hey guys, I'm wanting to wire a switch to turn off my fans. They are run through a fan controller that takes both the 12 volt and five volt line. How would I go about wiring this up? Would this Switch work? http://www.radioshack.com/product/i...witches&numProdsPerPage=100&parentPage=search
If you are just using the 5 volt and 12 volt line for power and no ground it will work if you are using all 3 then you need a double pole switch. basically its like 2 of those switches in one housing. http://www.radioshack.com/product/i...witches&numProdsPerPage=100&parentPage=search
You can hook them up using that switch, but it won't be able to have controlled speed or give RPM readings. If that isn't a problem then it should be fine. Just wire up the 12v and ground, which will be typically red and black, and forget the other wire, typically yellow. hydro_electric_655, I don't think that hooking up the 5v+ and the 12v+ to the fan would work, you would need the ground and either the 5v+ or 12v+ to work.
2 things one do you want to turn off the entire fan controlling unit or just the individual fan? Depending on the output if its only 2 wires+ and - then a simple spst switch turns off the fan 1 per fan. If you want the whole unit off then read above. matt yellow is 12 volts red is 5 better check your info before you tell someone misswiring can cause serious damage. I belive that your fan controller has a molex pluging into it but infact only uses 12 volt and ground so that switch on the yellow 12 volt line would shut everything down. Got model numbers/pics?
Hmm, I am confused now because my fans do not have the yellow wire connected, and yet they are connected to 12v and are running fine and at a fairly high speed. Very strange. Sorry for the confusion, I am not sure what I am talking about now... EDIT The hardware book says different (I'm pretty sure its wrong though, why would there be 2 grounds??) http://www.hardwarebook.net/connector/pc/mbcpufan.html Again, a site saying that middle pin (red typically?) is 12v and the third is something else. http://pinouts.ru/Motherboard/MbCpuFan_pinout.shtml Yes it would seem CPU fans are wired like this: http://forums.slickdeals.net/showpost.php?p=4522581&postcount=3 I am confused? Are case fans different? You can connect a case fan to a motherboard header, so they must be the same?
sorry guys, I haven't replied in a while. Here's what I've got. A fan controller that I want to be able to switch off so I sleep in the dark without the blue leds on the front of it. The controller is powered by the standard 4 pin molex connector. So with the two pole switch I would just cut my red and yellow lines and solder the yellow to connectors on one side and the red to the connectors on the other? Thanks for the help.
As said, although the controller connects to a 4-pin molex it's highly likely it only uses the 12V line (yellow wire on the molex) and a ground (a black wire), so a single pole, single throw switch on the 12V line will turn it off. But switching the power off will stop the fans as well as the LEDs, so don't have the CPU fan controlled. mattthegamer463, the speed wire on fans is often yellow, nothing to do with the yellow 12V wire on a 4-pin molex. And a fan's 12V wire is red, nothing to do with the red 5V wire on a 4-pin molex. And a molex has 2 grounds to share the return current from the 12V and 5V power lines, it's better than using a single thicker ground wire.
All you need is one of those pieces that fans come with normally, where its a male molex and a female molex with about 4cm of wire between them. Cut through the 12v (yellow wire) and put in a switch. Get one thats fairly high current rating, just to be safe. If they are LED fans they may or may not use the 5v line for the LEDs, if they do then you'll need another switch on the 5v (red wire) to control LEDs. Your fans probably aren't like that though.
Just out of curiosity... how about just switching the ground?? that way you will effectively turn off both 12V and 5V using just one switch
But 4 pin molex utilizes 2 grounds, so if you wanted to put a switch on ground you would still need 2 (unless you put both grounds on one switch, but I don't think thats advised.)
Cutting the ground is only a good idea when all devices share the same 'common' power input. Say a +12v input, but if they use more than one power input such as both +5v and +12v then cutting the ground still leaves the potiential difference between +5v and +12v. And anyone who has done the +7v fan mod will know that there is still power there. Also electronics have a weird way of finding a path through other devices for power. Any good switch you would have should be at least a dpst switch or something similar, so that it can switch both the power and the ground. but if you only have the option, cut the power.
make sure you get a break before make switch so it breaks the connections first (most rotary switches?)
