Re: [CAD_CAM_EDM_DRO] Re: Brand new to the group

Richard wrote:

> Ian,I fooled with some timers and then quit. I looked at the spark
> waveforms using an oscilloscope and hidden in all the noise seemed to
> be a sawtooth waveform, a dead give away that what we have is a
> relaxation oscillator. The frequency of the arcing waveform is
> dependent on the capacitance, resistance and I'm sure the spark gap
> and the fluid used for the dielectric.Thus it seems to me that the
> frequencies will be dictated by the circuit and mechanics. Please
> don't get rough if you think I'm wrong.

Precisely. The EDM discharge is going to control the whole process,
for sure. But, you can control the nature of the spark by turning current
off after the discharge has been going for some desired time, and allow
ions to recombine for some desired time before making voltage
available to the electrode, again. I think this is how the electronically
controlled EDM systems work. I think the whole idea is to keep the
spark 'moving', ie. don't let the discharge keep burning in one spot
for more than a few microseconds, before you interrupt it and let a
new discharge develop at another point.

I'm going to have to try this, it doesn't sound too difficult.

Jon