Voltage control a pump via mobo header?

VanGoghComplex

VanGoghComplex

2[H]4U
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My wife's new watercooled build has an XSPC Ion pump/reservoir combo unit. The pump is rated for 6w @ 12v, or 0.5a of current draw. It has a two-pin molex power connector with no tach wire.

Assuming an available mobo header with voltage control, could I lop off that molex and put a fan plug on it, and control the pump that way? The main reason I want to control it is that it's noisy at 12v, and I don't need it going flat-out for such a small loop cooling a 65w processor.
 
VanGoghComplex said:
My wife's new watercooled build has an XSPC Ion pump/reservoir combo unit. The pump is rated for 6w @ 12v, or 0.5a of current draw. It has a two-pin molex power connector with no tach wire.

Assuming an available mobo header with voltage control, could I lop off that molex and put a fan plug on it, and control the pump that way? The main reason I want to control it is that it's noisy at 12v, and I don't need it going flat-out for such a small loop cooling a 65w processor.
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Yea you can do that and chance burning out that header. I would get a fan controller or wire the molex to 7v.
 
thesmokingman said:
Yea you can do that and chance burning out that header. I would get a fan controller or wire the molex to 7v.
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At a half amp? Most can supply at least one. o_0

I did find a molex - molex voltage controller for $5 on FrozenCPU, which I'm sure is just a rheostat in a box. I'll try it out first, but being able to vary the pump via software would be pretty neat.

pendragon1 said:
its within spec for a fan header. if you can set the fan header to DC instead of PWM it should work fine. some boards require a rpm signal to vary the speed so it may lock to 100%(12v). have to try, just make sure to get the +/- right or buy an adapter.
https://www.moddiy.com/products/4%2dPin-Molex-to-3%2dPin-Fan-Adapter-Cable.html
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That RPM signal being required or not is what's gonna sink me. I know the headers on the mobo will do PWM or voltage control, but I don't know if it relies on an RPM signal. Guess I'll find out.
 
VanGoghComplex said:
At a half amp? Most can supply at least one. o_0

I did find a molex - molex voltage controller for $5 on FrozenCPU, which I'm sure is just a rheostat in a box. I'll try it out first, but being able to vary the pump via software would be pretty neat.

That RPM signal being required or not is what's gonna sink me. I know the headers on the mobo will do PWM or voltage control, but I don't know if it relies on an RPM signal. Guess I'll find out.
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Can probably save a couple bucks getting a zalman fan mate 2 on amazon, 8 or 9 bucks prime. I avoid running pumps off the motherboard and instead opt for pwm. Yea, that pump is pretty weak but I've had my share of headers die regardless of what a mb header spec is. Some of the higher end boards come with pump specific headers to suit the higher and constant load of a pump so its not an issue.
 
Okay, it's worth noting for anyone else using a Biostar X370GTN motherboard that voltage control is not possible on either fan header with or without a tach. You've got PWM, or you've got full blast.
 
I just lock a water pump rpm to a lower rpm and let it run never changing it.

Water will absorb the same heat whether it's slow or fast in velocity.

You can always buy a voltage based fan control knob and use that.
 
tangoseal said:
I just lock a water pump rpm to a lower rpm and let it run never changing it.

Water will absorb the same heat whether it's slow or fast in velocity.

You can always buy a voltage based fan control knob and use that.
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Those things are exactly what I did.
 
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