Class A: Self Commutated by a Resonating Load

1) When the SCR is triggered, anode current flows and charges up C with the dot as positive. The L-C-R form a second order under-damped circuit.

2) The current through the SCR builds up and completes a half cycle.

3) The inductor current will then attempt to flow through the SCR in the reverse direction and the SCR will be turned off.

4) The capacitor voltage is at its peak when the SCR turns off and the capacitor discharges into the resistance in an exponential manner.

5) The SCR is reverse-biased till the capacitor voltages returns to the level of the supply voltage V.