Detecting when the brushes are off the magnetic neutral axis can be difficult, especially if the motor is inaccessible during operations. Using voltage analysis in the time domain makes the job of properly setting the brushes for the desired load much easier. The voltage waveforms should be relatively smooth through the commutation. However, when the brushes are off the magnetic neutral axis, the voltage waveforms in the time domain become full of voltage transients during the commutation cycle.
Tip provided by PdMA Corporation