AC Dimmer w/ DC fan???

[carrotmalt]

First off, I don't know beans about electronics. As part one of my DIY stir plate attempt, I connected a DC power supply directly to an old computer fan as I've seen done here in several threads. Runs like a champ. I planned on getting a DC rheostat from Radio-shack to control the speed, but I have an unused light dimmer switch in the garage. My question is:

Can I run an AC dimmer switch in line to vary the speed of a DC fan, or am I going to burn the house down?

I figured I'd ask rather than make assumptions in case it's the later.

 

[leboeuf]

AC, DC, it doesn't matter with resistance.

EDIT: BAD INFO BELOW.....
The dimmer is targeted to handle 120V so you may find that the adjustment is 10X coarser than you want it to be.

 

[carrotmalt]

Thanks for the quick reply! I'll give it a shot when I get home.

 

[GNBrews]

Don't use an A/C dimmer switch with a DC load, it's not going to work. Dimmer switches are not simple resistors, they are a circuit which relies on the voltage alternating in order to work.

More info here:
http://home.howstuffworks.com/dimmer-switch2.htm

 

[carrotmalt]

Don't use an A/C dimmer switch with a DC load, it's not going to work. Dimmer switches are not simple resistors, they are a circuit which relies on the voltage alternating in order to work.

More info here:
http://home.howstuffworks.com/dimmer-switch2.htm

You're right. It didn't work. I guess a trip to Radio-shack is in order. Good news is the house survived .

 

[leboeuf]

My bad carrotmalt...
Funny enough the only dimmer I've messed with is in my house, which was built in the 40's...
Thanks for the info GNBrews, I should have known that!