Light dimmers?

[Warlord2]

Can you use a light dimmer to slow down your fans?



I havent heard anything on the topic and was wondering if it has been done?

[wildbilly2k]

well i dont know if anybody has tried it but it is a sure good idea. My friend has bout 4 80mm delta screamers at his house and i hate to use his comp cause it is so loud cant here my music. Why dont you try it and then post somthin and tell us how it went!!

[Warlord2]

I think I might

I would of thought that there will be more posts thin this by now so Im assuming nobody has tryed this

I think I will give it a go and post my results if nobody objects

[Crazy Jayhawk]

A light dimmer is a type of rheostat, which can be used to control fan speed.

[Quaky]

A light dimmer is in most cases designed with a triac. This works for AC only. Using it on AC fans will make them more noisy because the vibration increases. ;)

You can try it, but I doubt you will be seeing any dimming effect on your 12v fans. It could be that the fan refuses to spin because the dimmer cuts its power. It could also be that the fan gets full 12v. If you try, will you let us know?

Hope this helps...

[Veland]

..but you can use the dimmer from a car! Often they have a dimmer for the dasboard lights, and thats designed for dimming 12 volts. I agree that normal 120/240 dimmers won't work. But there are some dimmers for halogen lights too? And those run of 12 volt..

[UnseenMenace]

Hmm now this is a interesting idea

[Quaky]

If I am not mistaken a light dimmer of a car is basically just a rheostat. It might still be interesting if you have a lot of fans. Finding rheostats able to control a lot of current can be tricky. A car dimmer has probably a higher wattage. If you have only one fan however I would use a simple rheostat. If you use a rheostat, you can adapt it to the fan's current draw and have finer control of the fan's rpms...

[Veland]

..or you could make a fan controller based om the LM317 for an even broader range of adjustment. You coluld even use a separate transformer to give the posibility to "overclock" you fan.
So, my list that goes from easy but not many posibilities to complex but total control would be:

1. Run at 5 volt. If the fan starts.
2. Run at 7 volts. But this can damage your PSU.
3. Use a high power resistor to limit the voltage.
4. Build a baybus
5. Use a rheostat of some sort. But powerful ones are expensive.
6. Build a rheobus
7. Build a fan controller based on LM317 or similar.
8. As number 7 but with a separate transformer for "overclocking"

I'm working on number 8.. Should be ready soon :)

[Owenator]

I tried a cheapo $4 light dimmer/rheostat from home depot, it didn't work. I took it apart and tried to use the parts but no luck there either. I don't remember much about AC from my Elec. fundamentals from college but I would guess that the AC dimmers won't work with DC, they didn't when I tried. I guess you could use a dimmer in conjuntion with the circuit that converts AC to DC, that might work? I have tried all 8 of the methods on veland's list and I prefet the LM317 circuit with 1500k Ohm LINEAR rheostats with on/off switches and led's, at 12 Volts in they work great! The only problem with using a higher voltage input (I tried 24 Volts) is that the little LM317's get hot and the resistors in the circuit get really hot!

O

[Mord-Sith]

Veland is right this is what you should do



Full tutorial on making a voltage regulator (http://casemods.pointofnoreturn.org/vregtut/tutorial-1.html)

It way more efficent then a rheo stat and very easy to build

[Fink]

Originally posted by Mord-Sith
Veland is right this is what you should do



Full tutorial on making a voltage regulator (http://casemods.pointofnoreturn.org/vregtut/tutorial-1.html)

It way more efficent then a rheo stat and very easy to build

Great reference. Gonna build one of these things or its bigger brother to see how well they work. Finding a reasonably priced rheostat that will take more than 5 watts at ~100ohms has proved difficult....

[Warlord2]

Thanks for the help everyone


I think I will see how much dimmers are that go on cars and RV's before I make one though

I realy wanted something I could buy easly that I can attach to my case without a great deal of work=/

so I think car dimmers are my best bet

[The Coolest]

I just put a switch from old 486 power switch :cool: