Re: Home brew servo board

["Tom" <designer-at-ezwv.com>]

                Hi,
                    I am new to the CNC stuff and I am in the process of
designing a small system to cut and route PC Boards and front panels for
instruments that I build.  A VCO can be designed for positive or negitive
input voltages or design for a positive input and put an absolute value
circuit in the front end.  With this type of front end you can have positive
or negitive inputs.  Hope this helps with your question on VCO inputs.
Tom C

----- Original Message -----
From: "Darrell Gehlsen" <darrell-at-machinemaster.com>
To: "Multiple recipients of list" <emc-at-nist.gov>
Sent: Sunday, May 14, 2000 1:50 AM
Subject: Home brew servo board


>
> What is the current status of the home brew servo board?
> I just had a thought for an add on for running steppers from EMC.
> If you use the servo board to feed +/- 10 volts to a Voltage Controled
> Oscilator and drive the stepper driver with the output of the VCO that
would
> give you a smooth step signal. You could then either use an encoder for
feed
> back to EMC or for an open loop system just feed the VCO output back to
EMC.
> Now all you have to do is "tune" the PID for your steppers. What I haven't
> figured out yet is if a VCO will accept the -10V for input or if you would
> have to convert the signal some way.
> Darrell
>
>
>