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how can I calculate the value of a potenciometer? Answered

There are some projects where I needed to use potenciometers, but I don't know how to calcute their values. Can someone teach me that?

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steveastrouk (author)2013-06-26
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If it helps, I would like to use one to adjust am electric motor's speed. It runs on 19v dc 3.42 amps. However I would like to learn how to calcute it's value.

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user

That is DEFINITELY NOT a job for a potentiometer. There, you need to use a PWM motor controller.

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user

how can I make one? If possible, simple.

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user

Try searching Ibles
https://www.instructables.com/id/The-ultimate-PWM-driver-for-many-applications/

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framistan (author)2013-06-26

Just measure the value with an OHM meter. You can purchase an ohm meter for just 5 dollars if you live near a harbor freight tools company. Some potentiometers are marked with a value like " 1 K 5 " The means 1.5 Kilo-Ohms. There are basically 2 types of potentiometer. LINEAR-taper and AUDIO-taper. The linear kind will change value EQUALLY as you turn the knob. The AUDIO taper type will change value LOGRITHMICLY as you turn the knob. Most pots are LINEAR.

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tgferreira184 (author)framistan2013-06-28

You didn't understood the question. I asked how can I calcute it's value while planning to use it, not when salvaging it.

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tgferreira184 (author)2013-06-27

If it helps, I would like to use one to adjust am electric motor's speed. It runs on 19v dc 3.42 amps. However I would like to learn how to calcute it's value.

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rickharris (author)2013-06-26

A potentiometer will have 3 connections - The outside 2 will connect to the end of the resistance and will show the full resistance i.e. the value marked on it.

The middle connection is connected to a wiper which contacts the resistance track in many possible places depending on how far you move the potentiometer.

The resistance from the middle to either end will vary according to where the wiper is positioned from zero to the maximum value.

The resistance between the middle and either end will be proportional to the position of the wiper.

Much depends on what your intending to use the potentiometer for.

You may possibly be confusing the term potential divider with Potentiometer.

Please clarify.

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mpilchfamily (author)2013-06-26

Depends on your circuit. What kind of resistance range is needed for the circuit.

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