Hey all, My main system is a Hackintosh running an i3 and a GTX 260 GPU. I usually run the system without any case fans and the temps never really get to worrying levels (i3 sits at around 40C and the GPU around 48C), my case has really good air flow. However occasionally I like to do a bit of gaming on my Windows partition. The GPU kicks out a lot of heat and I have two fans installed to help it keep it cool when gaming, one of them is a huge case fan connected via a molex interrupting cable directly to the power supply and it also has a motherboard 3 pin header so I can get a reading on the speed (but no control). The other is a cooler which takes up one of my card slots and sits next to my GPU, it works great for keeping temps down but is only connected directly via molex. Both fans aren't really noisy but they're noticeable. Sadly I have no system control over them in OS X or Windows and at the moment whenever I want to do a bit of gaming I'm on my hands and knees reconnecting the fans and then disconnecting them when I go back to work or casual use. Because I like to have my machine ultra quiet and it's safe to run it without the two case fans during general use I'd like someway to turn them on and off easily (FYI I don't really have the budget nor the want to start buying totally silent fans or water cooling, I'm just not that much into it all). I was thinking of some sort of switch but I don't know what type or how. I know I'll need to interrupt the power from the PSU to the fan but which cable do I break into? Does it have to be both or just one? What kind of switch do I need? I've done Mega Drive mods etc where it's a double throw something or other but what do I need in this case to just either be supplying power or not? It doesn't need to be something that can be switched when the machine is on, I don't mind having to power off the machine to adjust it. Just something like a simple flick switch mounted on the back of the case would be good, it also needs to be safe too, I don't want power supply wires connected to the metal case or anything lol. Any thoughts?
If the fans are 3 wires you will need a 2 pole switch. Probably a DPDT to interrupt the yellow 12 volt and red 5 volt lines. DPST switches are kinda hard to find. you can also get a cheap fan controller. Some models allow for speed adjustment in terms of percentage and even allow them to turn off. They work on the 3 wire models depending on what you get. A simple eBay search should turn something affordable up.
Thanks. The fans run off only two wires, black and red. DPDT switches are easy to get here, question is if for arguments sake I'm only talking about one fan here that is powered by two wires. Can I just interrupt one wire?
Yes, breaking either wire will stop the fan. With a +ve power supply like this, the convention is to put the switch in the +ve line.
