How to detect if a motor moves

published Jul 07, 2016 12:55 by admin ( last modified Jul 16, 2016 04:47 )

I'm gonna copy a part of Reddit user gnorty's comment and paste here:

1- detect the physical rotation - you could use an encoder, a magnetic region on the rotor and a reedswitch, a high contrast colour change and a photodetector, a physical gap in the rotating part and a proximity switch/laser/other thing that "sees" the change. Any of these work essentially the same way - if you don't see the signal change in a set time you can assume no rotation.

2- Sense the current on the motor. Most types of motor will draw a higher current according to the torque it is applying. You can measure this current and if it rises significantly above "normal" you can again assume something is wrong with either the motor or the mechanical movement. Obviously the same if the current is too low. Most motors use this system to some extent, as the high current will trip the motor protection (fuse, breaker etc). Some breakers have very precise settings for exactly this purpose.