Could I check will I cause any damage to a 12V DC submersible pump like this in the long run http://www.ebay.com/itm/12V-200L-H-Mini-Submersible-Water-Pump-Aquarium-Fish-Pond-w-Suction-Cups-Filter-/381128747476?, if I were to run it on PWM via a mosfet to reduce its speed.
I have read on other forums stating that not all pumps are happy to accept PWM, and could somehow damage it, but they did not explain further. Any advice appreciated.
moderator:
@xolbrin
You do not answer the question Byork stated, not even for your shops product. That makes your post in fact spam. The reason why I did not remove your post is that the product mentioned is quite on topic.
So please elaborate your answer.
The detailed specifications claim that this pump uses a brushless motor. This means it's not suitable for PWM control.
I would not have expected that it was brushless and it's possible that the specification is wrong but if you haven't purchased this item, turn away and go looking for something else.
I actually have it on hand. It appears to be brushless. I have attempted to PWM it to test it, although they appear to work, it produces some kind of whine, and sometimes somewhat loud vibration. I won't be controlling it using PWM, now that it's confirmed that brushless motors aren't suitable.
I just tried using a buck converter with a flyback diode to lower it's voltage and thus speed, the whine and vibration appears to be gone. Thanks for your reply.
Most water pumps that are designed to run continuously are brushless, as a brushed motor operating like this will rapidly wear out the brushes.
Brushless motors arnt designed for PWM.
More importantly brushed motors cannot have the rotor embedded in a plastic impeller inside the fluid flow!
Pumps are often induction or synchronous AC, or DC brushless.