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Where have all the EE's gone; long time passing...... Answered

I'm trying to upgrade the control circuit on my cheap TIG welder. The existing control is a 10k ohm potentiometer, mounted on the welder. It's wired up such that the voltage drop across the pot is proportional to the welders output. Instead of having one knob that controls the output, I want one knob on the welder's panel that selects the maximum output, and another knob ( to be mounted in a foot pedal control) that allows me to select output power from zero up to the maximum value that is set on the panel knob. Seems to me that there should be a relatively simple, elegant solution that gets covered in the second year of an electrical engineering course. Or am I just insane to think that such a thing should be simple? I've tapped out my own social network, and I can't find anyone who will admit to being an electrical engineer. Thanks.


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12 years ago

. Put the two pots in series. Use the present 10K to set the max output and something that will provide enough range in the foot pedal (I'll guess somewhere in the 1K to 5K range - experiment). . Think of the 10K as a coarse setting and the foot pedal as the fine adjustment.