Gecko g540 control box
I removed all the caps from my original circuit when I was fighting the OE branch. That is higher than any cutting voltage you will have.
GECKO G540 CONTROL BOX FULL
If you are using a THCAD 10 then I would shoot for a full scale of about 180V. You are using the THCAD with a well behaved HT box so a simple series resistor will work. The voltage divider I built (I up loaded the schematic earlier today) was originally met to work with any plasma box, blowback, HV,HV/HV and not cook the THCAD or other AtoD. He is very knowledgeable about all things plasma. He wanted to build his own external THC module using UCCNC.
I was put onto this by a guy in Melbourne who calls himself Beefy on some other plasma forums. Now I have a 120 amp machine, I need a bigger ACS758 module so this is of no use to me. If you are interested, send me a message here as the forum emails are pretty unreliable This could open up a whole new world as you can synthesise your own arcOK signal based on a current threshold and do precision centre punch marks by turning off the arc at a low current threshold. So then you could connect the amplified signal and be able to read the arc current via one of the 7i76e analog inputs.
The LM358 will allow connecting 24 volts to it and step the 5v up to a few percent less than 24v. The ACS758 would need to be placed in series with the electrodes in your plasma cutter and will output a 0-5 volt analog output representing 0-50 amps. Phill if you are into hacking hardware and want to pimp your Hypertherm 30 amp machine, I have a 50 amp ACS758 DIN rail mount current sensor module here and an LM358 low signal amplifier module I'd be more than happy to donate to the plasmac cause.