Re: Servo only moving one way

Jim,

I'd strongly recommend you use a 74ACT541 instead.

The 74HCT part has a 7.8 mA current sink capability which is
insufficient for the 16 mA required by our drives. The 74ACT series
has well over +/-24 mA output drive. Same pinout, same 1.5V
threshold, same package. It also makes a dandy 3.3V to 5V level
shifter to take care of those pesky new parallel port 3.3V signals.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, <james_cullins@s...> wrote:
> INDECO
> On the sound Logic board the Led has a separate driver (
uln2803 ) from
> the signal (74hct541 ). The LED can work and the signal not work,
so you
> need to check on the DIR terminal pin and determine if it is
changing form
> 5v to 0.
> If not please let Bob or me know and we will replace it for you.
> Jim Cullins
> Sound Logic
>
>
> ----- Original Message -----
> From: "Jon Elson" <elson@p...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Friday, March 12, 2004 12:31 PM
> Subject: Re: [CAD_CAM_EDM_DRO] Re: Servo only moving one way
>
>
> >
> >
> > jmkasunich wrote:
> >
> > >--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...>
wrote:
> > >
> > >
> > >>INDECO wrote:
> > >>
> > >>
> > >>
> > >>> Yes I am using Gecko drives with Bob Campbells Breakout
> > >>>board and Mach 2 software.
> > >>>I have niether a logic probe or a oscilloscope to check it.
> > >>>However the direction light on the board is not lit up as
> > >>>the Y axis is, however the light on the Y only lights when
> > >>>I jog to the left then goes out when I jog right. Is this
> > >>>right?
> > >>>
> > >>>
> > >>>
> > >>That's the way it is SUPPOSED to work.
> > >>
> > >>
> > >
> > >The "Y" axis is acting the way it's supposed to. But nowhere
> > >does he say that "X" is doing the same thing as Y,
> > >
> > Yes, I meant that the Y behavior was entirely normal, and the lack
> > of a light on X was definitely related.
> >
> > > in fact he
> > >says "the direction light on the board is not lit up as the
> > >Y axis is", so that implies that the X light is _not_ working.
> > >He previously stated that the problem axis is X, so the dark
> > >LED points to a computer/parport/cable issue, NOT a drive
> > >issue.
> > >
> > >
> > Maybe. If the X LED is in SERIES with the LED in the driver's
> > optocoupler, then a problem with wiring or the driver could cause
the
> > LED on the breakout board to not work.
> >
> > Jon
> >
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> > Post Messages: 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@a...,
> timg@k...
> > Moderator: pentam@c... indigo_red@q... davemucha@j...
> [Moderators]
> > URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> >
> > OFF Topic POSTS: General Machining
> > If you wish to post on unlimited OT subjects goto:
> aol://5863:126/rec.crafts.metalworking or go thru Google.com to
reach it if
> you have trouble.
> > http://www.metalworking.com/news_servers.html
> >
> > http://groups.yahoo.com/group/jobshophomeshop I consider this
to be a
> sister site to the CCED group, as many of the same members are
there, for OT
> subjects, that are not allowed on the CCED list.
> >
> > NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY
POSTING THEM.
> DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> > bill
> > List Mom
> > List Owner
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >