Author Options:

can a 12 volt fan work with a 24 volt transformer? if so how would i hook it up? Answered



Is the fan a/c or d/c?  The transformer is a/c unless it's got a bridge or some diodes etc.

If the transformer is d/c then you can use a voltage regulator very easily to reduce the voltage to 12.  If it's a/c then you'll have to use resistors.

Eitherway it's got to match the fan motor.

transformer is 120vac in 24vac out into rectifier to change to dc. what kind of voltage regulator?

A voltage regulator like this.  Radio shack stocks them but you can get them almost anywhere parts are sold.  You might be able to find one in something that has 12 volt output.

would i need to build a circuit board with the capacitors to go with the voltage regulator?

 Your 24v ac are converted to dc?  Re-design is right, the regulator will drop the voltage to 12.  It doesn't need any capacitors because you don't need ripple-free dc for a fan.  My only question would be, how much current does the fan require and how much current can the converter handle?

BTW,  as Re-design asks, is the fan ac or dc?  If it's ac, then the regulator won't work.  Computer fans are dc, I believe, and room fans are ac.

its a microfan out if a computer supply. the fan is dc.  i have a full wave bridge rectifier rated at 25 amps and 50 volts to convert the transformer to dc.

 If the fan is dc, the voltage regulator will work fine, or hooking two fans together as Lemonie suggests.

You couldn't get another 12V fan to put in series?


ok thanks for the help and advise.  i think ill do that it looks like the easiest thing to do

i came across another fan that is dc. what would hooking them in series do? would that change the 24 volts to 12 volts per fan?

If the two fans are similar, in series they'll split the 24V to ~ 12V each. It might be your easiest option.


if the transformer puts out AC, then you can use a diode to drop the voltage

No, it will burn out the fan.  The transformer doesn't happen to have 3 wires coming out, does it?  If it does, the middle one might be 12 v, which would work.

If not, maybe someone here can tell you a practical way to drop the 24v to 12 for the fan.