I already went through the design guidelines found online where you are supposed to find the intrinsic inductance and capacitance of the circuit using the intrinsic ringing frequency. The results I got were my intrinsic inductance is around

**47 micro H**and intrinsic capacitance is around

**37 nano F.**

Using the values of this capacitance and inductance i found a range in which my RC components should lie.

**R****<35 ohms**and

**3.5 pico F <**

*C*< 1 micro F.I have tried experimenting with different values of RC in this range .

I have 2 capacitors available of 225 nano F, using them i make 112 nano F, 450 nano F, and just 225 nano F.

There is still some voltage overshoot and ringing when the SCRs turn off, I can't seem to find the RC values that will snub the ringing completely. Some combinations help reduce the voltage overshoot, and some combinations reduce the damping but increase the overshoot. I am confused as to how to select an RC from the range I obtained.

max switching frequency: 100Hz

max voltage : 1400V

SCR holding current: 0.4A

I'll attach some photos of the ringing that i observe (the 2 pictures show ringing at different snubber circuit combinations).