Permanent Magnet Pump Speed Control

[Cudaxtreme]

Hi,

I have a submerged magnetic water pump that is pushing too much water at 8500L/hr. I know that the propeller rpm depends on the frequency of the AC supply but how can I build a simple circuit to reduce the frequency?

Thanks

 

[sridhar_n]

...

Could you brief me about ur device so that I can try to figure out some way of reducing the frequency.? How does your pump work?


Sridhar

 

[Cudaxtreme]

Its has a magnetic rotor that will spin when switched on, this rotor is connected to a propeller that pushes the water. I need something that can reduce the frequency of the AC supply so that the propeller will spin at a lower rpm. The best solution would be something like a rheostat where I can adjust the speed with a turn of a knob.

 

[Jimmy]

Do you know the current rating of the motor?

I found this schematic that you might be able to use.

http://www.electronics.50g.com/cacspeed.htm

 

[Cudaxtreme]

Its a small pump, rated at 17watts/230V/50Hz.

I would need something for 230V

Thanks!

 

[Jimmy]

Sorry, I shouldn't assume 110/120 V.

Not much current draw at all. That control circuit is rated at 10 A at 120V. The maximum power it can handle is 1200W. Since your motor is rated at 17 watts, it would have no problem handling the power requirements of your pump at 230V.

A google search for "AC motor speed control" will yield lots of hits if you want to look for other circuit designs.