Re: boom

--- In CAD_CAM_EDM_DRO@y..., "Carol & Jerry Jankura"
<jerry.jankura@s...> wrote:

> One thing to consider - If you disconnect the drivers from the

motors,

> you're breaking the circuit in an "unanticipated way" so any

snubbers or

> other circuitry to account for the di/dt voltage spike may not work

as

> expected.
>
> -- Jerry
>

Exactly!

Most chopper circuits turn on the appropriate transistors to re-
circulate the currents in the off condition. They don't know to do
this if a human decides to disconnect the load. Power Mosfets are
especially very unforgiving if their rated voltage is exceeded even
in the nano seconds before snubber diodes can kick in.

Also... only a small fraction of the field is discharged before the
chopper reapplies power at a trip point.

As for semiconductors that heal themselves? Wouldn't that be just the
coolest of cool?

Tom M.