Control units: Square wave or sine wave

[digiman]

A short time ago I modified my Claud Butler with a kit from "Electric Bike Conversions" and have been very happy with both the result and the support from the firm. I also modified a friend's bike successfully. I understand that the control unit supplied is a square wave device which gives the motor a distinctive whine when used. I believe a sine wave controller runs silently? Does anyone have any info about this topic?

 

[anotherkiwi]

I read that and so I only have sine wave controllers. The Mxus one is a little noisy the one I have now is dead silent except for loud regular "clack" noises when drawing full amps. At first I thought it was a pedal problem but no, just very loud noises coming from the controller box that have a metal on plastic ring to them.

 

[Deleted member 4366]

Many of the controllers sold as sinewave are not. You need an oscilloscope to be sure, but you can often tell by the silence of the motor.