power SCR healthyness


Joined Apr 20, 2004

Your meter should be good for the test. Out of circuit, the SCR should check open C - A and A - C. The gate will show conductance to the cathode, probably in both directions. As long as it is also open when checking to the anode, all should be well.

If you want to check by o'scope, make sure the circuit common is shared by the 'scope. Otherwise, you may blow up your vertical amp. Probe at some point past the SCR, and see if the waveform is controlled. It should be no more than 1/2 cycle, and show a decrease in conduction as the gate is controlled to smaller conduction angles.