Nickranger

Sorry newguy, Link won`t work but you can find it on Hydrogen Garage site. I can provide a component list with corresponding locations on the board. Best I can do. Hope this helps.

Newguy, Love to help you out, but drawing up a channel is slightly over my head. Thats why I`m asking for help. If you can follow it there is very good pics of the G board front and back here: http://stores.homestead.com/hydrogengarage/-strse-31/PWM3f%2C-pulsed-width-modifier%2C/Detail.bok       I can provide a component list with corresponding  placement on the board if that will help. Best I can do.

Yes Bob`s boards are opto-isolated. I have them all but the hex controller. Problem is they output about 12vdc. I want to pulse 200+ vdc, 5amps at around 42,000khz. 

I study everything Bob Boyce. I don`t know what you mean.

Could someone point me to a good opto-isolated mosfet switching circuit. I`m looking for something that will afford a little more protection than just switching a fet. I have seen in the past elaborate circuits with snubber diodes, caps,resistors,est. Maybe someone makes a prefab module ? I need to switch 200vdc at around 5 amps in the 40,000khz range.

Steve , I actually thought about this and wondered if it could work. It is a Boyce G board I want to use. This board is able to reach a wide range of freq. and duty cycles. The  IRP540Z fets switch fast and sharp. It is already optoisolated. Its only downfall is a duty cycle over 35 - 40 % on time will heat up the fets and burn them up. No schematics are available for the G board, but a detail view of the board itself, top and bottom can be viewed at the Hydrogen Garage site. You might swap out the fets and isolate the input from the rest of the board but that might be beyond what I know how to do.

I was looking for something opto-isolated to afford a little more protection for a freq. generator I cherish a lot. Maybe you could sketch something up for me ?