SCR in parallel, but not triggered at the same time

[nic2k.09]

First I should say the SCRs are able to handle the load individually, they're in parallel to allow 2 different ways to switch the load. I'm interfacing two flash control circuits to one flash and that SCR is the quench control.

I've read a lot on the problems and effects of dv/dt and di/dt and parallel SCR, but nothing on 2 SCR side by side used one at a time. I can't risk to blow the SCR to test it and feel I've lost objectivity.

What I want to know is will one SCR being triggered and having a large current flow through it, make the other one turn on partially due to the rapid change of voltage between its cathode and anode? It's my understanding that the effects of dv/dt apply to an SCR in the off state when to voltage rises rapidly at the anode. What do you think?

 

[crutschow]

Yes, it's the voltage rising rapidly at the anode, not a rapid fall, that's the problem. Turning on one SCR should have no effect on the other due to the rapid fall in voltage.

 

[nic2k.09]

Thanks for the quick answer. That's great, I wasn't sure it would work the way I want and was too worried about blowing the original SCR. I searched everywhere and couldn't find any confirmation. I was to the point of trying to run a spice simulation, I even downloaded LTspice, just figured it might take a while to learn to use it. Thanks again.