Wiring issue

[9fishers]

Today I took apart my old hood and retrofitted my pc's. All wired and working fine. But I was going to wire a 12v fan in the circuit and had it all wired and then had a thought. WAY too much voltage for the little fan. So how can I wire this to my circuit to come on when the lights come on? Any expert wiring reefers out there? Please dont offer "I thinks...." because I dont particularly want to be electricuted today I need some "I know for sure's..."

TIA

[Minnreefer]

You can't mix 12 volt and 120 volt. you need to go to radio shack and get a regular 12volt wall plug in convertow, wire that up to you fan and you will have to get a spilter on the outlet where your PC's are wired up.

HTH

Jon

[Geoff]

Originally posted by Minnreefer
You can't mix 12 volt and 120 volt. you need to go to radio shack and get a regular 12volt wall plug in convertow, wire that up to you fan and you will have to get a spilter on the outlet where your PC's are wired up.

HTH

Jon

yep.

G~

[PJenkins]

You don't say if your fan is 12v AC or DC. If its AC then you need a step down transformer to go from 120V to 12V. a doorbell transformer or lo-voltage lighting tranformer can work. If your fan is DC then you need a DC power supply @12V. These can be the little wall wart supplies sold at radio shack or electronics section in dept. stores. You have to pay attention to current handling though. For example if your fan is DC it should have a current rating, like 12V 2A, or 12V 1500 mA. Most likely it will be around 500 mA to 1000 mA thats 1/2 amp to 1 amp. You would want make sure your power supply can provide more than the fan requires.

[9fishers]

so my best bet is to wire this little fan(12vdc) back to the 12vdc/120v adapter. And then put a dual outlet on the timer and connect both the light and the fan to the timer? That will work. Boy am I glad I didnt leave it wired as before and then plug it in!!!! Talking about a shock!!!
I'll try it and see how it goes.
Thanks for the advice!

[Doug1]

Pat, aren't the chances its 12v AC pretty slim?
9fishers it should say 12 vdc on the back of the fan. Also the current draw expressed in prolly milliamps like Pat stated, remember to multiply the current draw by the number of fans used. I.E. if each one is 500 ma(milliamp) and you use 3 fans
3x500= 1500 ma or 1.5 amps. Did I get that right Pat ?
Also some of the radio shack power converters have switchable outputs ie
1.5-3-4.5-6-7.5-9-12 vdc outputs so by changing the setting you can adjust the fan speed. If I remember right DC fans deal with less voltage better than AC equipment. PAt correct me if I am wrong here

[PJenkins]

On the probabilty thats its DC rather than AC, in my business we see both about equally and in voltage ratings from 6V to 120V. But I would say that the muffin fans most commonly sold at places like R. Shack are of the 12V DC kind. I just didn't want to assume anything

On the second point, adding fans together, you are correct. As you add fans to the circuit the current requirements go up ,as you explained.

Yes, with DC fans you can vary the voltage somewhat and get speed control, depending on the fan though,it may not start up until it receives near its operating voltage and then you can slow it down . You just have to play with it.

[Mkelly]

Big wall of 120v fans right in raido shack all of the very same type for what we use them for. Just get a new fan and dont play with the converters.