Extending PWM potentiometer wires - how far?

[lisney56]

Hello, I want to use a PWM motor speed controller on our motorhome. It has a rear engine. I want to fit the PWM down the back of the engine but need to be able to adjust it from the driving position 7 mts away.
Can I extend the pot wires that far? Or is it going to upset the PWM through resistance from the longer wires? I would think the wires would only need to be thin? Any advice for this novice would be greatly appreciated. As you can tell, I only know enough to be dangerous.  Many thanks.

 

[Hero999]

It depends on the PWM circuit.

The resistance shouldn't be a problem since the potentiometer's resistance will dominate but inductance and capacitance (if the potentiometer forms part of the oscillator) or noise pick-up could be a problem.

Do you have the schematic?

Noise can be reduced by twisting the wires together.

Does the potentiometer just vary the voltage?

If so inductance and capacitance would be a problem.

The noise can be mitigated by twisting the wires together and connecting 100nF capacitors from either side of the pot to the wiper at the PWM circuit side of the cable.