DC-motor makes BS1 act weird. Why? [mike almost happy]
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Thanks Russell & all you folks who answered this!
I am almost there now, I grounded the case as Russell proposed (that
was the easiest solution to try ...), and
one direction now works fine! I still have probs when the craft
moves backwards, but I think a couple of capacitors from the motor
to ground should do it, or a delta-wiring as Beau mentioned.
As Jon pointed out, I cannot ground the batterypack to the motor,
because of the "split" power
supply driving the motor. (Half-Bridge).
I now think I can get this to work... Hopefully anyway.
If you can think of anything else in this matter, feel free to
mail me at micke.axen@t....
Thanks!
Mike
--- In basicstamps@yahoogroups.com, "Russell \(Warburton
Technology\)" <russell@w...> wrote:
> Hi Mike,
>
> Try connecting the motor casing to ground. I experienced a similar
problem
> controlling a DC motor with a relay and a BS2-IC, but it solved
the problem.
> Good luck.
>
> Best regards,
>
> Russell Warburton
> email: russell@w...
> website: http://www.warburtech.com
> telephone: +44 (0)7814 044 754
>
>
Original Message
> From: "mikaelaxen" <micke.axen@t...>
> To: <basicstamps@yahoogroups.com>
> Sent: Monday, March 29, 2004 4:57 PM
> Subject: [noparse][[/noparse]basicstamps] Re: DC-motor makes BS1 act weird. Why?
>
>
> Thanks for your reply!
>
> Yes, I have a transistor buffer, and yes, I have
> a diod across the relay coils. Does not help.
> I can control the relays without disturbing the servo,
> but as soon as I connect the DC motor, the servo goes wild.
> I have unplugged the control line to the servo, but still
> powering it, and no problem occurs. So it looks like it´s
> the signal line from BS1 that makes the servo crazy ...
> More ideas ? (please ...)
>
> / Mike
>
>
>
> --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
> wrote:
> > Are you connected directly to the relays? Very bad news if yes.
> Use a transistor buffer between the BASIC Stamp and any high-
current
> devices like relays. The other thing that you may need to do is
> connect a diode across the relay coils. When you relax the relay,
> the magnetic field collapse induces a current and that could be
> upsetting the BASIC Stamp.
> >
> > -- Jon Williams
> > -- Applications Engineer, Parallax
> > -- Dallas Office
> >
> >
> >
Original Message
> > From: mikael_axen2002 [noparse][[/noparse]mailto:mikael_axen@h...]
> > Sent: Monday, March 29, 2004 12:47 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] DC-motor makes BS1 act weird. Why?
> >
> >
> > Howdy!
> > I have two relay-schemes connected to two I/O on my BS1.
> > The ídea is that one relay controls a DC motor on/off, and the
> other reverses the polarity (to the DC motor) to control
> forward/backward. The motors are powered by a 2x1.5v battery pack
> (1.5v per direction). The BS1 is powered by a 9v battery. I also
have
> a servo to steer the craft with, this is powered by a 4x1.5v
> batterypack.
> > The DC motor is taken from a cheap wired control toycar.
> > Now to the *problem* : When I run the DC motor, the servo goes
> wild, uncontrallable. Just controlling the relays works fine! Just
> controlling the servo works fine! The problem occurs only when
> actually running the DC motor. I think maybe the DC motor creates
> some AC that somehow goes into BS1? Maybe a capacitor to ground
could
> help? But how big in that case...? Any ideas are appreciated!
> >
> > Thanks!
> > Mike / Sweden
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
> Yahoo! Groups Links
I am almost there now, I grounded the case as Russell proposed (that
was the easiest solution to try ...), and
one direction now works fine! I still have probs when the craft
moves backwards, but I think a couple of capacitors from the motor
to ground should do it, or a delta-wiring as Beau mentioned.
As Jon pointed out, I cannot ground the batterypack to the motor,
because of the "split" power
supply driving the motor. (Half-Bridge).
I now think I can get this to work... Hopefully anyway.
If you can think of anything else in this matter, feel free to
mail me at micke.axen@t....
Thanks!
Mike
--- In basicstamps@yahoogroups.com, "Russell \(Warburton
Technology\)" <russell@w...> wrote:
> Hi Mike,
>
> Try connecting the motor casing to ground. I experienced a similar
problem
> controlling a DC motor with a relay and a BS2-IC, but it solved
the problem.
> Good luck.
>
> Best regards,
>
> Russell Warburton
> email: russell@w...
> website: http://www.warburtech.com
> telephone: +44 (0)7814 044 754
>
>
Original Message
> From: "mikaelaxen" <micke.axen@t...>
> To: <basicstamps@yahoogroups.com>
> Sent: Monday, March 29, 2004 4:57 PM
> Subject: [noparse][[/noparse]basicstamps] Re: DC-motor makes BS1 act weird. Why?
>
>
> Thanks for your reply!
>
> Yes, I have a transistor buffer, and yes, I have
> a diod across the relay coils. Does not help.
> I can control the relays without disturbing the servo,
> but as soon as I connect the DC motor, the servo goes wild.
> I have unplugged the control line to the servo, but still
> powering it, and no problem occurs. So it looks like it´s
> the signal line from BS1 that makes the servo crazy ...
> More ideas ? (please ...)
>
> / Mike
>
>
>
> --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
> wrote:
> > Are you connected directly to the relays? Very bad news if yes.
> Use a transistor buffer between the BASIC Stamp and any high-
current
> devices like relays. The other thing that you may need to do is
> connect a diode across the relay coils. When you relax the relay,
> the magnetic field collapse induces a current and that could be
> upsetting the BASIC Stamp.
> >
> > -- Jon Williams
> > -- Applications Engineer, Parallax
> > -- Dallas Office
> >
> >
> >
Original Message
> > From: mikael_axen2002 [noparse][[/noparse]mailto:mikael_axen@h...]
> > Sent: Monday, March 29, 2004 12:47 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] DC-motor makes BS1 act weird. Why?
> >
> >
> > Howdy!
> > I have two relay-schemes connected to two I/O on my BS1.
> > The ídea is that one relay controls a DC motor on/off, and the
> other reverses the polarity (to the DC motor) to control
> forward/backward. The motors are powered by a 2x1.5v battery pack
> (1.5v per direction). The BS1 is powered by a 9v battery. I also
have
> a servo to steer the craft with, this is powered by a 4x1.5v
> batterypack.
> > The DC motor is taken from a cheap wired control toycar.
> > Now to the *problem* : When I run the DC motor, the servo goes
> wild, uncontrallable. Just controlling the relays works fine! Just
> controlling the servo works fine! The problem occurs only when
> actually running the DC motor. I think maybe the DC motor creates
> some AC that somehow goes into BS1? Maybe a capacitor to ground
could
> help? But how big in that case...? Any ideas are appreciated!
> >
> > Thanks!
> > Mike / Sweden
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
> Yahoo! Groups Links
Comments
>Thanks Russell & all you folks who answered this!
>
>I am almost there now, I grounded the case as Russell proposed (that
>was the easiest solution to try ...), and
>one direction now works fine! I still have probs when the craft
>moves backwards, but I think a couple of capacitors from the motor
>to ground should do it, or a delta-wiring as Beau mentioned.
>As Jon pointed out, I cannot ground the batterypack to the motor,
>because of the "split" power
>supply driving the motor. (Half-Bridge).
One last kick on this subject... use the CENTER tap of the split
power as the grounding terminal for your motor.
>I now think I can get this to work... Hopefully anyway.
>If you can think of anything else in this matter, feel free to
>mail me at micke.axen@t....
>
>Thanks!
> Mike
Beau Schwabe Mask Designer National Semiconductor Corporation
500 Pinnacle Court, Suite 525
Home: polygon_man@h... Mail Stop GA1
Work: bschwabe@a... Norcross, GA 30071