Pak V w/motor
Archiver
Posts: 46,084
Please help,
I am a beginner. I just bought the Pak-V for pwm so that I could
run a motor while my Stamp was doing something else. But I am not
sure what I need to do to get the motor turning. I finally
determined the command to run the Pak-V on my Basic Stamp 2sx. I can
now get the desired voltage but the motor will not turn. It is only
a little Radio Shack motor. It is rated for 9 volts but I only need
to use 2-3 volts. Also, it only needs to run in one direction. Is
there anything easy I can do to get this motor turning? I am really
not sure exactly what I am doing.
Thank You for your input. Please be as detailed as possible.
Mike
I am a beginner. I just bought the Pak-V for pwm so that I could
run a motor while my Stamp was doing something else. But I am not
sure what I need to do to get the motor turning. I finally
determined the command to run the Pak-V on my Basic Stamp 2sx. I can
now get the desired voltage but the motor will not turn. It is only
a little Radio Shack motor. It is rated for 9 volts but I only need
to use 2-3 volts. Also, it only needs to run in one direction. Is
there anything easy I can do to get this motor turning? I am really
not sure exactly what I am doing.
Thank You for your input. Please be as detailed as possible.
Mike
Comments
I'm really interested in the answer to your question too. I'm also a beginner,
and have just worked this same task. So I will relay some of what I've
learned. Hopefully, other will review my words for correctness. First off,
I also purchased a motor from Radio Shack. I drive it with a 9.7 volt
cordless drill motor battery. So I had lots of power. That's the first item
of discussion. Your motor needs to be powered by a separate circuit from your
stamp, as the motor will draw down the voltage that your stamp will see, and
cause it to shut down. I have a power mosfet switch that used the low amperage
signal from the stamp to turn on the power for the motor.
My second bit of experience is that the Radio Shack motor was of very low
quality. The motor gave of a tremendous amount of EMI (electrical
interference). I have other servos on my machine, and when I turned on the
Radio Shack motor, those other servos started doing the Watusie (sp). So I
changed motors in the end. The motor I finally used came out of an old Floppie
disk drive.
Finally, if you are applying 2-3 volts to your motor, than that may not be
enough to turn a 9 volt motor. If you haven't done it already, power the motor
directly from a 9 volt battery or power supply. If it doesn't turn, there is
something wrong with it.
Hope this helps,
Dave Cousins
--- mcmgamer@n... wrote:
> Please help,
>
> I am a beginner. I just bought the Pak-V for pwm so that I could
> run a motor while my Stamp was doing something else. But I am not
> sure what I need to do to get the motor turning. I finally
> determined the command to run the Pak-V on my Basic Stamp 2sx. I can
> now get the desired voltage but the motor will not turn. It is only
> a little Radio Shack motor. It is rated for 9 volts but I only need
> to use 2-3 volts. Also, it only needs to run in one direction. Is
> there anything easy I can do to get this motor turning? I am really
> not sure exactly what I am doing.
>
> Thank You for your input. Please be as detailed as possible.
>
> Mike
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
__________________________________________________
Do You Yahoo!?
Get email at your own domain with Yahoo! Mail.
http://personal.mail.yahoo.com/
motor.
Here's some steps you might want to consider:
1-Connect all grounds together.
2-Hook one end of motor to +V (whatever 3V, 9V, etc.)
3-Ground the other end of the motor and observe it spinning.
4- Disconnect the ground end of the motor. Put a suitable transistor (2N2222
for a 100mA or less) with the collector on the ground end of the motor, the
emitter to ground. Put a small resistor (say 1K) from base to ground. Power
up. No spin. Move the resistor from ground to +5. Motor should spin again.
5-Remove the +5 end of the resistor and connect it to the output of the
PAK-V.
6-With the PAK-V software make sure that the baud rate constant is correct
(remember, the BS2 does not use the same baudrate numbers as BS2SX, BS2P).
At each stage, make sure you have it working. For example, if you can't get
step 3 to spin the motor, you don't have enough battery power or something.
At step 4, you should be able to turn the motor on and off. If not, you are
not saturating the transistor, or some other transistor problem.
Let me know if any of that helps.
Al Williams
AWC
*NEW: PAK-IX floating point A/D: http://www.al-williams.com/awce/pak9.htm
>
Original Message
> From: mcmgamer@n... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rRp-lxIbCEGJNLW2LzaOw7oEzTVS7jOmG3lSFso3T9w7mbYrl2tThDeRkj98tGsgeCyk7Uu_jBb4h47D]mcmgamer@n...[/url
> Sent: Monday, April 09, 2001 9:02 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Pak V w/motor
>
>
> Please help,
>
> I am a beginner. I just bought the Pak-V for pwm so that I could
> run a motor while my Stamp was doing something else. But I am not
> sure what I need to do to get the motor turning. I finally
> determined the command to run the Pak-V on my Basic Stamp 2sx. I can
> now get the desired voltage but the motor will not turn. It is only
> a little Radio Shack motor. It is rated for 9 volts but I only need
> to use 2-3 volts. Also, it only needs to run in one direction. Is
> there anything easy I can do to get this motor turning? I am really
> not sure exactly what I am doing.
>
> Thank You for your input. Please be as detailed as possible.
>
> Mike
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
to put some 0.1 Mfd capacitors across the motor leads at the motor, and to
have a voltage regulator with a minor amount of filtering to power the BS2.
My robot has a 4 Ah 12-volt gel-cell running two 12-volt gearmotors via
MotorMind B's, and powering a BS2sx chip through a homemade board with its
own regulator. I'm also powering all of my sensors, servos and stuff of the
regulator.
Original Message
> I'm really interested in the answer to your question too. I'm also a
beginner,
> and have just worked this same task. So I will relay some of what I've
> learned. Hopefully, other will review my words for correctness. First
off,
> I also purchased a motor from Radio Shack. I drive it with a 9.7 volt
> cordless drill motor battery. So I had lots of power. That's the first
item
> of discussion. Your motor needs to be powered by a separate circuit from
your
> stamp, as the motor will draw down the voltage that your stamp will see,
and
> cause it to shut down. I have a power mosfet switch that used the low
amperage
> signal from the stamp to turn on the power for the motor.
directly to it (3 volts). So I know the motor works. I was hoping
that all I would need to do was, via Pak-V, send 3 volts from the Pak
to the motor. But that did not turn the motor. I have the command
programmed correctly because I am measuring 3 volts with a multimeter
off of the Pak-V connection to the motor.
Given this information, do I just need to add a transistor to my
circuit or is it more complicated than that? I have no spare parts
(ie. transistors) to experiment.
Al Williams - Do you still suggest the steps you posted below? If
so, where can I purchase the transistor and I am not exactly sure
where that 1k resistor goes ("base to ground"??). Thank you.
Thank You Everyone for your input.
Mike
--- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> I'm not sure what you mean by "voltage". You don't want to use an
RC with a
> motor.
>
> Here's some steps you might want to consider:
>
> 1-Connect all grounds together.
>
> 2-Hook one end of motor to +V (whatever 3V, 9V, etc.)
>
> 3-Ground the other end of the motor and observe it spinning.
>
> 4- Disconnect the ground end of the motor. Put a suitable
transistor (2N2222
> for a 100mA or less) with the collector on the ground end of the
motor, the
> emitter to ground. Put a small resistor (say 1K) from base to
ground. Power
> up. No spin. Move the resistor from ground to +5. Motor should spin
again.
>
> 5-Remove the +5 end of the resistor and connect it to the output of
the
> PAK-V.
>
> 6-With the PAK-V software make sure that the baud rate constant is
correct
> (remember, the BS2 does not use the same baudrate numbers as BS2SX,
BS2P).
>
> At each stage, make sure you have it working. For example, if you
can't get
> step 3 to spin the motor, you don't have enough battery power or
something.
> At step 4, you should be able to turn the motor on and off. If not,
you are
> not saturating the transistor, or some other transistor problem.
>
> Let me know if any of that helps.
>
> Al Williams
> AWC
> *NEW: PAK-IX floating point A/D: http://www.al-
williams.com/awce/pak9.htm
>
>
>
> >
Original Message
> > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > Sent: Monday, April 09, 2001 9:02 PM
> > To: basicstamps@y...
> > Subject: [noparse][[/noparse]basicstamps] Pak V w/motor
> >
> >
> > Please help,
> >
> > I am a beginner. I just bought the Pak-V for pwm so that I
could
> > run a motor while my Stamp was doing something else. But I am not
> > sure what I need to do to get the motor turning. I finally
> > determined the command to run the Pak-V on my Basic Stamp 2sx. I
can
> > now get the desired voltage but the motor will not turn. It is
only
> > a little Radio Shack motor. It is rated for 9 volts but I only
need
> > to use 2-3 volts. Also, it only needs to run in one direction.
Is
> > there anything easy I can do to get this motor turning? I am
really
> > not sure exactly what I am doing.
> >
> > Thank You for your input. Please be as detailed as possible.
> >
> > Mike
> >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
You should not drive the motor directly from any logic IC output including
the Stamp or the PAK-V. If you are measuring 3VDC with a meter directly at
the output of the PAK-V then the meter is probably averaging the PWM for you
(an analog meter perhaps?).
You can find 2N2222s just about anywhere including Radio Shack, but be sure
your motor doesn't draw over, say 100mA. If the motor has significant
inductance you may also need a diode (for example a 1N914 or 1N4148 -- also
at Radio Shack) across the motor "backwards" (that is, the stripe of the
diode points to the + supply). This will absorb high voltage spikes the
motor may produce when you start or stop it. Maybe $2 in parts.
The final circuit would look like this:
Pin (PAK or Stamp) --- 1K resistor
Base of 2N2222
Emitter of 2N2222 --- ground
Collector of 2N2222
"side A" of motor (either side)
+3V
"side B" of motor (other side)
Side B of motor ---- striped end of diode
Side A of motor
The PAK-V outputs 0 to 5V. You don't want to average it for motor control
(although you might for other reasons). You need something to make 5V switch
3V on and off. In this case we switch the ground which is just as good.
Al Williams
AWC
*NEW: PAK-IX floating point A/D: http://www.al-williams.com/awce/pak9.htm
(Last day at this price)
>
Original Message
> From: mcmgamer@n... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=K39kYTRR0jwDV76qSWwSGL9eiSaO_dhWRaBncy9_wsChF9uF9Kv3dAjama8F3V6-NcmlFUbtHcNXtdP6njfSqg]mcmgamer@n...[/url
> Sent: Tuesday, April 10, 2001 1:50 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Re: Pak V w/motor
>
>
> The motor turns the way I want when I hook up two AA batteries
> directly to it (3 volts). So I know the motor works. I was hoping
> that all I would need to do was, via Pak-V, send 3 volts from the Pak
> to the motor. But that did not turn the motor. I have the command
> programmed correctly because I am measuring 3 volts with a multimeter
> off of the Pak-V connection to the motor.
>
> Given this information, do I just need to add a transistor to my
> circuit or is it more complicated than that? I have no spare parts
> (ie. transistors) to experiment.
>
>
> Al Williams - Do you still suggest the steps you posted below? If
> so, where can I purchase the transistor and I am not exactly sure
> where that 1k resistor goes ("base to ground"??). Thank you.
>
>
> Thank You Everyone for your input.
> Mike
>
> --- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> > I'm not sure what you mean by "voltage". You don't want to use an
> RC with a
> > motor.
> >
> > Here's some steps you might want to consider:
> >
> > 1-Connect all grounds together.
> >
> > 2-Hook one end of motor to +V (whatever 3V, 9V, etc.)
> >
> > 3-Ground the other end of the motor and observe it spinning.
> >
> > 4- Disconnect the ground end of the motor. Put a suitable
> transistor (2N2222
> > for a 100mA or less) with the collector on the ground end of the
> motor, the
> > emitter to ground. Put a small resistor (say 1K) from base to
> ground. Power
> > up. No spin. Move the resistor from ground to +5. Motor should spin
> again.
> >
> > 5-Remove the +5 end of the resistor and connect it to the output of
> the
> > PAK-V.
> >
> > 6-With the PAK-V software make sure that the baud rate constant is
> correct
> > (remember, the BS2 does not use the same baudrate numbers as BS2SX,
> BS2P).
> >
> > At each stage, make sure you have it working. For example, if you
> can't get
> > step 3 to spin the motor, you don't have enough battery power or
> something.
> > At step 4, you should be able to turn the motor on and off. If not,
> you are
> > not saturating the transistor, or some other transistor problem.
> >
> > Let me know if any of that helps.
> >
> > Al Williams
> > AWC
> > *NEW: PAK-IX floating point A/D: http://www.al-
> williams.com/awce/pak9.htm
> >
> >
> >
> > >
Original Message
> > > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > > Sent: Monday, April 09, 2001 9:02 PM
> > > To: basicstamps@y...
> > > Subject: [noparse][[/noparse]basicstamps] Pak V w/motor
> > >
> > >
> > > Please help,
> > >
> > > I am a beginner. I just bought the Pak-V for pwm so that I
> could
> > > run a motor while my Stamp was doing something else. But I am not
> > > sure what I need to do to get the motor turning. I finally
> > > determined the command to run the Pak-V on my Basic Stamp 2sx. I
> can
> > > now get the desired voltage but the motor will not turn. It is
> only
> > > a little Radio Shack motor. It is rated for 9 volts but I only
> need
> > > to use 2-3 volts. Also, it only needs to run in one direction.
> Is
> > > there anything easy I can do to get this motor turning? I am
> really
> > > not sure exactly what I am doing.
> > >
> > > Thank You for your input. Please be as detailed as possible.
> > >
> > > Mike
> > >
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
had to add a few things.
The motor I am using is Radio Shack model number 273-255 (12VDC High
Speed Motor). I looked at the specsheet and it mentions pretty high
currents. Does this mean I need a different transistor? Also, the 3
volt supply in your circuit diagram, could I just have that directly
be the Stamp's Power supply? Then the Pak-V could effectively reduce
that down to 3 volts or so to the motor. I'm not sure if that is how
it works though. I just don't want to use a second power supply. I
also would like to run the motor at a couple different speeds. I was
hoping to accomplish this with the Pak-V.
In the circuit you posted, would I be able to vary the speed of the
motor by effectively varying the motor's voltage between 0-3 volts
using the Pak-V?
I'm sorry for all the questions.
Mike
--- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> Hi Mike,
>
> You should not drive the motor directly from any logic IC output
including
> the Stamp or the PAK-V. If you are measuring 3VDC with a meter
directly at
> the output of the PAK-V then the meter is probably averaging the
PWM for you
> (an analog meter perhaps?).
>
> You can find 2N2222s just about anywhere including Radio Shack, but
be sure
> your motor doesn't draw over, say 100mA. If the motor has
significant
> inductance you may also need a diode (for example a 1N914 or
1N4148 -- also
> at Radio Shack) across the motor "backwards" (that is, the stripe
of the
> diode points to the + supply). This will absorb high voltage spikes
the
> motor may produce when you start or stop it. Maybe $2 in parts.
>
>
> The final circuit would look like this:
>
> Pin (PAK or Stamp) --- 1K resistor
Base of 2N2222
>
> Emitter of 2N2222 --- ground
>
> Collector of 2N2222
"side A" of motor (either side)
>
> +3V
"side B" of motor (other side)
>
> Side B of motor ---- striped end of diode
Side A of motor
>
>
> The PAK-V outputs 0 to 5V. You don't want to average it for motor
control
> (although you might for other reasons). You need something to make
5V switch
> 3V on and off. In this case we switch the ground which is just as
good.
>
> Al Williams
> AWC
> *NEW: PAK-IX floating point A/D: http://www.al-
williams.com/awce/pak9.htm
> (Last day at this price)
>
>
>
> >
Original Message
> > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > Sent: Tuesday, April 10, 2001 1:50 PM
> > To: basicstamps@y...
> > Subject: [noparse][[/noparse]basicstamps] Re: Pak V w/motor
> >
> >
> > The motor turns the way I want when I hook up two AA batteries
> > directly to it (3 volts). So I know the motor works. I was
hoping
> > that all I would need to do was, via Pak-V, send 3 volts from the
Pak
> > to the motor. But that did not turn the motor. I have the
command
> > programmed correctly because I am measuring 3 volts with a
multimeter
> > off of the Pak-V connection to the motor.
> >
> > Given this information, do I just need to add a transistor to my
> > circuit or is it more complicated than that? I have no spare
parts
> > (ie. transistors) to experiment.
> >
> >
> > Al Williams - Do you still suggest the steps you posted below? If
> > so, where can I purchase the transistor and I am not exactly sure
> > where that 1k resistor goes ("base to ground"??). Thank you.
> >
> >
> > Thank You Everyone for your input.
> > Mike
> >
> > --- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> > > I'm not sure what you mean by "voltage". You don't want to use
an
> > RC with a
> > > motor.
> > >
> > > Here's some steps you might want to consider:
> > >
> > > 1-Connect all grounds together.
> > >
> > > 2-Hook one end of motor to +V (whatever 3V, 9V, etc.)
> > >
> > > 3-Ground the other end of the motor and observe it spinning.
> > >
> > > 4- Disconnect the ground end of the motor. Put a suitable
> > transistor (2N2222
> > > for a 100mA or less) with the collector on the ground end of the
> > motor, the
> > > emitter to ground. Put a small resistor (say 1K) from base to
> > ground. Power
> > > up. No spin. Move the resistor from ground to +5. Motor should
spin
> > again.
> > >
> > > 5-Remove the +5 end of the resistor and connect it to the
output of
> > the
> > > PAK-V.
> > >
> > > 6-With the PAK-V software make sure that the baud rate constant
is
> > correct
> > > (remember, the BS2 does not use the same baudrate numbers as
BS2SX,
> > BS2P).
> > >
> > > At each stage, make sure you have it working. For example, if
you
> > can't get
> > > step 3 to spin the motor, you don't have enough battery power or
> > something.
> > > At step 4, you should be able to turn the motor on and off. If
not,
> > you are
> > > not saturating the transistor, or some other transistor problem.
> > >
> > > Let me know if any of that helps.
> > >
> > > Al Williams
> > > AWC
> > > *NEW: PAK-IX floating point A/D: http://www.al-
> > williams.com/awce/pak9.htm
> > >
> > >
> > >
> > > >
Original Message
> > > > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > > > Sent: Monday, April 09, 2001 9:02 PM
> > > > To: basicstamps@y...
> > > > Subject: [noparse][[/noparse]basicstamps] Pak V w/motor
> > > >
> > > >
> > > > Please help,
> > > >
> > > > I am a beginner. I just bought the Pak-V for pwm so that I
> > could
> > > > run a motor while my Stamp was doing something else. But I
am not
> > > > sure what I need to do to get the motor turning. I finally
> > > > determined the command to run the Pak-V on my Basic Stamp
2sx. I
> > can
> > > > now get the desired voltage but the motor will not turn. It
is
> > only
> > > > a little Radio Shack motor. It is rated for 9 volts but I
only
> > need
> > > > to use 2-3 volts. Also, it only needs to run in one
direction.
> > Is
> > > > there anything easy I can do to get this motor turning? I am
> > really
> > > > not sure exactly what I am doing.
> > > >
> > > > Thank You for your input. Please be as detailed as
possible.
> > > >
> > > > Mike
> > > >
> > > >
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
that's right) power FET which should be good to about 2A if you heat sink
it. This is a FET so the hook up is a little different. Treat the FET's
source as the emitter and the drain as the collector. You can connect the
gate directly to the PAK-V or Stamp, but put a 1M resistor from the gate to
ground to keep from collecting static when power is off.
The Stamp will not run on 3V. The PAK-V has some power supply leeway, but
mixing supplies is not wise unless you know how to do it and even then
requires special techniques.
When you use PWM to control a motor speed you are NOT changing the voltage
to the motor. What you should do is switch to a 12V supply, run the Stamp
and the motor from it, and use PWM to control how fast the motor goes.
Consider this. A motor is made to operate at a particular voltage. When you
reduce that voltage the motor may slow down, but it also develops less
torque which is not desirable. Also, reducing voltage is typically not
efficient. Think about a motor with a variable resistor feeding it a lower
voltage. If you are absorbing 6V in the resistor and delivering 6V into the
motor, you are burning off a lot of power in the resistor, right?
That's what PWM is for. With PWM you slam the motor full on for a time, and
then turn it off for a time. You make sure the average on time is a certain
percentage. Now when the motor is spinning it is spinning under full power
and will develop its design torque. When the PWM is off, there is no power
wasted as heat, so your efficiency is good.
This is similar to AC motor speed control where you use a Triac to send less
than 360 degrees of the AC power to the motor. Switching power supplies also
use a similar scheme -- full on for awhile and then full off.
So don't think of using a voltage to control the motor speed. Think of using
a duty cycle of pulses and you'll be happier.
Does that make sense?
Al Williams
AWC
*Last day for special pricing on the NEW PAK-IX:
http://www.al-williams.com/awce/pak9.htm
>
Original Message
> From: mcmgamer@n... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=zgvvdOGQIC7zWRHw3pNQWP7y6uBRhOv00GbqyDmqt8CpNs3-kidxcGMWn96bWRl8yxCZF8FnLVQ6c4ZzTw6JJg]mcmgamer@n...[/url
> Sent: Tuesday, April 10, 2001 4:08 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Re: Pak V w/motor
>
>
> Thank You very much Al Williams. You have been a big help. I just
> had to add a few things.
>
> The motor I am using is Radio Shack model number 273-255 (12VDC High
> Speed Motor). I looked at the specsheet and it mentions pretty high
> currents. Does this mean I need a different transistor? Also, the 3
> volt supply in your circuit diagram, could I just have that directly
> be the Stamp's Power supply? Then the Pak-V could effectively reduce
> that down to 3 volts or so to the motor. I'm not sure if that is how
> it works though. I just don't want to use a second power supply. I
> also would like to run the motor at a couple different speeds. I was
> hoping to accomplish this with the Pak-V.
>
> In the circuit you posted, would I be able to vary the speed of the
> motor by effectively varying the motor's voltage between 0-3 volts
> using the Pak-V?
>
> I'm sorry for all the questions.
>
> Mike
>
>
> --- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> > Hi Mike,
> >
> > You should not drive the motor directly from any logic IC output
> including
> > the Stamp or the PAK-V. If you are measuring 3VDC with a meter
> directly at
> > the output of the PAK-V then the meter is probably averaging the
> PWM for you
> > (an analog meter perhaps?).
> >
> > You can find 2N2222s just about anywhere including Radio Shack, but
> be sure
> > your motor doesn't draw over, say 100mA. If the motor has
> significant
> > inductance you may also need a diode (for example a 1N914 or
> 1N4148 -- also
> > at Radio Shack) across the motor "backwards" (that is, the stripe
> of the
> > diode points to the + supply). This will absorb high voltage spikes
> the
> > motor may produce when you start or stop it. Maybe $2 in parts.
> >
> >
> > The final circuit would look like this:
> >
> > Pin (PAK or Stamp) --- 1K resistor
Base of 2N2222
> >
> > Emitter of 2N2222 --- ground
> >
> > Collector of 2N2222
"side A" of motor (either side)
> >
> > +3V
"side B" of motor (other side)
> >
> > Side B of motor ---- striped end of diode
Side A of motor
> >
> >
> > The PAK-V outputs 0 to 5V. You don't want to average it for motor
> control
> > (although you might for other reasons). You need something to make
> 5V switch
> > 3V on and off. In this case we switch the ground which is just as
> good.
> >
> > Al Williams
> > AWC
> > *NEW: PAK-IX floating point A/D: http://www.al-
> williams.com/awce/pak9.htm
> > (Last day at this price)
> >
> >
> >
> > >
Original Message
> > > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > > Sent: Tuesday, April 10, 2001 1:50 PM
> > > To: basicstamps@y...
> > > Subject: [noparse][[/noparse]basicstamps] Re: Pak V w/motor
> > >
> > >
> > > The motor turns the way I want when I hook up two AA batteries
> > > directly to it (3 volts). So I know the motor works. I was
> hoping
> > > that all I would need to do was, via Pak-V, send 3 volts from the
> Pak
> > > to the motor. But that did not turn the motor. I have the
> command
> > > programmed correctly because I am measuring 3 volts with a
> multimeter
> > > off of the Pak-V connection to the motor.
> > >
> > > Given this information, do I just need to add a transistor to my
> > > circuit or is it more complicated than that? I have no spare
> parts
> > > (ie. transistors) to experiment.
> > >
> > >
> > > Al Williams - Do you still suggest the steps you posted below? If
> > > so, where can I purchase the transistor and I am not exactly sure
> > > where that 1k resistor goes ("base to ground"??). Thank you.
> > >
> > >
> > > Thank You Everyone for your input.
> > > Mike
> > >
> > > --- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> > > > I'm not sure what you mean by "voltage". You don't want to use
> an
> > > RC with a
> > > > motor.
> > > >
> > > > Here's some steps you might want to consider:
> > > >
> > > > 1-Connect all grounds together.
> > > >
> > > > 2-Hook one end of motor to +V (whatever 3V, 9V, etc.)
> > > >
> > > > 3-Ground the other end of the motor and observe it spinning.
> > > >
> > > > 4- Disconnect the ground end of the motor. Put a suitable
> > > transistor (2N2222
> > > > for a 100mA or less) with the collector on the ground end of the
> > > motor, the
> > > > emitter to ground. Put a small resistor (say 1K) from base to
> > > ground. Power
> > > > up. No spin. Move the resistor from ground to +5. Motor should
> spin
> > > again.
> > > >
> > > > 5-Remove the +5 end of the resistor and connect it to the
> output of
> > > the
> > > > PAK-V.
> > > >
> > > > 6-With the PAK-V software make sure that the baud rate constant
> is
> > > correct
> > > > (remember, the BS2 does not use the same baudrate numbers as
> BS2SX,
> > > BS2P).
> > > >
> > > > At each stage, make sure you have it working. For example, if
> you
> > > can't get
> > > > step 3 to spin the motor, you don't have enough battery power or
> > > something.
> > > > At step 4, you should be able to turn the motor on and off. If
> not,
> > > you are
> > > > not saturating the transistor, or some other transistor problem.
> > > >
> > > > Let me know if any of that helps.
> > > >
> > > > Al Williams
> > > > AWC
> > > > *NEW: PAK-IX floating point A/D: http://www.al-
> > > williams.com/awce/pak9.htm
> > > >
> > > >
> > > >
> > > > >
Original Message
> > > > > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > > > > Sent: Monday, April 09, 2001 9:02 PM
> > > > > To: basicstamps@y...
> > > > > Subject: [noparse][[/noparse]basicstamps] Pak V w/motor
> > > > >
> > > > >
> > > > > Please help,
> > > > >
> > > > > I am a beginner. I just bought the Pak-V for pwm so that I
> > > could
> > > > > run a motor while my Stamp was doing something else. But I
> am not
> > > > > sure what I need to do to get the motor turning. I finally
> > > > > determined the command to run the Pak-V on my Basic Stamp
> 2sx. I
> > > can
> > > > > now get the desired voltage but the motor will not turn. It
> is
> > > only
> > > > > a little Radio Shack motor. It is rated for 9 volts but I
> only
> > > need
> > > > > to use 2-3 volts. Also, it only needs to run in one
> direction.
> > > Is
> > > > > there anything easy I can do to get this motor turning? I am
> > > really
> > > > > not sure exactly what I am doing.
> > > > >
> > > > > Thank You for your input. Please be as detailed as
> possible.
> > > > >
> > > > > Mike
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > > > >
> > >
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
I am going to buy the IRF510 and try that route. But, I have no
experience with heat sinks. Any suggestions? I would like to stick
with Radio Shack parts, if possible, since they are just down the
street.
The 3 volt question I had was actually NOT whether I could power the
Stamp with 3 volts, but rather if I could use the 5 volts from the
Stamp's Board of Education instead of the 3 volts in your circuit
diagram.
Al - Thank you for the detailed description of pwm. That made a lot
of sense.
Mike
--- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> I'm not familiar with that motor. Radio Shack sells an IRF510 (I
think
> that's right) power FET which should be good to about 2A if you
heat sink
> it. This is a FET so the hook up is a little different. Treat the
FET's
> source as the emitter and the drain as the collector. You can
connect the
> gate directly to the PAK-V or Stamp, but put a 1M resistor from the
gate to
> ground to keep from collecting static when power is off.
>
> The Stamp will not run on 3V. The PAK-V has some power supply
leeway, but
> mixing supplies is not wise unless you know how to do it and even
then
> requires special techniques.
>
> When you use PWM to control a motor speed you are NOT changing the
voltage
> to the motor. What you should do is switch to a 12V supply, run the
Stamp
> and the motor from it, and use PWM to control how fast the motor
goes.
>
> Consider this. A motor is made to operate at a particular voltage.
When you
> reduce that voltage the motor may slow down, but it also develops
less
> torque which is not desirable. Also, reducing voltage is typically
not
> efficient. Think about a motor with a variable resistor feeding it
a lower
> voltage. If you are absorbing 6V in the resistor and delivering 6V
into the
> motor, you are burning off a lot of power in the resistor, right?
>
> That's what PWM is for. With PWM you slam the motor full on for a
time, and
> then turn it off for a time. You make sure the average on time is a
certain
> percentage. Now when the motor is spinning it is spinning under
full power
> and will develop its design torque. When the PWM is off, there is
no power
> wasted as heat, so your efficiency is good.
>
> This is similar to AC motor speed control where you use a Triac to
send less
> than 360 degrees of the AC power to the motor. Switching power
supplies also
> use a similar scheme -- full on for awhile and then full off.
>
> So don't think of using a voltage to control the motor speed. Think
of using
> a duty cycle of pulses and you'll be happier.
>
> Does that make sense?
>
> Al Williams
> AWC
> *Last day for special pricing on the NEW PAK-IX:
> http://www.al-williams.com/awce/pak9.htm
>
>
>
>
> >
Original Message
> > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > Sent: Tuesday, April 10, 2001 4:08 PM
> > To: basicstamps@y...
> > Subject: [noparse][[/noparse]basicstamps] Re: Pak V w/motor
> >
> >
> > Thank You very much Al Williams. You have been a big help. I
just
> > had to add a few things.
> >
> > The motor I am using is Radio Shack model number 273-255 (12VDC
High
> > Speed Motor). I looked at the specsheet and it mentions pretty
high
> > currents. Does this mean I need a different transistor? Also,
the 3
> > volt supply in your circuit diagram, could I just have that
directly
> > be the Stamp's Power supply? Then the Pak-V could effectively
reduce
> > that down to 3 volts or so to the motor. I'm not sure if that is
how
> > it works though. I just don't want to use a second power
supply. I
> > also would like to run the motor at a couple different speeds. I
was
> > hoping to accomplish this with the Pak-V.
> >
> > In the circuit you posted, would I be able to vary the speed of
the
> > motor by effectively varying the motor's voltage between 0-3 volts
> > using the Pak-V?
> >
> > I'm sorry for all the questions.
> >
> > Mike
> >
> >
> > --- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> > > Hi Mike,
> > >
> > > You should not drive the motor directly from any logic IC output
> > including
> > > the Stamp or the PAK-V. If you are measuring 3VDC with a meter
> > directly at
> > > the output of the PAK-V then the meter is probably averaging the
> > PWM for you
> > > (an analog meter perhaps?).
> > >
> > > You can find 2N2222s just about anywhere including Radio Shack,
but
> > be sure
> > > your motor doesn't draw over, say 100mA. If the motor has
> > significant
> > > inductance you may also need a diode (for example a 1N914 or
> > 1N4148 -- also
> > > at Radio Shack) across the motor "backwards" (that is, the
stripe
> > of the
> > > diode points to the + supply). This will absorb high voltage
spikes
> > the
> > > motor may produce when you start or stop it. Maybe $2 in parts.
> > >
> > >
> > > The final circuit would look like this:
> > >
> > > Pin (PAK or Stamp) --- 1K resistor
Base of 2N2222
> > >
> > > Emitter of 2N2222 --- ground
> > >
> > > Collector of 2N2222
"side A" of motor (either side)
> > >
> > > +3V
"side B" of motor (other side)
> > >
> > > Side B of motor ---- striped end of diode
Side A of motor
> > >
> > >
> > > The PAK-V outputs 0 to 5V. You don't want to average it for
motor
> > control
> > > (although you might for other reasons). You need something to
make
> > 5V switch
> > > 3V on and off. In this case we switch the ground which is just
as
> > good.
> > >
> > > Al Williams
> > > AWC
> > > *NEW: PAK-IX floating point A/D: http://www.al-
> > williams.com/awce/pak9.htm
> > > (Last day at this price)
> > >
> > >
> > >
> > > >
Original Message
> > > > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > > > Sent: Tuesday, April 10, 2001 1:50 PM
> > > > To: basicstamps@y...
> > > > Subject: [noparse][[/noparse]basicstamps] Re: Pak V w/motor
> > > >
> > > >
> > > > The motor turns the way I want when I hook up two AA batteries
> > > > directly to it (3 volts). So I know the motor works. I was
> > hoping
> > > > that all I would need to do was, via Pak-V, send 3 volts from
the
> > Pak
> > > > to the motor. But that did not turn the motor. I have the
> > command
> > > > programmed correctly because I am measuring 3 volts with a
> > multimeter
> > > > off of the Pak-V connection to the motor.
> > > >
> > > > Given this information, do I just need to add a transistor to
my
> > > > circuit or is it more complicated than that? I have no spare
> > parts
> > > > (ie. transistors) to experiment.
> > > >
> > > >
> > > > Al Williams - Do you still suggest the steps you posted
below? If
> > > > so, where can I purchase the transistor and I am not exactly
sure
> > > > where that 1k resistor goes ("base to ground"??). Thank you.
> > > >
> > > >
> > > > Thank You Everyone for your input.
> > > > Mike
> > > >
> > > > --- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> > > > > I'm not sure what you mean by "voltage". You don't want to
use
> > an
> > > > RC with a
> > > > > motor.
> > > > >
> > > > > Here's some steps you might want to consider:
> > > > >
> > > > > 1-Connect all grounds together.
> > > > >
> > > > > 2-Hook one end of motor to +V (whatever 3V, 9V, etc.)
> > > > >
> > > > > 3-Ground the other end of the motor and observe it spinning.
> > > > >
> > > > > 4- Disconnect the ground end of the motor. Put a suitable
> > > > transistor (2N2222
> > > > > for a 100mA or less) with the collector on the ground end
of the
> > > > motor, the
> > > > > emitter to ground. Put a small resistor (say 1K) from base
to
> > > > ground. Power
> > > > > up. No spin. Move the resistor from ground to +5. Motor
should
> > spin
> > > > again.
> > > > >
> > > > > 5-Remove the +5 end of the resistor and connect it to the
> > output of
> > > > the
> > > > > PAK-V.
> > > > >
> > > > > 6-With the PAK-V software make sure that the baud rate
constant
> > is
> > > > correct
> > > > > (remember, the BS2 does not use the same baudrate numbers as
> > BS2SX,
> > > > BS2P).
> > > > >
> > > > > At each stage, make sure you have it working. For example,
if
> > you
> > > > can't get
> > > > > step 3 to spin the motor, you don't have enough battery
power or
> > > > something.
> > > > > At step 4, you should be able to turn the motor on and off.
If
> > not,
> > > > you are
> > > > > not saturating the transistor, or some other transistor
problem.
> > > > >
> > > > > Let me know if any of that helps.
> > > > >
> > > > > Al Williams
> > > > > AWC
> > > > > *NEW: PAK-IX floating point A/D: http://www.al-
> > > > williams.com/awce/pak9.htm
> > > > >
> > > > >
> > > > >
> > > > > >
Original Message
> > > > > > From: mcmgamer@n... [noparse][[/noparse]mailto:mcmgamer@n...]
> > > > > > Sent: Monday, April 09, 2001 9:02 PM
> > > > > > To: basicstamps@y...
> > > > > > Subject: [noparse][[/noparse]basicstamps] Pak V w/motor
> > > > > >
> > > > > >
> > > > > > Please help,
> > > > > >
> > > > > > I am a beginner. I just bought the Pak-V for pwm so
that I
> > > > could
> > > > > > run a motor while my Stamp was doing something else. But
I
> > am not
> > > > > > sure what I need to do to get the motor turning. I
finally
> > > > > > determined the command to run the Pak-V on my Basic Stamp
> > 2sx. I
> > > > can
> > > > > > now get the desired voltage but the motor will not turn.
It
> > is
> > > > only
> > > > > > a little Radio Shack motor. It is rated for 9 volts but I
> > only
> > > > need
> > > > > > to use 2-3 volts. Also, it only needs to run in one
> > direction.
> > > > Is
> > > > > > there anything easy I can do to get this motor turning?
I am
> > > > really
> > > > > > not sure exactly what I am doing.
> > > > > >
> > > > > > Thank You for your input. Please be as detailed as
> > possible.
> > > > > >
> > > > > > Mike
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > Your use of Yahoo! Groups is subject to
> > > > http://docs.yahoo.com/info/terms/
> > > > > >
> > > >
> > > >
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
Motor + to the power source.
Motor - to the collector of the transistor.
Emitter of the transistor to ground.
Connect one end of a 10k resistor to your stamp pin and the other to the
base of the transistor.
When the stamp pin is high, the motor will run. You can use PULSOUT to vary
the speed of the motor somewhat.
Original Message
> You should not drive the motor directly from any logic IC output including
> the Stamp or the PAK-V. If you are measuring 3VDC with a meter directly at
> the output of the PAK-V then the meter is probably averaging the PWM for
you
> (an analog meter perhaps?).
>
> You can find 2N2222s just about anywhere including Radio Shack, but be
sure
> your motor doesn't draw over, say 100mA.
good for about 1 amp with a heat sink. If your chip, sensors and motor don't
add up to more than about 600-750 ma, it should work. This would be the
terminals marked vdd on the breadboard area.
Original Message
> I am going to buy the IRF510 and try that route. But, I have no
> experience with heat sinks. Any suggestions? I would like to stick
> with Radio Shack parts, if possible, since they are just down the
> street.
>
> The 3 volt question I had was actually NOT whether I could power the
> Stamp with 3 volts, but rather if I could use the 5 volts from the
> Stamp's Board of Education instead of the 3 volts in your circuit
> diagram.
I now can get the motor turn at different speeds. I only have one
complaint. The motor is making a high pitch buzz when it runs. It
doesn't seem to matter what speed it is turning at either.
The motor is Radio Shack model number 273-255 (12VDC High Speed
Motor). I am using the 5 Volts from the Stamp's Board of Education
as the source. Can anyone tell me why the motor could be making this
buzz. It is very annoying.
Thank you
Mike
--- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
> I'm not familiar with that motor. Radio Shack sells an IRF510 (I
think
> that's right) power FET which should be good to about 2A if you
heat sink
> it. This is a FET so the hook up is a little different. Treat the
FET's
> source as the emitter and the drain as the collector. You can
connect the
> gate directly to the PAK-V or Stamp, but put a 1M resistor from the
gate to
> ground to keep from collecting static when power is off.
times the pulses. Ever heard the noise a variable speed cordless drill makes
when you barely pull the trigger? Same thing.
Original Message
> Thank You Al for the advice.
>
> I now can get the motor turn at different speeds. I only have one
> complaint. The motor is making a high pitch buzz when it runs. It
> doesn't seem to matter what speed it is turning at either.
To: basicstamps@yahoogroups.com
Date: Tue, 10 Apr 2001 08:17:35 -0700 (PDT)
>My second bit of experience is that the Radio Shack motor was of very low
>quality. The motor gave of a tremendous amount of EMI (electrical
>interference). I have other servos on my machine, and when I turned on the
You should use bypass capacitors on this sort of motor, a 0.1mF from each
terminal to the metal case of the motor with as short a connection as
possible would be a great help.
--
Regards,
Derryck Croker