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Starting DD D4 pump on a rheobus

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coil

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Mar 26, 2004
Hey, ive got the DD 12v pump and i want to run it at a lower voltage. The pump requires 12v to start so my sunbem rheobus doesnt start the pump from cold if the knob is lower than max.

Does anyone know of any fan controllers that supplys 12v to the output at the start and then switch to whatever it was set at on the dial. I heard the coolermaster aerogate does but does any others? Does the vantec nexus series?

Cheers
 
I could be wrong - but I believe motors the size of a pump require very different rheobus switches than one designed for an 80mm fan. for instance, for my 540cfm blower I need to use a PWM circuit and potentiometer knob.
 
Actually I THINK the D4 requires 18v to start up. I may be wrong about this though. After that, you can drop back to 7v. I don't remember which, but there's a rheobus that'll do this for you automatically.
 
Its 18watts the pump uses, but it rated at 25watts.

So does anyone know a rheobus that does what i asked in the 1st post?
 
RedViper said:
Dangerden, do you recommend 2 D4's on one PSU, provided I have the spare capacity?

Rofl...he is quoting from the store DangerDen. You can definitely run two pumps off your PSU if you have the capacity (duh).
 
klath said:
Rofl...he is quoting from the store DangerDen. You can definitely run two pumps off your PSU if you have the capacity (duh).

Dude, what's wrong with you? Didn't you see this "Originally Posted by DangerDen"? I know very little about power and I'm not a pump specialist.

Why should you "laugh" because I asked a question?
 
The pump doesnt start with just 6 volts tho..thats the thing, it requires 12 to get going then you can bring it down after..

The pump just makes a wierd noise like its trying to start but wont at 6v from cold.
 
greenman100 said:
fair enough

but it is of note joekamel runs a 2xD4 setup

better to invest into Iwaki?

Good! ;)

I wasn't aware of that. I'd REALLY like to hear about his rig.

Maybe. But the smallest Iwaki I've seen was fairly large. And two pumps, for me at least, would not only increase performace (I'm thinking about slapping another rad in) but would kill the single-point-of-failure principle.
 
coil said:
The pump doesnt start with just 6 volts tho..
The problem is the starting current -- it take more to get it running than to keep it running. With a simple passive/resistive rheobus, if you set it to 6V based on the running current you'll get a much lower voltage when the pump tries to draw the starting current.

You have to use a circuit with active voltage control. I make my own stuff, so I don't know what commercial products would work. Might want to e-mail the manufactures, ask if their stuff is passive/resistive or actively controlled.
 
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