I need to vary the speed of a DC bilge water pump.

[scmx5driver]

I'm attempting to make a "cool suit" system.
If you don't know what that is... It's a shirt with small tubes running up and down the outside area. Cold water is pumped from a cooler thru the tubbing to cool your core temp. You can change how cool you get by changing the flow rate of the water thru the tubes. And that is ware my question comes in...

Can I change the speed of the 12V DC water pump with a reostat? (almost sure that is misspelled.)

thanks for the help

 

[RCinFLA]

You would do it with PWM (pulse width modulation) of supply to pump motor. The success may depend on pump and motor design. For example there may be a minimum drive level where the motor stops rotating and just draws current which you want to avoid.

You may be better off just doing an adjustable timer where the pump runs full for so many seconds then shuts down for so many seconds.

Running the pump slower may just result in the first third of your chest getting cooled. Running it at full speed for a time that flushed all the tubing in a given area may be better and use some amount of therma insulation to avoid an extreme temp shock allowing the cool water to gradually transfer heat from the body. After some time, when the tubing 'charge' has depleted its absorption of heat, then reflush the tubing with a new charge of cool water.

NASA uses this water cooling scheme in their space suits. You might do some google quiries to see what turns up on their work.

 

[scmx5driver]

So you don't think something as simple as a potentiometer would work?
I'm hopping to keep this simple as I can.

But I must say the idea of the timer is interesting.

 

[3v0]

So you don't think something as simple as a potentiometer would work?
I'm hopping to keep this simple as I can.

But I must say the idea of the timer is interesting.

A potentiometer will draw full current regardless of how fast the pump was running.

 

[3v0]

Changed my mind.