Please anyone to help me with a circuit that will trigger three SCRs.
This circuit will receive two inputs no.1, is 0 to 10vdc from an external potentiometer.
No.2, 0 to 5vdc from an external potentiometer.
These inputs in combination should give a proportional trigger to the three SCRs at the same time.

 

The first thought that comes to my mind is "comparator".

 

What are the SCRs switching?
Is it a 3-phase AC circuit?

What's a "proportional" trigger?

 

Yes The SCRs switching is three phase AC

 

What I intend to mean by 'proportional trigger ' is as the both input potentiometers varies from zero to maximum displacement, the SCRs trigger voltage should also varies from minimum to maximum. Thanks

 

Symetrical triggering of three SCRs accurately is rather complicated, and more often done with digital schemes if the triggering needs to be accurate. 30 years ago there were some motor controls that did a fair job of even triggering but they were not simple.