Re: [CAD_CAM_EDM_DRO] Re: EDM machine

marble here wrote:

> Hi there
> Would an Precision Crystal oscillator at a 1.000 MHZ
> work.

This is not really of much use for EDM applications.
The EDM process is somewhat asynchronous, anyway.
A better method would be to use an adjustable one-shot
that is started when the EDM current commences. It allows
the current to flow for some adjustable time, then shuts the
power off for another adjustable time. When that 2nd time
expires, the power is turned on again, but current may not
start until the EDM fluid breaks down, which is up to the
conditions in the workpiece at that instant.

Two 555 timer chips and a circuit to detect the discharge
current and trigger the first 555 are about all that is needed
for the control. The power switch is a bit more complicated.

Jon