Motor (still) glitching stamp robot
I know there's some proper protocol for eliminating motor noise here,
but I just don't know what it is.
I need to reduce the noise in this circuit somehow but don't know
anything about chokes or which caps to use or where to put 'em.
Some of my 6 networked stamps are glitching, I think.
Each of my motors goes through a reversing relay, and
is attached to a nice LARGE can transistor (like a 3055npn). I
was hoping to simplify my design.
I have the two 12vdc (robot propulsion) motors on
their own 12 v supply, yet they still seem to be causing
some problems. The resistance on them's of course near to 0 ohms,
although the load plate says 1.2a under max load. They're good dayton
gear motors.
My intent was to turn them on and off in my program
loop (not using pwm) for some kind of speed control duty cycle. Seems
to be a bad idea. Nuts!
PS: I also have a VERRRY noisy robotic arm with
similar problems that I just don't dare use. For little tiny motors,
they seem to be eating up to 14w each and make THEIR ENTIRE BANK
of 7805's very HOT! They WERE originally meant to use 3v and there
were only 4d cells in the system (maybe you know the owi arm I'm
refering to). Each axis is hooked up like my drive motors, except
SLIGHLTY smaller power transistors. Suggestions welcome...
Please help. I thought I was overkill here.
I haven't dared to add the old 386 laptop to the system yet.
So close, yet so far...
but I just don't know what it is.
I need to reduce the noise in this circuit somehow but don't know
anything about chokes or which caps to use or where to put 'em.
Some of my 6 networked stamps are glitching, I think.
Each of my motors goes through a reversing relay, and
is attached to a nice LARGE can transistor (like a 3055npn). I
was hoping to simplify my design.
I have the two 12vdc (robot propulsion) motors on
their own 12 v supply, yet they still seem to be causing
some problems. The resistance on them's of course near to 0 ohms,
although the load plate says 1.2a under max load. They're good dayton
gear motors.
My intent was to turn them on and off in my program
loop (not using pwm) for some kind of speed control duty cycle. Seems
to be a bad idea. Nuts!
PS: I also have a VERRRY noisy robotic arm with
similar problems that I just don't dare use. For little tiny motors,
they seem to be eating up to 14w each and make THEIR ENTIRE BANK
of 7805's very HOT! They WERE originally meant to use 3v and there
were only 4d cells in the system (maybe you know the owi arm I'm
refering to). Each axis is hooked up like my drive motors, except
SLIGHLTY smaller power transistors. Suggestions welcome...
Please help. I thought I was overkill here.
I haven't dared to add the old 386 laptop to the system yet.
So close, yet so far...
Comments
First, make sure your stamp(s) have a "pull-down" resistor on the ATN line.
Simply place a 1K resistor between the ATN line and Ground. This will stop
the ATN line from "floating" (which will reset the stamp) from nearby
voltage spikes.
Second, make sure your "reversing relays" have diodes across the coils to
catch the back-EMF spikes that occur when the relays de-energize. A relay
without a diode doesn't even have to be electrically connected your other
circuitry, to cause problems.
Jim
>
> From: Anubis
> Reply To: basicstamps@egroups.com
> Sent: Friday, July 21, 2000 10:47 am
> To: basicstamps@egroups.com
> Subject: [noparse][[/noparse]basicstamps] Motor (still) glitching stamp robot
>
> I know there's some proper protocol for eliminating motor noise here,
> but I just don't know what it is.
> I need to reduce the noise in this circuit somehow but don't know
> anything about chokes or which caps to use or where to put 'em.
> Some of my 6 networked stamps are glitching, I think.
>
> Each of my motors goes through a reversing relay, and
> is attached to a nice LARGE can transistor (like a 3055npn). I
> was hoping to simplify my design.
>
> I have the two 12vdc (robot propulsion) motors on
> their own 12 v supply, yet they still seem to be causing
> some problems. The resistance on them's of course near to 0 ohms,
> although the load plate says 1.2a under max load. They're good dayton
> gear motors.
> My intent was to turn them on and off in my program
> loop (not using pwm) for some kind of speed control duty cycle. Seems
> to be a bad idea. Nuts!
>
> PS: I also have a VERRRY noisy robotic arm with
> similar problems that I just don't dare use. For little tiny motors,
> they seem to be eating up to 14w each and make THEIR ENTIRE BANK
> of 7805's very HOT! They WERE originally meant to use 3v and there
> were only 4d cells in the system (maybe you know the owi arm I'm
> refering to). Each axis is hooked up like my drive motors, except
> SLIGHLTY smaller power transistors. Suggestions welcome...
>
> Please help. I thought I was overkill here.
> I haven't dared to add the old 386 laptop to the system yet.
> So close, yet so far...
>
>
>
>
>
But I'll try the pull-down resistor - Thanks!
--- In basicstamps@egroups.com, "Howard, Jim" <Jim.Howard@d...> wrote:
> OK here's a couple of things you might want to try...
>
> First, make sure your stamp(s) have a "pull-down" resistor on the
ATN line.
> Simply place a 1K resistor between the ATN line and Ground. This
will stop
> the ATN line from "floating" (which will reset the stamp) from
nearby
> voltage spikes.
>
> Second, make sure your "reversing relays" have diodes across the
coils to
> catch the back-EMF spikes that occur when the relays de-energize. A
relay
> without a diode doesn't even have to be electrically connected your
other
> circuitry, to cause problems.
>
> Jim
>
> >
> > From: Anubis
> > Reply To: basicstamps@egroups.com
> > Sent: Friday, July 21, 2000 10:47 am
> > To: basicstamps@egroups.com
> > Subject: [noparse][[/noparse]basicstamps] Motor (still) glitching stamp robot
> >
> > I know there's some proper protocol for eliminating motor noise
here,
> > but I just don't know what it is.
> > I need to reduce the noise in this circuit somehow but don't know
> > anything about chokes or which caps to use or where to put 'em.
> > Some of my 6 networked stamps are glitching, I think.
> >
> > Each of my motors goes through a reversing relay, and
> > is attached to a nice LARGE can transistor (like a 3055npn). I
> > was hoping to simplify my design.
> >
> > I have the two 12vdc (robot propulsion) motors on
> > their own 12 v supply, yet they still seem to be causing
> > some problems. The resistance on them's of course near to 0 ohms,
> > although the load plate says 1.2a under max load. They're good
dayton
> > gear motors.
> > My intent was to turn them on and off in my program
> > loop (not using pwm) for some kind of speed control duty cycle.
Seems
> > to be a bad idea. Nuts!
> >
> > PS: I also have a VERRRY noisy robotic arm with
> > similar problems that I just don't dare use. For little tiny
motors,
> > they seem to be eating up to 14w each and make THEIR ENTIRE BANK
> > of 7805's very HOT! They WERE originally meant to use 3v and there
> > were only 4d cells in the system (maybe you know the owi arm I'm
> > refering to). Each axis is hooked up like my drive motors, except
> > SLIGHLTY smaller power transistors. Suggestions welcome...
> >
> > Please help. I thought I was overkill here.
> > I haven't dared to add the old 386 laptop to the system yet.
> > So close, yet so far...
> >
> >
> >
> >
> >