RE: [CAD_CAM_EDM_DRO] Re: Hysteresis Brake

> > Neat idea! I might add that a source of cheap (as in free) shaded
> > pole AC fan motors is defunct microwave ovens. Pick them up at the
> > curb on trash day, or at the local recycling center.
> >
> > The little transformer on the oven control panel usually
> has a diode
> > bridge and filter cap, and might have just enough current output to
> > drive the brake. Can't beat free for that, either!
> >
> > Dave
>
>
> The transformer on the one I checked out was a 2kv secondary.
> a tad too high for much of anything. I have heard that
> someone had used high voltage for metal erosion. Never found
> any other information on that though.
>
> lots of switches, great find.
>
> a work light. (don't overlook the odd things.)
>
> On one, I pulled an SCR, another had some 15 amp relays on
> the control board.
>
> High voltage wires, possibly a timer.
>
> Dave

The ones he was talking about have an LCD or LED display, these have a small
transformer to drop 240v (or 120v) to 12v or 24v (depends on the relays) to
run the IC and assorted stuff. If the display is a VFD (vacuum fluorescent)
then there will be a 2-3v secondary as well, to drive the filament of the
VFD. Similar to what you'd find in a wall wart.

The ovens with two knobs (time & power) don't need that stuff. Those
controls come in handy, they usually run off main voltage, and can directly
switch it. They have a little motor inside. Useful when you want something
to run for up to an hour then switch off.

Tony