ELEE3306 A & B Electronic Systems Spring 09
Lab 1- Diode Circuits
Lab Experiment 1 Diode Circuits
A. OBJECTIVES
Observe and measure properties of pn-junction diodes.
Build simple series resistor diode circuit.
B. EQUIPMENT REQUIRED
Power Supply
Breadboard
Digital Multimeter
C. PARTS REQUIRED
(1) small signal diodes (1N4148) and (1) 5-6 Volt Zener diode (1N47XX series)
(2) Resistors 1MΩ, 1kΩ, and 100 ΩΩ, and 100 Ω
D. IN THE LAB
(a) Diodes typically have a stripe around one end to identify the cathode, as shown in
Figure 1. Remember that in ideal diode operation, current flows easily with the arrow
(forward bias), but is prevented from flowing against the arrow (reverse bias). One
simple way to verify that a diode is "good" is to test it with an ohmmeter. The ohmmeter
attempts to pass a kΩ, and 100 Ωnown current through the device being tested, and uses the resulting
voltage to determine the resistance. The current from the ohmmeter generally comes out
of the meter on the positive (red) lead and returns on the negative (blackΩ, and 100 Ω) lead.
Figure 1 Figure 2
Set up your multimeter to measure resistance on its 2 kΩ, and 100 Ωilohm or 4 kΩ, and 100 Ωilohm scale (many
multimeters have a setting with a diode symbol that is usually a redundant 2 or 4 kΩ, and 100 Ωilohm
scale). Verify the positive direction of the diodes with the meter and record their
measured diode forward resistance. Do not touch the exposed leads with your fingers
during the measurement since your body resistance in parallel may change the values.
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