Re: [CAD_CAM_EDM_DRO] Re: Why gecko drives don't support DC brushless servo ? do they ?

Dennis Schmitz wrote:

>Generally driving sine waves (via pwm) into the windings should smooth the
>cogging of a brushless. You could think of it in the same way as
>microstepping, since it's basically the same thing anyway.
>
>
>

This is not so easy, however. The simple brushless drive only has the 3
Hall
effect sensors for commutation. It doesn't know exact position, and
therefore
can't determine when the current should peak, and where to start bringing
it back down. You'd need to connect the encoder to the drive, too, and have
some more sophisticated circuitry counting encoder pulses to program the
current. The drive would also have to be programmed to know the number
of motor poles and the number of encoder counts/rev.

Jon