Single-Turn Potentiometers vs. Multi-Turn Potentiometers

Assuming you're a mechanical type, think of it in terms of gears. A 1:1 ratio turns your widget one time with one rotation. A 10:1 gear ratio takes 10 turns to move your widget through one rotation, and you get much finer control of how precisely the widget turns.

Hello vscid,

As bhankiii said, the multi turn have very much finer adjustment. In audio for instance, if you have several thousand watts of power, it could break some instruments and deafen anyone too near, if you used a single turn, as you would go from zero to B*O*O*M instantly. It is much easier to finely adjust a sound system or anything you may need a potentiometer to change the potential in/out phase, if you need delicate adjustments, with a multi turn potentiometers.

Take care...............Hope you find this helpful......................

What Bhankiii has told in his GA, is right. But I would like to add few more details:

Normally single turn potentiometer turns by 20 deg only. Thus, the resolution you get is 1000/270 ohms (just as an example... this doesn't mean that you turn the potentiometer in single deg steps,)

But multiturn you get rotation of almost 360 X no. of turns. 10 turn potetiometer you get almost 3600 deg rotation. Besides, you can attach mechanical counter to multiturn potetiometer, so that just by viewing the counter reading, you can set the potentiometer to reasonably good set point.

In single turn potetiometer, counter can not be fitted, and you have to use angle dial, which is not good enough to set the value to reasonably accurate set point, as even the manual errors will be there due to paralax

Hello gsuhas:

I was not aware you could get potentiometers which tuned than many times?.Some new I have learned.

How are you gsuhas? I have not spoken for some time.

Take care my friend..................................

Hello gsuhas:,

I know these OK. I thought you were talking of a digital readout?

Very useful for presets.

Take care.............................

For simple understanding - Say you are adjusting an input between 0 to 10V.

A pot with single turn will give a possibility of 0 to 10V in single turn but a 10 turn pot will give the same in 10 turns. So you get a finer control with a 10T pot. It is as simple as that.

well the Others allready answered correctly but the name itself should have been a strong hint

Hello Epke,

How are you? I like your sense of humour!

Take care........,

Just a comment... If I were building a 10 turn pot, I would probably use a CERMET pot as the resistive element. Can you imagine a wire wound pot where the resistance would go Boing! Boing! as you passed the wiper from one wire to the next? Quantizing error!

So basically, a 10 turn pot is a single turn pot (not wire wound) whose feed is mechanically geared down to allow more precision.

Bill

Multi-turn wire-wound pots are indeed available. I believe that the wiper does not only contact one turn at a time, but is always in contact with at least 1 turn.

Also, FYI (OP), a single-turn pot turns only 270 degrees, mostly.

Sciesis

You are misunderstanding. No gearing is there for multiturn. It is a spiral of 3600 deg, as against only 270 deg in case of single turn.

Besides, wiper is touching more than 1 turn at a time. It doesn't jump wire to wire. Besides, it may be conductive plastic or hybrid, instead of wires only, to get infinite resolution.

Please go through

http://www.bourns.com/data/global/pdfs/OnlinePotentiometerHandbook.pdf

It is everything about potentiometers.

There is one other big difference that no one has mentioned. The 1/2 watt 270 degree pots are only good for about 60 adjustments and they they start to lose integrity. I have never has a multiturn potentiometer wear out so quickly.