hi everybody, i'm new here.. first post:] so.. the thing is, i own the acceleroS1 cooling installed on my Palit 8800GT 512MB video card. i would like to install 2 120mm fans on the heatsink without too many cables going around.. my idea is using the video card's power source which also offers speed control for fans following are my questions about it.. 1. should i just solder the fans together to the connector and thats it? or do i need any resistor or something like that? 2. is it possible to control the two fans via connecting the speed control cables to their matching pin? thanks in advance daniel
hey. you can get fan splitters... I would not advise running 2 fans off the GFX card, run the extra fan off a MB connector. ED
Two fans with same operating voltages must be connected in parallel with no extra resistors. The thing is that the total current consumption will be the sum of the current consumption of each fan. This means in other words that if each fan is 500mWatt under 12 volts, then for each fan the current will be: P=V*I => I=P/V = 500/12 = 41.6mAmps The total thus will be 83.2mAmps (41.6+41.6). You must cinsider this when choosing power source Better get or make or ask someone else (for example these guys here that are expert on this) for a PWM fan control. This is the best way on controling your own fans. I really do not know what will happen if you connect both the fans to the m/b output. As far as i know, the 3 cables they have is one positive power, one negative and one speed measure, not control. I have heard that control is achieved with PWM. I hope i help
kammenos is right. If you link two fans to a power source that cant handle the combined current, you could damage the fan controller. I dont know if you can find that sort of info from the cards spec sheet. Producing a circuit that would be able to take the pwm signal from the graphics card and up the current capability would be relatively easy. Its basicly a medium power transistor, couple of resitors and a matter of finding a 12v power line. The power line bit isn't hard, there are many in your pc that would be up to the task, One of the molex ones being the obvious choice Depends how far you want to go basicly.
A transistor booster circuit as justblair says would probably be best to maximise things. A small wide bit of heatshrink would be enough to house it, or make a little box, or just hot glue it, whatever, and just one pair of thin power wires to run to a spare molex. It wouldn't be hard to route the little circuit & the cable out of sight, all you'd really notice is the two 120mm fans! The transistor circuit also has the advantage of the fans using next to no power from the gpu board, which means more for the core compared to standard, and the fans can run at full speed. It would cost like $1, and you get an onboard, driver controllable fan speed controller! Blair wins the official bit-tech mini cheesecake award:
Thank you guys.. You've helped me a lot. But I think since I'm buying a relatively silent fan, it woult be stupid to make it controllable since its already silent at maximum RPM so maybe I would connect them both to the motherboard. Another advantage is, if in a few months i would like to tear this all thing apart, I wouldn't need to unsolder wires and get messed up with these kind of things. Thanks again. By the way, does anybody know a way to connect the fans to the AcceleroS1 other than zip-ties?
