Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual
Appendix B: Verification
077114601 / March 2019
B-35
To check DC current readback accuracy (10 A and 1 A ranges):
1. Set the voltmeter as follows:
a. Set to measure DC volts.
b. Set the current range to autorange.
c.
Calculate the amperes (instead of volts) by multiplying the voltmeter reading result by 1/(R1), where R1
represents the high-
accuracy 0.05 Ω shunt.
2. Check the current readback accuracy on the 10 A range.
3. Set the device under test (DUT) to 100% of the full-scale output voltage.
4. Set the DUT to 0% of the test current. See the following table.
Model
Range
0% test
current (A)
10% test
current (A)
50% test
current (A)
100% test
current (A)
2281S
10 A
0
0.32
1.6
6
1 A
0
0.1
0.5
1
5. Turn the DUT output on.
6. Enter the voltmeter reading/(R1 + R2) in the DC current readback accuracy table.
7. Enter the DUT current readout in the DC current readback accuracy table under the current
readout column.
8. Calculate the difference of the two measurements taken in steps 7 and 8. Enter the absolute
value of the calculated value in the difference column of the DC current readback accuracy table.
9. Increase the DUT output current to 10% of full-scale output current and repeat step 6 through
step 9.
10. Increase the DUT output current to 50% of full-scale output current and repeat step 6 through
step 9.
11. Increase the DUT output current to 100% of full-scale output current and repeat step 6 through
step 9.
12. Repeat steps 3 through 12 to check current readback accuracy on 1 A range.
