Re: [CAD_CAM_EDM_DRO] New file uploaded to CAD_CAM_EDM_DRO

Hi Jan,

No doubt what you say is correct! (although I have a few '194's in the
"box")!

NOTE: The motor supply is 5v. I'd suggest going to 24v and using an
appropriate L/R resistor. IC's still to get +5v. Also NOTE: The "cold
end of the motor windings" (inside motor?) IMO, are intended to be
connected to ground, along with the back EMF diodes!

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??

Possible improvements: I suspect this is a "wave" sequence generator.
Anyone care to convert it to 1/2 step?

Extra credit: Add acceleration/dceleration to the '555.

I thought it was an interesting circuit, 'tho. Good for experimenting
"on the cheap"!

Alan KM6VV


JanRwl@... wrote:

>
> In a message dated 23-May-01 01:48:49 Central Daylight Time,
> CAD_CAM_EDM_DRO@yahoogroups.com writes:
>
> > http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/CIRCUITS/stepper.gif
> >
>
> This schematic shows a (now-obsolete) "standard" TTL IC (the 74194) SOURCING
> into 270R base-resistors. That implies maybe 10 mA source. NOT possible
> with that old series! Much better, use 74HC194!!! And you COULD raise those
> base-resistors to 390R, I think! 470R???
>
> [Non-text portions of this message have been removed]
>
> Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the discussion of shop built systems, for CAD, CAM, EDM, and DRO.
>
> Addresses:
> Post message: CAD_CAM_EDM_DRO@yahoogroups.com
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> bill,
> List Manager
>
> FAQ: http://www.ktmarketing.com/faq.html
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/