Re: [CAD_CAM_EDM_DRO] Re: Gecko and Anaheim

In a message dated 8/10/00 5:17:58 PM Central Daylight Time,
john@... writes:

<< Surely a 4V motor running on 80v supply will burn out.
Am I missing something here ? >>
Yes. The DC is "pulsed" with duty-cycle instantaneously based upon the
"average" current flowing under the particular inductive conditions at that
instant. See "pulse-width modulation", "average effective current", "bipolar
chopper" (and why "chopper"), etc. The "old way" was to simply insert a 100
W. power-wasting "power-resistor" of a few ohms in series with the +ve
common. That kinda almost-nearly permitted an "approximation" of useful
max-current under instantaneous conditions. I like "chopping" better, but I
are too ignernt to "brew my own", as I COULD do with the "old system". Duh...

Jan Rowland