LAB PROJECT: DIODES, DC and AC applications mer:091718 REPORT A written report will be required based on the information you acquire in this lab. The lab will count for one grade and the report will count for another grade. A rubric for doing the report is included. The report will require displays from the computer screen (see the report rubric) This can be accomplished by doing a "Print Screen", then "Paste" the information into a "MS Word" document. At a later time, the capture can then be cropped. OBJECTIVES: 1. Theoretically Analyze the operation of a given diode circuit 2. Measure the circuit parameters . Use the measurements to analyze the operation of the circuit TROUBLE SHOOTING RULE - If you know what to expect, you can determine if the circuit is working properly. - If the circuit is not working properly you can then draw a conclusion as to "why" it is not and determine how to repair it! MATERIALS LIST: Computer with Multisim PROCEDURE SECTION: 1. REFERENCE VOLTAGE: A diode can be used for a reference voltage so that V2 point will stay constant even if the battery voltage source drops (due to the battery becoming discharged) LR4 12V $1KQ Enter the circuit below as shown into Multisim. Reference Voltage . Predict (calculate) the "Reference Voltage" at D4 various level of the battery (V2), as per the table 1N914 below Use the Multimeter to measure the "Reference Voltage" at various level of the battery (V2), as per the table below V2 Battery Level 14V 12V 10V 8V Predicted Reference Voltage Level Measured Reference Voltage Level DELLPage 2 2. REVERSE POLARITY PROTECTION: A diode can be added to the Voltage Supply that will protect circuits if the voltage supply is connected the wrong way. In this scenario a Printed Circuit Board calls for +12v, the "sensitive circuit components will be compromised if those components are connected to -12v Printed Circuit Board Manson Supply VOLTAGE SUPPLY CONNECTED CORRECTLY Enter the circuit as shown into Multisim. Predict the voltage supply level going to the sensitive circuit components: Using the Multimeter, Measure the voltage supply level going to the sensitive circuit components: Both the predicted value and the measure value should coincide. If not check your work and/or contact the instructor! Voltage In Printed Circuit Board Voltage Supply To Sensitive Circuit Components Voltage In VOLTAGE SUPPLY CONNECTED WRONG! Modify the Multisim circuit as shown. Predict the voltage supply level going to the sensitive circuit components: Using the Multimeter, Measure the voltage supply level going to the sensitive circuit components: Both the predicted value and the measure value should coincide. If not check your work and/or contact the instructor! Did the reverse protection diode function properly? (Yes or No)Page 3 3. OVERVOLTAGE INPUT SIGNAL PROTECTION: Diodes can be used to prevent too large of an input signal from damaging sensitive circuit components. (As shown in a ECG schematic.) Enter the circuit below as shown into Multisim. You will be setting the Signal Input level per the table below Use the Oscilloscope to measure the Level of the "Signal Voltage Input To Sensitive Components" for each setting per the table below. Record you answers in the table. Signal Input Level 100m Vp 1 Vp 30 Vp 100Vp 200 Vp Signal Level at Input To Sensitive Circuit Components: 15V VCC Printed Circuit Board D2 IN4007 Signal Voltage Input R3 To Sensitive Circuit Components SIGNAL 1KQ RZ INPUT D3 $1MQ 100 HZ IN4007 -15V VDD Observation: If the input signal is the correct size, the signal passes to the Sensitive Circuit Components If the input signal become too large, the diode will limit the size of the signal and thus protecting the Sensitive Circuit Components Theoretical Analysis Based on the knowledge that didoes turn on when VArea. > Vestness (By = 0. 7v) then at what voltage w liodes in the circuit turn ON: +/- V peak Does this voltage coincide your measurements (yes or no) f not check your work and/or contact the instructor