Re: EDM home brew units ?

> I have not seen a working non-capacitor EDM circuit. Since the

readily

> available circuits use capacitors, I am still thinking capacitors.
>
> That would mean your formula is not relavant to the R/C type

machines,

> but is really for a non-capacitor circuit.
>
> do you have a schematic for such a circuit ?

I didn't say it was for an RC circuit!

The sodick wire edm I use does not have capacitors neither does the
hurco sinker. The circuit is a DC supply a current limiting
resister and a mosfet/transister. In reality they tend to have
several resisters and mosfets in parallel when you select the
current you actually select the number of transisters.

> I agree that there is a sweet spot, but that has not been offered

as a > known formula that I am aware of.

That is why each EDM machine comes with a book of "technology"
settings for the machine for differing materials and finishes etc.

> OK, now I'm confused. if there is no capacitor and the resistor is
> not in the discharge path, but it has an effect on the energy,

then it > must be in the active circuit.

You thought that the equation related to RC circuits and thought
changing R would increase the energy, I am saying that R in an RC
circuit will not change the energy as it is not in the discharge
circuit.

In a switched circuit the current limiting resister is in the
discharge path and offers a way to affect the current at the working
voltage controlled by the servo system.

Graham