October 26th, 2008 by admin
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I. OBJECTIVES
A. Identify safety hazards common to the general shop and electronics laboratory.
B. Measure the electrical resistance of your body using the ohmmeter function of the Electronic VOM.
C. Familiarize yourself with the safety precautions to be used when working with electronic circuits.
D. State the proper operating procedure when using a power supply.
E. Demonstrate the correct method of connecting voltmeters and ammeters for circuit measurement.
II. MATERIALS AND EQUIPMENTS
Power Source 0-6 Vdc. 10mA
Ammeter 0-10mAdc
Voltmeter 0-10Vdc
Electronic VOM
Practical Electronics Trainer
R1 –1kΩ, 1W
S1 –SPST, Component Module Konnect-All board
III. PROCEDURES
B. Measure the electrical resistance of your body using the ohmmeter function of the Electronic VOM.
- Right hand to left hand
- Right (left) hand to right (left) ankle
- Wet: right hand to left hand
- Wet: right (left) hand to right (left) ankle
C. Familiarize yourself with the safety precautions to be used when working with electronic circuits.
-Set it in 220V
-Make sure the power supply and meter leads are connected with the correct polarity
-All variable voltage controls are set for minimum voltage before applying power.
-After turning on, slowly advance the variable voltage control to the desired voltage.
D. State the proper operating procedure when using a power supply.
-Check the polarity of the test leads.
-The range must be higher than the value being measured.
-Voltmeter are connected across in parallel.
-Ammeter is connected into series with the circuit.
1. Set-up the circuit shown in Fig. 1-2. Use the power supply to provide the 6Vdc and panel voltmeter to measure the voltage across the resistor.
2. Close switch S1 and adjust the power supply until 6Vdc is indicated by voltmeter
3. Open switch S1 and remove the voltmeter leads from R1
4. Insert the ammeter in series with your circuit. The ammeter is connected between one terminal of the switch and resistor R1, with the positive lead toward the switch.
5. Close switch S1 and measure the circuit current indicated by the ammeter.
6. Open S1 and add the voltmeter to your circuit connecting it as in (1)
7. Close S1 and note that you can now measure current and voltage with a single test set-up.
8. Return the voltage to zero