Re: Plasma voltage servo

Hi Todd, As you can see from the note in the files section, this
circuit was designed by Mariss, of Geckodrive fame. It was designed
due to a thread in which I started when I asked why a stepper
couldn't be controlled by voltage variations. Mariss asked what the
voltage parameters were an the best I could do with my limited
knowledge is give him the info from my hypertherm manual. If anyone
can correct or fine tune the circuit it would be Mariss. I'm sure
your added information on what is required will be helpful. What type
and model of plasma are you using? how are you conducting the test?,
by hooking the unit to a complete machine, or by varying the unit by
hand? My hypertherm manual reccomends a 1/16" distance from the torch
to the material. this may be difficult to maintain with a hand test.
A 1/16" varience may fall inside the5%. What are the voltages you are
dealing with? What seems to be the optimum voltage for the "dead
band"? how far outside the band do the voltages go? Does the voltage
increase when the arc distance increases or when it decreases?
Sorry about so many questions, some of them will no doubt help
Mariss, and some will help myself and others when implementing the
circuit. I have built the circuit, but have not yet gotten my drives
far enough along to test it.
Thanks,
Dale
P.S. the original thread was about a month ago and could be found
easily with a search of "plasma torch height controll". Also, the
design was purely theoretical,and probably a great starting place.
With your help, I imagine we can turn it into something really cool!
thanks
again.

--- In CAD_CAM_EDM_DRO@y..., "morgtod" <todmorg@h...> wrote:
> Hi-
> Has anyone tried building the plasma voltage servo circuit
listed
> in the files section? I just built one and it only steps when the
> voltage is between the 5% comparator. For plasma control I need
the
> steps to happen outside the 5% going towards center, with a +/- 5%
(
> or less )dead band. Any ideas on how to get there from here?
> Thanks
> Todd