Instructables

Power a 12VDC cooling fan using LEAST amount of space possible using a switch. This needs to fit in a small helmet.

I bought a 40MM 12VDC Cooling Fan (130mA 1.56W) from Raido Shack and I am trying to put it inside my modded Mark VI helmet from the Halo video game series. I bought a small Switch from Hobby Lobby (teamnovak.com Switch Harness #5600) and a 9V battery. I know the volts are off so I need to know what I need to do/buy to get this working.
I connected the fan (+) to the switch (+) and those to the battery (+), then the fan (-) to the switch (-) and those to the battery (-)
It worked just how I wanted but after about 60 seconds the battery got VERY VERY hot. I did my research and found that this outcome is normal but couldnt find out how to fix it.
PS: I am new to this website ans suck at electrical stuff.
Any questions or pictures need email me @ hunter_ii7@yahoo.com
(hunter_ii7)

Picture of Power a 12VDC cooling fan using LEAST amount of space possible using a switch. This needs to fit in a small helmet.
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caarntedd2 years ago
You say it worked OK? It's a little hard to tell, but from your description and pics it looks like the switch isn't doing anything. Did the fan switch on and off when you operated the switch?
When you operate the switch, (if I am understanding you correctly) You are shorting the battery terminals.
It should be: Battery + to switch +. Switch - to Fan +. Fan - to Battery -.

As I understand it, when you operate the switch in your present configuration, in one switch position the fan would run. In the other position it would stop because you are short circuiting the battery terminals. That would make the battery hot.
HUNTER II7 (author)  caarntedd2 years ago
im new to this so i had a question real quick. since you answered my question but i am deciding to use a different setup do i ask another question or just post the new question here.

(I think i dont need to have any more assistance becuase i see where i made the mistake but just in case i mess up again i wanted to know where i should go)
If you have more stuff to ask about the same topic, start up a new question. Try and be specific, give it a different title and word it differently. If it sounds the same as your original question people will think you are wasting their time and won't answer. If you post more questions here, they may be overlooked as you have already marked this as answered.
HUNTER II7 (author)  caarntedd2 years ago
eveything worked like i said but after about 60seconds it got extremly hot.
the switch turned off and on the fan just like i wanted but like i said the battery.


Ahh i see thanks. I will try this but now i changed my play a bit. Im thinking of using two 9V batteries to power 4 3.5v LEDs and the 12v Fan.
9*2=18
3.5(4)+12=26
now that i know how to wire it im thinking it would work but idk since the volts dont match...
I know to make it work better i would need an additional 9v (3 9volt batteries) but im not sure.
HUNTER II7 (author)  HUNTER II72 years ago
its hard to see the switch wires but all i did was connect all the negative and all the positive together wich worked but battery over heated. i thought due to the 12v vs the 9v
frollard2 years ago
Buy or make something that holds 8 AA or AAA batteries (AA is better).

Wire them all in series, + to -, then have + on one end of the batteries go to red on the fan, and - on the other end go to the fan thru the switch.

Keep the batteries somewhere else in the suit, and run the wires up the back of your neck - nobody will see them, or hide them in what looks like air-hose. It will last a LOT longer and you can use rechargables.
HUNTER II7 (author)  frollard2 years ago
This was my 1st idea but i wanted to make everything in the helmet because i wouldnt want to have to have the suit on to wear the helmet. or a wire hanging from it
I suppose there is some spare room - just be sure you can cram 8 AA's in there :D 2 4x1 holders should fit somewhere.