PWM - Mosfet/motor introducing noise

[Acetronics2]

This seems to be what you are describing.

http://www.kronosrobotics.com/an142/GAN142.htm

Hi, Ben

Yes ... that's a nice tutorial ... but some tips still missing !!! ( diode, low esr cap, inductor ...)

note here, in this example, motors can be reversed ... so, the diode can't be placed on the motor terminals, but close to the "reversing commutator" ( relay, transistors bridge ...)

Alain