Does anybody know whether it is possible to easily regulate the throughput of a DC water pump? E.g. one you would use for your pond or indoor fountain.
I would like to avoid lowering the duty cycle by switching on and off: one can get used to a continuous noise but a switched noise is irritating.
If I were to make an educated guess I would say that the pump uses a brushless DC motor. External leads are only +12V and GND.
So, would any of the following work without damaging / stalling the pump:
- Switching with very high frequency, i.e. PWM
- lowering the drive voltage statically
- controlling permitted current draw
Which would give the best control over the throughput?
Note: the aim is to reduce the current draw and the noise of the pump.