Re: [CAD_CAM_EDM_DRO] New file uploaded to CAD_CAM_EDM_DRO

Hi Jan,

I've seen "special parts" that do a excellent job in these regards. But
for a low cost, "buy parts at Radio Shack" project, it's not bad! I can
enjoy circuits at both ends, from low cost to high end. I'm currently
using a pair of Gecko G210A's, a few Maxnc 4-phase boards, both Superior
Electric and API modules, some 1974 CW/CCW drivers, and a 'couple home
brew boards too!

Alan KM6VV


JanRwl@... wrote:

>
> In a message dated 23-May-01 22:20:51 Central Daylight Time, KM6VV@...
> writes:
>
> > Possible change: Put the TIP120's with their emitters to ground, and
> > pulling the "coil ends" down the Collectors would then all go to +24v,
> > through a 10 ohm (or appropriate) L/R resistor. I haven't built the
> > circuit, I just found it! OK, whose gonna try it? Jan? Bill??
> >
>
> Gawrsch, yes! I had forgotten this was an emitter-follower circuit! UGH!
>
> The emitters SHOULD be @ ground, and the Collectors to the windings! Then,
> the commons to the motor-windings (taps) should be THROUGH the low-R, high-W
> resistors to +24 VDC!!! Of course!
>
> General Instrument sells (did sell?) an IC... 29G41??? that had four
> "phase-outputs" for driving Darlingtons, an half-step input, and "all
> windings off" input, I think. It was much more useful for doing
> stepper-drives (unipolar!) than kludgery, but it cost as much as a year-old
> Toyota! 18-pin DIP. I used a dozen before I "grew up" and began buying
> "store-bought" ready-made driver/power-supply packages. I am now looking
> seriously at the Gecko circuits! Look nice! We'll see...