Download V HG

UNIVERSITY OF CALIFORNIA
College of Engineering
Department of Electrical Engineering and Computer Sciences
EE 105
Spring 2012
Prof. Pister
Names of lab partners: ________________________________ and __________________________________
LAB 1 Diodes
1) Dangerous introduction to measurement: Using your handheld DMM, measure the three voltages between the
three pairs of terminals of one of the outlets in the lab. BE CAREFUL. 110VAC can be fatal.
Do NOT touch the metal probe tips when you are putting them in the outlet. DO make sure that your
DMM is set to AC Volts, at a setting at or above 200V. DO make sure that the DMM leads are plugged in
to “COM” and “VmA” on the DMM.
If you have any questions, concerns, or doubts about making this measurement, ask your professor or TA for
advice. If you do this right, it’s safer than plugging in an extension cord.
N=neutral
H=hot
VHG =
VHN =
VGN =
G=ground
Wire up your circuit board with the following circuit. Use the 25V Agilent power supply for the 11V supply and
ground. Plug in all of your diodes, making sure to ground the cathode not the anode. Cathodes are almost always
indicated with a line on the package.
1K
10K
100K
2) Checking out the equipment
a) Check the accuracy and input impedance of your handheld digital multimeter (DMM) and the Agilent DMM.
Measure the voltage VDD with both your handheld and the Agilent DMM. Do they give the same answer
within the accuracy of the display? If not, how would you tell which one is right, if either?
Using both DMMs, measure the voltage at the bottom of each resistor. With an ideal voltmeter, there
should be no current, so the readings should be identical to the measurement of Vdd. If there’s a difference, it
means that your instrument has a finite input impedance. Calculate it.
VDD
Handheld
Agilent
V1k
V10k
V100k
V1M
RIN
b) Check the source resistance of your HP power supply.
If you ground the 1K resistor, you may be observer a voltage drop on VDD. If so, use that to calculate the
output resistance of the Agilent power supply.
Estimated RS=
3) Measure diode forward I/V characteristic, temperature sensitivity, and reverse breakdown. Currents should be
accurate to 10%. How will you know? Voltages should be accurate to a few mV.
To test temperature response, with 100uA flowing put your finger on the body of the diode (make sure not to
touch the metal leads). This is a qualitative measurement: enter +, 0, or – to indicated how the diode voltage
changes when the diode warms up.
To test reverse bias, use the 1M resistor, and adjust the supply voltage to try to get 1uA to flow. Some of the
diodes may not allow 1uA to pass at the max reverse voltage you can apply. Right down the voltage on the diode
and the corresponding current.
V(10uA)
V(100uA)
Temp
resp.
V(1mA)
V(10mA)
Vreverse @ Ireverse
1N4002
Zener
1N5817
(Schottky)
Germanium
Green LED
Yellow LED
4) Build a few rectifiers: R, RC
R
1M
S
Build the rectifiers on the left, using a 60Hz 5V sine wave and whichever diodes you like. Display all three node
waveforms on the scope at the same time, and show the TA.
Build the rectifier on the right, with 1k, 10k, and 100k resistor values. Show the TA and discuss.
LAB 1 Diodes - Report
No report is due. Make sure that your TA has checked off your work on each part of the lab, and keep your lab
report for future reference.