I made a video that discusses the coil that is present in the circuit for treadmill motors. I perform some tests to demonstrate the behavior of the motor with the coil vs. without the coil. Watch the video to see what effect that coil has on the operation of the motor.
This is a response to a question that a viewer posted in my previous video that showed the replacement of the treadmill controls with a 10K potentiometer.
Previous Treadmill Motor Video: