Making Fan On/Off switch

[TheGreatSatan]

I have a fan I'd like to have the ability to turn it on or off. I've seen fan speed controllers that will let me turn it down, but I want it off most of the time. I have one of those boxes that plug into a cathode to turn it off and on. Can it be converted to work on a fan?

[slaveofconvention]

Easily - all you have to do is cut the black OR red wire and solder the two ends to two of the connectors on the switch. Most switches that come with cathodes are SPST so it's pretty impossible to get wrong - it makes no difference which wire you connect to which terminal (assuming there are only two terminals)

The small pile of switches I have here from old cathode kits all have small holes in the terminals, so you can even try just tying the wires to them to make sure it does work the way you want it to.

[TheGreatSatan]

but then I have to get get a molex connection too

[slaveofconvention]

Most of those kits - the switch is connected with a couple of spade connectors - it usually just pulls right out. You can still connect the fan to a normal fan connector

[TheGreatSatan]

Also, can I add a resistor to the power to make it slower too? If so, what kind?

[xr4man]

i'd start with a a 1/4 watt axial resistor in about 500 ohms. then i would increase or decrease the resistance until the fan runs at the speed you want it to.

ok, i am sort of confused here though. i mean, i've seen your mods on here and they a re impressive. so with the talent i've seen here, it's hard to believe that you don't know how to wire in a switch on the fan's power line. this isn't april first is it? or some tbcs version of it?

[AmEv]

I may be able to mail a molex-fan adapter to you.

[SXRguyinMA]

tell me what you need, what kind of connectors and how long you need it and I'll make one for you :D

[AmEv]

Mine looks 100% like this (http://t2.gstatic.com/images?q=tbn:ANd9GcQEI80SzF-m0r9zs_giHf2BJjM0Mk9FQIrWiuvVyuCG7NpthaXdSQ).

I may be able to stuff it in an envelope to keep shipping down, and they are tough to break or crush.

[TheGreatSatan]

I've got those.

[Oneslowz28]

FWIW Noctua uses 1/4w resistors on their fan speed lowering pigtails. So I am sure 1/4w will do it. Just start with a 1kohm and if thats still to fast move lower to an 800, and then 500.

[SXRguyinMA]

1/4W 68-Ohm

http://www.thebestcasescenario.com/forum/showpost.php?p=307383&postcount=62

[Twigsoffury]

Light dimmer switches work exceedingly well.

They'll go 100% all the way to off.

Check my Vento 3600 thread to see some pics of my ghetto fan controller. although mines made for 115v fans and not 12v

i like some torque with my fans.

[edit]

http://www.homedepot.ca/wcsstore/HomeDepotCanada/images/catalog/663ea078-39e0-4791-aad3-e9045b8b3469_4.jpg

http://img231.imageshack.us/img231/106/dscf8854ks1.jpg

http://img231.imageshack.us/img231/636/dscf8853qo6.jpg



http://i43.tinypic.com/ulah1.jpg


i don't see a reason why this wouldn't work for a 12v line, i've done it before with 110v rheostats and its worked... still working matter o fact in bud420's computer.

These volcano12 fans pull some dank amps/wattages.

Volume knob off a stereo would work flawlessly to. there all 12v rheostats.

[xr4man]

yes, the dimmer switch you posted would work just fine for 12v. all it is is a variable resistor. just because it's rated for up to 240 V at whatever amps, doesn't mean you can't use it with much lower voltages.

it would sort of be like using a nice 1000w power supply with an atom mobo. it won't hurt anything, you just won't be taxing it by any stretch of the imagination.