DC-motor makes BS1 act weird. Why?
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Posts: 46,084
Howdy!
I have two relay-schemes connected to two I/O on my BS1.
The
I have two relay-schemes connected to two I/O on my BS1.
The
Comments
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:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=hzB8zddrJne0lVlLCkFcxQdDHBnQeihbt7PlUpu3hf2eCN6l2x9gN_R_LZv4_mWHGJcIZOvFJjPzO6lSEvU7oQ4]mikael_axen@h...[/url
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
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
external I/O leads to shunt out RF trash? Also, does everyone know about
stacking little picofarad-range disc caps on top of electrolyte caps. Since
electrolytic caps are rolled up inside, they have a lot of inductance which
will present a high impedance to RFI. I suspect that many users are simply
putting big honking 1,000 microfarad caps across the power supply feeds,
which will help with sagging supplies from current draw, but will let
high-frequency garbage zing right on through. Every external line used in a
shared RFI/Computer environment (and yes, as Basic Stamp is certainly a
computer, and yes relay coils and such can generate RFI) needs to be
properly terminated, shielded, and RFI protected. Noise is a bad thing....
Mike Sokol
mike@f...
www.fitsandstarts.com
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "mikaelaxen" <micke.axen@t...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, March 29, 2004 10:57 AM
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
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relay that controls direction and place a diode in reverse
bias there. From the sounds of it, you are driving your
motor in a half-bridge configuration with the relays. This
is fine but may not be conducive to adding diodes.
Another approach (AND/OR with the above) is to use a delta
capacitor pattern between the motor and ground.
GND <---||---o---||---o---||---> GND
A B
Note:
- A and B terminals go across your motor.
- ALL capacitors are .1uF ceramic disc type.
The statement you make "The DC motor is taken from a cheap
wired control toycar" says it all. The brushes on these
type of motors generate LOTS of noise. The capacitor
scheme above should clean a majority of this up.
>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
>
>
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
>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
Mike -
Are all your grounds tied to one common point ? If not, they need to be.
Bruce Bates
>--- 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.
>
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>
>
>
>
>At 03:57 PM 3/29/04 +0000, mikaelaxen wrote:
> >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
>
>Mike -
>
>Are all your grounds tied to one common point ? If not, they need to be.
>
>Bruce Bates
Bruce,
He's not going to be able to do this easily with a "split" power
supply driving the motor. (Half-Bridge)
In his case it might be better to connect all of the grounds
EXCEPT the motor circuit, thus completely isolating both power
and ground of the motor.
> >--- 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
> >>
> >>
> >> 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
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
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.
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