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Fan speed control

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#1 epee

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Posted 25 May 2020 - 11:41 AM

Which potentiometer should I buy to control the speed of a 12v PWM case fan?

Links to specific models and order sites are greatly appreciated.

#2 Pinbout

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Posted 25 May 2020 - 11:54 AM

https://www.youtube....&index=51&t=15s

 

pwm off amazon


Edited by Pinbout, 25 May 2020 - 11:59 AM.

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#3 skywolf856

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Posted 25 May 2020 - 12:24 PM

This is the one I bought.

 

https://www.amazon.c...90427437&sr=8-6


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#4 TG

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Posted 26 May 2020 - 02:24 AM

Look for CPU fan control on Amazon. LED voltage controllers generally don’t work because they use switching.
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#5 Bob4BVM

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Posted 26 May 2020 - 02:51 AM

Simplify !

While not as high tech and less efficient than PWM, you can certainly use a simple bare  potentiometer to control speed of a typical PC case fan, connected as a rheostat in series with the fan it will limit current & voltage to fan thereby controlling speed.

A good rating for the pot would be 200-300 ohms, 2 watts, which you should be able to get at any electronics supply place. These fans typically draw 100 - 150 mA at 12V, so a 2W pot can handle that kind of power.

 

If you want to take the next step in complexity, you can choose your speed with a 3-pin voltage regulator like an LM 7808 or 9.

My fans use that approach, where I switch in the 7808 for a pretty low speed when observing or switch it out of ckt for pre-cooling at the full 12V supply voltage.  Ckt consists of the regulator IC and one .1uF capacitor, plus a little DPDT switch. 

Been using both those schemes for years, both work great at almost no cost, maybe a buck or two if you have no parts laying around, free to most who've been messing with electronics for a long enough to have a decent parts stash.

 

CS

Bob


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#6 StevenYood

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Posted 26 May 2020 - 03:45 AM

I  a number of cheap option before I bit the bullet and bought a board from Dew Buster.

http://www.dewbuster...-c-fanctrl.html

These are costly, but they work flawlessly.  I now have three of them!


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#7 epee

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Posted 26 May 2020 - 10:47 AM

On order!

 

Thanks folks!


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#8 skywolf856

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Posted 26 May 2020 - 10:12 PM

Look for CPU fan control on Amazon. LED voltage controllers generally don’t work because they use switching.

Mine works no problem.




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