Back electromotive force
Also: back-EMF, counter-EMF
Voltage generated by a spinning motor that opposes the applied drive.
In a linear motor model e = k_eω; it reduces armature current as speed rises and vanishes near zero speed.
- Units
- volt (V)
- Formula
e = k_eω
Example Startup current is high because the stationary motor initially produces almost no back-EMF.
Common misconception Back-EMF is not an extra power source independent of motor motion.