Re: servo driver on a chip ?

I don't think it's meaningful to make that distinction. Once the
command signal comes into the controller, it will either be open loop
or closed loop, and backing up to the command signal saying that it's
open loop back from there doesn't mean much.

An RC servo is simply a packaged controller+drive+motor+gears+actuator
that takes a command signal in the form of a pulse width. (Not the
same as the PWM that drives the motor -- that PWM is a chopper to
control the voltage at the winding.)

On 8/3/06, Hugh Prescott <hugh345@...> wrote:
>
> Normal RC servos are closed loop within in the servo itself. Their is no
> feedback to the transmitter stick or encoder.
>
> In CNC EMC and some others read the encoders back into the program for
> complete closed loop. RC servos would be sort of like a step and
> direction Gecko servo drive. The encoder is read back to the servo drive
> not the program driving the servo driver.
>
> Or one could say one is closed loop and one is absoutle closed loop.
>
> Hugh