Drive 12V Relay
Archiver
Posts: 46,084
Sure, a standard transistor driver will do the trick. Read:
http://www.wd5gnr.com/faqs/index.php?qframe=1&faq=1&article=16
The only thing that I need to change in that article is to mention that
you need a "reverse" diode across the relay coil.
Al Williams
AWC
* Floating point math for the Stamp, PIC, SX, or any microcontroller
http://www.al-williams.com/awce/pak1.htm
>
Original Message
> From: S Parkis [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=7dFQ5-pnUmrawIxSzj2DxtU2RS60ZzZnCOHl7B2W2b1ZNJXQsHp7iHI6paBqvDy28G521g8NvgtS71YrIg]parkiss@e...[/url
> Sent: Sunday, May 05, 2002 11:42 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Drive 12V Relay
>
>
> Can someone suggest a simple circuit to control a 12V (coil
> voltage) relay from a Stamp I/O pin?
>
> Thanks,
>
> Steve
>
> To UNSUBSCRIBE, just send mail to:
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>
http://www.wd5gnr.com/faqs/index.php?qframe=1&faq=1&article=16
The only thing that I need to change in that article is to mention that
you need a "reverse" diode across the relay coil.
Al Williams
AWC
* Floating point math for the Stamp, PIC, SX, or any microcontroller
http://www.al-williams.com/awce/pak1.htm
>
Original Message
> From: S Parkis [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=7dFQ5-pnUmrawIxSzj2DxtU2RS60ZzZnCOHl7B2W2b1ZNJXQsHp7iHI6paBqvDy28G521g8NvgtS71YrIg]parkiss@e...[/url
> Sent: Sunday, May 05, 2002 11:42 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Drive 12V Relay
>
>
> Can someone suggest a simple circuit to control a 12V (coil
> voltage) relay from a Stamp I/O pin?
>
> Thanks,
>
> Steve
>
> 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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> http://docs.yahoo.com/info/terms/
>
Comments
relay from a Stamp I/O pin?
Thanks,
Steve
resistance - however it should be OK for this - however you may need heat
sink - .54ohms*24volts = 13 watts power to dissipate !!
http://www.irf.com/product-info/datasheets/data/irf510.pdf
richard
Original Message
From: "S Parkis" <parkiss@e...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, May 06, 2002 4:41 PM
Subject: RE: [noparse][[/noparse]basicstamps] Drive 12V Relay
> Much obliged to Al & Ray for the help. After a thorough read of Al's
> link, I think I can skip the relay and use an IFR-510 to directly do
> the switching job. I'll be making/breaking a loop with slightly
> under 1 Amp @ something under 50 volts DC (application: replace
> mercury switch in evaporative cooler thermostat so I can use a Stamp
> to control its operation).
>
> The way I read the IFR-510 spec's, it can handle up to 4 Amps at up
> to 100 volts across drain to source, so this shouldn't even make it
> breathe hard--make sense?
>
> Thanks again and regards,
>
> Steve
>
> 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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>
>
resistance times the switched voltage. P=IV or P=(I^2)R, or something like
(0.3^2) x 0.54 = 0.05 watts. No heat sink needed.
Clark Hughes
Richard Friedrich wrote:
>
> 510s are bad for some applications due to their relatively high on
> resistance - however it should be OK for this - however you may need heat
> sink - .54ohms*24volts = 13 watts power to dissipate !!
>
> http://www.irf.com/product-info/datasheets/data/irf510.pdf
>
> richard
across the fet .54 ohm junction:
I*R or .54 * 4 = 2.16 volts
Power (E*I):
2.16 * 4 = 8.64 watts
Or did I miss something?
Leroy
I might be willing to make a small wager on whether an AC valve,
solenoid, or other type of coil could be run on an equivalent value of
DC, if there are any takers, I could use some extra money. :-))))
Richard Friedrich wrote:
>
> 510s are bad for some applications due to their relatively high on
> resistance - however it should be OK for this - however you may need heat
> sink - .54ohms*24volts = 13 watts power to dissipate !!
>
> http://www.irf.com/product-info/datasheets/data/irf510.pdf
>
> richard
>
>
Original Message
> From: "S Parkis" <parkiss@e...>
> To: <basicstamps@yahoogroups.com>
> Sent: Monday, May 06, 2002 4:41 PM
> Subject: RE: [noparse][[/noparse]basicstamps] Drive 12V Relay
>
> > Much obliged to Al & Ray for the help. After a thorough read of Al's
> > link, I think I can skip the relay and use an IFR-510 to directly do
> > the switching job. I'll be making/breaking a loop with slightly
> > under 1 Amp @ something under 50 volts DC (application: replace
> > mercury switch in evaporative cooler thermostat so I can use a Stamp
> > to control its operation).
> >
> > The way I read the IFR-510 spec's, it can handle up to 4 Amps at up
> > to 100 volts across drain to source, so this shouldn't even make it
> > breathe hard--make sense?
> >
> > Thanks again and regards,
> >
> > Steve
> >
> > 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/
--
NOTE: This e-mail is confidential and may also be privileged; under no
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NOT: Bu elektronik posta mesaj
richard
Original Message
From: "Leroy Hall" <leroy@f...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, May 06, 2002 4:22 PM
Subject: Re: [noparse][[/noparse]basicstamps] Drive 12V Relay
> I thought power = E*I NOT R*E. At four amps of current we would have
> across the fet .54 ohm junction:
>
> I*R or .54 * 4 = 2.16 volts
>
> Power (E*I):
>
> 2.16 * 4 = 8.64 watts
>
> Or did I miss something?
>
> Leroy
>
> I might be willing to make a small wager on whether an AC valve,
> solenoid, or other type of coil could be run on an equivalent value of
> DC, if there are any takers, I could use some extra money. :-))))
>
>
>
> Richard Friedrich wrote:
> >
> > 510s are bad for some applications due to their relatively high on
> > resistance - however it should be OK for this - however you may need
heat
> > sink - .54ohms*24volts = 13 watts power to dissipate !!
> >
> > http://www.irf.com/product-info/datasheets/data/irf510.pdf
> >
> > richard
> >
> >
Original Message
> > From: "S Parkis" <parkiss@e...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Monday, May 06, 2002 4:41 PM
> > Subject: RE: [noparse][[/noparse]basicstamps] Drive 12V Relay
> >
> > > Much obliged to Al & Ray for the help. After a thorough read of Al's
> > > link, I think I can skip the relay and use an IFR-510 to directly do
> > > the switching job. I'll be making/breaking a loop with slightly
> > > under 1 Amp @ something under 50 volts DC (application: replace
> > > mercury switch in evaporative cooler thermostat so I can use a Stamp
> > > to control its operation).
> > >
> > > The way I read the IFR-510 spec's, it can handle up to 4 Amps at up
> > > to 100 volts across drain to source, so this shouldn't even make it
> > > breathe hard--make sense?
> > >
> > > Thanks again and regards,
> > >
> > > Steve
> > >
> > > 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/
>
> --
> NOTE: This e-mail is confidential and may also be privileged; under no
> circumstances should you forward it, or copy or disclose its contents,
> to any other person without the prior consent of the sender. If you are
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> Internet communications are not secure and subject to possible data
> corruption, either accidentally or on purpose, and may contain viruses.
> Furthermore e-mail is an informal and often abbreviated method of
> communication. For these reasons, it will normally be inappropriate to
> rely on any information or advice contained herein without also
> discussing it with the sender.
>
> (The note below is a Turkish version of the above disclaimer)
>
> NOT: Bu elektronik posta mesaj
.54 ohms (1/2 ohm) at 24 volts is 44.4 AMPS! (E=IR) (I=E/R)
(R=E/I) (P=I*E) 24 * 44.4 = 1066.6 watts!
Did I read the resistance correct as point 54 ohms?? (1/2 ohm? Were
talking almost a dead short here !! ) Did you perhaps mean .54 amps?? That
would be 13 watts..
Mike B.
Original Message
From: "J. Clark Hughes" <jchughes@a...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, May 06, 2002 2:12 PM
Subject: Re: [noparse][[/noparse]basicstamps] Drive 12V Relay
> Check the physics here. Power losses will be current times voltage loss,
not
> resistance times the switched voltage. P=IV or P=(I^2)R, or something
like
> (0.3^2) x 0.54 = 0.05 watts. No heat sink needed.
>
> Clark Hughes
>
> Richard Friedrich wrote:
> >
> > 510s are bad for some applications due to their relatively high on
> > resistance - however it should be OK for this - however you may need
heat
> > sink - .54ohms*24volts = 13 watts power to dissipate !!
> >
> > http://www.irf.com/product-info/datasheets/data/irf510.pdf
> >
> > richard
>
> 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/
>
>
link, I think I can skip the relay and use an IFR-510 to directly do
the switching job. I'll be making/breaking a loop with slightly
under 1 Amp @ something under 50 volts DC (application: replace
mercury switch in evaporative cooler thermostat so I can use a Stamp
to control its operation).
The way I read the IFR-510 spec's, it can handle up to 4 Amps at up
to 100 volts across drain to source, so this shouldn't even make it
breathe hard--make sense?
Thanks again and regards,
Steve
>I thought power = E*I NOT R*E. At four amps of current we would have
>across the fet .54 ohm junction:
>
>I*R or .54 * 4 = 2.16 volts
>
>Power (E*I):
>
>2.16 * 4 = 8.64 watts
>
>Or did I miss something?
>
>Leroy
>
>I might be willing to make a small wager on whether an AC valve,
>solenoid, or other type of coil could be run on an equivalent value of
>DC, if there are any takers, I could use some extra money. :-))))
Leroy, I've seen 120 VAC coils burned up by 24 VDC. It all depends on the
DC resistance of the coil. I'm sure you can find a solenoid that works
fine if you search hard enough, but in general, without knowing the
specifications of the solenoid beforehand, recommending use of DC to power
an AC solenoid, voltage remaining the same, is a very bad idea. As to any
bet, Leroy, just give it a few hours to a day and maybe some of the other
guys who have been there will straignten you out - and it won't cost you a
dime.
>NOTE: This e-mail is confidential and may also be privileged; under no
>circumstances should you forward it, or copy or disclose its contents,
>to any other person without the prior consent of the sender. If you are
>not an intended recipient of this e-mail, please notify us immediately.
>Internet communications are not secure and subject to possible data
>corruption, either accidentally or on purpose, and may contain viruses.
>Furthermore e-mail is an informal and often abbreviated method of
>communication. For these reasons, it will normally be inappropriate to
>rely on any information or advice contained herein without also
>discussing it with the sender.
>
>(The note below is a Turkish version of the above disclaimer)
>
>NOT: Bu elektronik posta mesaj
I use a Darlington driver circuit in a ULN2003A (Allegra) for this
purpose. Stamp pin ---> Driver Input. Driver Output ---> 1K pullup
resistor ---> 5 Volts. Driver Ouput ---> Low (Common) side of relay.
12V ---> High side of relay. Setting the Stamp pin High grounds the
relay driver circuit, and turns the relay on. This Open Collector
configuration is described in the BS1 Stamp Manual in the section on
driving a Unipolar stepper motor with only 2 Stamp pins.
Dennis
Original Message
From: S Parkis [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=SmLbK56iSExzchOjnPQ7e76r8xUJSgo0uD1jq3HcO84Z77trXghoHWutOyxJnn-S2mbx3c8GFVaxbdzCedAQTA]parkiss@e...[/url
Sent: Sunday, May 05, 2002 9:42 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Drive 12V Relay
Can someone suggest a simple circuit to control a 12V (coil voltage)
relay from a Stamp I/O pin?
Thanks,
Steve
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject
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Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>Can someone suggest a simple circuit to control a 12V (coil voltage)
>relay from a Stamp I/O pin?
Steve - what is the intended load?
The simplest technique is a single NPN transistor such as 2n4401: E
grounded, B to stamp pin via a 1K resistor, C to one leg of relay coil,
other leg of relay coil to +12V supply, 1n4001 diode connected across relay
coil with cathode (stripe) to + supply.
For added reliability, add another 1K resistor from E to B on the
transistor. This does 2 things: keeps the transistor turned OFF if the
Stamp pin should ever be left as an input and also improves the noise
immunity of the relay driver: it now takes at least 1.1V with at least half
an mA before the transistor can turn on.
dwayne
Dwayne Reid <dwayner@p...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax
Celebrating 18 years of Engineering Innovation (1984 - 2002)
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Do NOT send unsolicited commercial email to this email address.
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the character Z. Z is a function of the DC resistance and the reactance
of the coil XL. XL is derived from the term 2PIfl, where pi= 3.141
(approx) f is the frequency of the AC supply, and l = is the inductance
of the coil.
Z= SQR (XL^2 * R^2).
Typically in a coil designed for AC use R is small and XL is large (this
determines "Q" factor, but we won't go there). And that is why using AC
coils on DC is not a hot idea.
Rob
Original Message
From: Jim Higgins [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=qrJGjAHIk2IS_ci1EVSCc_nLre4Imny-9G7ZmT-zWxKFzSBXZl6WxYef_xSRJBOb-OHR2xi3Axz-]HigginsJ@s...[/url
Sent: 06 May 2002 23:28
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Drive 12V Relay
At 17:22 05/06/02, Leroy Hall wrote:
>I thought power = E*I NOT R*E. At four amps of current we would have
>across the fet .54 ohm junction:
>
>I*R or .54 * 4 = 2.16 volts
>
>Power (E*I):
>
>2.16 * 4 = 8.64 watts
>
>Or did I miss something?
>
>Leroy
>
>I might be willing to make a small wager on whether an AC valve,
>solenoid, or other type of coil could be run on an equivalent value of
>DC, if there are any takers, I could use some extra money. :-))))
Leroy, I've seen 120 VAC coils burned up by 24 VDC. It all depends on
the
DC resistance of the coil. I'm sure you can find a solenoid that works
fine if you search hard enough, but in general, without knowing the
specifications of the solenoid beforehand, recommending use of DC to
power
an AC solenoid, voltage remaining the same, is a very bad idea. As to
any
bet, Leroy, just give it a few hours to a day and maybe some of the
other
guys who have been there will straignten you out - and it won't cost you
a
dime.
>NOTE: This e-mail is confidential and may also be privileged; under no
>circumstances should you forward it, or copy or disclose its contents,
>to any other person without the prior consent of the sender. If you are
>not an intended recipient of this e-mail, please notify us immediately.
>Internet communications are not secure and subject to possible data
>corruption, either accidentally or on purpose, and may contain viruses.
>Furthermore e-mail is an informal and often abbreviated method of
>communication. For these reasons, it will normally be inappropriate to
>rely on any information or advice contained herein without also
>discussing it with the sender.
>
>(The note below is a Turkish version of the above disclaimer)
>
>NOT: Bu elektronik posta mesaj
Z= SQR (XL^2 * R^2).
Should be:-
Z= SQR (XL^2 + R^2).
Hey, it's early in the morning, that's my excuse.
Rob
idea! Would a small resistor, sized appropriately, be a bad idea as
well? I would think the DC current should be reduced to the same value
as the RMS AC current as the coil would normally use?
Leroy
Rob wrote:
>
> The "resistance" of an AC coil is if fact the term impedance, denoted by
> the character Z. Z is a function of the DC resistance and the reactance
> of the coil XL. XL is derived from the term 2PIfl, where pi= 3.141
> (approx) f is the frequency of the AC supply, and l = is the inductance
> of the coil.
>
> Z= SQR (XL^2 * R^2).
>
> Typically in a coil designed for AC use R is small and XL is large (this
> determines "Q" factor, but we won't go there). And that is why using AC
> coils on DC is not a hot idea.
>
> Rob
>
>
Original Message
> From: Jim Higgins [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=702yRaSSQPJRqTWSTVvyewwOeQoJoNjMIiz8VcUizTUDcsNp3PFheOxV8ERO95ZaJM4BO_ESvdCAnfEWEA]HigginsJ@s...[/url
> Sent: 06 May 2002 23:28
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Drive 12V Relay
>
> At 17:22 05/06/02, Leroy Hall wrote:
> >I thought power = E*I NOT R*E. At four amps of current we would have
> >across the fet .54 ohm junction:
> >
> >I*R or .54 * 4 = 2.16 volts
> >
> >Power (E*I):
> >
> >2.16 * 4 = 8.64 watts
> >
> >Or did I miss something?
> >
> >Leroy
> >
> >I might be willing to make a small wager on whether an AC valve,
> >solenoid, or other type of coil could be run on an equivalent value of
> >DC, if there are any takers, I could use some extra money. :-))))
>
> Leroy, I've seen 120 VAC coils burned up by 24 VDC. It all depends on
> the
> DC resistance of the coil. I'm sure you can find a solenoid that works
> fine if you search hard enough, but in general, without knowing the
> specifications of the solenoid beforehand, recommending use of DC to
> power
> an AC solenoid, voltage remaining the same, is a very bad idea. As to
> any
> bet, Leroy, just give it a few hours to a day and maybe some of the
> other
> guys who have been there will straignten you out - and it won't cost you
> a
> dime.
>
> >NOTE: This e-mail is confidential and may also be privileged; under no
> >circumstances should you forward it, or copy or disclose its contents,
> >to any other person without the prior consent of the sender. If you are
> >not an intended recipient of this e-mail, please notify us immediately.
> >Internet communications are not secure and subject to possible data
> >corruption, either accidentally or on purpose, and may contain viruses.
> >Furthermore e-mail is an informal and often abbreviated method of
> >communication. For these reasons, it will normally be inappropriate to
> >rely on any information or advice contained herein without also
> >discussing it with the sender.
> >
> >(The note below is a Turkish version of the above disclaimer)
> >
> >NOT: Bu elektronik posta mesaj