Controlling pwm pump without motherboard

engstrom0304 · 6 Aug 2015 at 14:18

hi,
im using an ek D5 pwm and that defaults at the minimum speed without pwm header plugged in.
Trouble is im not cooling a pc so don't have a header for the pwm

Can I use a fan controller for it? Any fan controller? And which one is cheapest that will work?

Thanks

Tim

BattFink · 6 Aug 2015 at 14:31

Are you sure it's running at minimum speed?, my EK D5 pwm pump runs at maximum speed when the PWM header isn't connected

engstrom0304 · 6 Aug 2015 at 14:55

I think so. When I touch the pump the vibration is so small it cant be full speed. It feels almost non existent

tyler_jrb · 6 Aug 2015 at 15:02

Mine was the same when i built my pc, you could see the jet of water coming out of the Pump. what are you doing with it? there is a way to force it onto full speed quite easily. But Its more of a temporary measure.

engstrom0304 · 6 Aug 2015 at 15:03

Its for cooling peltiers for Li-ion batteries.. university research group. will be running a few months only

engstrom0304 · 6 Aug 2015 at 15:03

ie. Thermoelectric cooling to control tab temperatures of batteries

tyler_jrb · 6 Aug 2015 at 15:15

Plugged into the molex yes?

Basically take a piece of wire and plug it into the PWM plug so that its in the same hole as the green wire. Plug the opposite end through the back of the pump's molex connector furthest from the red (copper cable has to be quite long to go through the Pumps molex and into the powered one, maybe 1.5inch long)

it forces the pump to 5v or full speed. Id just make sure that you wrap the connections on the molex and pwm with some electrical tape to protect them.

engstrom0304 · 6 Aug 2015 at 15:19

so essentially its green to black?

tyler_jrb · 6 Aug 2015 at 15:21

engstrom0304 said:
so essentially its green to black?

pretty much but make sure its. Green to furthest hole away to the red cable on the molex (hole at the very end on the plug itself), as this is essentially the molex's 5v circuit (thus full speed).

engstrom0304 · 6 Aug 2015 at 15:23

the pump only uses the first two holes.. red and black

engstrom0304 · 6 Aug 2015 at 15:23

and its worth saying im running from a 12v source. no 5v

tyler_jrb · 6 Aug 2015 at 15:30

engstrom0304 said:
and its worth saying im running from a 12v source. no 5v

The molex on the pump has 2 connections red and black which are 12v and ground. You stick a piece of wire on the furthest hole through the pump molex and into the powered one thus re-routing the 5v cable on the molex to the pwm connector.

The pwm connector requires 5v to tell the pump to run at full speed.

engstrom0304 · 6 Aug 2015 at 15:32

ok well in that case I need to find a 5v supply as my power supply is only 12v and 2 of the molex pins in the connector are empty.

tyler_jrb · 6 Aug 2015 at 15:34

engstrom0304 said:
ok well in that case I need to find a 5v supply as my power supply is only 12v and 2 of the molex pins in the connector are empty.

A standard 12v PSU will work. As i said the Molex has 12v ground ground 5v cables. Im talking about the actual 4 cables on the connector itself.

engstrom0304 · 6 Aug 2015 at 15:38

But im not using a PC power supply. Im just using a 12v supply with no 5v rail. I couls get 5v from a usb charger?

engstrom0304 · 6 Aug 2015 at 15:38

or I could just find a PC power supply.

tyler_jrb · 6 Aug 2015 at 15:40

engstrom0304 said:
But im not using a PC power supply. Im just using a 12v supply with no 5v rail. I couls get 5v from a usb charger?

ahh ok, aslong as it is 5v then yes.

A pc's PSU would be more convinient. Could pick up a second hand one for less than £10.

Brian18741 · 6 Aug 2015 at 21:12

Defo pick up a cheap second hand PSU. My D5 hardly runs at all without being connected to a mobo. It was so slow that I thought it was broken when I first got it!