- Joined
- Jul 18, 2010
- Location
- Spokane, WA
Hello,
I've recently noticed the CPU fan header on my motherboard has stopped effecting my pump speed as it did in the past. I had a brand new pump in the box (thinking it may have been the pump). Swapped them out, same result. It runs at full speed all the time (even though it shouldn't based off my BIOS settings).
My pump is a MCP 35X http://www.performance-pcs.com/catalog/index.php?main_page=product_info&products_id=29201 and has built in PWM control.
I researched some PWM diagrams to find out a simple way to just add a manual knob control to it and came across this site: http://www.bit-tech.net/modding/2001/12/03/pwm_fan_controller/1
I noticed on the diagram, they just use a 10k rheostat so I figured, hey, I'll just run down to radio shack and grab a 10k rheostat and hook it up to my pwm lines... http://www.radioshack.com/product/index.jsp?productId=2062299 Well, it does work (I'm sure all you electrical guys are laughing at this point). The pump acts essentially the same as if I were to just short the two wires (green and blue), it slows down to about half speed. turning the rheostat knob doesn't effect the speed at all.
Anyone know what I may be doing wrong here? (I hate electrical stuff).
What if I just hooked it up to the power leads on the pump? How would that work though with 2 wires and only 3 terminals on the rheostat?
My water-cooled box isn't any quieter than my old air-cooled system with my pump running at full speed all the time now
Thanks in advance for any tips!
EDIT: Hmm, looks like I got a 25 ohm rheostat when what was used in the diagram was a 10k potentiometer. Will this make a difference at all though? The problem is this pump runs at 18 watts and the potentiometers I saw at the shack said like .5 watts or something (for speakers and such). But will that matter since I'm just on the PWM leads anyway?
How the heck to people normally slow down their pumps for a quieter system?
I've recently noticed the CPU fan header on my motherboard has stopped effecting my pump speed as it did in the past. I had a brand new pump in the box (thinking it may have been the pump). Swapped them out, same result. It runs at full speed all the time (even though it shouldn't based off my BIOS settings).
My pump is a MCP 35X http://www.performance-pcs.com/catalog/index.php?main_page=product_info&products_id=29201 and has built in PWM control.
I researched some PWM diagrams to find out a simple way to just add a manual knob control to it and came across this site: http://www.bit-tech.net/modding/2001/12/03/pwm_fan_controller/1
I noticed on the diagram, they just use a 10k rheostat so I figured, hey, I'll just run down to radio shack and grab a 10k rheostat and hook it up to my pwm lines... http://www.radioshack.com/product/index.jsp?productId=2062299 Well, it does work (I'm sure all you electrical guys are laughing at this point). The pump acts essentially the same as if I were to just short the two wires (green and blue), it slows down to about half speed. turning the rheostat knob doesn't effect the speed at all.
Anyone know what I may be doing wrong here? (I hate electrical stuff).
What if I just hooked it up to the power leads on the pump? How would that work though with 2 wires and only 3 terminals on the rheostat?
My water-cooled box isn't any quieter than my old air-cooled system with my pump running at full speed all the time now
Thanks in advance for any tips!
EDIT: Hmm, looks like I got a 25 ohm rheostat when what was used in the diagram was a 10k potentiometer. Will this make a difference at all though? The problem is this pump runs at 18 watts and the potentiometers I saw at the shack said like .5 watts or something (for speakers and such). But will that matter since I'm just on the PWM leads anyway?
How the heck to people normally slow down their pumps for a quieter system?
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