cooling fan wiring questions

[ohio reefer]

ok, i went to radio shack and i got what i think is all i need for the cooling fan set-up.

1) 2 12VDC cooling fans
2) 25.2-volt AC 2-amp power transformer
3) 6 foot AC line chord

is this all i need?

if it is how do i wire it?

A)the cooling fans have a red and black wire
B) the transformer has two yellow wires with a black wire on the top and two black wires on the bottom.
C) the AC chord has two wires.

sorry about the stupid question but i am teribble at wiring things and i dont want to burn down my house.

i'll try to send some pictures

thanks

mark

 

[ohio reefer]

heres the stuff

 

[Electrobes]

whoa wait you got a 25.2 volt ac adapter!? If they are 12 volt fans.. you should be able to use a 12 volt ac adapter... you just need a higher mA rating. For instance I am running two 92 mm fans off a variable 3-12 volt ac adapter.. with 800 mA.

 

[ohio reefer]

so i go back to radio shack get a 12 volt AC adapter and that should do it?

how about wiring?

i'm assuming the two black wires are for the ac chord, how about the the two yellow wires with the black? is one a ground?

sorry i'm an idiot. whats mA? AMPS?

thanks

mark

 

[Electrobes]

yeah. When you get the 12 volt adapter make sure its got a decently high mA rating on it. After you get the AC adapter you need to find which wire is the positive one and which is the negative wire, usually the red one is positive and the black one is negative. Once you do that find out which wires on the fans are negative and which are positive. Once that happens then we can start getting to business.
Okay to mkae it simple you are just going to get the positive wires together, and the negatives together as well. Just a note: you're not combining all of the wires together.. just the negatives with the negatives and the positives with the positives. Once you figure that out you can choose one of the following methodes below.. I like the second one the best.
There are two ways of connection wires.. wirenutting.. which takes a wirenut and two bare (stripped of the plastic coating) wire ends (of the wires you want to connect). Take the two bare ends and semi twist them together, then take the wirenut, put it over the twisted and and then twist the wirenut and voila you have a connection.
The other method is the one I like best because its nice and clean and more solid, plus it won't carrode.. sodering. For this you need a sodering set (which is like 20 bucks total at radio shack or any hardware shop. You also need some shrink tubing (the tube that shrinks when you apply a lighter to it. First you slide the shrink tubing onto one of the sides of the wires you want to connect and slide it out of the way. Then you take the two wires (bare ends) that you want to connect and soder them together. After that you slide back the shrink tubing onto where you sodered and apply a lighter to it evenly and letting it shrink around the sodered area, nice and tight. And voila you have a solid connection and no corrosion or trickle possibility.

 

[yaksplat]

mA = milliamps

you should wire the fans in parallel to the transformer. Connect all of the positive wires together and then all of the negative wires together. You may want to wire in a switch just in case you want to turn the fans off at some point. I dont know about you, but i don't like to have to hunt for the right plug when i turn something off, they all tend to look the same .

Jim

 

[ohio reefer]

thanks electrobes, that should get me started.

when i mount the fans, do i want the fans to blow on the lights or to draw the heat out of the canopy?

mark

p.s if i have any questions can i pm you?

 

[BillyZ]

one thing not mentioned yet is a fuse! I would highly recommend an inline fuse after the transformer. Just make sure the Fuse is rated for ... ack... I forget the rule of thumb... is it 20% more than normal draw?

 

[Electrobes]

i think you're right billy - nono don't have it blow on the bulbs.. it'll create cool spots on the bulbs

 

[ohio reefer]

thanks for everything

 

[TheMadNucleus]

Yikes!!! Hold everything.

In your first post you list that you bought:

1) 2 12VDC cooling fans
2) 25.2-volt AC 2-amp power transformer
3) 6 foot AC line chord

In subsequent posts Electrobes corrected that you need a 12V power transformer then Yaksplat indicated to parallel wire.

so i go back to radio shack get a 12 volt AC adapter and that should do it?

However, You have a current type mismatch. The transformer is 12V AC and the fans are rated 12 V DC.

If you run it this way your fans will oscillate 60 times a second back and forth or may just blow out.

You need a 12V DC power pack. I recommend a 12V DC wall power pack with a power rating greater than the sum of the two power requirements of the fans by at least 20 % Then wire as indicated above.

This one is proabably good (just check the mA of both fans)
http://www.radioshack.com/product.a...name=CTLG_009_001_001_001&product_id=273-1776

This is cheaper and definitely has enough power if you can wait for mail order:
http://www.allelectronics.com/cgi-bin/category.cgi?category=790&item=DCTX-1219&type=store


Alternatively you can use the line cord and 12V AC transformer but then you must add a full wave Bridge Rectifier to convert the AC output to DC.

Note: sometimes the wall plug-in transformers are called AC adapters but they can have AC output or be rectified to DC output, you have to check each. Sometimes these are called power-packs as well.

Any questions please let me know.

Tom

 

[ohio reefer]

whoa, thanks tom

 

[Centurion]

i think electrobes meant dc. he wouldnt set you astray on purpose. i also like how dc is direct current and ac is activated carbon. i will second the switch as well. and/or a potentiometer. you cant have too much cooling but you can have too much noise.

 

[yaksplat]

Just hold on a second. Is that why the activated carbon in my filter isn't working well as a UPS? This changes everything...

 

[ohio reefer]

i will keep everybody updated

thanks everyone

mark

 

[TheMadNucleus]

Yaksplat - LOL, that is a really funny post