Re: Pulsing circut

Howdy..

I have a small program in visual basic 6 (compileable) that lets
the joystick output pulses on the same parallel lines as my Larken
stepper drives.

It works great, has no accell and decell thou. I have been doing
that manually by hand.. (I do have a bargraph limit and speed)

David




--- In CAD_CAM_EDM_DRO@yahoogroups.com, David Paulson <stlspply@s...>
wrote:

> Hi
> I am in the process of constructing a rotary table for use with my
> welding robot. I have a large (36" dia) cnc rotary table that I had
> purchased on ebay. It has a 140v DC servo mounted on it for the
> movement. I have purchased a AMC brush type dc servo amp that has a
> step (com, +10v) and direction (com, +10v) pins. My idea was to
> program a plc with the required foot switch and two limit switches (one
> for each position of the table) to control the servo amp and

communicate

> with the robot controller. I chose to power the servo though the servo
> amp because when power is removed from the step pin, the motor will

stop

> instantly, but the problem is the speed at which the table turns. The
> limit switches do not accurately activate at the same place each time.
> So my next idea is to install another set of limit switches approx. 1
> 1/2" before the position limit switch and to send a pulsing circuit to
> the servo amp to effectively slowing down the motor so that the

position

> limit switch can more accurately sensed. Does this make sense to
> anyone? So my question is, does anyone know how to build such a
> circuit, possibly using a pot to adjust the frequency of a +10v

pulse.

> Thanks
>
> David Paulson