical measure- ments and diagnostic training. CL-1919-06 Ohm’s Law and DC Circuits Trainer 95-CL-1919-06 Introduction consulab.com info@consulab.com 5 Front Panel Component Identification Front View 1. Trainer power cord receptacle, master ON/OFF switch and main fuse holder. 2. Positive (red) receptacles for circuit construction. These receptacles are only to be used with the trainer and not to be connected to any external devices as damage could result. 3. Negative (black) receptacles for circuit construction. These receptacles are only to be used with the trainer and not to be connected to any external devices as damage could result. 4. Digital Display for available trainer voltage (Displays the DC voltage that has been set by the voltage adjustment knob). 5. Power supply voltage adjustment knob (Adjusts the available DC voltage from 2-14 ± VDC). 6. Power supply safety reset button (Resets the internal protection cut-out. Push and hold until the O.L. light flashes, then release. The voltage display will read 0.000 when the O.L. lamp is on.). 7. Power supply “OVERLIMIT” indicator light (If a short circuit is created between the Positive & Negative sides of the trainer, the internal protection cut-out will trip and turn on the O.L. indicator light. It will remain on until the problem has been corrected and the RESET button is pushed). 8. PWM (Pulse Width Modulation) generator positive and negative receptacles. 9. PWM Adjustment knob (0-100% duty cycle). 10. Digital Multi-meter. Side View 1 3 2 47 6 5 9 8 10 95-CL-1919-06 Introduction consulab.com info@consulab.com 6 Electrical Component Identification 11. L1 – # 194 Bulb. 12. L2 – # 194 Bulb. 13. D1 – LED Bulb. 14. B1 – BUZZER. 15. T1 – NPN Transistor. 16. T2 – PNP Transistor. 17. D2 – Diode. 18. L3 – # 3157 LED Bulb. 19. M1 – DC Motor. 20. RL1 – ISO 5-pin Relay. 21. Electronic Flasher. 22. POT – 75Ω Potentiometer. 23. R1 – 100Ω Resistor. 24. R2 – 40Ω Resistor. 25. R3 – 20Ω Resistor. 26. R4 – 20Ω Resistor. 27. R5 – 2Ω Resistor. 28. F1 – Optional Circuit Fuse (ATC 2-3A). 29. SW1 – SPST Toggle Switch. 30. PB1 – N.O. Push Button Switch. Front View 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 95-CL-1919-06 Introduction consulab.com info@consulab.com 7 Electrical Accessories Storage Bag Main Fuse Main Fuse Specifications: Model 239002P 2A, 250V, 239 Series, Slo-Blow Fuse (5 mm x 20 mm). Storage Bag Jumper Leads CL-1919-05 POWER SUPPLY FUSE SPECIFICATIONS – 239002P 2A, 250V, 239 Series, Slo-Blow Fuse (8mm x 20mm) TRAINERS MAIN FUSE LOCATION PULL TAB AWAY UNTIL FUSE HOLDER POPS OUT CLOSE UP OF MAIN FUSE HOLDER CLOSE UP OF MAIN FUSE HOLDER SPARE FUSE FUSE IN CIRCUIT CL-1919-05 POWER SUPPLY FUSE SPECIFICATIONS – 239002P 2A, 250V, 239 Series, Slo-Blow Fuse (8mm x 20mm) TRAINERS MAIN FUSE LOCATION PULL TAB AWAY UNTIL FUSE HOLDER POPS OUT CLOSE UP OF MAIN FUSE HOLDER CLOSE UP OF MAIN FUSE HOLDER SPARE FUSE FUSE IN CIRCUIT CL-1919-05 POWER SUPPLY FUSE SPECIFICATIONS – 239002P 2A, 250V, 239 Series, Slo-Blow Fuse (8mm x 20mm) TRAINERS MAIN FUSE LOCATION PULL TAB AWAY UNTIL FUSE HOLDER POPS OUT CLOSE UP OF MAIN FUSE HOLDER CLOSE UP OF MAIN FUSE HOLDER SPARE FUSE FUSE IN CIRCUIT Your product may be equipped with either of the below jumper wire styles. They are identical in specifications and performance. All CL-1919-06’s will be shipped with banana plug jumper leads including: • 10 Red Jumper Leads — 23” (60cm) long • 10 Black Jumper Leads — 23” (60cm) long 95-CL-1919-06 Introduction consulab.com info@consulab.com 8 Trainer Use and Operation The CL-1919-06-93 manual is designed to provide instructors and students with the necessary information for the prop- er and safe operation of the trainer. Note that the CL-1919-06 trainer includes student assignments (95-CL-1919-06 ) and an instructors manual (CL-1919-06-96). Be sure to read, understand and follow the instructions for each section. The CL-1919-06 is designed to be used as a “stand alone” resource to aid the instructor and students in the learning of basic electricity, Ohm’s Law, DMM meter use, basic electrical and electronic component operation, basic operational circuit construction and diagnosis and troubleshooting of circuit problems. NOTE: Before proceeding with this manual, the following tasks should have already been successfully performed and understood: 1. Familiarization with the CL-1919-06 component layout and identification (pages 5-8). 2. The CL-1919-06 should be set up on a bench/tabletop with the cover removed, the power cord plugged into the trainer and a 120VAC outlet and the master ON/OFF switch turned “on”. NOTE- The cover lid of the trainer can be placed on a table, then move the trainer on top of the cover. This po- sitions the trainer with a slight tilt providing an easier access for users. If properly completed, the digital display should be indicating the available DC voltage. For normal operation, and unless otherwise directed, the display should be adjusted to a reading of 14.0 - 14.6 ± volts. Rating Specifications: • Voltage: 100-240 VAC, single phase • Frequency: 50/60 Hz • Input Current: 2.2 A @120 VAC, 1.2 A @ 230VAC • Output current : 2-14 VDC, 4 A max. • Indoor use only • Temperature: 10 ºC – 30 ºC (50 ºF – 86 ºF) • Humidity (non-condensing): 90 % max. • Altitude : 2,000 m (6,562 ft) • Pollution Degree 2 • Overvoltage Category II Students conducting the circuit learning assignments should have completed the following Learning Modules which contain the prerequiste skills and knowledges: • Understanding basic digital multi-meter setup, use & interpretation (Student Learning Module #1). • Basic electricity (Student Learning Module #2). • Ohm’s Law (Student Learning Module #3). • Component explanation (Student Learning Module #4) • Ability to read and follow written instructions. • Ability to read and interpret basic electrical wiring schematics. 95-CL-1919-06 Introduction consulab.com info@consulab.com 9 Warnings and Cautions Even though the power supply is internally protected against short-circuits and wiring errors, students should carefully read, understand and follow all activity instructions to avoid errors. NOTE- If the digital display shows “0.000” volts and the O.L. lamp is “on”, an overcurrent situation has been detected. To re-set the system, find and correct the wiring error, then push and hold the RESET button until the O.L. lamp flashes, then release. If the reset procedure was successfully completed, the display should read available voltage: 1. The 2-3A ATC blade type fuse on the trainer is for optional use by instructors and students as needed. Circuits can be connected with the fuse if desired. Remember that the trainer is internally protected to trip the over-current protection if current exceeds 4 A. 2. Access to fuse compartment and any other components inside of unit to be performed only by trained skilled per- sonnel. 3. L1 and L2 bulbs are made of glass and could break if impacted hard enough, therefore potentially creating a cutting hazard. 4. Do not connect any external device to be powered by the trainer as they may exceed the designed limits of the power supply and components. 5. Be sure to read, understand and follow each set of instructions. Be sure to ask your instructor if you have any ques- tions about any instruction or component. 6. Never “guess” about the results of a circuit. Always follow written instructions to avoid “guesswork”. 7. This product is intended for use in educational establishments by STUDENT OPERATORS at least 14 years of age and under the supervision of theRESPONSIBLE PERSON. 10 95-CL-1919-06 Introduction consulab.com info@consulab.com Student Learning Modules The CL-1919-06 manuals contain Student Learning Modules designed to provide information and resources to assist stu- dents in mastering various skills and knowledges covered with this trainer. Each module comes with educational support information, student activity assignments, student answer sheets, instructor keys and assessment tests. Instructors can use them as they see fit for their programs. Student answer sheets, schematics and assignments can be duplicated and distributed within the schools programs only. PDF fillable answer sheets are also available. Duplication of documents used for outside sources is prohibited. Assignment and test answer sheets can be filed in student files for record keeping of progress. It is recommended that instructors follow the chronological order of the assignments. However, each mod- ule can be presented on its own if desired. The CL-1919-06 Learning Modules 1. UNDERSTANDING THE DIGITAL MULTIMETER — SETUP, USE & INTERPRETATION 2. BASIC ELECTRICITY 3. OHM’S LAW 4. COMPONENT EXPLANATION 5. STUDENT EXPERIMENTS 6. ADVANCED STUDENT CIRCUIT ASSIGNMENTS 11 95-CL-1919-06 Module 5 — Student Experiments consulab.com info@consulab.com MODULE 5 Student Experiments 12 95-CL-1919-06 Module 5 — Student Experiments consulab.com info@consulab.com Student Assignment Guidelines Each of the following student assignments are designed to reinforce and apply the concepts, theories and explanations previously discussed in this manual. Be sure to carefully read and understand the directions for each as- signment. Assignments also require the careful completion of a Student Answer Sheet for each assignment. Be sure to obtain the correct Student Answer Sheet for the assignment you are working on. NOTE : For the purposes of this manual and student use of the CL-1919-06 trainer, all manual references to the direc- tion of electron flow will use the CONVENTIONAL ELECTRON THEORY which is from positive to negative in the circuit. Prerequisites Before starting the student assignments the following instructional modules should have been completed and the as- sessment tests and/or quizzes successfully taken and evaluated by your instructor : • Meter setup, use and reading interpretation unit • Basic electricity • Ohm’s Law • Component operation explanation Most assignments will be organized using the following format : • Students will be given wiring instructions for the correct hookup of the RED and BLACK jumper wires to complete the circuit. • Students will be asked to draw the circuit they are building on a blank template and label it with the name of the circuit being constructed. • If students are asked to make voltage, resistance or amperage measurements, specific instructions on how to ac- complish the readings will not be given as this information was covered in the Meter Unit. • Students are asked to fill out a student answer sheet for each assignment and turn in to their instructor when com- pleted. Trainer set up Unless otherwise noted, it is expected that the trainer is properly plugged into a 120V receptacle and the power supply is turned on. The displayed voltage should be approximately 14.0 - 14.6 volts. 13 95-CL-1919-06 Module 5 — SA-16 consulab.com info@consulab.com SA-16 — Light Bulb with Diode SA-16 — Circuit Explanation This assignment demonstrates the operation of a diode in circuits. The diode performs the function of an electrical “one-way” check valve and can be used to block electrical flow in one direction. SA-16 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-16 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the RED positive receptacles to terminal O of SW1. B. Terminal I of SW1 to terminal A (anode) of diode D2. C. Terminal K (cathode) of diode D2 to terminal C of bulb L2. CONNECT BLACK JUMPER WIRES BETWEEN : A. Terminal D of bulb L2 to any of the BLACK ground receptacles. 2. Draw the circuit you have just constructed on a blank template and label it : SA-16 LIGHT BULB WITH DIODE. 3. Turn switch SW1 to the “ON” position. Bulb L2 should be illuminated with full brilliance. Double check the operation of your circuit. If the circuit does not operate as described, go over your connections and make necessary correc- tions. 4. Measure the voltage drop across diode D2 and record your measurement on the answer sheet. 5. Measure the voltage drop across bulb L2 and record your measurement on the answer sheet. 6. Measure the amperage draw of the circuit and record your measurement on the answer sheet. 7. Using Ohm’s Law, calculate the resistance of bulb L2 and record your answer on the answer sheet. 8. Using Ohm’s Law, calculate the resistance of diode D2 and record your answer on the answer sheet. 9. Add the resistances of bulb L2 and diode D2 together. 10. Fill in the below calculated or measured values on the answer sheet : A. TOTAL CIRCUIT RESISTANCE. B. TOTAL CIRCUIT AMPERAGE. C. SUPPLY VOLTAGE. 14 95-CL-1919-06 Module 5 — SA-16 consulab.com info@consulab.com 11. Using Ohm’s Law, prove out that the total circuit resistance, supply voltage and circuit amperage all mathematically “fit together”. Fill in the below calculated values on the answer sheet. A. Voltage divided by amperage equals ? ohms of total circuit resistance. B. Voltage divided by resistance equals ? amps of total circuit amperage. C. Amperage times resistance equals ? volts of circuit supply. 12. Do your calculations match the measured values above ? Yes or No. Put your answer on the answer sheet). 13. Turn switch SW1 to the “OFF” position. CIRCUIT EXPLANATION : The diode D2 is conducting current flow in a “forward bias” direction. Diode schematic sym- bols indicate the direction of current flow. Notice that the power “feed” enters the diode at terminal A and exits the diode at terminal K as it flows into bulb L2 and then through the bulb to ground. The arrow on the schematic symbol indicates that the diode “flows” in the direction of the arrow. The diode D2 in the circuit draws a very small amount of current because it’s low resistance is connected in series with the light bulb and total resistance of the circuit is accu- mulative. The diodes low resistance compared to the light bulb’s resistance is very low, but because it is a series circuit, adding additional low resistances will have very little effect on total circuit amperage. 14. Reverse the RED jumper wires at terminals A and K of diode D2. 15. Turn switch SW1 to the “ON” position. 16. What describes the operation of the circuit now ? Put your answer on the answer sheet. 17. Measure the voltage drop across diode D2 and record your reading on the answer sheet. 18. What conclusions can you make from the reading taken in Step 17 (describe it on the answer sheet). 19. Install a jumper wire from terminals A to K of diode D2 and describe the circuit performance on answer sheet. 20. Turn switch SW1 to the “OFF” position. CIRCUIT EXPLANATION : Reversing the positive wires at the diode causes the current to attempt to flow “backwards” through the diode. This is called “reverse bias” and unless the diode is defective, it will block electron flow. There are very technical explanations that describe the internal operation of a diode, but for the purposes of this basic assign- ment, it will suffice to say that a diode conducts in a forward bias condition and blocks electron flow in a negative bias condition. Installing the jumper wire takes the diode out of the circuit and allows current flow to the light bulb. 15 95-CL-1919-06 Module 5 — SA-16 consulab.com info@consulab.com SA-16 — Light Bulb with Diode - Student Answer Sheet Name : Group : Date : 4. Voltage drop of diode D2 volts. Expressed as : 5. Voltage drop of bulb L2 volts. Expressed as : 6. Amperage draw of circuit amps. Expressed as : 7. Bulb L2 resistance ohms. Expressed as : 8. Diode D2 resistance ohms. Expressed as : 9. Total circuit resistance ohms. Expressed as : 10. A. total circuit resistance. Expressed as : B. total circuit amperage. Expressed as : C. supply voltage. Expressed as : 11. A. Voltage divided by amperage equals ohms of total circuit resistance. Expressed as : B. Voltage divided by resistance equals amps of total circuit amperage. Expressed as : C. Amperage multiplied by resistance equals supply voltage. Expressed as : 12. Yes/No. 16. 17. voltage drop across diode D2. Expressed as : 18. 19. Instructor grade : Comments : 16 95-CL-1919-06 Module 5 — SA-17 consulab.com info@consulab.com SA-17 — Light Bulb Circuits SA-17 — Circuit Explanation This assignment is designed to demonstrate the relationship between bulb resistance and illumination brightness. How bright a light bulb is depends on the amount of designed internal resistance. SA-17 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-17 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal O of switch SW1. B. Terminal I of switch SW1 to the LO terminal of bulb LED L3 LO. C. Using the piggy back feature, terminal I of switch SW1 to terminal A of bulb L1. D. Using the piggy back feature, terminal I of switch SW1 to terminal C of bulb L2. E. Using the piggy back feature, terminal I of switch SW1 to terminal E of LED D1. F. Any of the four RED power terminals to left-hand terminal of switch PB1. G. Right-hand terminal of switch PB1 to the HI terminal of bulb LED L3 HI. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to the COM terminal of bulb LED L3. B. Terminal B of bulb L1 to any of the four ground receptacles. C. Terminal D of bulb L2 to any of the four ground receptacles. D. Terminal F of LED D1 to any of the four ground receptacles. 2. Draw the circuit you have just constructed on a blank circuit schematic template and label it : SA-17 LIGHT BULB CIRCUITS. 3. Turn switch SW1 to the ON position. Bulbs L1 & L2, LED L3 LO and the LED D1 should all be on. Confirm proper circuit operation and correct any errors. 4. Push the PB1 switch pushbutton down and the HI side of bulb LED L3 should come on. Confirm proper circuit opera- tion and correct any errors. 5. Using the ammeter feature of the DMM measure the individual current flow of bulbs L1, L2, LED L3 LO, LED L3 HI and the LED D1. Record your measurements on the student answer sheet : A. ? amps for L1. B. ? amps for L2. 17 95-CL-1919-06 Module 5 — SA-17 consulab.com info@consulab.com C. ? amps for LED L3 LO. D. ? amps for LED D1. E. ? amps for LED L3 HI. 6. Using the voltmeter function of the DMM, measure the voltage drop across each bulb and record on the student answer sheet : A. ? voltage drop across L1. B. ? voltage drop across L2. C. ? voltage drop across LED L3 LO. D. ? voltage drop across LED D1. E. ? voltage drop across LED L3 HI. 7. Turn switch SW1 to the OFF position. 8. Based on your readings, is the circuit you have constructed a “series” or a “parallel” circuit. Put your answer on the answer sheet. 9. Using Ohm’s Law, calculate and record the bulb resistances for L1, L2, LED L3 LO, LED L3 HI and LED D1. Record your answers on the answer sheet. 10. Evaluate your calculations of individual bulb resistances. What bulb has the highest resistance ? (Answer sheet). 11. What bulb has the lowest resistance ? Put your answer on the answer sheet. 12. What bulb was the brightest ? Put your answer on the answer sheet. 13. Compare the amount of current used and the amount of light produced by LED D1 and incandescent bulb L1. Put your answer on the answer sheet. 14. What is the advantage LED’s have over incandescent bulbs ? CONCLUSIONS : The brightness of an incandescent bulb is controlled by its internal resistance. LEDs have much higher internal resistance and also lower current draw than incandescent bulbs, but can give off much brighter light. This is the main advantage of today’s vehicles using LED bulbs. The operate with much less current, lower temperatures and last much longer than incandescent bubs. The higher the resistance, the “dimmer” the bulb will be when compared to anoth- er bulb with less resistance. Any light bulb is designed to operate with a designed amount of supply voltage and a good ground circuit. Any unwanted resistance in either side of the circuit will result in improper performance and the bulb being “dimmer” than designed. The next assignment demonstrates the effect of having unwanted resistance in lighting circuits. 18 95-CL-1919-06 Module 5 — SA-17 consulab.com info@consulab.com SA-17 — Light Bulb Circuits - Student Answer Sheet Name : Group : Date : 2. Draw the constructed circuit on a blank template and label the circuit “LIGHT BULBS”. Use RED for positive wires and BLACK for negative wires. 5. A. amps for L1. Expressed as : B. amps for L2. Expressed as : C. amps for LED L3 LO. Expressed as : D. amps for LED D1. Expressed as : E. amps for LED L3 HI. Expressed as : 6. A. voltage drop across L1. Expressed as : B. voltage drop across L2. Expressed as : C. voltage drop across LED L3 LO. Expressed as : D. voltage drop across LED D1. Expressed as : E. voltage drop across LED L3 HI. Expressed as : 8. SERIES or PARALLEL. 9. A. ohms of resistance for L1. Expressed as : B. ohms of resistance for L2. Expressed as : C. ohms of resistance for LED L3 LO. Expressed as : D. ohms of resistance for LED D1. Expressed as : E. ohms of resistance for LED L3 HI. Expressed as : 10. What bulb has the highest resistance ? 11. What bulb has the lowest resistance ? 12. What bulb was the brightest ? 13. 14. Instructor grade : Comments : 19 95-CL-1919-06 Module 5 — SA-18 consulab.com info@consulab.com SA-18 — Light Bulb Circuits with Resistances SA-18 — Circuit Explanation This assignment is designed to demonstrate the effect of resistance in lighting circuits. Poor lighting circuit performance and dim light bulbs is often the cause of unwanted resistance somewhere in the circuit. It is the technician’s job to accu- rately locate and repair the resistance problem. SA-18 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-18 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal O of switch SW1. B. Terminal I of switch SW1 to terminal Q of resistor R4. C. Terminal P of resistor R4 to terminal LO of bulb LED L3. D. Using the piggy back feature, terminal I of switch SW1 to terminal C of bulb L2. E. Using the piggy back feature, terminal I of switch SW1 to terminal O of resistor R3. F. Terminal N of resistor R3 to terminal A of bulb L1. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to the COM terminal of bulb LED L3. B. Terminal B of bulb L1 to any of the four ground receptacles. C. Terminal D of bulb L2 to any of the four ground receptacles. 2. Draw the circuit you have just constructed on a blank circuit schematic template and label it : SA-18 LIGHT BULB CIRCUITS WITH RESISTANCES. 3. Turn switch SW1 to the ON position and observe circuit performance. Describe the circuit performance on your answer sheet : A. Describe bulb L1’s operating condition ? B. Describe bulb L2’s operating condition ? C. Describe bulb LED L3 LO operating condition ? 95-CL-1919-06 Module 5 — SA-18 consulab.com info@consulab.com 20 4. Using the voltmeter function of the DMM, conduct voltage drop testing of the following bulbs or circuits. Record your measurements on the answer sheet : A. Voltage drop across bulb L1. B. Voltage drop across bulb L2. C. Voltage drop across bulb LED L3 LO. D. Voltage drop of the ground circuit of bulb LED L3 LO. E. Voltage drop of the ground circuit of bulb L1. F. Voltage drop of the ground circuit of bulb L2. 5. Evaluate your measurements. Each bulb is designed to operate on full source voltage (12.6 – 14.5 V). If unwanted resistance is present, it reduces the available voltage to the light bulb and thus, causes dimmer performance. CONCLUSION : The voltage drop testing performed can be interpreted as follows : A. There is unwanted resistance in bulb L1 circuit and it is NOT in the ground circuit because the voltage drop is within accepted parameters. B. There is no unwanted resistance in bulb L2 circuit and it is operating normally. C. Even though there is unwanted resistance in the LED L3 LO positive circuit (R4), it has NO EFFECT on the operation of the LED bulb. This is because the internal dynamic resistance of the LED bulb is 427± ohms and adding R4 (20Ω) to the circuit will have a very insignificant affect on the L3’s performance. The resistance is there, but does not affect the circuit. The resistance is there, but does not affect the circuit. This is another advantage of LED bulb. SA-18 — Locating the Unwanted Resistance When attempting to locate unwanted resistance in a circuit, many technicians utilize a testing procedure called “point to point” testing which if conducted properly, will identify the problem. In the following steps, you will practice the process of identifying the unwanted resistance in bulb L1 circuit. Obviously, you can observe that the unwanted resistance (R3) is installed in the positive side between the switch SW1 and terminal A of bulb L1, but in a vehicle, this would not be the case. Remember that we know the problem isn’t in the ground circuit because the voltage drop measured from terminal B of bulb L1 to the ground receptacles was acceptable. 6. Leave one lead of the voltmeter attached to the RED positive receptacles and connect the other voltmeter lead to the following test points and record each voltage drop on the answer sheet : A. Terminal O of switch SW1. B. Terminal I of switch SW1. C. Terminal O of resistor R3. D. Terminal N of resistor R3. E. Terminal A of bulb L1. 21 95-CL-1919-06 Module 5 — SA-18 consulab.com info@consulab.com 7. There are several different methods of voltage drop testing. Some technicians measure the voltage drop across the ends of each connection of the circuit. While accurate, this method is often a very time consuming process due to lack of accessibility of the different components in the circuit. For explanation purposes only, if the circuit were to be tested using this approach, the test points are listed below. 8. If you wish to make these measurements, you may do so : A. RED positive receptacle to terminal O of switch SW1 (will result in normal readings). B. Terminal O to terminal I of switch SW1 (will result in normal readings). C. Terminal I of switch SW1 to terminal O of resistor R3 (will result in normal readings). D. Terminal O to terminal N of resistor R3. NOTE : This is where the unwanted resistance would first show up. E. Terminal N of resistor R3 to terminal A of bulb L1 (will result in normal readings). CONCLUSIONS : Checking voltage drops in the positive side of the circuit revealed that everything from the RED pos- itive receptacles to terminal O of resistor R3 was within normal ranges. As soon as the voltmeter lead was moved to terminal N of resistor R3, the voltage drop increased significantly. Therefore, the problem (unwanted resistance) must be located between terminals O and N of resistor R3. CONFIRMATION : 9. With the circuit operating, install a jumper wire to connect terminals O and N of resistor R3. 10. Measure the positive circuit voltage drop from the RED positive receptacles to terminal A of bulb L1. (answer sheet) 11. Describe the operational condition of bulb L1 with the jumper installed (Answer sheet). SA-18 — Voltage Drop Testing of Bulb Led L3 Lo Circuit These steps will demonstrate another method of voltage drop testing to locate the source of unwanted resistance. 12. Measure the available voltage at bulb LED L3 LO and record your measurement on answer sheet. EVALUATION : Anything less than full source voltage indicates an unwanted resistance in the circuit. You will use voltage drop testing to locate the source of the resistance. Obviously, there is a problem here in this circuit. 13. Conduct voltage drop test of the ground circuit and record your measurement on the answer sheet. NOTE : Your readings should indicate that there is no voltage drop in the ground circuit. 14. Leave one lead of the voltmeter attached to any of the four RED positive receptacle and make voltage drop tests to the following locations. Record your measurements on the answer sheet : A. Terminal P of resistor R4. B. Terminal Q of resistor R4. C. Terminal I of switch SW1. D. Terminal O of switch SW1. E. RED positive receptacles of trainer. consulab.com info@consulab.com 22 95-CL-1919-06 Module 5 — SA-18 CONCLUSIONS : The voltage drop testing of the LED L3 LO positive circuit (with one lead of voltmeter attached to any of the four RED power receptacles, the first testing point was Terminal P of resistor R4. The reading showed a drop of about 0.750 volts. That indicates an unwanted resistance is somewhere in the circuit. The next testing point was terminal Q of resistor R4 indicated a “normal” reading. That confirms that the unwanted resistance was located between termi- nals P and Q of resistor R4. All of the remaining voltage drop test points reveals a very low drop. Voltage drop testing is a very valuable method of locating unwanted resistances in either the positive or ground side of any circuit. Many technicians use the “jumper method” of testing with a fused jumper to temporarily bypass a wire or connection during diagnosis. This process saves time where accessibility problems block access to circuit components and connections. NEVER bypass a component with a fused jumper wire as this can remove all resistance in the circuit and create a short. The next assignment involves unwanted resistances in the ground circuit. 23 95-CL-1919-06 Module 5 — SA-18 consulab.com info@consulab.com SA-18 — Light Bulb Circuits with Resistances - Student Answer Sheet Name : Group : Date : 3. What is the description of each bulb’s performance ? A. Bulb L1’s condition. B. Bulb L2’s condition. C. Bulb LED L3 LO’s condition. 4. Voltage drop testing of circuit : A. Voltage drop across bulb L1. Expressed as : B. Voltage drop across bulb L2. Expressed as : C. Voltage drop across bulb LED L3 LO. Expressed as : D. Voltage drop of the ground circuit of bulb LED L3 LO. Expressed as : E. Voltage drop of the ground circuit of bulb L1. Expressed as : F. Voltage drop of the ground circuit of bulb L2. Expressed as : 6. Voltage drop testing for the positive side of bulb L1 circuit with one voltmeter lead on RED positive receptacles. A. Terminal O of switch SW1. Expressed as : B. Terminal I of switch SW1. Expressed as : C. Terminal O of resistor R3. Expressed as : D. Terminal N of resistor R3. Expressed as : E. Terminal A of bulb L1. Expressed as : 10. Voltage drop of positive side of bulb L1 circuit. Expressed as : 11. Condition of bulb L1 : 12. Available voltage at bulb LED L3 LO. Expressed as : 13. Voltage drop of bulb LED L3 LO ground circuit. Expressed as : 14. Voltage drop testing of bulb LED L3 LO positive circuit. A. Terminal P of resistor R4. Expressed as : B. Terminal Q of resistor R4. Expressed as : C. Terminal I of switch SW1. Expressed as : 15. D. Terminal O of switch SW1. Expressed as : E. RED positive receptacles of trainer. Expressed as : Instructor grade : Comments : 24 95-CL-1919-06 Module 5 — SA-19 consulab.com info@consulab.com SA-19 — Light Bulb Circuits with Problems SA-19 — Circuit Explanation This assignment will demonstrate the negative effects of resistances in both the positive and ground paths in lighting circuits and how to best identify and locate the problems. SA-19 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-19 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal O of switch SW1. B. Terminal I of switch SW1 to terminal O of resistor R3. C. Terminal N of resistor R3 to terminal A of bulb L1. D. Using the piggy back feature, terminal I of switch SW1 to terminal C of bulb L2. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to terminal B of bulb L1. B. Terminal D of bulb L2 to terminal P of resistor R4. C. Terminal Q of resistor R4 to any of the four BLACK ground receptacles. 2. Draw the circuit you have just constructed on a blank circuit schematic template and label it : SA-19 LIGHT BULB CIRCUITS WITH PROBLEMS. 3. Turn switch SW1 to the ON position and observe circuit performance. Describe the circuit performance on your answer sheet : A. Describe bulb L1’s operating condition ? B. Describe bulb L2’s operating condition ? 4. Measure the available voltage to both bulbs and record your measurements on the answer sheet : A. Available voltage at bulb L1. B. Available voltage at bulb L2. 25 95-CL-1919-06 Module 5 — SA-19 consulab.com info@consulab.com 5. Conduct a voltage drop tests of bulbs L1 & and L2 positive and ground circuits and record your measurements on the answer sheet : A. Voltage drop of bulb L1 positive circuit from terminal A to RED positive receptacles. B. Voltage drop of bulb L1 ground circuit from terminal B to BLACK ground receptacles. C. Voltage drop of bulb L2 positive circuit from terminal C to RED positive receptacles. D. Voltage drop of bulb L2 ground circuit from terminal D to BLACK ground receptacles. 6. Evaluate the results of the voltage drop tests and describe whether each measurement is “normal” or “abnormal” on the answer sheet. CONCLUSIONS : Both bulbs L1 and L2 are operating dimmer than normal. The available voltage at the bulb should be close to the source voltage (14.00V ±). Your measurements should have indicated that the available voltage at each bulb was less the source voltage, therefore there must be unwanted resistance in the circuits. Because bulb L1 had a voltage drop in the positive circuit, the unwanted resistance must be located there. Because bulb L2 had a voltage drop in the ground circuit, the unwanted resistance must be located there. As has been stated before, voltage drop testing MUST be performed on operating circuits. If voltage drop testing is attempting on electrically dead circuits, the results will be erroneous and mean nothing. The next step will demonstrate this. 7. Install the voltmeter to measure available voltage at bulb L1. Now, carefully remove bulb L1 from its socket and record the available voltage for L1 on the answer sheet. 8. Reinstall bulb L1 and measure available voltage and record on answer sheet. CONCLUSIONS : As stated before, voltage drop testing MUST be performed on live operating circuits connected to a load. In the case of bulb L1, when the bulb was removed, the voltmeter reading should be close to source voltage. Why does this happen ? Because even though current is still flowing through the installed resistance (R3), the voltmeter reads close to source voltage with no voltage drop due to the very high internal resistance or impedance of the voltmeter (about 10-20 MΩ) and the current flowing in the circuit is extremely low. The meter therefore does not represent a load to the circuit and it reads close to source voltage at bulb L1 socket because due to the high resistance, it appears as an “open circuit” at the bulb socket. As soon as the bulb is installed in the circuit, the bulb’s resistance combines with resistor R3 to become a series circuit and each component, (bulb and resistor) creates a voltage drop in the circuit. The bulb and the resistor have a much lower resistance than the meter. Today’s digital multimeters are designed with very high impedance so that they don’t “load the circuit” that they are connected to. This feature protects sensitive electron- ics and solid-state components. SA-19 — Identifying the Location of Unwanted Resistance There are several different methods to locate the source of unwanted resistance in a circuit. Let’s examine a few. NOTE : The power switch and switch SW1 should both be ON to perform the below steps. 9. Make a fused jumper wire by connecting a RED jumper wire from any of the four RED positive receptacles to one terminal of the fuse F. 26 95-CL-1919-06 Module 5 — SA-19 consulab.com info@consulab.com 10. Connect another RED jumper wire from the other terminal of fuse F and hold the other end from touching any ground source. You now have a positive fused jumper wire connected to the power source. We will use it to tem- porarily bypass all circuit wiring and controls to bulb L1 and L2 to determine if any unwanted resistance is in the positive side of the circuit. 11. Connect the end of the jumper wire to terminal A of bulb L1. Describe any noticed results on the answer sheet. 12. Remove the jumper and connect it to terminal C of bulb L2 and describe any noticed results on the answer sheet. 13. Remove both RED jumper wires used to make the fused positive jumper wire. 14. Make a fused ground jumper wire by connecting a BLACK jumper wire from any of the four BLACK ground recepta- cles to either terminal of fuse F. Connect another BLACK jumper wire from the other terminal of fuse F and hold the other end from touching any positive source. 15. Connect the end of the BLACK jumper wire to terminal B of bulb L1 and describe any noticed results on the answer sheet. 16. Connect the end of the BLACK jumper wire to terminal D of bulb L2 and describe any noticed results on the answer sheet. CONCLUSIONS : Because the fused jumper wire was used to substitute a known good positive and ground circuits, it is possible to determine if the unwanted resistance is in the positive or ground side of the circuit. Although using a fused jumper wire will work on light bulb circuits that are easily observed, it may not work on motor or other types of circuits where one cannot observe normal circuit performance. Installing fused jumper wires can be a valuable method in diag- nosing circuit problems. Using a voltmeter to measure the actual voltage drop in a circuit is the best and most accurate method of circuit testing. In assignment # 19, bulb L1 had resistor R3 in series in the positive side of the circuit and bulb L2 had resistor R4 in series with the ground circuit. Both bulbs had equal voltage drops although in opposite circuits. The bulbs operated equally because the values of resistors 3 and 4 are identical. It is important to remember that unwanted resistances can occur in either the positive or ground sides of a circuit and accurate voltage drop testing will determine which part of the circuit is causing the problem. 27 95-CL-1919-06 Module 5 — SA-19 consulab.com info@consulab.com SA-19 — Light Bulb Circuits with Problems - Student Answer Sheet Name : Group : Date : 3. What is the description of each bulb’s performance ? A. Bulb L1’s condition. B. Bulb L2’s condition. 4. A. Available voltage at bulb L1. Expressed as : B. Available voltage at bulb L2. Expressed as : 5. Voltage drop testing of bulbs L1 and L2 : A. Voltage drop of bulb L1 positive circuit from terminal A to RED positive receptacles. Expressed as : B. Voltage drop of bulb L1 ground circuit from terminal B to BLACK ground receptacles. Expressed as : C. Voltage drop of bulb L2 positive circuit from terminal C to RED positive receptacles. Expressed as : D. Voltage drop of bulb L2 ground circuit from terminal D to BLACK ground receptacles. Expressed as : 6. Measurement A (NORMAL or ABNORMAL). Measurement B (NORMAL or ABNORMAL). Measurement C (NORMAL or ABNORMAL). Measurement D (NORMAL or ABNORMAL). 7. Available voltage at L1 socket with bulb removed. Expressed as : 8. Available voltage at L1 socket with bulb installed. Expressed as : 11. Bulb L1 condition with positive fused jumper wire connected to terminal A. 12. Bulb L2 condition with positive fused jumper wire connected to terminal C. 15. Bulb L1 condition with ground fused jumper wire connected to terminal B. 16. Bulb L2 condition with ground fused jumper wire connected to terminal D. Instructor grade : Comments : 28 95-CL-1919-06 Module 5 — SA-20 consulab.com info@consulab.com SA-20 — Relay Circuits This assignment will demonstrate how relays are used to control circuit components. A relay is an electrical component that is able to switch on and off, components that draw high amounts of current by using a very low current control circuit. Many different relays are typically used in vehicles and in industrial applications. SA-20A — Relay Control Circuit Circuit Explanation A relay has two internal circuits. One is called the “low-current” or “control” circuit. It consists of a power feed to one end of the relay’s internal coil and also a ground to the other end of the coil. The circuit you will construct below is the “control” circuit. As has been previously explained in the COMPONENT EXPLANATION module, when the relay’s coil is energized, terminals # 30 to 87 will be connected. When the relay is shut off, relay terminals # 30 and 87a are connect- ed. SA-20A — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-20 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to the left-hand terminal push button switch PB1. B. Right-hand terminal of push button switch PB1 to terminal 86 of relay RL1. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to terminal 85 of relay RL1. 2. Confirm that trainer is plugged into a 120V receptacle and the master ON/OFF switch is turned ON. 3. Push the PB1 switch button down and listen for a “clicking” sound coming from the relay. This indicates that the relay is receiving a power and ground circuit to the relay coil. 4. Install the ohmmeter leads on relay terminals # 30 and # 87a. 5. Fill in the results of the ohmmeter readings on the student answer sheet with the PB1 switch OFF and ON. A. ohms with PB1 switch OFF B. ohms with PB1 switch ON 6. Install the ohmmeter leads on relay terminals # 30 and # 87, then repeat step # 5 and record the results on the answer sheet. A. ohms with PB1 switch OFF B. ohms with PB1 switch ON 29 95-CL-1919-06 Module 5 — SA-20 consulab.com info@consulab.com 7. Using the digital multimeter set up to measure amperage, measure the amperage of relay RL1 coil control circuit. Fill in your reading on the student answer sheet. CONCLUSIONS : The experiment above confirms the operation of the relay and what terminals are connected and not connected with the relay both ON and OFF. The “controlled” side of the relay has not been connected to any compo- nent yet, but the relays “control” circuit still operates normally. SA-20B — Relay Controlled Circuit Circuit Explanation The relay controlled circuit is the circuit where the high amperage of the controlled device is turned on and off. It is separated from the control circuit. The controlled circuit often has a separate power supply circuit which normally is connected to terminal # 30 of the relay (there are some exceptions to this depending on application). Terminal # 87 is connected to the component that is controlled by the relay when the relay is turned on. SA-20B — Procedure 8. CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal # 30 of relay RL1. B. Terminal # 87 of relay RL1 to terminal HI of bulb L3. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to terminal COM of bulb L3. 9. Push switch PB1 and confirm that bulb L3 HI circuit operates normally. 10. Using the digital multimeter set up to measure amperage, measure the amperage of bulb L3 HI circuit. Fill in your reading on the student answer sheet. CONCLUSIONS : It should be obvious that the relay is able to control a relatively high current circuit with a very low amount of control circuit. Compare the ammeter reading of step # 7 to the reading taken in step 10. 11. Connect a RED jumper wire from terminal # 87a of relay RL1 to terminal C of bulb L2. 12. Connect a BLACK jumper wire from terminal D of bulb L2 to any of the four BLACK ground receptacles. 13. Push the PB1 button and record the circuit performance on the student answer sheet. A. Bulb L2 with relay OFF. B. Bulb L2 with relay ON. C. Bulb L3 HI with relay OFF. D. Bulb L3 HI with relay ON. CONCLUSIONS : This assignment confirms the normal operation of a relay when it is both ON and OFF. Many emergen- cy vehicles use this type of circuit with a flasher to alternately flash ON/OFF headlights, RED and blue lights. 14. Draw the entire circuit you have just constructed on a blank circuit schematic template and label it : SA-20B RELAY CONTROLLED CIRCUITS. After completion of SA-20 student assignment, ask your instructor TEST 12. 30 95-CL-1919-06 Module 5 — SA-20 consulab.com info@consulab.com SA-20 — Relay Circuits - Student Answer Sheet Name : Group : Date : A. RELAY CONTROL CIRCUIT 3. Connection between # 30 and # 87a : A. ohms with PB1 switch OFF. Expressed as : B. ohms with PB1 switch ON. Expressed as : 6. Connection between # 30 and # 87 : A. ohms with PB1 switch OFF. Expressed as : B. ohms with PB1 switch ON. Expressed as : 7. amps of RL1 coil circuit. Expressed as : B. RELAY CONTROLLED CIRCUIT 10. amps of bulb LED L3 HI circuit. Expressed as : 13. What is the performance of bulbs LED L3 HI and bulb L2 with the relay ON and OFF ? A. Bulb L2 with relay OFF is . B. Bulb L2 with relay ON is is . C. Bulb LED L3 HI with relay OFF is . D. Bulb LED L3 HI with relay ON is . After completion of SA-20 student assignment, ask your instructor TEST 12. Instructor grade : Comments : 31 95-CL-1919-06 Module 5 — SA-21 consulab.com info@consulab.com SA-21 — Flasher Controlled Circuit SA-21 — Circuit Explanation This assignment will demonstrate how electronic flashers are used in circuits. Electronic flashers differ from older style “thermal” flashers in that they operate with a different technology. Electronic flashers can control higher amounts of current than thermal flashers and also are not dependent on a specific amount of current flowing through it before it will turn on/off. Thermal flashers were usually identified as a round metal can with two or three electrical terminal blades that plugged into a receptacle. As additional bulbs were added to the circuit, the rate of flashing increased accordingly this creating a rapid on/off rate. This was especially true when hooking up a trailer to a vehicle. Solutions involved ob- taining a “heavy duty flasher” which could handle the additional current. Today’s electronic flashers typically have three electrical terminals. One is for a power feed circuit to the flasher, one is a ground circuit for the flasher and the third is for the circuit controlled on and off by the flasher. SA-21 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-21 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal O of switch SW1. B. Terminal I of switch SW1 to BAT of the electronic flasher. C. SIG terminal of the electronic flasher to terminal A of bulb L1. D. Terminal A of bulb L1 to terminal C of bulb L2. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to terminal GND of the electronic flasher. B. Terminal B of bulb L1 to terminal D of bulb L2. C. Terminal B of bulb L1 to any of the four BLACK ground receptacles. 2. Draw the circuit you have just constructed on a blank circuit schematic template and labeled : SA-21 FLASHER CONTROLLED CIRCUIT. 3. Confirm that the trainer is plugged into a 120V receptacle and the master power switch is in the ON position. 4. Turn switch SW1 to the ON position. Bulbs L1 and L2 should now be flashing with equal brightness.Confirm the cor- rect operation of the circuit. After circuit confirmation, turn switch SW1 to the OFF position. 32 95-CL-1919-06 Module 5 — SA-21 consulab.com info@consulab.com CIRCUIT PROBLEMS : As with any electrical circuit, unwanted resistance can cause circuit performance problems. The below steps will demonstrate this. 5. Remove the RED jumper wire from terminal I of SW1 and connect it to terminal N of resistor R3. 6. Connect a RED jumper wire from terminal I of switch SW1 to terminal O of resistor R3. 7. Turn switch SW1 ON and observe circuit performance. 8. Connect another RED jumper wire to terminal O of resistor R3 and while the circuit is operating, touch terminal N of resistor R3. This action temporarily bypasses the resistor and the circuit performance should return to normal operation. 9. Describe the circuit performance with the resistance insert in the circuit on the answer sheet. 10. Remove the resistance from the circuit and restore the circuit to normal operating conditions. 11. Remove the BLACK ground wire coming from bulb L2 that connects to terminal B of bulb L1 and re-connect it to terminal L of resistor R2. 12. Connect a BLACK jumper wire from any of the four BLACK ground receptacles to terminal M of resistor R2. 13. Turn on switch SW1 and observe circuit performance. Describe the circuit performance on the answer sheet. CONCLUSIONS : When diagnosing circuit problems, it is very important to have a correct wiring diagram for the circuit being repaired. This provides valuable information as to how the power and ground circuits are constructed which can save significant time during diagnosis. 33 95-CL-1919-06 Module 5 — SA-21 consulab.com info@consulab.com SA-21 — Flasher Controlled Circuit - Student Answer Sheet Name : Group : Date : 9. 13. Instructor grade : Comments : 34 95-CL-1919-06 Module 5 — SA-22 consulab.com info@consulab.com SA-22 — PWM Circuit with Motor SA-22 — Theory It is very common in vehicle engine performance circuits to have an internal circuit with transistors controlled by Pulse Width Modulation. A commonly used term is a “Quad Driver”. Quad-Drivers are integrated circuits within the ECM or PCM that control certain types of circuits. Many Quad-Drivers are controlled by using Pulse Width Modulation which are also within the ECM/PCM. Pulse Width Modulation controls a circuit by turning on and off a B+ supply very quickly. For example, a light bulb can be turned on and off very rapidly so that it can be off, on at varying amounts of brightness to being on a full brightness all controlled by Pulse Width Modulation. Fuel Injectors are also commonly controlled by PWM. PWM circuits operate at varying frequencies. The circuit is either ON or OFF and the quad-driver controls the amount of on time. The amount of “on” time is called DUTY CYCLE. Duty cycle is measured either as a percentage or can also be measured with the amount of on time called “PULSE WIDTH”. The important thing to remember about PWM, it that the voltage to the device being controlled will be either full voltage (14.6 for example) or zero. If a blower motor was controlled by PWM and it was running at half-speed, the DUTY CYCLE would be at 50%. If a digital voltmeter was connected to the blower motor, it would indicate about 7.3V± because the meter cannot read the on/off signals that are occuring in milli-seconds. So, the meter just “averages” the signals. One must remember, that a PWM circuit cannot be accurately tested or measured with a voltmeter. An oscilloscope is the only tool that will display the true on and off pulse width modulated circuit. Some scan tools can give a DUTY CYCLE or PULSE WIDTH readout, but those also are averages and not the true PWM signals. SA-22 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-22 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below : CONNECT RED JUMPER WIRES BETWEEN : A. The RED + terminal of the PWM generator to the + terminal of the DC motor. CONNECT BLACK JUMPER WIRES BETWEEN : A. A. The BLACK – terminal of the PWM generator to the – terminal of the DC motor. 2. Connect the voltmeter to the DC motor to read motor supply voltage. 3. Confirm that the PWM adjustment knob is turned fully counter-clockwise. 4. Confirm that the trainer is plugged into a 120V receptacle and the master power switch is in the ON position. 5. Adjust the trainer supply voltage display until a reading of between 13.00 – 14.00 volts is obtained. 35 95-CL-1919-06 Module 5 — SA-22 consulab.com info@consulab.com 6. Slowly turn the PWM adjustment knob clockwise. As you do, the motor should begin to rotate and increase in speed as the knob is adjusted clockwise. 7. Turn the PWM adjustment knob so that the voltmeter reads about ½ of the trainers display voltage. The reading should be between 6.5 and 7 volts. The motor will be rotating at about ½ of normal speed. CIRCUIT EXPLANATION : At this point, the motor is running at what is described as a 50% DUTY CYCLE. It is called that because at 50%, the volt- age is on an equal amount of time as it is off. If the voltage is measured at the motor, it will read ½ of the supply voltage. NOTE : If the digital meter was equipped to measure “DUTY CYCLE”, the correct reading at this point would be 50%. If a digital storage oscilloscope was hooked up to the RED positive motor lead, it would show a pattern that had equal horizontal lines at “12 volts” as well as equal horizontal lines at “0” volts. An example of the oscilloscope pattern would be : 12V 0V 12V 0V 12V 0V 8. Pulse Width Modulation provides an accurate method of controlling circuits such as lights, motors and solenoids. 9. Turn the PWM adjustment knob slowly counter-clockwise until the motor is just barely turning. The voltmeter should be reading between 2.5 and 3.0 volts. CIRCUIT EXPLANATION : At this point, the motor is running at what is described as a “low” DUTY CYCLE. The voltage available to the motor is off more than it is on. A meter measuring DUTY CYCLE would read approximately 25%. An example of the oscilloscope pattern would be : 12V 0V 12V 0V 12V 0V 95-CL-1919-06 Module 5 — SA-22 consulab.com info@consulab.com 36 10. Turn the PWM adjustment knob slowly clockwise to its full CW position. The motor should be running at its fastest speed. The motor is now running at what is described at a 100% DUTY CYCLE. The volt meter should be reading about 1.0 volt less than the display voltage (due to internal circuitry). The voltage available to the motor is on more than it is off. An example of the oscilloscope pattern would be : 12V 0V 12V 0V 12V 0V Answer the following questions on the Student Answer Sheet. 11. If a 12 volt circuit was commended to run at 50% duty cycle, what would the digital multimeter display for a voltage at the controlled device ? 12. If a 12 volt circuit was connected to run at 25% duty cycle, what would the digital multimeter display for a voltage at the controlled device ? 13. True or False Even though a voltmeter displays 6 volts connected to a 12 volt PWM controlled device running at 50% duty cycle, it is really operating at 12 volts. 37 95-CL-1919-06 Module 5 — SA-22 consulab.com info@consulab.com SA-22 — PWM Circuit with Motor - Student Answer Sheet Name : Group : Date : 11. V at 50% duty cycle. Expressed as : 12. V at 25% duty cycle. Expressed as : 13. True or False. Instructor grade : Comments : 38 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com SA-23 — Transistor Controlled Circuits This circuit assignment demonstrates how transistors can be used to control components. As has been previously dis- cussed, there are an NPN and PNP transistor types on the CL-1919-06 trainer. Looking at the schematic diagram on each transistor, you will notice that the emitter arrow either points to the base (PNP) or away from the base (NPN). There are several “mental tricks” designed to help you remember how to identify a transistor type. A very common one is to look at the direction of the arrow on the emitter line. If the arrow “points in” to the base of the transistor, the transistor is an PNP type (pointing “N”). If the arrow is not pointing towards the base, the transistor is the NPN type (not pointing “N”). The most important reason to properly identify NPN and PNP transistors is because they are installed in a circuit very differently. SA-23A — NPN Transistor Circuit as a “Relay” Controlled Circuit SA-23A Circuit Explanation This circuit will consist of an NPN transistor serving as a “relay” like component that controls a series of components on the CL-1919-06 trainer. Remember that one of the primary uses of a transistor is to control high amounts of current by using a very low current switching circuit flowing through control circuit. The transistor can serve as an electronic relay much the same as an ISO relay does. NOTE : On the CL-1919-05, bulb L3 which was a 3157 incandescent bulb has been replaced with an LED version of the 3157. The primary reason for this change was to eliminate the very hot surfaces of the incandescent 3157 bulb. Because the LED 3157 bulb L3 is not a very high current device, additional devices will be connected in parallel to increase circuit amperage that will be controlled by the transistor. SA-23A — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-23 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below. BE VERY CAREFUL TO CORRECT INSTALL EACH WIRE : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal A of bulb L1. B. Terminal A of bulb L1 (piggy back) to terminal C of bulb L2. C. Terminal C of bulb L2 (piggy back) to terminal P of resistor R4. D. Terminal P of resistor R4 (piggy back) to terminal N of resistor R3. E. Any of the four RED power receptacles to terminal O of switch SW1. F. Terminal I of switch SW1 to terminal K of resistor R1. G. Terminal J of resistor R1 to terminal B (BASE) of transistor T1 (NPN). H. Terminal D of bulb L2 to terminal C (COLLECTOR) of transistor T1 (NPN). 39 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com I. Terminal D of bulb L2 (piggy back) to terminal B of bulb L1. J. Terminal B of bulb L1 (piggy back) to terminal Q of resistor R4. K. Terminal Q of resistor R4 (piggy back) to terminal O of resistor R3. CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to terminal E of transistor T1 NPN. NOTE : It will be noticed that this NPN circuit uses RED wires on both sides of the load components. This is correct because schematics show circuits in the OFF position and full supply voltage can be measured to ground at both termi- nals of all loads until the transistor turns on. This will then switch half of the loads to ground. 2. Draw the circuit you have just constructed on a blank circuit schematic template and label it : SA-23A NPN TRANSIS- TOR CIRCUIT AS A RELAY CIRCUIT. 3. Confirm that the trainer is plugged into a 120V receptacle and the master power switch is in the ON position. 4. Adjust the trainer voltage to about 14.6± volts. 5. Turn switch SW1 to ON position. Bulbs L1 and L2 should both be on at full brightness. Confirm proper circuit opera- tion and repair any mistakes in wiring the components. CIRCUIT DESCRIPTION : In an NPN transistor circuit, the current of the controlled device (Bulbs L1, L2 and resistors 3 & 4) passes from the source voltage to terminals A & C of bulbs L1 and L2, through the bulb’s filaments and exits bulb L1 & L2 at terminals B & D, then on to the COLLECTOR of transistor T1. In addition, bulbs L1 and L2 and connected in parallel with resistors R3 and R4. Remembering Ohm’s Law, adding resistances in a parallel circuit will increase the current flow. These four components were connected in this circuit to create a “load” of about 2 amps. Using a single bulb or L3 LED would create a current draw in milli-amps and would not demonstrate the “relay” op- eration of the transistor. When the transistor is turned on by switch SW1, low current (control) circuit passes into the transistor’s BASE (B) circuit, through the transistor and out at the EMITTER terminal and continues to ground. The COL- LECTOR to EMITTER portion of the transistor is called the “HIGH CURRENT” portion of the circuit. The LOW CURRENT control circuit flows from source voltage through switch SW1 and on to the BASE terminal of transistor T1. The control circuit then exits the transistor through the EMITTER terminal (E) and on to ground. The EMITTER circuit carries both the control and the controlled circuit currents. Therefore : A. In an NPN circuit, the low current control circuit is connected BASE to EMITTER. B. In an NPN circuit, the high current controlled circuit is connected between COLLECTOR and EMITTER. C. The EMITTER to ground circuit carries both the low current control circuit (B to E) and the high current con- trolled circuit (C to E). 40 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com COMPARISON OF AN NPN TRANSISTOR TO A RELAY : Look at the below drawings comparing an NPN transistor to a standard 4-pin relay. The low current control circuit is the relay’s coil and in a transistor is BASE to EMITTER. The high current controlled circuit is the relay’s contacts and in a transistor is COLLECTOR to EMITTER. With in NPN transistor, the “LOAD” can be either on the positive side (COLLECTOR) or the ground side (EMITTER) of the transistor. 6. Carefully examine and understand the circuit you have constructed. 7. Measure the available voltage to the following components. Put your readings on the student answer sheet. A. Bulb L1 : volts. Expressed as : B. Bulb L2 : volts. Expressed as : C. Resistor R3 : volts. Expressed as : D. Resistor R4 : volts.Expressed as : 8. What type of circuit construction are L1, L2, R3 and R4 connected in ? 9. Turn trainer on, turn switch SW1 on and measure the current flowing through the following circuits : A. COLLECTOR CIRCUIT : amps. Expressed as : B. EMITTER CIRCUIT : amps. Expressed as : C. BASE CIRCUIT : amps. Expressed as : 10. While monitoring COLLECTOR current, predict what will happen if you temporarily disconnect the two- wire connec- tion at bulb L1 terminal A. Predict what happened on the answer sheet. 11. Disconnect the two-wire connection at bulb L1 terminal A and describe what happened. Describe what happened on the answer sheet. 12. Disconnect the EMITTER ground wire at either the EMITTER receptacle or any of the four BLACK ground recepta- cles. Describe what happened on the answer sheet. 13. Explain why the circuit behaved the way it did when you disconnected the EMITTER wire. Use the answer sheet. 14. Measure the voltage to ground at loads L1, L2, Resistors R3 & R4 and COLLECTOR of NPN transistor. Put your read- ing on the student answer sheet. 15. Is the NPN control circuit a positive switched or negative switched ? 16. Turn SW1 OFF and turn trainer OFF. Remove all RED and BLACK wires from the trainer. 17. Proceed on to SA-23B Assignment which uses the same answer sheet as SA-23A. 41 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com SA-23B — PNP Transistor Circuit as a “Relay” Controlled Circuit SA-23B Circuit Explanation This circuit will consist of a PNP transistor serving as a “relay” like component that controls a series of components on the CL-1919-06 trainer. A PNP transistor is connected differently than an NPN transistor. The BASE of a PNP transistor is the switched circuit, but is on the ground side of the transistor circuit. The EMITTER is connected to the power supply and the COLLECTOR is connected to the LOAD. The COLLECTOR circuit goes to the LOAD, then connects to ground. The control circuit of a PNP transistor is “ground switched”. NOTE- On the CL-1919-06, bulb L3 which was a 3157 incan- descent bulb has been replaced with an LED version of the 3157. The primary reason for this change was to eliminate the very hot surfaces of the incandescent 3157 bulb. Because the LED 3157 bulb L3 is not a very high current device, additional devices will be connected in parallel to increase circuit amperage that will be controlled by the transistor. SA-23B — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-23 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below. BE VERY CAREFUL TO CORRECT INSTALL EACH WIRE : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to the EMITTER terminal of transistor T2 (PNP) CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground receptacles to terminal O of switch SW1 B. Terminal I of switch SW1 to the BASE terminal of transistor T2 (PNP) C. Terminal C of bulb L2 to the COLLECTOR of transistor T2 (PNP) D. Terminal C of bulb L2 (piggy back) to terminal A of bulb L1 E. Terminal A of bulb L1 (piggy back) to terminal P of resistor R4 F. Terminal P of resistor R4 to terminal N of resistor R3 G. Terminal B of bulb L1 (piggy back) to terminal D of bulb L2 H. Terminal D of bulb L2 (piggy back) to terminal Q of resistor R4 I. Terminal Q of resistor R4 (piggy back) to terminal O of resistor R3 J. Terminal O of resistor R3 (piggy back) to any of the four BLACK ground terminals NOTE : It will be noticed that this PNP circuit uses BLACK wires on both sides of the load components. This is correct because schematics show circuits in the OFF position and full supply voltage can be measured to positive at both termi- nals of all loads until the transistor turns on. This will then switch half of the loads to B+ positive. 2. Draw the circuit you have just constructed on a blank circuit schematic template labelled : SA-23B PNP TRANSISTOR CIRCUIT AS A RELAY CIRCUIT. 3. Confirm that the trainer is plugged into a 120V receptacle and the master power switch is in the ON position. 42 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com 4. Adjust the trainer voltage to about 14.6± volts. 5. Turn switch SW1 to ON position. Bulbs L1 and L2 should both be on at full brightness. Confirm proper circuit opera- tion and repair any mistakes in wiring the components. CIRCUIT DESCRIPTION : In an PNP transistor circuit, the current of the controlled device (Bulbs L1, L2 and resistors 3 & 4) passes from the COLLECTOR of transistor T2 (PNP) to terminals A & C of bulbs L1 and L2, terminals P and N of resistors R3 and R4. It then flows through the bulbs filaments and resistors R3 & R4 to ground. Remembering Ohm’s Law, adding resistances in a parallel circuit will increase the current flow. These four components were connect- ed in this circuit to create a “load” of about 2 amps. Using a single bulb or L3 LED would create a current draw in mil- li-amps and would not demonstrate the “relay” operation of the transistor. The PNP transistor is “turned on” by switch SW1 connecting the BASE transistor terminal to ground. The lower CONTROL current flows from the EMITTER to BASE to ground. This then connects the EMITTER (+) circuit to the COLLECTOR (-) terminal which then connects to the load. The HIGH controlled current flows from the EMITTER to COLLECTOR to ground through each load. Therefore : A. In an PNP circuit, the low current control circuit is connected EMITTER (+) TO BASE (-) through a switch to ground. B. In an PNP circuit, the high current controlled circuit is connected between EMITTER (+ FEED) and the COLLECTOR (- LOAD) to ground. C. The EMITTER (+) to positive circuit carries both the low current control circuit (E+ to B-) and the high current con- trolled circuit (E+ to C-). 6. What type of circuit construction are L1, L2, R3 and R4 connected in ? : . 7. Turn trainer on, turn switch SW1 on and measure the current flowing through the following circuits : NOTE : You must completely understand this circuit in order to correct conduct the below measurement. A. CONTROLLED CIRCUIT : amps. Expressed as : B. EMITTER CIRCUIT : amps. Expressed as : C. CONTROL CIRCUIT : amps Expressed as : 8. Which circuit are both the control and controlled currents carried on ? . 9. Is this PNP relay control circuit ground switched or positive switched ? . consulab.com info@consulab.com 43 95-CL-1919-06 Module 5 — SA-23 10. Measure the voltage to positive at loads L1, L2, Resistors R3 & R4 and COLLECTOR of PNP transistor : volts. Expressed as : 11. Confirm your answer sheet has been correctly filled out, then turn in to your instructor. 12. Turn switch SW1 OFF, then remove all RED and BLACK wires from the trainer. DESCRIPTION PNP NPN TRANS OFF-POWER AVAILABLE AT : EMITTER & BASE COLLECTOR LOW CONTROL CURRENT CKT : BASE - to EMITTER + BASE + to EMITTER - HIGH CONTROLLED CURRENT CKT : EMITTER to COLLECTOR COLLECTOR to EMITTER SWITCHED IN : GROUND SIDE POSITIVE SIDE TRANSISTOR REFERENCE CHART FOR PNP AND NPN TRANSISTORS 44 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com SA-23 — Transistor Controlled Circuits - Student Answer Sheet Name : Group : Date : SA-23A NPN TRANSISTOR CIRCUIT 7. Measure the available voltage to the following components. Put your readings on the student answer sheet. A. Bulb L1 : volts. Expressed as : B. Bulb L2 : volts. Expressed as : C. Resistor R3 : volts. Expressed as : D. Resistor R4 : volts.Expressed as : 8. Bulbs L1, L2 and resistors R3 and R4 are connected in : 9. Turn trainer on, turn switch SW1 on and measure the current flowing through the following circuits : A. COLLECTOR CIRCUIT : amps. Expressed as : B. EMITTER CIRCUIT : amps. Expressed as : C. BASE CIRCUIT : amps. Expressed as : 10. Prediction : 11. Description : 12. Description : 13. Explanation : 14. Voltage to ground at loads L1, L2, Resistors R3 & R4 and COLLECTOR of NPN transistor : volts. Expressed as : . 15. Positive or Negative switched control circuit ? 45 95-CL-1919-06 Module 5 — SA-23 consulab.com info@consulab.com SA-23B PNP TRANSISTOR CIRCUIT 6. What type of circuit construction are L1, L2, R3 and R4 connected in ? 7. Turn trainer on, turn switch SW1 on and measure the current flowing through the following circuits : NOTE : You must completely understand this circuit in order to correct conduct the below measurement. A. CONTROLLED CIRCUIT : amps. Expressed as : B. EMITTER CIRCUIT : amps. Expressed as : C. CONTROL CIRCUIT : amps Expressed as : 8. Which circuit are both the control and controlled currents carried on ? 9. Is this PNP relay control circuit ground switched or positive switched ? 10. Measure the voltage to the ground of all points of LOAD (L1, L2, Resistors R3 & R4 and PNP COLLECTOR) : volts. Expressed as : . 11. Confirm your answer sheet has been correctly filled out, then turn in to your instructor. Instructor grade : Comments : 46 95-CL-1919-06 Module 6 — Advanced Assignments consulab.com info@consulab.com MODULE 6 Advanced Student Circuit Assignments 47 95-CL-1919-06 Module 6 — SA-24 consulab.com info@consulab.com SA-24 — Using M1 as a Generator The M1 motor used on this trainer is a DC motor with an armature (coil of wire) and a magnetic field (magnets). The pulley is attached to a gear reduction system that was designed to allow the flywheel to turn very slowly. If the motor pulley is rotated by hand, because of the gear reduction system, the motor would turn at a much faster rate that if it was powered by the voltage supplied by the trainer. This phenomenon will cause the motor to become a “GENERATOR”. The Laws of Physics state that in electricity, in order to generate electricity, three things are required. They are : 1- A coil of wire, 2- A magnetic field and 3- Motion of either 1 or 2. Given those three things, you can generate electricity. In addition, if you have 1- A coil of wire and 2- A magnetic field and also supply electricity, you will obtain “MOTION” which is how any electric motor works. So, M1 motor has a magnetic field and a coil of wire. If we supply electricity to the RED and BLACK receptacles, M1 starts to rotate and becomes a MOTOR. However, M1 can also become a generator. Let’s experiment with this concept. SA-24 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-24 student answer sheet to record all of your measurements and question answers. 1. Leave the trainer OFF. No power supplied and the voltage display should be blank. 2. Connect a RED wire from M1 RED receptacle to the RED receptacle of D1. 3. Connect a BLACK wire from M1 BLACK receptacle to the BLACK receptacle of D1. 4. Grab the M1 flywheel and rotate in one direction. (Clock-wise or Counter-Clockwise) 5. Fill in the Student Answer Sheet describing what D1 does in either direction of M1. 6. Carefully remove D1 and rotate it 180º then reinstall it into the D1 receptacle. 7. Fill in the Student Answer Sheet describing what D1 does in either direction of M1. 8. Explain the “why” of the behavior of D1 from steps #4 and #6. 9. Leave the trainer OFF. Then connect the voltmeter to both the RED and BLACK M1 receptacles. 10. Rotate M1 in a clock-wise direction and measure the output voltage of M1 generator on the answer sheet. 11. Rotate M1 in a counter-clockwise direction and measure the output voltage of M1 generator on the answer sheet. 12. Answer this question on the Student Answer Sheet : Why does the M1 generator generate a voltage in either direc- tion, but D1 only operates in one direction ? 13. Connect an ammeter in series with either the RED or BLACK wires to D1 and measure the current in both directions of rotation. CW = amps CCW = amps. NOTE : The Fluke digital multimeter used with this trainer does not have a “milli-amp” scale. Therefore, for the purposes of measuring the current output of M1 as directed, you will have to turn the flywheel very fast in order to generate only 1-2 milliamps of current. The meter may show only “zeros” depending on how fast you can turn M1’s flywheel. 48 95-CL-1919-06 Module 6 — SA-24 consulab.com info@consulab.com 14. Explain the results of step #13 on the Student Answer Sheet. Why did you get the results as measured ? 15. Remove the RED and BLACK wires connecting to D1 and switch them to bulb L1. 16. Rotate the flywheel in an attempt to light bulb L1. What happens ? 17. Explain the results of step #16 on the answer sheet. 18. Remove the wires you used to complete SA-24 assignment and turn the trainer power switch to OFF 19. Turn in your completed answer sheet to your instructor. After completing this assignment, you should understand that a MOTOR can also become a GENERATOR given certain conditions. In hybrid and electric vehicles (EV), the term MG1 and MG2 are often used. “MG” stands for “MOTOR GENER- ATOR”. This component is used in hybrids and EV’s to either propel the vehicle down the road by using battery voltage or can become generator when the vehicle goes in “regenerative braking” using the inertia of the vehicle to drive the electric drive motors as generators. “Re-Gen” braking is a very common system used on most hybrids and EV vehicles. The desired understanding with this assignment is that a motor can also become a generator. The difference deals with the four elements of motor and power generation. They are : 1. A coil of wire 2. A magnetic field 3. Electricity 4. Motion. If you have two of the three, you can obtain the third. For example : A generator would need a coil of wire, a magnetic field and motion (of the field or the coil of wire). Doing so will generate electricity. For a motor, you would need elec- tricity, a magnetic field and coil of wire. As soon as electricity is applied to the coil of wire, motion will occur. There are many variations of how the three required components are arranged and constructed in motors and generators, but the physics are the same. 49 95-CL-1919-06 Module 6 — SA-24 consulab.com info@consulab.com SA-24 — Using M1 as a Generator - Student Answer Sheet Name : Group : Date : 5. Clockwise direction : Counter-Clockwise direction : 7. Clockwise direction : Counter-Clockwise direction : 8. Explain why : 10. volts. Expressed as : 11. volts. Expressed as : 12. BE SURE TO READ THE NOTE INCLUDED WITH STEP 13 BEFORE COMPLETING ATTEMPTING TO MEASURE CURRENT. 13. CW = amps. Expressed as : CCW = amps. Expressed as : 14. Explanation of Step 13 : 16. 17. Why ? Instructor grade : Comments : 50 95-CL-1919-06 Module 6 — SA-25 consulab.com info@consulab.com SA-25 — Alarm System — Option 1 The CL-1919-06 trainer has components that can be used to create many other types of circuits that were not covered to date by the 24 previous assignments. SA-25 and additional assignments ask you to apply the knowledge and under- standing from the activities you have completed to create some of these circuits. There will NOT be step by step instructions given that guide you through connecting the RED and BLACK wires. You will be responsible to designing each circuit that matches the performance criteria listed for each one. Be sure to use a blank template of the trainer to properly draw the RED and BLACK wires as you build each circuit. Be sure to label each schematic with the proper assignment number. SA-25 — Circuit Criteria Using the components on the trainer, design and build an alarm circuit that will turn on a buzzer if the push button (which will be consider a vehicle door tamper switch) is in the “OPEN” or OFF position and shuts off the buzzer when the door is “CLOSED”, the switch is in the ON position. 1. Draw your designed circuit for assignment SA-25 on a blank schematic template and label it : SA-25 ALARM SYSTEM - OPTION 1. SA-25 — Circuit Explanation Use the SA-25 student answer sheet to record all of your question answers. 2. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit. 3. Does circuit work properly according to the described circuit criteria ? Yes No 4. Turn in your answer sheet to your instructor. 51 95-CL-1919-06 Module 6 — SA-25 consulab.com info@consulab.com SA-25 — Alarm System — Option 1 - Student Answer Sheet Name : Group : Date : 1. Draw your designed circuit for assignment SA-25 ALARM SYSTEM - OPTION 1 on a blank schematic template and label it properly. 2. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit : 3. Does circuit work properly according to the described circuit criteria ? Yes No Instructor grade : Comments : 52 95-CL-1919-06 Module 6 — SA-26 consulab.com info@consulab.com SA-26 — Alarm System — Option 2 SA-26 — Circuit Criteria Design and build an alarm circuit similar to the OPTION 1 circuit, except now lights L1 and L2 will flash on and off when the alarm system is tripped. The buzzer will be on constantly, but the lights will flash on an off. The push button simu- lates the door switches of the vehicle and when the door is closed the alarm system is “armed”, but all warning devices are OFF. As soon as the “door” opens, the alarm will trip and turn on the devices. 1. Draw your designed circuit for assignment SA-26 on a blank schematic template and label it : SA-26 ALARM SYSTEM - OPTION 2. SA-26 — Circuit Explanation Use the SA-26 student answer sheet to record all of your question answers. 2. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit. 3. Does circuit work properly according to the described circuit criteria ? Yes No 4. Turn in your answer sheet to your instructor. 53 95-CL-1919-06 Module 6 — SA-26 consulab.com info@consulab.com SA-26 — Alarm System — Option 2 - Student Answer Sheet Name : Group : Date : 1. Draw your designed circuit for assignment SA-26 ALARM SYSTEM - OPTION 2 on a blank schematic template and label it properly. 2. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit : 3. Does circuit work properly according to the described circuit criteria ? Yes No Instructor grade : Comments : 54 95-CL-1919-06 Module 6 — SA-27 consulab.com info@consulab.com SA-27 — Light Bulb Dimming SA-27 — Circuit Criteria Design and build a circuit that will cause bulb L1 and bulb L3 HI both get brighter and dimmer and the control knob is ro- tated. Make the circuit so that the bulbs get dimmer when the control knob is turned counter-clockwise and get brighter when the knob is turned clockwise. 1. Draw your designed circuit for assignment SA-27 on a blank schematic template and label it : SA-27 LIGHT BULB DIMMING. Use the SA-27 student answer sheet to record all of your question answers. 2. Does the circuit operate exactly as the criteria describes ? Yes No SA-27 — Circuit Explanation 3. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit. 4. Did the circuit work properly as described in the explanation ? Yes No 5. Now re-wire the circuit so that the control knob causes the bulbs to get brighter in the counter-clockwise rotation and dimmer in the clockwise position. Describe what you re-wired on the answer sheet. 6. What was the only device that you had to change the wiring on to reverse dimming direction ? 7. Turn in your answer sheet to your instructor. 55 95-CL-1919-06 Module 6 — SA-27 consulab.com info@consulab.com SA-27 — Light Bulb Dimming - Student Answer Sheet Name : Group : Date : 1. Draw your designed circuit for assignment SA-27 LIGHT BULB DIMMING on a blank schematic template and label it properly. 2. Does circuit work properly according to the described circuit criteria ? Yes No 3. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit : 4. Did the circuit work properly as described in the explanation ? Yes No 5. What did you have to do to reverse the dimming direction with the control knob ? 6. What was the only device that you had to change the wiring on to reverse dimming direction ? Instructor grade : Comments : 56 95-CL-1919-06 Module 6 — SA-28 consulab.com info@consulab.com SA-28 — Horn Circuit with Relay SA-28 — Circuit Criteria Design and build a circuit that will operate the horn (buzzer B1) which will be turned on by relay R1 using push button PB1 to control the relay. This is very typical non-CAN Bus horn circuit. 1. Draw your designed circuit for assignment SA-28 on a blank schematic template and label it : SA-28 HORN CIRCUIT WITH RELAY. Use the SA-28 student answer sheet to record all of your question answers. 2. Does circuit work properly according to the described circuit criteria ? Yes No SA-28 — Circuit Explanation 3. Does the circuit operate exactly as the criteria describes ? 4. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit. 5. Demonstrate proper circuit performance to your instructor. 6. Now, make a modification to the circuit that will cause LED D1 to be “on” when the horn is “off”. This could be a horn location indicator light circuit on a vehicle. The important thing is that the LED goes off when the horn comes on. 7. Describe what modifications you had to make to the circuit to comply with step 5 ? 8. Turn in your answer sheet to your instructor. 57 95-CL-1919-06 Module 6 — SA-28 consulab.com info@consulab.com SA-28 — Horn Circuit with Relay - Student Answer Sheet Name : Group : Date : 1. Draw your designed circuit for assignment SA-28 HORN CIRCUIT WITH RELAY on a blank schematic template and label it properly. 2. Does circuit work properly according to the described circuit criteria ? Yes No 3. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit : 7. Describe what modifications you had to make to the circuit to comply with step 6 ? Instructor grade : Comments : 58 95-CL-1919-06 Module 6 — SA-29 consulab.com info@consulab.com SA-29 — Alternately Flashing Lights SA-29 — Circuit Criteria Design and build a circuit that will cause bulb L1 and bulb L2 to alternately flash on and off. Control this circuit with switch SW1, but when switch SW1 is in the OFF position, no lights will be on. 1. Draw the designed circuit on a blank schematic template and label it : SA-29 ALTERNATELY FLASHING LIGHTS. Use the student answer sheet SA-29 to record all of your question answers. 2. Does the circuit operate exactly as the criteria describes ? 3. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit. 4. Demonstrate proper circuit performance to your instructor. 5. Turn in your answer sheet to your instructor. 59 95-CL-1919-06 Module 6 — SA-29 consulab.com info@consulab.com SA-29 — Alternately Flashing Lights - Student Answer Sheet Name : Group : Date : 1. Draw the designed circuit on a blank schematic template and label it : SA-29 ALTERNATELY FLASHING LIGHTS. 2. Does circuit work properly according to the described circuit criteria ? Yes No 3. In your own words, explain how this circuit works explaining both the positive and negative sides of the circuit : Instructor grade : Comments : 60 95-CL-1919-06 Module 6 — SA-30 consulab.com info@consulab.com SA-30 — Throttle Position Sensor Circuit SA-30 — Circuit Explanation Many position sensors in the automobile use a three-wire circuit design. The sensor consists of a fixed resistance manu- factured in either a straight line or in a circle design. The “third” wire is a movable arm that contacts the fixed resistance as it is moved either in a straight line or rotates in a circular movement. A throttle position sensor is typically the circular design and the movable arm is connected to the throttle linkage of the engine and rotates as the throttle is opened or closed. The TPS (throttle position sensor) is used to tell the ECM and other computers what the position of the throttle plate is. See below for further explanation : SA-30 THROTTLE POSITION SENSOR CIRCUIT EXPLANATION Many posi*on sensors in the automobile use a three-wire circuit design. The sensor consists of a fixed resistance manufactured in either a straight line or in a circle design. The “third” wire is a movable arm that contacts the fixed resistance as it is moved either in a straight line or rotates in a circular movement. A throAle posi*on sensor is typically the circular design and the movable arm is connected to the throAle linkage of the engine and rotates as the throAle is opened or closed. The TPS (throAle posi*on sensor) is used to tell the ECM and other computers what the posi*on of the throAle plate is. See below for further explana*on: As the throAle linkage is moved, the terminal B signal circuit will vary from 0 to 5V±. Terminal A will be a constant 5V± and terminal C is the Ground circuit. NOTE: The resistor is shown in a straight-line format here, but could be in a circular shape with no change in sensor opera*on. The important thing to remember is that the movable arm (terminal B) moves with the throAle linkage and varies the signal voltage from 0-5V±. This is how the ECM “knows” the posi*on of the throAle plate. NOTE: Newer vehicles with “drive by wire” systems use two throAle posi*on sensors and the name of the sensors is changed to Accelerator Pedal Posi*on sensor (APP). One APP sensor will have the signal voltage go up with throAle movement and the other will have the signal voltage go down with throAle movement. These redundant signals are used to verify proper APP circuit opera*on. The CL-1919-06 Trainer can be used to create a “TPS” circuit using the poten*ometer (POT). Terminals G and I can be either the 5V or Ground circuits and terminal H is the TPS signal circuit. The trainer’s voltage supply will be adjusted as close to 5.0V as possible. Abnormal condi*ons can be introduced by using resistors R1 through R5 in any of the three circuits of the TPS sensor. A- 5V IN C- GND B- 0-5V SIG TPS CONNECTOR TPS SCHEMATIC MOVEMENT SA-30 THROTTLE POSITION SENSOR CIRCUIT EXPLANATION Many posi*on sensors in the automobile use a three-wire circuit design. The sensor consists of a fixed resistance manufactured in either a straight line or in a circle design. The “third” wire is a movable arm that contacts the fixed resistance as it is moved either in a straight line or rotates in a circular movement. A throAle posi*on sensor is typically the circular design and the movable arm is connected to the throAle linkage of the engine and rotates as the throAle is opened or closed. The TPS (throAle posi*on sensor) is used to tell the ECM and other computers what the posi*on of the throAle plate is. See below for further explana*on: As the throAle linkage is moved, the terminal B signal circuit will vary from 0 to 5V±. Terminal A will be a constant 5V± and terminal C is the Ground circuit. NOTE: The resistor is shown in a straight-line format here, but could be in a circular shape with no change in sensor opera*on. The important thing to remember is that the movable arm (terminal B) moves with the throAle linkage and varies the signal voltage from 0-5V±. This is how the ECM “knows” the posi*on of the throAle plate. NOTE: Newer vehicles with “drive by wire” systems use two throAle posi*on sensors and the name of the sensors is changed to Accelerator Pedal Posi*on sensor (APP). One APP sensor will have the signal voltage go up with throAle movement and the other will have the signal voltage go down with throAle movement. These redundant signals are used to verify proper APP circuit opera*on. The CL-1919-06 Trainer can be used to create a “TPS” circuit using the poten*ometer (POT). Terminals G and I can be either the 5V or Ground circuits and terminal H is the TPS signal circuit. The trainer’s voltage supply will be adjusted as close to 5.0V as possible. Abnormal condi*ons can be introduced by using resistors R1 through R5 in any of the three circuits of the TPS sensor. A- 5V IN C- GND B- 0-5V SIG TPS CONNECTOR TPS SCHEMATIC MOVEMENT TPS SCHEMATIC TPS CONNECTOR As the throttle linkage is moved, the terminal B signal circuit will vary from 0 to 5V±. Terminal A will be a constant 5V± and terminal C is the Ground circuit. NOTE : The resistor is shown in a straight-line format here, but could be in a circu- lar shape with no change in sensor operation. The important thing to remember is that the movable arm (terminal B) moves with the throttle linkage and varies the signal voltage from 0-5V±. This is how the ECM “knows” the position of the throttle plate. NOTE : Newer vehicles with “drive by wire” systems use two throttle position sensors and the name of the sensors is changed to Accelerator Pedal Position sensor (APP). One APP sensor will have the signal voltage go up with throttle movement and the other will have the signal voltage go down with throttle movement. These redundant signals are used to verify proper APP circuit operation. The CL-1919-06 Trainer can be used to create a “TPS” circuit using the potentiometer (POT). Terminals G and I can be either the 5V or Ground circuits and terminal H is the TPS signal circuit. The trainer’s voltage supply will be adjusted as close to 5.0V as possible. Abnormal conditions can be introduced by using resistors R1 through R5 in any of the three circuits of the TPS sensor. SA-30 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-30 student answer sheet SA-30 to record all of your measurements and question answers. 1. Obtain the schematic labeled : THROTTLE POSITION SENSOR CIRCUIT PART 1 and build the circuit on your trainer. Double check all connections. NOTE : Switch SW1 will be used for an ignition switch. 61 95-CL-1919-06 Module 6 — SA-30 consulab.com info@consulab.com 2. Using very light adjustments, try to adjust the trainer’s voltage supply readout so that it is as close to 5 volts as pos- sible. Most vehicle manufacturers use 5V as the operating voltage of position sensors. 3. Turn the trainer off and disconnect the three wires to the potentiometer (POT). 4. Now, measure the total resistance value of the potentiometer. Use the answer sheet. 5. The trainers potentiometer is being used as a typical throttle position or accelerator pedal position sensor. Connect your ohmmeter RED lead to terminal G of the potentiometer and the BLACK ohmmeter lead to terminal H of poten- tiometer. 6. Turn POT adjustment knob fully counter-clockwise and read the resistance. Use the answer sheet. 7. Turn POT adjustment knob fully clockwise and read the resistance. Use the answer sheet. 8. With the POT still at full CW, make a prediction of what the resistance measurement be if your ohmmeter leads were connected to terminals I and H, and then H and G ? Put your answer on the answer sheet. 9. Make those changes and confirm your prediction by making measurements. What happened to the resistance read- ings ? Use the answer sheet. 10. Reconnect all wires removed from Step 3, remove ohmmeter leads and turn on the trainer. 11. Connect RED lead of voltmeter to terminal H of POT and BLACK lead of voltmeter to ground. 12. With “ignition key” (SW1) turned on, rotate the POT adjustment knob while watching the voltage. 13. Make voltage measurements at the following knob positions. A. Fully counter-clockwise. Use the answer sheet. B. ¼ way between full CCW. Use the answer sheet. C. ½ way between full CCW. Use the answer sheet. D. ¾ way between full CCW. Use the answer sheet. E. Fully clockwise. Use the answer sheet. 14. Many cars use two APP sensors, with each one giving an “opposite” signal as the other one in the pair. This is a safe- ty design. So, to simulate this, re-wire your potentiometer so that the signal voltage readings now read opposite as they did before. What circuit changes did you have to make to accomplish this ? Use the answer sheet. 15. Upon completion of steps 1 through 15, in your own words, describe what a throttle position or accelerator pedal position sensor are ? How do they work ? Use the answer sheet. 16. With ignition key “ON”, adjust the POT knob until you have a TPS signal voltage to ground of about 2.5 V (one-half way). Put your TPS signal voltage on the answer sheet. Turn switch SW1 to OFF. 17. Obtain the schematic labeled : THROTTLE POSITION SENSOR CIRCUIT PART 2 and build the circuit on your trainer. Notice that resistor R4 is now in the TPS signal circuit. Double check all connections. EXPLANATION : You have inserted an unwanted resistance (R4) in the TPS signal circuit. The next steps will explain how to properly diagnose this circuit and what effect unwanted resistance in the circuit will have on TPS operation. 18. With trainer on, measure the TPS signal voltage. Use the answer sheet SA-30. 19. Explain in your own words, why the signal voltage changed ? Use the answer sheet. 95-CL-1919-06 Module 6 — SA-30 consulab.com info@consulab.com 62 SA-30 — Using Voltage Drop Testing to Find the Location of the Unwanted Resistance 20. Move the RED lead of your voltmeter from terminal H of POT to terminal P of resistor R4. Make a TPS signal voltage measurement. Use the answer sheet. 21. Move the RED lead of your voltmeter from terminal P of R4 to terminal Q of R4 and measure TPS signal voltage. Use the answer sheet. 22. Now, remove the end of the BLACK wire from the BLACK system ground receptacles that connects to terminal Q of R4 (do not remove it from the resistor) and measure TPS signal voltage again. Use the answer sheet. After making the voltage measurement, re-connect the BLACK wire back to the system ground receptacles. 23. The above tests reveals that there is unwanted resistance in the TPS signal circuit which causes the correct signal voltage of 2.5±VDC = ½ throttle, to be about 1.25±VDC = ¼ throttle. This condition would cause vehicle perfor- mance issues as the vehicle ECM thinks the throttle is at ¼ open when it is really ½ open. 24. Now, let’s use VOLTAGE DROP TESTING to locate the unwanted resistance even though in this case, you can obvi- ously see that it is resistor R4. 25. With ignition switch SW1 in the ON position, measure the voltage between terminal H of POT and terminal P of resis- tor R4. Use the answer sheet. 26. Explain in your own words what a desirable or “normal” reading should be. Use the answer sheet. 27. Measure the voltage between terminal P and terminal Q of resistor R4. Use the answer sheet. 28. Explain in your own words what a desirable or “normal” reading should be. Use the answer sheet. 29. Measure the voltage between terminal Q of resistor R4 and system ground. Use the answer sheet. 30. Explain in your own words what a desirable or “normal” reading should be. Use the answer sheet. 31. Now, evaluate your voltage measurements and describe your conclusions from the three voltage readings you have made. Use the answer sheet. 32. Now, place the RED voltmeter lead to terminal H of POT and the BLACK voltmeter lead to system ground. 33. Remove the BLACK wire connected to system ground coming from terminal Q of resistor R1 and measure the TPS signal voltage. Use the answer sheet. 34. Explain in your own words why the TPS signal voltage changed when the ground wire was disconnected. Use the answer sheet. 35. Remove all wires from the trainer, double check your answer sheet for missing answers, then turn in to your instruc- tor. 63 95-CL-1919-06 Module 6 — SA-30 consulab.com info@consulab.com SA-30 — Throttle Position Sensor Circuit - Student Answer Sheet Name : Group : Date : 4. ohms 6. ohms at full CCW 7. ohms at full CW 8. 9. ohms between H and I and ohms between H and G 13. A- volts full CCW B- volts ¼ from full CCW C- volts ½ from full CCW D- volts ¾ from full CCW E- volts at full CW 14. 15. 16. TPS volts 18. TPS volts 19. 20. TPS volts 21. TPS volts 22. TPS volts (with ground wire removed) 25. volts between terminal H of POT to terminal P of resistor R4 26. A normal voltage reading should be : 27. volts between terminal P and terminal Q of resistor R4. 28. A normal voltage reading should be : 29. volts between terminal Q of resistor R4 and system ground. 64 95-CL-1919-06 Module 6 — SA-30 consulab.com info@consulab.com 30. A normal voltage reading should be : 31. EVALUATION : 33. volts 34. EXPLANATION : Instructor grade : Comments : 65 95-CL-1919-06 Module 6 — SA-31 consulab.com info@consulab.com SA-31 — PWM Controlled NPN Transistor Circuit SA-31 — Circuit Explanation & Theory It is very common in vehicle engine performance circuits to have an internal circuit with transistors controlled by Pulse Width Modulation. A commonly used term is a “Quad Driver”. Quad-Drivers are integrated circuits within the ECM or PCM that control certain types of circuits. Many Quad-Drivers are controlled by using Pulse Width Modulation which are also within the ECM/PCM. Pulse Width Modulation controls a circuit by turning on and off a B+ supply very quickly. For example, a light bulb can be turned on and off very rapidly so that it can be off, on at varying amounts of brightness to being on a full brightness all controlled by Pulse Width Modulation. Fuel Injectors are also commonly controlled by PWM. PWM circuits operate at varying frequencies. The circuit is either ON or OFF and the quad-driver controls the amount of on time. The amount of “on” time is called DUTY CYCLE. Duty cycle is measured either as a percentage or can also be measured with the amount of on time called “PULSE WIDTH”. The important thing to remember about PWM, it that the voltage to the device being controlled will be either full voltage (14.6 for example) or zero. If a blower motor was controlled by PWM and it was running at half-speed, the DUTY CYCLE would be at 50%. If a digital voltmeter was connected to the blower motor, it would indicate about 7.3V± because the meter cannot read the on/off signals that are occuring in milli-seconds. So, the meter just “averages” the signals. One must remember, that a PWM circuit cannot be accurately tested or measured with a voltmeter. An oscilloscope is the only tool that will display the true on and off pulse width modulated circuit. Some scan tools can give a DUTY CYCLE or PULSE WIDTH readout, but those also are averages and not the true PWM signals. SA-31 — Procedure Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the SA-31 student answer sheet to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below. BE VERY CAREFUL TO CORRECT INSTALL EACH WIRE : CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED power receptacles to terminal O of switch SW1 B. Terminal I of switch SW1 to terminal A of bulb L1 C. Terminal B of bulb L1 to terminal C (collector) of transistor T1 D. RED receptacle of the PWM generator to terminal K of resistor R1 (Make sure the PWM knob is fully CCW) E. Terminal J of resistor R1 to terminal B (base) of transistor T1 CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground terminals to terminal E (emitter) of transistor T1 B. Any of the four BLACK ground terminals to the BLACK terminal of the PWM generator 66 95-CL-1919-06 Module 6 — SA-31 consulab.com info@consulab.com NOTE : It will be noticed that this NPN circuit uses RED wires on both sides of bulb L1. This is correct because schemat- ics show circuits in the OFF position and full supply voltage can be measured to ground at both terminals of bulb L1. When the transistor turns ON, the wires connected to the COLLECTOR become ground wires and turn the bulb on. 2. Draw the circuit you have just constructed and label it : SA-31 PWM NPN TRANSISTOR CONTROLLED CIRCUIT. EVALUATION OF THE CIRCUIT : 3. Make sure switch SW1 is in the OFF position. 4. Measure the voltage from terminal K of resistor R1 to ground in the following conditions (use answer sheet) : A. With PWM knob fully CCW. volts B. With PWM knob one-half way between fully CCW & CW volts C. With PWM knob fully CW. volts. (Return to fully CCW position) 5. Measure the voltage at terminal J of resistor R1 to ground in the following conditions : (use answer sheet) : A. With PWM knob fully CCW. volts B. With PWM knob one-half way between fully CCW & CW volts C. With PWM knob fully CW. volts. (Return to fully CCW position) 6. The above steps demonstrate the resistor R1 serves as a current limiting device for transistor T1 (NPN) BASE circuit. And, it also demonstrates that the transistor can be turned on at different voltages even though it is not actually controlling anything at this point (WHY ? Because switch SW1 is still in the OFF position). Remember that the “con- trol” circuit of an NPN transistor is BASE to EMITTER) (Return to fully CCW position). 7. Turn switch SW1 to the ON position. 8. Measure the voltage to ground at terminal C (COLLECTOR) of transistor T1 (NPN). volts. This step demonstrates that there is voltage present at the transistor COLLECTOR but the transistor is turned OFF so the light bulb does not illuminate. 9. Now adjust the PWM knob to the below positions and measure the voltage of COLLECTOR to ground and describe bulb L1’s operation at each position (use answer sheet) : A. Fully CCW volts. Bulb L1’s performance B. ½ between full CCW and CW. Bulb L1’s performance C. Fully CW volts. Bulb L1’s performance (Return to fully CCW position) 10. EXPLANATION : As soon as the PWM generator starts to turn on the transistor, terminal B of bulb L1 and the COLLECTOR terminal becomes a path to ground. Therefore, the voltage at the COLLECTOR will start to drop as the transistor is turned on for longer periods of time. The voltage at terminal A of bulb L1 will stay the same at system voltage because it is on the positive side of the circuit. 11. The PWM generator is simply used in this case as a “variable” ON circuit to control the brightness of the bulb. Other examples of component control could be electric motors, relays, solenoids, fuel injectors or ignition coils which can be all controlled by PWM and transistors. 67 95-CL-1919-06 Module 6 — SA-31 consulab.com info@consulab.com 12. Predict what would happen if you connected a RED jumper wire from B+ supply voltage to terminal K of resistor R1. (use answer sheet) 13. Without making any other circuit changes, install a RED jumper wire from any of the four RED B+ supply voltage receptacles to the K terminal of resistor R1. Describe what happened (use answer sheet). 14. Make sure your answer sheet is completely filled out, then turn in to instructor. 15. Remove all wires from the trainer and turn off both the trainer and the digital multimeter. 68 95-CL-1919-06 Module 6 — SA-31 consulab.com info@consulab.com SA-31 — PWM Controlled NPN Transistor Circuit - Student Answer Sheet Name : Group : Date : 4. A. PWM knob fully CCW volts. Expressed as : B. PWM knob ½ way volts. Expressed as : C. PWM knob fully CW volts. Expressed as : 5. A. PWM knob fully CCW volts. Expressed as : B. PWM knob ½ way volts. Expressed as : C. PWM knob fully CW volts. Expressed as : 8. volts at COLLECTOR. Expressed as : 9. A. PWM knob fully CCW volts. Expressed as : B. PWM knob ½ way volts. Expressed as : C. PWM knob fully CW volts. Expressed as : 12. PREDICTION : 13. DESCRIPTION : Instructor grade : Comments : 95-CL-1919-06 Module 6 — SA-32 consulab.com info@consulab.com 69 SA-32 — PWM Controlled PNP Transistor Circuit CIRCUIT EXPLANATION & THEORY : In the previous assignment SA-31, an NPN transistor was used to control bulb L1 and the transistor was controlled by the PWM generator. In this assignment (SA-32), you will use a PNP transistor and learn the differences between the NPN and PNP in how they control circuits and how they are properly wired in a circuit. The NPN transistor controlled the “positive” side of the bulb circuit. The PNP circuit controls the “ground” side of the circuit. The EMITTER of both an NPN and a PNP transistor carries both the low “control” current and the higher “controlled” current. The BASE to EMITTER is the “control” or low current circuit and the COLLECTOR to EMITTER is the “controlled” or high current circuit. SA-32 — PWM PNP Transistor Controlled Circuit — Part A PROCEDURE : Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the student answer sheet SA-32 to record all of your measurements and question answers. 1. Connect RED and BLACK jumper wires as instructed below. BE VERY CAREFUL TO CORRECT INSTALL EACH WIRE : CONNECT RED JUMPER WIRES BETWEEN : A. RED receptacle of the PWM generator to the terminal E (emitter) of transistor T2 (PNP). (Make sure the PWM knob is fully CCW) CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground terminals to terminal O of switch SW1 B. Terminal I of switch SW1 to terminal K of resistor R1 C. Terminal J of resistor R1 to terminal B (base) of transistor T2 (PNP) D. Any of the four BLACK ground terminals to the BLACK terminal of the PWM generator. E. Any of the four BLACK ground terminals to terminal B of bulb L1 F. Terminal A of bulb L1 to terminal C (collector) of transistor T2 (PNP) NOTE : It will be noticed that this PNP circuit uses BLACK wires on both sides of bulb L1. This is correct because sche- matics show circuits in the OFF position and both terminals of bulb L1 are “technically” ground until the transistor is turned on. When the transistor turns ON, the wire connected to the COLLECTOR becomes positive wire and turns the bulb on. 2. Draw the circuit you have just constructed and label it : SA-32 PWM PNP TRANSISTOR CONTROLLED CIRCUIT - Part A. 95-CL-1919-06 Module 6 — SA-32 consulab.com info@consulab.com 70 EVALUATION OF THE CIRCUIT : 3. Make sure the PWM adjustment knob is fully counter-clockwise. UNDERSTANDING THE LOW AND HIGH CURRENT CIRCUITS IN A PNP TRANSISTOR : 4. Turn switch SW1 to ON and also turn the PWM adjustment knob fully clockwise and confirm that bulb L1 is illuminated. 5. Measure the current in the following circuits : (use answer sheet) A. The PNP BASE circuit amps B. The PNP COLLECTOR circuit amps C. The PNP EMITTER circuit amps (Return PWM knob to fully CCW position) 6. Which PNP circuit draws the least current ? 7. Which PNP circuit draws the most current ? 8. Which PNP circuit carries both the control and controlled current ? 9. Which PNP circuit is the “controlled” circuit ? 10. Which PNP circuit is the “control” circuit ? 11. Turn PWM adjustment knob fully counter-clockwise and turn switch SW1 to the OFF position. EXPLANATION OF CIRCUIT : Transistor T2 (PNP) is serving as a relay. Relays have a low current control circuit which is the relay coil (terminals 86 & 85). A PNP transistor’s low current control circuit is from the BASE to the EMITTER. Relays also have a high current controlled circuit which is from 30 to 87. A PNP transistor’s high current circuit is from COLLEC- TOR to EMITTER and controls the ground side. A current limiting resistor is usually installed in the BASE circuit to control the amount of current flowing in the control circuit. SA-32 — PWM PNP Transistor Controlled Circuit — Part B PROCEDURE : 12. Make the following modifications to the circuit : CONFIRM THAT THE TRAINERS POWER IS TURNED OFF. A. Remove the RED wire from PWM RED receptable to terminal E (emitter) of transistor T2 (PNP) B. Install a RED wire from terminal E (emitter) of transistor T2 (PNP) to terminal I of switch SW1 C. Install a RED wire from any of the four RED positive receptacles to terminal O of switch SW1. 13. Draw the circuit you have just constructed and label it : SA-32 PWM PNP TRANSISTOR CONTROLLED CIRCUIT - Part B. EXPLANATION OF CIRCUIT CHANGES : The PWM generator has been removed from the circuit. Switch SW1 now sup- plies full battery voltage to the transistor and it will come on at full current control whenever the switch SW1 is closed. This change eliminated the ability to vary the amount of current flowing through transistor T2 (PNP) which previously served as a “dimmer” function for bulb L1. Transistors can either be ON/OFF switches or can be a variable ON/OFF switches. 95-CL-1919-06 Module 6 — SA-32 consulab.com info@consulab.com 71 14. Study the circuit and determine two different methods of adding bulb L2 to the circuit so that the transistor will control both L1 and L2 bulbs together. Describe them on the answer sheet. Once you have decided both methods, make one of your options to the circuit. After your modification, confirm that the circuit operates with both bulbs L1 and L2 coming on together. Modification #1 Modification #2 15. Which modification did you choose ? Use the answer sheet. 16. With the circuit modification in place, measure the controlled current (answer sheet) amps 17. Did the BASE current change from the previous circuit ? Y/N If yes, what is the new reading ? amps 18. Measure the EMITTER circuit current. amps 19. Compare it to the circuit where only L1 was on. What is the difference ? 20. Make sure your answer sheet is completely filled out, then turn in to instructor. 21. Remove all wires from the trainer and turn off both the trainer and the digital multimeter. 72 95-CL-1919-06 Module 6 — SA-32 consulab.com info@consulab.com SA-32 — PWM Controlled PNP Transistor Circuit - Student Answer Sheet Name : Group : Date : SA-32 Part A 5. A- The PNP BASE circuit : amps. Expressed as : B- The PNP COLLECTOR circuit : amps. Expressed as : C- The PNP EMITTER circuit : amps. Expressed as : 6. Which PNP circuit draws the least current ? 7. Which PNP circuit draws the most current ? 8. Which PNP circuit carries both the control and the controlled circuits ? 9. Which PNP circuit is the “controlled” circuit ? 10. Which PNP circuit is the “control” circuit ? SA-32 Part B 14. What two circuit modifications can be made to control bulb L2. A : B : 15. Which modification did you choose ? 16. Controlled current (with modification made) : amps. Expressed as : 17. Did the BASE current change ? Y/N If YES, what is the new reading ? amp Expressed as : 18. What is the EMITTER current ? amps. Expressed as : 19. Compare EMITTER current to the circuit before modifications. Comparison : Instructor grade : Comments : 95-CL-1919-06 Module 6 — SA-33 consulab.com info@consulab.com 73 SA-33 — Flashing Lights Transistor Controlled Circuit CIRCUIT EXPLANATION & THEORY : In assignments SA-31 & SA-32, both transistors were individually connected to a circuit. In SA-33, both NPN and PNP tran- sistors will be used to control alternate flashing of L1 and L2. This is the most complex circuit you will be constructing and the proper connections of all BLACK and RED wires is critical. SA-33A will connect all of the BLACK ground circuits and SA-33B will connect all the positive feed circuits. SA-33A — Flashing Lights Transistor Controlled Ground Circuits PROCEDURE : Be sure to carefully follow all instructions and always ask your instructor if you have any questions. Use the student answer sheet SA-33 to record all of your measurements and question answers. 1. BE VERY CAREFUL TO CORRECT INSTALL EACH WIRE : CONNECT BLACK JUMPER WIRES BETWEEN : A. Any of the four BLACK ground terminals to terminal K of resistor R1 B. Terminal J of resistor R1 to the B (base) terminal K of transistor T2 C. Any of the four BLACK ground terminals to the E (emitter) terminal of transistor T1 (NPN) D. Any of the four BLACK ground terminals to terminal 85 of relay RL1. E. Any of the four BLACK ground terminals to terminal B of bulb L1 F. Terminal A of bulb L1 to terminal C (collector) of transistor T2 (PNP) G. Any of the four BLACK ground terminals to the GND terminal of the electronic flasher NOTE : It will be noticed that this PNP circuit uses BLACK wires on both sides of bulb L1. This is correct because sche- matics show circuits in the OFF position and both terminals of bulb L1 are “technically” ground until the transistor is turned on. When the transistor turns ON, the wire connected to the COLLECTOR becomes positive wire and turns the bulb on. 2. Draw the circuit you have just constructed and label it : SA-30A FLASHING LIGHTS TRANSISTOR CONTROLLED GROUND CIRCUITS 95-CL-1919-06 Module 6 — SA-33 consulab.com info@consulab.com 74 SA-33B — Flashing Lights Transistor Controlled Positive Circuits PROCEDURE : 3. CONNECT RED JUMPER WIRES BETWEEN : A. Any of the four RED positive terminals to terminal C of bulb L2 B. Any of the four RED positive terminals to terminal O of switch SW1 C. Terminal I of switch SW1 to terminal 30 of relay RL1 D. Terminal I of switch SW1 to BAT terminal of the electronic flasher E. Terminal M of resistor R2 to terminal 87 of relay RL1 F. Terminal L of resistor R2 to B (base) terminal of transistor T1 (NPN) G. Terminal 86 of relay RL1 to the SIG terminal of the electronic flasher H. Terminal 87a of relay RL1 to the E (emitter) terminal of transistor T2 (PNP) I. Terminal D of bulb L2 to the C (collector) terminal of transistor T1 (NPN) 4. Draw the circuit you have just constructed and label it : SA-33B FLASHING LIGHTS TRANSISTOR CONTROLLED POSI- TIVE CIRCUITS CIRCUIT EXPLANATION : Transistor T1 and Bulb L2 Transistor T1 controls the flashing of bulb L2 by having transistor T1 turned on and off by the electronic flasher con- trolling the relay RL1 coil. The relay coil then turns on terminals 87 and 87a alternately because of the electronic flasher operation. When the relay turns on terminal 87, power exits the relay and flows through resistor R2 which limits the current in the BASE circuit of transistor T1. Power which was fed to bulb L2 and enters the C (collector) terminal of tran- sistor T1 then flows out of terminal E (emitter) of transistor T1 when the transistor is turned on. Power then flows back to ground and bulb L2 is turned on. As soon as the flasher turns the relay off, bulb L2 also goes off because transistor T1 is shut off. Transistor T2 and Bulb L1 Transistor T2 controls the flashing of bulb L1 by having transistor T1 turned on and off by the electronic flasher con- trolling the relay R1 coil. The relay coil then turns on terminals 87 and 87a alternately because of the electronic flasher operation. When the relay is turned off, power exits the relay from terminal 87a and flows to the E (emitter) terminal of transistor T2. The B (base) terminal of transistor T2 is connected through resistor R1 to ground which limits BASE current in the transistor. Terminal C (collector) of transistor T2 is connected to bulb L1, through the bulb and to ground. Thus, when power from relay terminal 87a is turned on, power flows into the E (emitter) circuit of transistor T2, it turns on the transistor and provides a ground path to bulb L1 which turns it on. The transistor T2 B (base) circuit is also connected to ground through resistor R1 and when power enters the E (emitter) terminal, transistor T2 is turned on providing a con- nection between E (emitter) and C (collector). 95-CL-1919-06 Module 6 — SA-33 consulab.com info@consulab.com 75 The process is reversed on and off as the electronic flasher controls the coil of relay RL1. Turning on terminals 30 to 87 of the relay RL1 will turn on bulb L2. When the flasher turns the relay coil off, it connects power from relay terminals 30 to 87a which provides power to the E (emitter) terminal of transistor T2 which turns on and provides a ground circuit for bulb L1. USE YOUR ANSWER SHEET FOR ANSWERING THE FOLLOWING QUESTIONS. ADJUST THE TRAINER’S SUPPLY VOLTAGE AS CLOSE TO 14.6 AS YOU CAN. 5. Which transistor controls bulb L1 ? 6. Which resistor provides current limiting for transistor T1 ? 7. What component provides power to the relay and the electronic flasher ? 8. When transistor T1 is turned on, what bulb also turns on ? 9. Which bulb would stay on constantly if the electronic flasher failed to operate ? 10. Which bulb would not come on if resistor R1 opened ? 11. What bulb would stay on if the wire from switch SW1 to terminal 30 of relay RL1 was open ? 12. Measure the current flow through bulb L1 : amps (You may have to “modify” the circuit to keep that circuit ON in order to measure current) 13. Measure the current flow through bulb L2 : amps (You may have to “modify” the circuit to keep that cir- cuit ON in order to measure current) 14. Measure the current flow in the wire from terminal 87a to terminal E (emitter) of transistor T2 : amps (You may have to “modify” the circuit to keep that circuit ON in order to measure current) 15. Measure the current of just the C (collector) circuit of transistor T2. amps 16. Make sure your answer sheet is completely filled out, then turn in to instructor. 17. Remove all wires from the trainer and turn off both the trainer and the digital multi-meter. After completion of SA-33, turn in your answer sheet to the instructor and ask for Test 13, then Test 14. 76 95-CL-1919-06 Module 6 — SA-33 consulab.com info@consulab.com SA-33 — Flashing Lights Transistor Controlled Circuit - Student Answer Sheet Name : Group : Date : 5. Which transistor controls bulb L1 ? 6. Which resistor provides current limiting for transistor T1 ? 7. What component provides power to the relay coil and the electronic flasher ? 8. When transistor T1 is turned on, what bulb also turns on ? 9. Which bulb would stay on constantly if the electronic flasher failed to operate ? 10. Which bulb would not come on if resistor R1 opened ? 11. What bulb would stay on if the wire from switch SW1 to terminal 30 of relay R1 was open ? 12. Measure the current flow through bulb L1 : amps. Expressed as : 13. Measure the current flow through bulb L2 : amps. Expressed as : 14. Measure the current flow in the wire from terminal 87a to terminal E (emitter) of transistor T2. amps. Expressed as : 15. Measure the current of just the C (collector) circuit of transistor T2. amps. Expressed as : Instructor grade : Comments : NOTE : A schematic for Assignment SA-33 showing both positive (RED) and ground (BLACK) circuits is provided in the Instructors manual in case you wish to have students draw the entire circuit. After completion of SA-33, turn in your answer sheet to the instructor and ask for Test 13, then Test 14. 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada © ConsuLab Educatech Inc, 2024. All rights reserved. Trainer Layout and Familiarization Front Panel Component Identification Electrical Component Identification Electrical Accessories Trainer Use and Operation Warnings and Cautions Student Learning Modules MODULE 5 Student Experiments Student Assignment Guidelines SA-16 — Light Bulb with Diode SA-16 — Light Bulb with Diode - Student Answer Sheet SA-17 — Light Bulb Circuits SA-17 — Light Bulb Circuits - Student Answer Sheet SA-18 — Light Bulb Circuits with Resistances SA-18 — Light Bulb Circuits with Resistances - Student Answer Sheet SA-19 — Light Bulb Circuits with Problems SA-19 — Light Bulb Circuits with Problems - Student Answer Sheet SA-20 — Relay Circuits SA-20 — Relay Circuits - Student Answer Sheet SA-21 — Flasher Controlled Circuit SA-21 — Flasher Controlled Circuit - Student Answer Sheet SA-22 — PWM Circuit with Motor SA-22 — PWM Circuit with Motor - Student Answer Sheet SA-23 — Transistor Controlled Circuits SA-23 — Transistor Controlled Circuits - Student Answer Sheet MODULE 6 Advanced Student Circuit Assignments SA-24 — Using M1 as a Generator SA-24 — Using M1 as a Generator - Student Answer Sheet SA-25 — Alarm System — Option 1 SA-25 — Alarm System — Option 1 - Student Answer Sheet SA-26 — Alarm System — Option 2 SA-26 — Alarm System — Option 2 - Student Answer Sheet SA-27 — Light Bulb Dimming SA-27 — Light Bulb Dimming - Student Answer Sheet SA-28 — Horn Circuit with Relay SA-28 — Horn Circuit with Relay - Student Answer Sheet SA-29 — Alternately Flashing Lights SA-29 — Alternately Flashing Lights - Student Answer Sheet SA-30 — Throttle Position Sensor Circuit SA-30 — Throttle Position Sensor Circuit - Student Answer Sheet SA-31 — PWM Controlled NPN Transistor Circuit SA-31 — PWM Controlled NPN Transistor Circuit - Student Answer Sheet SA-32 — PWM Controlled PNP Transistor Circuit SA-32 — PWM Controlled PNP Transistor Circuit - Student Answer Sheet SA-33 — Flashing Lights Transistor Controlled Circuit SA-33 — Flashing Lights Transistor Controlled Circuit - Student Answer Sheet
