SCR for motor control
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Does anyone know if an SCR can be used to control a motor through a
basic stamp? If not what about transistors?
Thanks,
Rob
basic stamp? If not what about transistors?
Thanks,
Rob
Comments
jim
Original Message
From: mstroboto2003 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=fqmhLL16BzJ9jmXBCDA-wzrYPxXh4FJMkUBrj7gyUM8Y88HXMhXIMGk15U512vEmAsWaQd5CKRk]monkeymack@a...[/url
Sent: Monday, April 07, 2003 8:42 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] SCR for motor control
Does anyone know if an SCR can be used to control a motor through a
basic stamp? If not what about transistors?
Thanks,
Rob
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the scr with a transistor . . . else try an Opto22
module (www.opto22.com). The mp120d4 module pulls
less than 10mw when driving 120 @3amps.
--- mstroboto2003 <monkeymack@a...> wrote:
> Does anyone know if an SCR can be used to control a
> motor through a
> basic stamp? If not what about transistors?
> Thanks,
> Rob
>
>
> 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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I'm assuming you're trying to control a DC motor with an SCR?
Although I haven't done it with the stamp, it does sound feasible.
However you will run into problems along the way with things such as
detecting the zero voltage crossing of the AC line, commutation
notches in the AC line as the motor runs, etc. etc. If your motor is
relatively small, you're probably better off going with an H-Bridge
type setup with four transistors, and then pulsing two at a time
(PWM) at set intervals to create an average DC voltage and run the
motor. If you need precise control over the motor you may need to
hook an encoder up to it to count revolutions. The stamp will
quickly become a limitation if your project requires this type of
feature.
Ron
--- In basicstamps@yahoogroups.com, "mstroboto2003" <monkeymack@a...>
wrote:
> Does anyone know if an SCR can be used to control a motor through a
> basic stamp? If not what about transistors?
> Thanks,
> Rob
anyone considered using a small bar magnet fixed to the shaft of the motor
so that one end passed near a Hall sensor (Hall's read a linear signal out
in direct proportion to the magnetic field, right?), and counting the sine
waves produced by the magnet/Hall effect combination as the magnet ends come
near the sensor?
It seems like that would be a VERY BEAMish idea, since you could a) gate a
window to count cycles in, and derive RPMs, b) calculate the sine angle and
thus degrees of rotation for a very slow, or even stepped motor, and c) just
plain count cycles, with a proper correction factor for the circumference of
the circle described by the magnet's poles, to obtain distance traveled.
For that matter, if you made sure that the motor shaft stuck straight up or
straight down (wouldn't matter which, really, you just have t make sure the
magnet is always at least near parallel to the earth's surface, so that it
comes into North/South alignment, and out, at a regular rate of speed) you
could calculate the change in angular velocity as the carrier vehicle turned
a corner (for very short periods), and possibly (like doppler shifting) read
the turn rate of the vehicle as a function of the sum or difference of the
resulting count rates.
Does that make sense? If not, and someone else would like to take a crack at
rephrasing it, great. Otherwise, if it doesn't seem clear, let me know and
I'll try to re-state the idea.
I wish I had some kind of graphic software to use to draw what I'm talking
about. Any advice on what to use, and where to get it?
Mic
Original Message
From: Ron Jeremy <ronjeremy912@y...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, April 09, 2003 5:14 AM
Subject: [noparse][[/noparse]basicstamps] Re: SCR for motor control
> Rob,
>
> I'm assuming you're trying to control a DC motor with an SCR?
> Although I haven't done it with the stamp, it does sound feasible.
> However you will run into problems along the way with things such as
> detecting the zero voltage crossing of the AC line, commutation
> notches in the AC line as the motor runs, etc. etc. If your motor is
> relatively small, you're probably better off going with an H-Bridge
> type setup with four transistors, and then pulsing two at a time
> (PWM) at set intervals to create an average DC voltage and run the
> motor. If you need precise control over the motor you may need to
> hook an encoder up to it to count revolutions. The stamp will
> quickly become a limitation if your project requires this type of
> feature.
>
> Ron
>
> --- In basicstamps@yahoogroups.com, "mstroboto2003" <monkeymack@a...>
> wrote:
> > Does anyone know if an SCR can be used to control a motor through a
> > basic stamp? If not what about transistors?
> > Thanks,
> > Rob
>
>
> 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.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
wrote:
> Does anyone know if an SCR can be used to control a motor through a
> basic stamp? If not what about transistors?
> Thanks,
> Rob
Hi Rob,
assuming you are trying to do variable speed control, pwm is a simple
way to pulse full voltage to a motor of yeild higher power at lower
speeds.
if you are interested in controlling speed, some form of encoder is
needed and you would also want to use a PID loop to cotrol the
signals.
I think the existing forms of motor speed contorllers for hobby size
motors are pretty good. when you get into the horsepower motors, you
run into monitoring amps, hertz and volts. then you are getting into
some heavy processing.
the IGBT transistors fire at 32,000 hz to eleminate the resonance
caused by the motor laminations vibrating. And then of course, there
are some step thru frequencies so that if a particular motor does
resonate at some frequency, you cna bypass that range.
maybe if you let us know the motor size your are looking into we
could offe a little more directon ?
Dave
want and it will interface with the Stamp. Look under the Whats New link on
their website.
Regards,
Bill Cramer
Atlanta, Ga. USA
Original Message
From: "Michael Duerksen" <michael_duerksen@c...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, April 10, 2003 8:44 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: SCR for motor control
> Not quite OT, especially if counting turns is required for a motor, but
has
> anyone considered using a small bar magnet fixed to the shaft of the motor
> so that one end passed near a Hall sensor (Hall's read a linear signal out
> in direct proportion to the magnetic field, right?), and counting the sine
> waves produced by the magnet/Hall effect combination as the magnet ends
come
> near the sensor?
>
> It seems like that would be a VERY BEAMish idea, since you could a) gate a
> window to count cycles in, and derive RPMs, b) calculate the sine angle
and
> thus degrees of rotation for a very slow, or even stepped motor, and c)
just
> plain count cycles, with a proper correction factor for the circumference
of
> the circle described by the magnet's poles, to obtain distance traveled.
>
> For that matter, if you made sure that the motor shaft stuck straight up
or
> straight down (wouldn't matter which, really, you just have t make sure
the
> magnet is always at least near parallel to the earth's surface, so that it
> comes into North/South alignment, and out, at a regular rate of speed) you
> could calculate the change in angular velocity as the carrier vehicle
turned
> a corner (for very short periods), and possibly (like doppler shifting)
read
> the turn rate of the vehicle as a function of the sum or difference of the
> resulting count rates.
>
> Does that make sense? If not, and someone else would like to take a crack
at
> rephrasing it, great. Otherwise, if it doesn't seem clear, let me know and
> I'll try to re-state the idea.
>
> I wish I had some kind of graphic software to use to draw what I'm talking
> about. Any advice on what to use, and where to get it?
>
> Mic
>
>
Original Message
> From: Ron Jeremy <ronjeremy912@y...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, April 09, 2003 5:14 AM
> Subject: [noparse][[/noparse]basicstamps] Re: SCR for motor control
>
>
> > Rob,
> >
> > I'm assuming you're trying to control a DC motor with an SCR?
> > Although I haven't done it with the stamp, it does sound feasible.
> > However you will run into problems along the way with things such as
> > detecting the zero voltage crossing of the AC line, commutation
> > notches in the AC line as the motor runs, etc. etc. If your motor is
> > relatively small, you're probably better off going with an H-Bridge
> > type setup with four transistors, and then pulsing two at a time
> > (PWM) at set intervals to create an average DC voltage and run the
> > motor. If you need precise control over the motor you may need to
> > hook an encoder up to it to count revolutions. The stamp will
> > quickly become a limitation if your project requires this type of
> > feature.
> >
> > Ron
> >
> > --- In basicstamps@yahoogroups.com, "mstroboto2003" <monkeymack@a...>
> > wrote:
> > > Does anyone know if an SCR can be used to control a motor through a
> > > basic stamp? If not what about transistors?
> > > Thanks,
> > > Rob
> >
> >
> > 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.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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Body of the message will be ignored.
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>
>
>
I understand, and I know that Gray Scale optical codecs have been around for
decades (but not always in IC form. We had to build them from discretes when
I was in the US Navy), but what I thought would be interesting was using
only two magnet/hall sensor assemblies (one on a rolling wheel and one on
the "compass card") to derive SO much info. And lurking in the back of my
mind was how much fun it would be to get all that info with a Stamp.
Mic
Original Message
From: Bill Cramer <billcramer@a...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, April 10, 2003 9:36 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: SCR for motor control
> www.alltronics.com sells an optical encoder which will do exactly what you
> want and it will interface with the Stamp. Look under the Whats New link
on
> their website.
>
> Regards,
> Bill Cramer
> Atlanta, Ga. USA
>
Original Message
> From: "Michael Duerksen" <michael_duerksen@c...>
> To: <basicstamps@yahoogroups.com>
> Sent: Thursday, April 10, 2003 8:44 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Re: SCR for motor control
>
>
> > Not quite OT, especially if counting turns is required for a motor, but
> has
> > anyone considered using a small bar magnet fixed to the shaft of the
motor
> > so that one end passed near a Hall sensor (Hall's read a linear signal
out
> > in direct proportion to the magnetic field, right?), and counting the
sine
> > waves produced by the magnet/Hall effect combination as the magnet ends
> come
> > near the sensor?
> >
> > It seems like that would be a VERY BEAMish idea, since you could a) gate
a
> > window to count cycles in, and derive RPMs, b) calculate the sine angle
> and
> > thus degrees of rotation for a very slow, or even stepped motor, and c)
> just
> > plain count cycles, with a proper correction factor for the
circumference
> of
> > the circle described by the magnet's poles, to obtain distance traveled.
> >
> > For that matter, if you made sure that the motor shaft stuck straight up
> or
> > straight down (wouldn't matter which, really, you just have t make sure
> the
> > magnet is always at least near parallel to the earth's surface, so that
it
> > comes into North/South alignment, and out, at a regular rate of speed)
you
> > could calculate the change in angular velocity as the carrier vehicle
> turned
> > a corner (for very short periods), and possibly (like doppler shifting)
> read
> > the turn rate of the vehicle as a function of the sum or difference of
the
> > resulting count rates.
> >
> > Does that make sense? If not, and someone else would like to take a
crack
> at
> > rephrasing it, great. Otherwise, if it doesn't seem clear, let me know
and
> > I'll try to re-state the idea.
> >
> > I wish I had some kind of graphic software to use to draw what I'm
talking
> > about. Any advice on what to use, and where to get it?
> >
> > Mic
> >
> >
Original Message
> > From: Ron Jeremy <ronjeremy912@y...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Wednesday, April 09, 2003 5:14 AM
> > Subject: [noparse][[/noparse]basicstamps] Re: SCR for motor control
> >
> >
> > > Rob,
> > >
> > > I'm assuming you're trying to control a DC motor with an SCR?
> > > Although I haven't done it with the stamp, it does sound feasible.
> > > However you will run into problems along the way with things such as
> > > detecting the zero voltage crossing of the AC line, commutation
> > > notches in the AC line as the motor runs, etc. etc. If your motor is
> > > relatively small, you're probably better off going with an H-Bridge
> > > type setup with four transistors, and then pulsing two at a time
> > > (PWM) at set intervals to create an average DC voltage and run the
> > > motor. If you need precise control over the motor you may need to
> > > hook an encoder up to it to count revolutions. The stamp will
> > > quickly become a limitation if your project requires this type of
> > > feature.
> > >
> > > Ron
> > >
> > > --- In basicstamps@yahoogroups.com, "mstroboto2003" <monkeymack@a...>
> > > wrote:
> > > > Does anyone know if an SCR can be used to control a motor through a
> > > > basic stamp? If not what about transistors?
> > > > Thanks,
> > > > Rob
> > >
> > >
> > > 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.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > 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.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
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