Re: Low cost Servo Controller

Dan Falck wrote:

> From: Dan Falck <dfalck@...>
>
> At 07:41 PM 9/13/1999 , you wrote:
> >From: David Howland <dhowland@...>
> >
> >Jon, Thanks for your feedback. You asked why anyone might want to apply
> servo motors to software which supplies step and direction signals, rather
> than obtain existing controllers and motors for one or the other? First
> of all, so far, no one has set me straight on the EMC (or other) drivers
> for servo or stepper controllers. Such information will be helpful. It
> may bring to light many facts concerning this.

Ok, what do you need to know?

Are you asking about commercial servo amplifiers that are compatible with
EMC? Almost all brush-motor servos over the last 20+ years use a
+/- 10 Volt signal to command velocity. The servo amp's job is to
make the tach feedback signal from the axis drive match the command
signal, times some gain factor. Servo Dynamics, Kollmorgen, Copley
Controls and many other companies make servo amps that work with
the same basic signals. I made my own PWM servo amps, and a bunch
of people are building copies, using a 'semi-kit' that I have supplied.

Right now, pretty much everyone is resigned to using the Servo-to-Go
card. I think the price has come down on the standard model, too.

Jon