Re: [CAD_CAM_EDM_DRO] ac servo motors

dave engvall wrote:

> Hi y'all
>
> I just reregistered....and this is my 3rd try at a
> post...maybe it will work this time. Ha.
>
> I just got some ac servo motors ( eBay .... the
> devil made me do it ). ;-)
>
> They have only the three connections for the
> phases.....so does this mean that on measures
> phase and amplitude and uses a dsp to control the
> driver?

Well, you will need an encoder for sure. Some encoders
have both the traditional A/B/Z signals and 3 commutation
signals for the servo drive. Some of the newer servo drives
derive commutation info from the A/B/Z signals. I guess
they search somewhat randomly for a phase that will move
the motor until the index pulse shows up, then they can
run properly from there.

Jon