Choosing right potenciometer

[SquaredLogic]

So, I want to make fan contoller with switches and potenciometers. And I got to the problem and this is what potenciometer to use? My fans are 12V 0.16A 120mm, I wouldn't like to my fans go below 4-5V. I also found one site where says that I need 100 Ohm pot. for this, which is by me a little to low. So can someone claim that ?

Site link : http://www.sevenforums.com/tutorials/87295-fan-speed-controller-build-your-own.html

[slightlyjaded]

So, I want to make fan contoller with switches and potenciometers. And I got to the problem and this is what potenciometer to use? My fans are 12V 0.16A 120mm, I wouldn't like to my fans go below 4-5V. I also found one site where says that I need 100 Ohm pot. for this, which is by me a little to low. So can someone claim that ?

Site link : http://www.sevenforums.com/tutorials/87295-fan-speed-controller-build-your-own.html

I suspect you're overthinking it. Most fan controllers just use a variable rheostat. (think light dimmer) They don't care what the imput voltage, ampage, and resistance is, they just step it down depending on how far you withdraw the inner coil from the outer coil.

[SquaredLogic]

I suspect you're overthinking it. Most fan controllers just use a variable rheostat. (think light dimmer) They don't care what the imput voltage, ampage, and resistance is, they just step it down depending on how far you withdraw the inner coil from the outer coil.

So you want to say that neverminds what i choose untill its not stupidly high? Like 10kOhm?

[slightlyjaded]

So you want to say that neverminds what i choose untill its not stupidly high? Like 10kOhm?

going to the extremes is always going to have an effect. Your input voltage is 5V, your ampage in large part depends on what fans you're using. Yes I could sit down and do the math for you, but it really isn't that hard....And I haven't had to do this form of math for about 2 decades.

[SquaredLogic]

going to the extremes is always going to have an effect. Your input voltage is 5V, your ampage in large part depends on what fans you're using. Yes I could sit down and do the math for you, but it really isn't that hard....And I haven't had to do this form of math for about 2 decades.

Yeah, you're probbaby right. So, what do you think will 1kOhm or 5 kOhm do it's job?

[slightlyjaded]

Yeah, you're probbaby right. So, what do you think will 1kOhm or 5 kOhm do it's job?

you're not very nice, you know that right...Okay assuming a noctua @0.1 amp max. 5V we're talking about 50 Ohm for the circuit. Assuming it's a linear progression for resistance to speed (it probably isn't but I don't know enough of the characteristics) @10% we're talking about 500 ohms. I would suggest overcompensating a little and using 1k, just because you can always turn the dial a little less, but it's really hard to turn the dial more than what the unit is rated for.