2 - Verification and Performance Tests
c.Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to amps and record this value (Iout). Also, record the current reading on the front panel display. The readings should be within the limits specified in the performance test record card for the appropriate model under Current Programming and Readback @ 0 Amps.
d.Program the output current to the
e.Divide the voltage drop (DVM reading) across the current monitoring resistor by its resistance to convert to amps and record this value (Iout). Also, record the current reading that appears on the front panel display. The readings should be within the limits specified in the performance test record card for the appropriate model under Current Programming and Readback @ Full Scale.
Current Sink (-CC) Operation
This test verifies current sink operation and readback.
a.Turn off the supply and connect the output as shown in Figure
b.Set the external power supply to 5 V and the current to the full scale current rating of the supply under test as in Table
c.Turn on the supply under test and program the output voltage to zero and the current to full scale as in Table 2- 2. The current on the UUT display should be negative and approximately 60% of the current rating.
d.Divide the voltage drop across the current monitoring resistor by its resistance to obtain the current sink value in amps and subtract this from the current reading on the display. The difference between the readings should be within the limits specified in the performance test record card under Current Sink Readback.
Low Range Current Readback Accuracy
This test verifies the readback accuracy of the 20 milliampere current range.
a.Turn off the supply and connect the output as shown in Figure
b.Turn on the supply under test and set the current range readback to Low or Auto. Program the output voltage to zero and the current to the full scale value in Table
c.Record the current reading on the DMM and the reading on the front panel display. The difference between the two readings should be within the limits specified in the performance test record card under 20mA Range Current Readback Accuracy @ 0A.
d.Program the output voltage to 8V and record the current reading on the DMM and the reading on the front panel display. If the meter indicates overrange, lower the 8 volts slightly. The difference between the readings should be within the limits specified in the performance test record card for the appropriate model under 20mA Range Current Readback Accuracy @ +20mA
e.Turn off the supply and connect the output and an external supply as shown in Figure
f.Turn on the external supply and program it to 8V and 1 amp. Then program the supply under test to zero volts and 1 amp. If the meter indicates overrange, lower the voltage of the external supply slightly. The UUT display should read approximately − 20 mA.
g.Record the current reading on the DMM and the reading on the front panel display. The difference between the two readings should be within the limits specified in the performance test record card under 20mA Range Current Readback Accuracy @ − 20 mA.
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