Proposed circuit for Basic Stamp to control relays
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Posts: 46,084
I have a need to turn on two relays using a basic
stamp for a car audio application. One relay will
turn on the amp, the other will turn on the DC-DC
power supply for the computer. Am I wiring things
correctly by using the transistor on the ground side
of the relays? Do I need to stick a few diodes in any
where.
The dashed lines are proposed lines that I had
questions on. I believe the "C" and "D" lines need to
be connected, but don't think that "A" or "B" should
be connected.
Eventually the Stamp(BS2p) will turn on a few
different 12V fans depending on the temperature.
Any thoughts appreciated. I'm not an electronics guy
by trade (Metallurgical Engineer--so I understand npn
junctions at the electron level...or so I should).
Thanks,
Darrick
__________________________________________________
Do You Yahoo!?
Yahoo! Health - Feel better, live better
http://health.yahoo.com
[noparse][[/noparse]Non-text portions of this message have been removed]
stamp for a car audio application. One relay will
turn on the amp, the other will turn on the DC-DC
power supply for the computer. Am I wiring things
correctly by using the transistor on the ground side
of the relays? Do I need to stick a few diodes in any
where.
The dashed lines are proposed lines that I had
questions on. I believe the "C" and "D" lines need to
be connected, but don't think that "A" or "B" should
be connected.
Eventually the Stamp(BS2p) will turn on a few
different 12V fans depending on the temperature.
Any thoughts appreciated. I'm not an electronics guy
by trade (Metallurgical Engineer--so I understand npn
junctions at the electron level...or so I should).
Thanks,
Darrick
__________________________________________________
Do You Yahoo!?
Yahoo! Health - Feel better, live better
http://health.yahoo.com
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
The schematic you're talking about is not visible...
The transistor(s) you need depend on the current, and of course you need a
diode to protect it.
Do you know the current needed by the relays ?
Phil.
Original Message
From: "Hartman Darrick" <ricko73@y...>
To: <basicstamps@yahoogroups.com>; "Dashpc" <dashpc@yahoogroups.com>
Sent: Wednesday, August 07, 2002 7:46 AM
Subject: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp to control relays
> I have a need to turn on two relays using a basic
> stamp for a car audio application. One relay will
> turn on the amp, the other will turn on the DC-DC
> power supply for the computer. Am I wiring things
> correctly by using the transistor on the ground side
> of the relays? Do I need to stick a few diodes in any
> where.
>
> The dashed lines are proposed lines that I had
> questions on. I believe the "C" and "D" lines need to
> be connected, but don't think that "A" or "B" should
> be connected.
>
> Eventually the Stamp(BS2p) will turn on a few
> different 12V fans depending on the temperature.
>
> Any thoughts appreciated. I'm not an electronics guy
> by trade (Metallurgical Engineer--so I understand npn
> junctions at the electron level...or so I should).
>
> Thanks,
>
> Darrick
>
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Health - Feel better, live better
> http://health.yahoo.com
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> 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/
>
>
You can find a good discussion on controlling relays in the Basic Stamp
FAQ (http://www.wd5gnr.com/stampfaq.htm).
You should not need the resistors going from the transistor base to
ground. You want to drive the transistors into saturation so that the
Vce will be <.3V or so and you'll get a clean fast turn on.
You don't want to connect ground to 12V so A and B should be omitted.
You do want 12V to your relay coils so the other connections look OK
with a few cautions:
1) When an inductor (like a relay coil) has a change in current it
generates a voltage. The amount of voltage is purely dependent on the
time of the change, so you can generate very large voltages. For this
reason you need a flyback diode across the coil. The diode "points"
towards the +12V supply so normally no current flows through it (to
speak of). When a large voltage appears, the diode will shunt it to the
12V buss. Without it, the transistor will blow when you exceed the
breakdown voltage of the BC junction.
2) I'm assuming this is going in a car. A 7805 by itself is a poor
choice for a car. The amount of garbage that is on the 12V (really
13.8V) line when you start the car and at certain other times is
amazing. You might want to preregulate the incoming voltage with a
zener. Nuts and Volts did an article on this some years back, but I
don't remember what technique they used. A power supply that works
nicely on the bench might not survive in a car very long :-)
Al Williams
AWC
* Floating point A/D
http://www.al-williams.com/awce/pak9.htm
>
Original Message
> From: Hartman Darrick [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=AAjabu1IJrKFKhriwlLYqhB5fUDBKYZMmnJarwiiTJ57NyU1S8R1FIqzfqai4Nq6awEVh9x80w]ricko73@y...[/url
> Sent: Wednesday, August 07, 2002 12:46 AM
> To: basicstamps@yahoogroups.com; Dashpc
> Subject: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp to
> control relays
>
>
> I have a need to turn on two relays using a basic
> stamp for a car audio application. One relay will
> turn on the amp, the other will turn on the DC-DC
> power supply for the computer. Am I wiring things
> correctly by using the transistor on the ground side
> of the relays? Do I need to stick a few diodes in any
> where.
>
> The dashed lines are proposed lines that I had
> questions on. I believe the "C" and "D" lines need to
> be connected, but don't think that "A" or "B" should
> be connected.
>
> Eventually the Stamp(BS2p) will turn on a few
> different 12V fans depending on the temperature.
>
> Any thoughts appreciated. I'm not an electronics guy
> by trade (Metallurgical Engineer--so I understand npn junctions at the
> electron level...or so I should).
>
> Thanks,
>
> Darrick
>
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Health - Feel better, live better http://health.yahoo.com
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> 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/
>
http://www.acroname.com/robotics/info/articles/drivers/drivers.html
Leroy
Hartman Darrick wrote:
>
> I have a need to turn on two relays using a basic
> stamp for a car audio application. One relay will
> turn on the amp, the other will turn on the DC-DC
> power supply for the computer. Am I wiring things
> correctly by using the transistor on the ground side
> of the relays? Do I need to stick a few diodes in any
> where.
>
> The dashed lines are proposed lines that I had
> questions on. I believe the "C" and "D" lines need to
> be connected, but don't think that "A" or "B" should
> be connected.
>
> Eventually the Stamp(BS2p) will turn on a few
> different 12V fans depending on the temperature.
>
> Any thoughts appreciated. I'm not an electronics guy
> by trade (Metallurgical Engineer--so I understand npn
> junctions at the electron level...or so I should).
>
> Thanks,
>
> Darrick
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Health - Feel better, live better
> http://health.yahoo.com
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
> 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/
Your link "http://www.wd5gnr.com/stampfaq.htm" is broken.
Leroy
Al Williams wrote:
>
> Hi Darrick,
>
> You can find a good discussion on controlling relays in the Basic Stamp
> FAQ (http://www.wd5gnr.com/stampfaq.htm).
>
> You should not need the resistors going from the transistor base to
> ground. You want to drive the transistors into saturation so that the
> Vce will be <.3V or so and you'll get a clean fast turn on.
>
> You don't want to connect ground to 12V so A and B should be omitted.
> You do want 12V to your relay coils so the other connections look OK
> with a few cautions:
>
> 1) When an inductor (like a relay coil) has a change in current it
> generates a voltage. The amount of voltage is purely dependent on the
> time of the change, so you can generate very large voltages. For this
> reason you need a flyback diode across the coil. The diode "points"
> towards the +12V supply so normally no current flows through it (to
> speak of). When a large voltage appears, the diode will shunt it to the
> 12V buss. Without it, the transistor will blow when you exceed the
> breakdown voltage of the BC junction.
>
> 2) I'm assuming this is going in a car. A 7805 by itself is a poor
> choice for a car. The amount of garbage that is on the 12V (really
> 13.8V) line when you start the car and at certain other times is
> amazing. You might want to preregulate the incoming voltage with a
> zener. Nuts and Volts did an article on this some years back, but I
> don't remember what technique they used. A power supply that works
> nicely on the bench might not survive in a car very long :-)
>
> Al Williams
> AWC
> * Floating point A/D
> http://www.al-williams.com/awce/pak9.htm
>
> >
Original Message
> > From: Hartman Darrick [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ubqqx6RcDZVdcznz940zdjjKFMyeqI-hc9UTt-oBYDofUfHeqe9yM2gFv5lLSseYag8vydEF61vW]ricko73@y...[/url
> > Sent: Wednesday, August 07, 2002 12:46 AM
> > To: basicstamps@yahoogroups.com; Dashpc
> > Subject: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp to
> > control relays
> >
> >
> > I have a need to turn on two relays using a basic
> > stamp for a car audio application. One relay will
> > turn on the amp, the other will turn on the DC-DC
> > power supply for the computer. Am I wiring things
> > correctly by using the transistor on the ground side
> > of the relays? Do I need to stick a few diodes in any
> > where.
> >
> > The dashed lines are proposed lines that I had
> > questions on. I believe the "C" and "D" lines need to
> > be connected, but don't think that "A" or "B" should
> > be connected.
> >
> > Eventually the Stamp(BS2p) will turn on a few
> > different 12V fans depending on the temperature.
> >
> > Any thoughts appreciated. I'm not an electronics guy
> > by trade (Metallurgical Engineer--so I understand npn junctions at the
>
> > electron level...or so I should).
> >
> > Thanks,
> >
> > Darrick
> >
> >
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Yahoo! Health - Feel better, live better http://health.yahoo.com
> >
> > [noparse][[/noparse]Non-text portions of this message have been removed]
> >
> >
> > 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/
Al Williams
AWC
>
Original Message
> From: Leroy Hall [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=-XbvGE8pZP_ZirK2BuKY5vAPFsneiE5Xf6vpLUDzU7YvGvt-BdNpD-lqNEuP5iUTDt0WHSsg-6l6]leroy@f...[/url
> Sent: Wednesday, August 07, 2002 9:08 AM
> To: basicstamps@yahoogroups.com; alw@a...
> Subject: Re: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp
> to control relays
>
>
> Dear Al,
>
> Your link "http://www.wd5gnr.com/stampfaq.htm" is broken.
>
> Leroy
>
> Al Williams wrote:
> >
> > Hi Darrick,
> >
> > You can find a good discussion on controlling relays in the Basic
> > Stamp FAQ (http://www.wd5gnr.com/stampfaq.htm).
> >
> > You should not need the resistors going from the transistor base to
> > ground. You want to drive the transistors into saturation
> so that the
> > Vce will be <.3V or so and you'll get a clean fast turn on.
> >
> > You don't want to connect ground to 12V so A and B should
> be omitted.
> > You do want 12V to your relay coils so the other
> connections look OK
> > with a few cautions:
> >
> > 1) When an inductor (like a relay coil) has a change in current it
> > generates a voltage. The amount of voltage is purely
> dependent on the
> > time of the change, so you can generate very large
> voltages. For this
> > reason you need a flyback diode across the coil. The diode "points"
> > towards the +12V supply so normally no current flows through it (to
> > speak of). When a large voltage appears, the diode will shunt it to
> > the 12V buss. Without it, the transistor will blow when you
> exceed the
> > breakdown voltage of the BC junction.
> >
> > 2) I'm assuming this is going in a car. A 7805 by itself is a poor
> > choice for a car. The amount of garbage that is on the 12V (really
> > 13.8V) line when you start the car and at certain other times is
> > amazing. You might want to preregulate the incoming voltage with a
> > zener. Nuts and Volts did an article on this some years back, but I
> > don't remember what technique they used. A power supply that works
> > nicely on the bench might not survive in a car very long :-)
> >
> > Al Williams
> > AWC
> > * Floating point A/D http://www.al-williams.com/awce/pak9.htm
> >
> > >
Original Message
> > > From: Hartman Darrick [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=hvdGH3eP1wGow2Fv0XvZ09Voecp-6Es2NYbOk3GUBpQWRLMVjQcCaxp6a68RiyWG6rAIvaX7WYQ]ricko73@y...[/url
> > > Sent: Wednesday, August 07, 2002 12:46 AM
> > > To: basicstamps@yahoogroups.com; Dashpc
> > > Subject: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp
> to control
> > > relays
> > >
> > >
> > > I have a need to turn on two relays using a basic
> > > stamp for a car audio application. One relay will
> > > turn on the amp, the other will turn on the DC-DC
> > > power supply for the computer. Am I wiring things correctly by
> > > using the transistor on the ground side of the relays?
> Do I need to
> > > stick a few diodes in any where.
> > >
> > > The dashed lines are proposed lines that I had
> > > questions on. I believe the "C" and "D" lines need to
> > > be connected, but don't think that "A" or "B" should
> > > be connected.
> > >
> > > Eventually the Stamp(BS2p) will turn on a few
> > > different 12V fans depending on the temperature.
> > >
> > > Any thoughts appreciated. I'm not an electronics guy
> > > by trade (Metallurgical Engineer--so I understand npn
> junctions at
> > > the
> >
> > > electron level...or so I should).
> > >
> > > Thanks,
> > >
> > > Darrick
> > >
> > >
> > >
> > > __________________________________________________
> > > Do You Yahoo!?
> > > Yahoo! Health - Feel better, live better http://health.yahoo.com
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > >
> > >
> > > 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/
>
--- In basicstamps@y..., "Al Williams" <alw@a...> wrote:
>
> Works from here... Anyone else having problems with it?
>
> Al Williams
> AWC
>
>
>
> >
Original Message
> > From: Leroy Hall [noparse][[/noparse]mailto:leroy@f...]
> > Sent: Wednesday, August 07, 2002 9:08 AM
> > To: basicstamps@y...; alw@a...
> > Subject: Re: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp
> > to control relays
> >
> >
> > Dear Al,
> >
> > Your link "http://www.wd5gnr.com/stampfaq.htm" is broken.
> >
> > Leroy
> >
> > Al Williams wrote:
> > >
> > > Hi Darrick,
> > >
> > > You can find a good discussion on controlling relays in the Basic
> > > Stamp FAQ (http://www.wd5gnr.com/stampfaq.htm).
> > >
> > > You should not need the resistors going from the transistor base to
> > > ground. You want to drive the transistors into saturation
> > so that the
> > > Vce will be <.3V or so and you'll get a clean fast turn on.
> > >
> > > You don't want to connect ground to 12V so A and B should
> > be omitted.
> > > You do want 12V to your relay coils so the other
> > connections look OK
> > > with a few cautions:
> > >
> > > 1) When an inductor (like a relay coil) has a change in current it
> > > generates a voltage. The amount of voltage is purely
> > dependent on the
> > > time of the change, so you can generate very large
> > voltages. For this
> > > reason you need a flyback diode across the coil. The diode "points"
> > > towards the +12V supply so normally no current flows through it (to
> > > speak of). When a large voltage appears, the diode will shunt it to
> > > the 12V buss. Without it, the transistor will blow when you
> > exceed the
> > > breakdown voltage of the BC junction.
> > >
> > > 2) I'm assuming this is going in a car. A 7805 by itself is a poor
> > > choice for a car. The amount of garbage that is on the 12V (really
> > > 13.8V) line when you start the car and at certain other times is
> > > amazing. You might want to preregulate the incoming voltage with a
> > > zener. Nuts and Volts did an article on this some years back, but I
> > > don't remember what technique they used. A power supply that works
> > > nicely on the bench might not survive in a car very long :-)
> > >
> > > Al Williams
> > > AWC
> > > * Floating point A/D http://www.al-williams.com/awce/pak9.htm
> > >
> > > >
Original Message
> > > > From: Hartman Darrick [noparse][[/noparse]mailto:ricko73@y...]
> > > > Sent: Wednesday, August 07, 2002 12:46 AM
> > > > To: basicstamps@y...; Dashpc
> > > > Subject: [noparse][[/noparse]basicstamps] Proposed circuit for Basic Stamp
> > to control
> > > > relays
> > > >
> > > >
> > > > I have a need to turn on two relays using a basic
> > > > stamp for a car audio application. One relay will
> > > > turn on the amp, the other will turn on the DC-DC
> > > > power supply for the computer. Am I wiring things correctly by
> > > > using the transistor on the ground side of the relays?
> > Do I need to
> > > > stick a few diodes in any where.
> > > >
> > > > The dashed lines are proposed lines that I had
> > > > questions on. I believe the "C" and "D" lines need to
> > > > be connected, but don't think that "A" or "B" should
> > > > be connected.
> > > >
> > > > Eventually the Stamp(BS2p) will turn on a few
> > > > different 12V fans depending on the temperature.
> > > >
> > > > Any thoughts appreciated. I'm not an electronics guy
> > > > by trade (Metallurgical Engineer--so I understand npn
> > junctions at
> > > > the
> > >
> > > > electron level...or so I should).
> > > >
> > > > Thanks,
> > > >
> > > > Darrick
> > > >
> > > >
> > > >
> > > > __________________________________________________
> > > > Do You Yahoo!?
> > > > Yahoo! Health - Feel better, live better http://health.yahoo.com
> > > >
> > > > [noparse][[/noparse]Non-text portions of this message have been removed]
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@y...
> > > > 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@y...
> > > 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/
> >