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Potentiometer for 20v?? Answered


I am trying to build a bench power supply from a laptop power supply and i need a potentiometer capable to handle 0-20v. I have tried many times with different potentiometers but they all start smoking and later starts burning :(
i don't know that much about elektroniks circuits so be gentle :)
Please help me!


Use the speed control pedal from an old sewing machine.

The old pedals are basically just variable resistors.

I think what you need is a variable voltage regulator circuit or components that are designed to throttle power such as rheostats, variacs, MOSFETs, power transistors, etc. The heat generated is the excess voltage in the resistor/potentiometer with no where to go.