Induction Motor Question

Thread Starter


Joined Mar 22, 2014
Is anyone here well schooled in single phase induction motors? I want to know if such motor can tolerate a square wave drive instead of a sine wave drive.

I want to drive the motor with a simple square wave so I may apply a variable frequency to adjust the speed over a moderate range.


Joined Jul 18, 2013
What type of single phase induction motors? small shaded pole motor or cap start/run type?
The former you may be able to variable speed it, but the cap variety do not take well to VFD type control, they tend to drop out of run when lowering the rpm under load, this is the reason that most wanting this type of control replace the 1ph with 3ph motors and supply it from a single phase to three phase VFD.


Joined Mar 14, 2008
Even if you could drive the motor with a square-wave, the square-wave harmonics will cause increased dissipation in the motor and reduce it's efficiency.