RE: [CAD_CAM_EDM_DRO] high-performance EDM power supply

Hmmm... I just thought if the requirements were clear, this would
be one of those circuits Mariss could whip out in a few minutes
and post to the files section ;^)

I'm sure there are at least a few people on the list that would be
capable of devising a circuit if the requirements were clear. Can
we start a list of requirements that would be typical of a modern
EDM power supply? This way, anyone who wants to tinker with a
circuit doesn't also have to be an EDM-guru. We can start by
filling in the blanks on the following topics, and adding any
others that are relevant. If there are enough responses, I could
try to compile the info into a single reference document for those
who might want to work on the electronics.

Here are some starter topics (please insert whatever you know, or
add new topics):

* "Ideal" power pulse characteristics (such as on vs. off times,
frequency, pulse shape, etc)
* Voltage and current requirements (typical ranges, peak vs.
continuous current, etc.)
* Requirements of machine motion to sustain optimum burn (feedback
loop - constant gap?, constant voltage? etc.,)
* Comparison of typical cutting speeds vs. power supply for
different machines (eg, XX in^2 per hour with a XXX watt supply,
on a XXX brand wire/sinker EDM machine)
* Difference between wire and sinker EDM power supply
characteristics.
* What parameters should be adjustable, and in what ranges?
(voltage, current, frequency, on/off times, etc.)
* What parameters are used to control surface finish?
* What parameters should be controlled by the power supply, by the
machine controller, or by the user?
* Etc:...


Regards,

Carlos Guillermo
VERVE Engineering & Design

-----Original Message-----
From: Jon Elson [mailto:elson@...]
Sent: Thursday, July 17, 2003 10:02 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] high-performance EDM power supply


Carlos Guillermo wrote:

>Hi All -
>
>Has anyone designed an "affordable" high-performance EDM power
>supply? Mariss, wouldn't this be right up your alley?? This is
>begging for somebody who knows power electronics and (maybe)
>microcontrollers to design it and offer a kit with plans and
>PCB's.
>
>

I've sketched out a few things, but haven't had time to get into
it.
I think it is getting into voltage ranges Mariss may be scared to
tread, for liability reasons. Also, he is in the business of
selling
tens of thousands of drives a month, and this is not likely to
come near that volume.

I was planning a simple on/off pulser, but some descriptions of
the arc starting circuits of a commercial 1970's vintage EDM
made it clear that better circuits could be made without great
additional cost.

Someday....

Jon