The basic idea behind this is that I don't like most of the fan controllers out there for computers. I am trying to build something that will work with an existing cpu header for myself, and would be adaptable for other people to use the same way or with their fan controller.
So to start out you have a fan header on a motherboard which through its own software will regulate the voltage coming out of the line and defaults at 12V.
The implementation of this would be for a water cooling setup, with multiple radiators. I'd like to be able to control all the fans on one radiator to behave one way tied to the output on the Motherboard header.. The problem is that your talking 3-4 fans per radiator, and 6-8 if your going push/pull. with most controllers offering 20w.
Going with the specs of the fan which require just over 6watts to startup. P = IV. Startup power needed is 0.53A .53*12=6.36 watts per fan. So at minimum your looking 19.08 watts for 3 fans, and 25.44 watts for 4, up to 50.88 watts for 8 fans.
The Input voltage would be propagated to the other Voltage lines for fans. The CPU header is attached to one fan so it gets back accurate tachometer info and the other fans just follow suite to how fan 1 is set. The idea is to set this up to bypass the wattage limit on any fan controller including the one from the CPU and attach multiple fans.
Based on a limit of 60watts from the power supply and assuming you have the 1 fan powered by the CPU fan cable, you could then connect 8 fans.
here is a the basic idea put into a basic schematic.
The yellow line which is the Tachometer is important for the CPU header to get as other fan controllers and the motherboard software use it to determine fan speed, but it will only accept one input which is why on the other fans they are ignored.
Searching the web I am not sure If I even need an arduino, or if it would help, and what I might need is a Single input multiple output(SIMO) but I am having a hard time tracking down one similar to what I would like to do. So i thought I would ask for help.
I suspect that where you have drawn "IC chip/Arduino" you actually need a transistor, switched by the fan control signal from the motherboard or 3rd party fan controller, which has a sufficient current rating to power your six fans. I'm not clear how this would be any better than just buying a fan controller with the correct rating, but since you don't say what you dislike about "most of the fan controllers out there" I couldn't guess whether the proposed system will address any of those issues.
The basics behind it is that most of the fan controllers themselves are Manual and adjust from the controller itself and are limited to the 60w of power from the molex that I labeled for their 4 channels, this would essentially allow for use WITH those controllers or with the Motherboard controller. The one solution out there is older and uses its own software and the company is out of business. Essentially the Motherboard manufacturers have supplied the software to do this with single fans and this will adapt it to for myself and those who use many fans.
The Ic Arduino part is just part of the Mockup as I dont know what needs to be inbetween consider it a ???. Ive been looking online and have seen about a Half H bridge and a way to use Arudino to maybe complete it with using the PWM output to a voltage but this may be complicating it more then it is.
I've built basic circuits in the past and know the basics of sodering, now I just need to find the parts and figure out a solution.
If anyone comes looking for something like this again. Here is your solution. Someone beat me to it, and with a better answer, using the 4 pin PWM on the mobo and translating the PWM into control for the 3 pin fans.
Wilken:
So to start out you have a fan header on a motherboard which through its own software will regulate the voltage coming out of the line and defaults at 12V.
Not necessarily. The 4-pin fans will not variate voltage. Instead it will have a PWM signal in the 4th pin, that is basically a really fast turn-on/turn-off signal. That will make the fan's speed vary.
your right I was simplifing it, basically its 6 half H bridges regulated by the PWM signal. It has those massive heatsinks on it, and It looks like I'll have to hook a fan up to cool them as the only problem with the solution is that it generates heat which can damage the controller itself with inadequate air flow.
