Sine wave vs Square wave test

[rocketman58]

I swapped out my 22a KT square wave controller for a 25a KT sine wave controller. The changes were more subtle than I expected with the exception of one. It reduced my top speed from just over 20mph down to just under 18mph. Why would this happen?

 

[neptronix]

Interesting, have you went through and programmed them ( are the settings the same? )

 

[rocketman58]

Only thing that changed was the controller so I did not reprogram anything. There really aren't any settings that would change.

 

[Chalo]

Are you running a motor that requires a very high eRPM? I don't really know, but it would make sense to me if a constructed sine wave tops out at a lower frequency than a trapezoidal wave.

 

[markglos]

I don't pretend to know the reasons behind it but it's fairly well known in the vesc community that you'll lose a small percentage of top end using sine over square. Have a search on the electric skateboard forums and i imagine you'll find a reason behind it

 

[Timmate]

Sine wave has less power take a look at "root mean squared" RMS. Square wave gives 100% power for a time period take a look at "pulse width modulation" PWM.