I just need to check my electrics here! So I have a Fan with 3 cables Red Black & White. I have USB cable (which i've cut) and it has cables coloured Green, Black & Red. It works if i ignore the green/white cables and just connect red>red and black>black it DOES work. Its not hugely fast but as i am using it for a roof fan for my small data cabinet it will suffice! My question to you is! Can this damage my pc (that its plugged into) Are the electrics right? Any hazards electricall? I presume fan is 12v and USB is only 5v? Is this ok it means it will just run slowly right? thanks VERY VERY much for you assistance with this in advance
Pretty much what you've said above is fine. Its 5v, shouldn't really damage anything and I've done this just fine myself in the past. Potentially if a higher power fan was used the PC maybe unable to power it as most are 500ma supply. Can't say for sure if the fan would try to draw more. Electrics are fine, red is +5v and black ground.
It would have to be a seriously fast fan at 12v to use more than 500mA at 5v. Current draw drops with PC fans in an almost linear fashion as you drop the voltage. So a typical 200mA 12v fan will likely draw less than 100mA at 5v so you'd be fine. Startup current might be higher though to overcome inertia but this'll last for just a moment.
Ace. Will pop this together and hopefully see some lower heat from my new dell servers. New 11g and 12g servers can cope with 40C but rather keep them cool!
