Looking for help with making my own low cost AC Constant current source using the attached simplified block diagram. This source will be used to check the accuracy of AC current transducers used in our component reliability test cabinet. Would like a fairly stable output with minimal drift and range (current is checked at 0.250A, 0.500A, 0.750A, 1.000A, 1.500A, 2.000A, 2.500A, 3.000A..... up to 5.000A).
I am current using a simple AC current source utilizing a very small variac (0.23kVA) to vary the voltage into a 120/6.4VAC stepdown transformer with a max current output of 20A. The output current varies too much to get accurate measurements. The range is still too much even when the current source is plugged into a programmable AC voltage supply set for 120VAC.
Thanks for any help offered.
I am current using a simple AC current source utilizing a very small variac (0.23kVA) to vary the voltage into a 120/6.4VAC stepdown transformer with a max current output of 20A. The output current varies too much to get accurate measurements. The range is still too much even when the current source is plugged into a programmable AC voltage supply set for 120VAC.
Thanks for any help offered.
Attachments

13.4 KB Views: 12