I am converting an old AC stick welder to a DC TIG, nothing fancy, no high frequency arc starting, or square wave or anything. I am just going to rectify the output from the secondary of the welder for DC, and vary the current to the primary with a large triac for remote current control. My question is, I would like to be able to use a microcontroller to drive the triac, a BTA40-800B, which needs a pretty hefty 80ma to drive the gate, so can I use a smaller triac to trigger the large one, and drive the small triac through an optoisolator from the micro? Or is there a better way I am not thinking of?
thanks for any input
thanks for any input