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I understand that the length of the conducting wire/object is directly related to the resistance to the passing electrical current. This is pretty straightforward to understand. But, I wonder, what is the effect of moving the slider/wiper very fast over the resistant surface on the instantaneous reading of the potentiometer?

Would it appear higher, or lower, or exact to the reading if the slider was stationary on the same spot?

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    \$\begingroup\$ Fast - like how fast? Relativistic fast? \$\endgroup\$
    – Eugene Sh.
    Commented Oct 1, 2021 at 18:56
  • \$\begingroup\$ The slider is a mechanical part, so I'd imagine it needs some finite time to re-establish full contact after the movement. \$\endgroup\$
    – Eugene Sh.
    Commented Oct 1, 2021 at 18:58
  • \$\begingroup\$ Potentially higher in the presence of poor contact (momentary open circuit, that gives the crackles on an old radio). \$\endgroup\$
    – user16324
    Commented Oct 1, 2021 at 19:09

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There may be "bouncing" if it's very fast. There will be CRV (contact resistance variation) and some voltage noise as well. CRV affects the reading if the wiper output is loaded, and has little effect if the pot is being used as a voltage divider into a high-impedance circuit.

You can minimize those effects by using a pot designed for motion such as a servo pot made with conductive plastic, alone or hybrid (over a wirewound element). The number of wiper contact points also has an effect.

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The resistance would be the same. Speed of the wiper does not affect resistance.

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