Voltage-controlled case fans

Yammer

Yammer

Yammer

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My Asus motherboard supports 2 PWM CPU fans and 3 voltage-controlled case fans via 4-pin headers. I've always used the supplied case fans with 2-pin PSU plug extenders, so the motherboard will only control the CPU fans' speeds.

One of my case fans has died, so I need a new one. I thought this would be a good opportunity to get three proper voltage-controlled case fans, but I'm struggling to work out which ones will do the job. The motherboard has 4-pin headers, but the case fans are voltage-controlled, not PWM. It may even support 3-pin connectors, as the polarity lug is off-centre. But which fans are 3-wire voltage controlled?

There are 2x 120mm and 1x 140mm case fans.

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Hi from what i remember three pin work on four pin sockets you miss out the 5volt pin when connecting as 5v will be the control for PWM.
Anyfan will be voltage controlled just like a light bulb normal switch on/off or dimmer all same bulb.
Reduces speed by means of resistance as that is all dimmer/speed control switches are/do.
 
area51 said:
Hi from what i remember three pin work on four pin sockets you miss out the 5volt pin when connecting as 5v will be the control for PWM.
Anyfan will be voltage controlled just like a light bulb normal switch on/off or dimmer all same bulb.
Reduces speed by means of resistance as that is all dimmer/speed control switches are/do.
Click to expand...
The fans I have now are 2-wire. I'm guessing voltage-controlled fans are 3-wire, otherwise what's the point of a 3-pin header?
 
Don't use them then. Connect a PWM splitter to the second PWM header and connect PWM case fans to that. I can't see any obvious reason why that wouldn't work.

None PWM fans usually have three wires. The third is the tacho wire so the speed can be monitored.
 
Yammer said:
The fans I have now are 2-wire. I'm guessing voltage-controlled fans are 3-wire, otherwise what's the point of a 3-pin header?
Click to expand...

Hi as Bremen1874 says Third wire is signal/tacho wire tells board sensor of speed/failed/died/dead etc
Just a two wore don't use the third wire but same plug

Voltage controlled fans do it by strangling the supply Just the same a a Bath/sink tap water pressure is a constant the tap just reduces the flow/speed as required! "No witchcraft is involved"
 
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