Oh, that kind of power supply.
"As a kid I used to cut patterns in aluminium foil using just a 12V car
battery as the
power source and it worked quite well."
You do realize how much amperage comes out of a car battery?
Robert
:)
-----Message d'origine-----
De :
Homebrew_PCBs@yahoogroups.com [mailto:
Homebrew_PCBs@yahoogroups.com] De
la part de Les Newell
Envoyé : juillet 2 2005 04:23
À :
Homebrew_PCBs@yahoogroups.comObjet : Re: RE : [Homebrew_PCBs] Re: Hmm, another thought....
I don't think the power supply has to be that complicated for this
application. Many moons ago I used to own a Sincleir ZX81 computer. The
Sinclair printer used special paper that was basically a thin coating of
aliminium over a black background. The printer used a toothed belt to
drag a metal stylus over the paper and wherever it needed to print a dot
it applied a voltage to the stylus and vapourised the coating. Being a
Sinclair product you can be sure the circuitry was very basic. Our needs
are very similar, the only real difference is that the coating is thicker.
Normal EDM needs a carefully designed power supply because each spark
removes a very small amount of material. We don't need that kind of
accuracy so we can use a much higher energy density. I think that if we
use a large capacitor and keep it charged through a simple linear power
supply the sparking will be pretty much self regulating. All we need is
a big beefy transistor to turn on the power when we want to remove
material. The transistor does not need to switch for every spark, it is
simply held on for as long as we need to remove copper. As a kid I used
to cut patterns in aluminium foil using just a 12V car battery as the
power source and it worked quite well.
Les
lcdpublishing wrote:
>Stefan,
>
>I looked over that schematic for the power supply - ouch, my head
>hurts from all the complexity of it. I think I will have to wait a
>while before I have enough "Smarts" to understand it. Now if I
>could do all that with a PIC I might have a fighting chance :-)
>
>
>
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