How to handle a latching valve/relay
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Posts: 46,084
Hi All,
What is the best way to use a latching valve or relay? The polarity to the
relay/valve must be reversed to open/close the valve.
Jonathan
www.madlabs.info
What is the best way to use a latching valve or relay? The polarity to the
relay/valve must be reversed to open/close the valve.
Jonathan
www.madlabs.info
Comments
the power?
-- Jon Williams
-- Parallax
Original Message
From: Jonathan Peakall [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=yucgvCpAHcKI4mygc8Q9AkeqaRzg02hZeTwwCQLiLQHHRArFhGmdCqCLa2t2T7iTaXA8pOTk_gwceQk]jpeakall@m...[/url
Sent: Wednesday, June 25, 2003 11:46 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
Hi All,
What is the best way to use a latching valve or relay? The polarity to
the relay/valve must be reversed to open/close the valve.
Jonathan
www.madlabs.info
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turn them off, but they are hard to find.
Original Message
> Does the relay have a spare set of contacts that you can use to route
> the power?
>
Original Message
> What is the best way to use a latching valve or relay? The polarity to
> the relay/valve must be reversed to open/close the valve.
for H2, and have 1/8" hose barbs on em, and are very small and draw low
current [noparse]:)[/noparse]
So, any ideas?
Jonathan
www.madlabs.info
Original Message
From: "Rodent" <daweasel@s...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 11:04 AM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> They make latching relays that do not require reversing the coil power to
> turn them off, but they are hard to find.
>
>
Original Message
>
> > Does the relay have a spare set of contacts that you can use to route
> > the power?
>
> >
Original Message
>
> > What is the best way to use a latching valve or relay? The polarity to
> > the relay/valve must be reversed to open/close the valve.
>
>
>
> To UNSUBSCRIBE, just send mail to:
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pin to drive the relay and one to fire the coil. I suspect there is probably
a way to do it with one Stamp pin, but I can't seem to think if it right
now.
Original Message
> I am going to have to work with these... The are 5V actuated, latching,
safe
> for H2, and have 1/8" hose barbs on em, and are very small and draw low
> current [noparse]:)[/noparse]
> > They make latching relays that do not require reversing the coil power
to
> > turn them off, but they are hard to find.
> >
> >
Original Message
> >
> > > Does the relay have a spare set of contacts that you can use to route
> > > the power?
> >
> > >
Original Message
> >
> > > What is the best way to use a latching valve or relay? The polarity to
> > > the relay/valve must be reversed to open/close the valve.
wires. Operate the relay coil with your stamp driver with diode protection
. Your fixed contacts get the +5 volt solenoid power supply. Wire 1 make
and the opposite break to the solenoid. Do the same on the other solenoid
wire. Now when the relay operates your voltage is reversed. When non
operated it is normal. The only disadvantage to this is there is always
power to the solenoid in either a make or break condition.
There is most certainly an electronic method that also would work and that
is the toggle flip flop being pulsed which would hold that state till
another pulse reverses it. As with everything you will need a driver
transistor or something to handle the solenoids current and reverse EMF.
Good Luck
Eric
Original Message
From: "Jonathan Peakall" <jpeakall@m...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 2:42 PM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> I am going to have to work with these... The are 5V actuated, latching,
safe
> for H2, and have 1/8" hose barbs on em, and are very small and draw low
> current [noparse]:)[/noparse]
>
> So, any ideas?
>
> Jonathan
>
> www.madlabs.info
>
>
Original Message
> From: "Rodent" <daweasel@s...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, June 25, 2003 11:04 AM
> Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
>
>
> > They make latching relays that do not require reversing the coil power
to
> > turn them off, but they are hard to find.
> >
> >
Original Message
> >
> > > Does the relay have a spare set of contacts that you can use to route
> > > the power?
> >
> > >
Original Message
> >
> > > What is the best way to use a latching valve or relay? The polarity to
> > > the relay/valve must be reversed to open/close the valve.
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
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and
> Body of the message will be ignored.
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>
jim
http://www.geocities.com/jimforkin2003/
Original Message
From: Jonathan Peakall [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=bI1oZ0jIactge_QPnZAeUiPakb-g3myQCz3FF55FpCWFw8Egx7vR7Z4mikZbadIY2vydKfNLHJm4G7A]jpeakall@m...[/url
Sent: Wednesday, June 25, 2003 2:43 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
I am going to have to work with these... The are 5V actuated, latching, safe
for H2, and have 1/8" hose barbs on em, and are very small and draw low
current [noparse]:)[/noparse]
So, any ideas?
Jonathan
www.madlabs.info
Original Message
From: "Rodent" <daweasel@s...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 11:04 AM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> They make latching relays that do not require reversing the coil power to
> turn them off, but they are hard to find.
>
>
Original Message
>
> > Does the relay have a spare set of contacts that you can use to route
> > the power?
>
> >
Original Message
>
> > What is the best way to use a latching valve or relay? The polarity to
> > the relay/valve must be reversed to open/close the valve.
>
>
>
> 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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transistors?
--Stu
Original Message
From: "Rodent" <daweasel@s...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 3:21 PM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> You could use a DPDT relay to swap the coil wires. You would need one
Stamp
> pin to drive the relay and one to fire the coil. I suspect there is
probably
> a way to do it with one Stamp pin, but I can't seem to think if it right
> now.
>
>
Original Message
>
> > I am going to have to work with these... The are 5V actuated, latching,
> safe
> > for H2, and have 1/8" hose barbs on em, and are very small and draw low
> > current [noparse]:)[/noparse]
>
> > > They make latching relays that do not require reversing the coil power
> to
> > > turn them off, but they are hard to find.
> > >
> > >
Original Message
> > >
> > > > Does the relay have a spare set of contacts that you can use to
route
> > > > the power?
> > >
> > > >
Original Message
> > >
> > > > What is the best way to use a latching valve or relay? The polarity
to
> > > > the relay/valve must be reversed to open/close the valve.
>
>
>
> 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://www.beam-online.com/Robots/Tutorials/Freeform/H-bridge/hbridge.html
--Stu
Original Message
From: "Stu Wrenn" <swrenn@z...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 4:26 PM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> If a relay isn't appealing, how about a small H-bridge using small FETs or
> transistors?
> --Stu
>
>
Original Message
> From: "Rodent" <daweasel@s...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, June 25, 2003 3:21 PM
> Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
>
>
> > You could use a DPDT relay to swap the coil wires. You would need one
> Stamp
> > pin to drive the relay and one to fire the coil. I suspect there is
> probably
> > a way to do it with one Stamp pin, but I can't seem to think if it right
> > now.
> >
> >
Original Message
> >
> > > I am going to have to work with these... The are 5V actuated,
latching,
> > safe
> > > for H2, and have 1/8" hose barbs on em, and are very small and draw
low
> > > current [noparse]:)[/noparse]
> >
> > > > They make latching relays that do not require reversing the coil
power
> > to
> > > > turn them off, but they are hard to find.
> > > >
> > > >
Original Message
> > > >
> > > > > Does the relay have a spare set of contacts that you can use to
> route
> > > > > the power?
> > > >
> > > > >
Original Message
> > > >
> > > > > What is the best way to use a latching valve or relay? The
polarity
> to
> > > > > the relay/valve must be reversed to open/close the valve.
> >
> >
> >
> > 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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> >
> >
> >
> >
>
>
>
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>
I was in Carson City, NV this afternoon holding a large sign protesting
proposed massive tax increases, while thinking about your valve circuit...
Using an H-bridge configuration with the valve connected where the motor
would normally be seems like a good approach. You can energize the valve in
either direction, or de-energize it. If you wanted to use two Stamp pins,
it would be a slam-dunk -- one pin turns on the bridge in the "forward"
direction, and one pin turns the bridge on in the "reverse" direction.
Except in this case we're talking "open" and "close" the valve instead of
forward and reverse. (I'm assuming that the valve does not need to be
continuously energized to maintain its current state -- is that correct?)
But do we really have to use two Stamp I/O pins? Each I/O pin has three
possible states -- output high, output low, and high-impedance/input. There
must be a way to take advantage of these three states and translate them to
the three states needed to control the H-bridge (forward/open,
reverse/close, and off)... I'm sure this has been done, but I can't think
of where right now, so I'm trying to re-invent the wheel (while waving my
"cut the budget" sign)...
Here's a configuration that seems like it would work, although I haven't
actually wired it up yet... Grab two optoisolators with NPN output
transistors, such as a 4N25 or a PS2501. Connect the LED of opto #1 (along
with appropriate current limiting resistor in series) between the Stamp I/O
pin and ground. When the Stamp I/O pin is high, the LED will be illuminated
and the opto's NPN transistor will be on.
Connect the LED of opto #2 (again with appropriate current limiting
resistor), between the _same_ Stamp I/O pin and +5V. This opto will turn on
when the Stamp pin is low. So when the Stamp I/O pin is an output, one of
the optos will be on and the other will be off, and they can be toggled by
changing the state of the Stamp pin.
But what about when the Stamp pin is an input -- effectively taking it out
of the circuit? Now current flows through both LEDs, though the current is
less than when only one LED is on (as above). With proper current limiting
resistor values, I believe the LEDs would be bright enough to turn on the
optos, and this will be the H-bridge "off" condition (valve coil
de-energized) -- since the outputs are now both in the same state.
Depending on your H-bridge implementation you'll want both optos to either
output a high or a low so the bridge will be in the off state and your valve
coil will not be energized. If you want both opto outputs to be high when
the LEDs are on, connect the opto's NPNs as emitter followers, with +5V to
the collectors, and a load resistor between the emitters and ground. The
outputs are taken from the emitters. If you want the outputs from the optos
to be low when the LEDs are on, connect the NPNs in a saturated switch
configuration with the emitters grounded and +5V connected through a load
resistor to each collector. The outputs are taken from the collectors.
Does this sound like it might work for your application?
Randy
www.glitchbuster.com
Original Message
From: "Jonathan Peakall" <jpeakall@m...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 11:42 AM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> I am going to have to work with these... The are 5V actuated, latching,
safe
> for H2, and have 1/8" hose barbs on em, and are very small and draw low
> current [noparse]:)[/noparse]
>
> So, any ideas?
>
> Jonathan
They provide isolation (Galvanic Isolation) between input and output
and are very easy to drive.
Nifty idea! Talk about multi-tasking, protesting tax increases AND designing
circuits in your head!
I'll give it a try. It'll be a week or so 'til the valves arrive, I'll let
you know how it turned out, I really like the idea of using one pin.
This list is so handy, I wouldn't have thought of that in a million years.
Jonathan
www.madlabs.info
Original Message
From: "Randy Jones" <randyjones@w...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 8:47 PM
Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> Hi Jonathan,
>
> I was in Carson City, NV this afternoon holding a large sign protesting
> proposed massive tax increases, while thinking about your valve circuit...
>
> Using an H-bridge configuration with the valve connected where the motor
> would normally be seems like a good approach. You can energize the valve
in
> either direction, or de-energize it. If you wanted to use two Stamp pins,
> it would be a slam-dunk -- one pin turns on the bridge in the "forward"
> direction, and one pin turns the bridge on in the "reverse" direction.
> Except in this case we're talking "open" and "close" the valve instead of
> forward and reverse. (I'm assuming that the valve does not need to be
> continuously energized to maintain its current state -- is that correct?)
>
> But do we really have to use two Stamp I/O pins? Each I/O pin has three
> possible states -- output high, output low, and high-impedance/input.
There
> must be a way to take advantage of these three states and translate them
to
> the three states needed to control the H-bridge (forward/open,
> reverse/close, and off)... I'm sure this has been done, but I can't think
> of where right now, so I'm trying to re-invent the wheel (while waving my
> "cut the budget" sign)...
>
> Here's a configuration that seems like it would work, although I haven't
> actually wired it up yet... Grab two optoisolators with NPN output
> transistors, such as a 4N25 or a PS2501. Connect the LED of opto #1
(along
> with appropriate current limiting resistor in series) between the Stamp
I/O
> pin and ground. When the Stamp I/O pin is high, the LED will be
illuminated
> and the opto's NPN transistor will be on.
>
> Connect the LED of opto #2 (again with appropriate current limiting
> resistor), between the _same_ Stamp I/O pin and +5V. This opto will turn
on
> when the Stamp pin is low. So when the Stamp I/O pin is an output, one of
> the optos will be on and the other will be off, and they can be toggled by
> changing the state of the Stamp pin.
>
> But what about when the Stamp pin is an input -- effectively taking it out
> of the circuit? Now current flows through both LEDs, though the current
is
> less than when only one LED is on (as above). With proper current
limiting
> resistor values, I believe the LEDs would be bright enough to turn on the
> optos, and this will be the H-bridge "off" condition (valve coil
> de-energized) -- since the outputs are now both in the same state.
>
> Depending on your H-bridge implementation you'll want both optos to either
> output a high or a low so the bridge will be in the off state and your
valve
> coil will not be energized. If you want both opto outputs to be high when
> the LEDs are on, connect the opto's NPNs as emitter followers, with +5V to
> the collectors, and a load resistor between the emitters and ground. The
> outputs are taken from the emitters. If you want the outputs from the
optos
> to be low when the LEDs are on, connect the NPNs in a saturated switch
> configuration with the emitters grounded and +5V connected through a load
> resistor to each collector. The outputs are taken from the collectors.
>
> Does this sound like it might work for your application?
>
> Randy
>
> www.glitchbuster.com
>
>
>
Original Message
> From: "Jonathan Peakall" <jpeakall@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, June 25, 2003 11:42 AM
> Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
>
>
> > I am going to have to work with these... The are 5V actuated, latching,
> safe
> > for H2, and have 1/8" hose barbs on em, and are very small and draw low
> > current [noparse]:)[/noparse]
> >
> > So, any ideas?
> >
> > Jonathan
>
>
> To UNSUBSCRIBE, just send mail to:
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> 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/
>
>
>
>
>
It's a valve, and no, it doesn't. There are two coil wires, and reversing
polarity changes the state of the valve.
Jonathan
www.madlabs.info
Original Message
From: "Jon Williams" <jwilliams@p...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, June 25, 2003 11:00 AM
Subject: RE: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
> Does the relay have a spare set of contacts that you can use to route
> the power?
>
> -- Jon Williams
> -- Parallax
>
>
Original Message
> From: Jonathan Peakall [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=00ebuHR7H5YVL5t5szKZK_s3ThYCej3WF8jg9RDzW6xow66BZemqJP9lQyRnuXV4RonhF2renD0hs3E]jpeakall@m...[/url
> Sent: Wednesday, June 25, 2003 11:46 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
>
>
> Hi All,
>
> What is the best way to use a latching valve or relay? The polarity to
> the relay/valve must be reversed to open/close the valve.
>
> Jonathan
>
> www.madlabs.info
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> http://docs.yahoo.com/info/terms/
>
>
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> This message has been scanned by WebShield. Please report SPAM to
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>
>
>
>
Drive the plus side with one stamp pin, and the
minus side with another stamp pin. Stamp pins
are good for +5 at 23 mA, so this should work.
Failing that, won't an 'H-bridge' allow you to
reverse the voltage and current in a motor?
Wouldn't that work for a latched relay, also?
--- In basicstamps@yahoogroups.com, "Jonathan Peakall"
<jpeakall@m...> wrote:
> I am going to have to work with these... The are 5V actuated,
latching, safe
> for H2, and have 1/8" hose barbs on em, and are very small and draw
low
> current [noparse]:)[/noparse]
>
> So, any ideas?
>
> Jonathan
>
> www.madlabs.info
>
>
Original Message
> From: "Rodent" <daweasel@s...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, June 25, 2003 11:04 AM
> Subject: Re: [noparse][[/noparse]basicstamps] How to handle a latching valve/relay
>
>
> > They make latching relays that do not require reversing the coil
power to
> > turn them off, but they are hard to find.
> >
> >
Original Message
> >
> > > Does the relay have a spare set of contacts that you can use to
route
> > > the power?
> >
> > >
Original Message
> >
> > > What is the best way to use a latching valve or relay? The
polarity to
> > > the relay/valve must be reversed to open/close the valve.
> >
> >
> >
> > 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/
> >
> >
> >
> >
> >