/diy/ - Do It Yourself

>>1665868
Here is a more accurate wiring diagram for the machine, this shows the correct 30v control voltage for the foot pedal, I circled the 'variable resistor' which is essentially a carbon brush wiping up and down a big (1" sq. x 2 1/2" long stack of copper plates - see pic in >>1665319
) I don't know why they didn't just draw it as a variable resistor. From vid i've seen this goes from 15 ohms to 2 ohms depending on how far the pedal is depressed. Still not sure how it can see 30VDC at 2 ohms when it's only rated for 135w....but
>>1665884
Is right, it's not seeing the 300A welding current, or anywhere near it, its a separate circuit controlling core saturation in the welding output transformer. I don't know what that means or its implications for the components I can use trying to emulate the big copper resistor, that's what I need to figure out.