Hi Folks,

Just trying to get my head around something.

I have a small 12v DC motor,that when I connect to the power supply it spins, that is fine, but when I reverse the voltage it spins the same way??? I thought if you connected a DC motor the wrong way it did not work

Is that correct as I am sure the last time I did this the motor did not work.

I am confused again

 

If the motor has permanent magnets, reversing the polarity of the voltage to the motor will cause it to spin the other way.

If the motor has field windings, it will still spin the same way. Starter motors typically have field windings.

If you really want to reverse the direction, you will have to either switch the polarity on just the brushes or just the field windings.

 

It is a small 12v submersible water pump so I assume it must have field windings.

Thanks again Wookie