can i replace a linear 100k potentiometer with multi turn potentiometer 100k to get more resolution. The linear potentiometer 100k which i mentioned is used in pwm which i brought from ebay for controlling speed of a 12v 9a 500rpm dc motor but when i am using 100k linear pot i am not able to get proper resolution in speeds of dc motor eg:at 1,2,3,4....hz.so i wanted to replace linear pot with multi turn pot is it possible or not.Do i need to mention anything else

  • \$\begingroup\$ Yes, you probably can replace it that way. Whether that solves the remaining problems would be hard to say. But I don't see a reason why you can't try it out and see. \$\endgroup\$ – jonk Feb 1 '18 at 5:42
  • \$\begingroup\$ Add schematics. It really depends on other circuitry as well, not just potentiometer. It really depends on whole chain of translating analog signal to pwm. Yes, you can change the pot. But resolution depends on other things as well. \$\endgroup\$ – Chupacabras Feb 1 '18 at 5:45

Allow me to be a dissenting voice. Maybe not. Multi-turn pots are not inherently higher resolution than single turn pots of the same element length (and type), many merely contain a mechanism that may make it easier to set the wiper to a given position. The mechanism may have effects such as backlash that are annoying.

Generally if you find yourself using only a small range of a pot, perhaps near one end, a better choice is to replace the unused part of the pot element with fixed resistors.

For example, if you had a 100K pot voltage divider with 5V applied and only used the first 1V of it you could add a series 80K resistor and shunt the element with 25K.

Some pots such as the 10-turn panel-mount Helipot wirewound style actually have a very long (helical) element and do give you greatly improved resolution, however it may still be worth considering limiting the range where appropriate.

  • 1
    \$\begingroup\$ +1 You are correct, 10-turns just make it easier to adjust the 1 turn and add other effects that are just as annoying. For a one-time trim pot they are better than the singles. \$\endgroup\$ – Trevor_G Feb 1 '18 at 14:21

Yes, if they are both 100k and the new one is rated at, or above the old one (in power and current), you can safely make the part swap.

Whether this will yield the results you are hoping for is unknown. We would need the schematic to know for sure.

  • \$\begingroup\$ You say yes, but will the result be what the OP wants? Ie more resolution? \$\endgroup\$ – Solar Mike Feb 1 '18 at 6:12
  • \$\begingroup\$ @SolarMike I doubt it, but I was answering to the fact that it is safe to make the swap. Your point is valid though, on a second reading of his question title. I’ll update. Thanks. \$\endgroup\$ – Blair Fonville Feb 1 '18 at 6:15
  • \$\begingroup\$ I doubt it as well, at least he’s prepared to find out though... \$\endgroup\$ – Solar Mike Feb 1 '18 at 6:17
  • \$\begingroup\$ @SolarMike Agreed. And who knows? If it’s a simple pwm generator, it might be exactly what he needs to do. \$\endgroup\$ – Blair Fonville Feb 1 '18 at 6:26
  • \$\begingroup\$ If he’s that lucky - if it was me ... never seems to work the first time.. \$\endgroup\$ – Solar Mike Feb 1 '18 at 6:28

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