Dear Kalapak,

Thanks for your reply,

I have used lots of back to back thyristor modules all high power ratings ranging from 92Amperes to 2000 Amperes for these modules i used pulse transoformer firing circuits. Never used modules for small current apps say less than 10Amps. Are there thyristor modules [back to back] avaialble in pcb mount packages? At present I have replaced my BT138 triacs with TYN612 SCRs back to back and firing them with MOC3062 opto drivers. Are there any better/ cheaper methods for small scr firings?

Thanks & Regards,
Prahlad Purohit