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attaching a relay on an output pin — Parallax Forums

attaching a relay on an output pin

ArchiverArchiver Posts: 46,084
edited 2003-11-27 16:04 in General Discussion
Hi, I'm trying to attach a 6vdc trigger industrial strength coil
relay to an output on my basic stamp 2. It is being used to control
the on/off of a 110 volts, 6 amps ac motor. But right now i'm just
stuck at making sure the relay works. I'v tested the relay that I
was planning to use and it works fine with a manual switch. But when
I hooked it up to the stamp it won't switch states. The led attached
to the same output is going from low to high, but the relay is not
following, it is getting power it's just not being triggered. I
don't know what I'm missing? I would appreaciate any and all
suggestions...Oh and I did have it hooked up to an opto isolater 4n32
but it didn't work so I began to strip it down and now I'm just as
confused as ever.

thanks jeff

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 15:13
    Hi, I'm no stamp expert but I do have an electronics
    background and I'm guessing that the stamp is not sourcing
    enough current for the relay. Relay's typically take a
    substantial amount of current to trigger. You might try
    looking at the specs for the relay and the output pin of
    the stamp that you are using. Probably you will have to
    use a transistor to switch a high current to the coil of
    the relay using the stamp as the trigger. Let me know if
    you need more information.


    On Wed, 26 Nov 2003 05:35:00 -0000
    "jeff_alten" <jeffalten@h...> wrote:
    >Hi, I'm trying to attach a 6vdc trigger industrial
    >strength coil
    >relay to an output on my basic stamp 2. It is being used
    >to control
    >the on/off of a 110 volts, 6 amps ac motor. But right now
    >i'm just
    >stuck at making sure the relay works. I'v tested the
    >relay that I
    >was planning to use and it works fine with a manual
    >switch. But when
    >I hooked it up to the stamp it won't switch states. The
    >led attached
    >to the same output is going from low to high, but the
    >relay is not
    >following, it is getting power it's just not being
    >triggered. I
    >don't know what I'm missing? I would appreaciate any and
    >all
    >suggestions...Oh and I did have it hooked up to an opto
    >isolater 4n32
    >but it didn't work so I began to strip it down and now
    >I'm just as
    >confused as ever.
    >
    >thanks jeff
    >
    >
    >
    >To UNSUBSCRIBE, just send mail to:
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    >the Subject and Body of the message will be ignored.
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    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 15:37
    You can not drive the relay with a Stamp output pin. You must use a
    Darlington transistor which is triggered by the Stamp. If the relay operates at
    6VDC
    then the voltage to the Darlington must be 6VDC. Connect the positive side of
    your relay to 6V, the negative side to the Darlington output. A high from
    the Stamp will turn the Darlington on, sending the collector to ground, which
    will close your relay.

    Sid


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 15:51
    For schematics to hook up relays, etc. to the stamps check out this web
    site:
    jim
    http://www.geocities.com/jimforkin2003/


    Original Message
    From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=io7NuE5WAeKKQX0mS7peaND6t0RP3MxRM6wD_UFZ6augRxnAXLePKvC1WiWIEwhW0CZgORAs]Newzed@a...[/url
    Sent: Wednesday, November 26, 2003 10:37 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin


    You can not drive the relay with a Stamp output pin. You must use a
    Darlington transistor which is triggered by the Stamp. If the relay
    operates at 6VDC
    then the voltage to the Darlington must be 6VDC. Connect the positive side
    of
    your relay to 6V, the negative side to the Darlington output. A high from
    the Stamp will turn the Darlington on, sending the collector to ground,
    which
    will close your relay.

    Sid


    [noparse][[/noparse]Non-text portions of this message have been removed]


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  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 16:06
    You do not need a Darlington device to drive a relay.
    Darlingtons are normally used when you need a very high gain.
    Darlingtons requires a more carefull design, the Vcesat is higher
    that a plain bjt device.
    Also the Icb and Ice leakage currents could be a problem if the
    circuit is not designed properly.
    a simple npn or pnp or even better a mosfet that is the only thing
    you need.
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 16:07
    A darlington will work. I personally like to use a logic level MOSFET (see
    http://www.al-williams.com/components.htm for an IRL520). These will turn on
    hard to ground when you put 5V on the gate and they are good to 9A (with
    heat sinking).

    The only trick I use when using them is to put a 100K or so resistor from
    the gate to ground. This doesn't really do anything for the circuit, but it
    makes it less likely that you will damage the part while handling the
    circuit -- it gives any ESD a place to go instead of through the gate oxide!

    Oddly enough, FETs are really what they were looking for when they developed
    the transistor. It just took awhile to get the FETs right and then longer
    still to make them handle power. But now they are cheap and easy to use so
    unless you are shaving pennies, I usually just use the FETs for everything.

    Al Williams
    AWC
    * New: Read position data: http://www.al-williams.com/pak11.htm


    >
    Original Message
    > From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=QBJw-grLAvg3eqU5ow_7MQaZyMMvOD2MYddWPXZDJDOQUrP3U4jAHlNZSXAXcPCSqmdzHfi5]Newzed@a...[/url
    > Sent: Wednesday, November 26, 2003 9:37 AM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin
    >
    >
    > You can not drive the relay with a Stamp output pin. You must use a
    > Darlington transistor which is triggered by the Stamp. If
    > the relay operates at 6VDC
    > then the voltage to the Darlington must be 6VDC. Connect the
    > positive side of
    > your relay to 6V, the negative side to the Darlington output.
    > A high from
    > the Stamp will turn the Darlington on, sending the collector
    > to ground, which
    > will close your relay.
    >
    > Sid
    >
    >
    > [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/
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 16:12
    check out http://www.geocities.com/jimforkin2003/ for schematics to hook up
    relays, lamps, etc. to stamps.
    jim


    Original Message
    From: STEVE JOHNSON [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=p2S0dW1YtoVyv8I54voXzgRJzGXDJ4HgZQ2871YCGUdTh66aqmIAmu4vEXhxgBP6BbvRomJh8IOV-i8GgIhdaQ]cmmdrdata@c...[/url
    Sent: Wednesday, November 26, 2003 10:14 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin


    Hi, I'm no stamp expert but I do have an electronics
    background and I'm guessing that the stamp is not sourcing
    enough current for the relay. Relay's typically take a
    substantial amount of current to trigger. You might try
    looking at the specs for the relay and the output pin of
    the stamp that you are using. Probably you will have to
    use a transistor to switch a high current to the coil of
    the relay using the stamp as the trigger. Let me know if
    you need more information.


    On Wed, 26 Nov 2003 05:35:00 -0000
    "jeff_alten" <jeffalten@h...> wrote:
    >Hi, I'm trying to attach a 6vdc trigger industrial
    >strength coil
    >relay to an output on my basic stamp 2. It is being used
    >to control
    >the on/off of a 110 volts, 6 amps ac motor. But right now
    >i'm just
    >stuck at making sure the relay works. I'v tested the
    >relay that I
    >was planning to use and it works fine with a manual
    >switch. But when
    >I hooked it up to the stamp it won't switch states. The
    >led attached
    >to the same output is going from low to high, but the
    >relay is not
    >following, it is getting power it's just not being
    >triggered. I
    >don't know what I'm missing? I would appreaciate any and
    >all
    >suggestions...Oh and I did have it hooked up to an opto
    >isolater 4n32
    >but it didn't work so I began to strip it down and now
    >I'm just as
    >confused as ever.
    >
    >thanks jeff
    >
    >
    >
    >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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  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 16:18
    check out this web site for information using darlingtons with the stamp.
    http://www.geocities.com/jimforkin2003/
    jim


    Original Message
    From: jeff alten [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=qVvwnv-3e0xAgWRd2dd24lod_Y3UxIeQtc1s9RDMx54TV3dFMc4XoiMsfDCXmlGVjs4V3yNtpITjTL0]jeffalten@h...[/url
    Sent: Wednesday, November 26, 2003 12:07 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin


    I have no idea what a darlington transistor is, are there many different
    ones with different specks or just a couple and where would I be able to
    find the right one for me?
    Original Message
    From: <Newzed@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, November 26, 2003 9:37 AM
    Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin


    > You can not drive the relay with a Stamp output pin. You must use a
    > Darlington transistor which is triggered by the Stamp. If the relay
    operates at 6VDC
    > then the voltage to the Darlington must be 6VDC. Connect the positive
    side of
    > your relay to 6V, the negative side to the Darlington output. A high from
    > the Stamp will turn the Darlington on, sending the collector to ground,
    which
    > will close your relay.
    >
    > Sid
    >
    >
    > [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
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  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 17:06
    I have no idea what a darlington transistor is, are there many different
    ones with different specks or just a couple and where would I be able to
    find the right one for me?
    Original Message
    From: <Newzed@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, November 26, 2003 9:37 AM
    Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin


    > You can not drive the relay with a Stamp output pin. You must use a
    > Darlington transistor which is triggered by the Stamp. If the relay
    operates at 6VDC
    > then the voltage to the Darlington must be 6VDC. Connect the positive
    side of
    > your relay to 6V, the negative side to the Darlington output. A high from
    > the Stamp will turn the Darlington on, sending the collector to ground,
    which
    > will close your relay.
    >
    > Sid
    >
    >
    > [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/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 17:12
    Hey steve thanks for the advice, I'm no expert in either. The stamp seems
    to only be putting out 3.52 volts and the coil does need about 5 volts. I
    tried using a tip 120 & 125, because I've used them to boost the voltage
    from a 555 but it doesn't seem to work with Basic Stamp. Is there any
    specific kind of transistor.
    thanks, jeff
    Original Message
    From: "STEVE JOHNSON" <cmmdrdata@c...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, November 26, 2003 9:13 AM
    Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin


    > Hi, I'm no stamp expert but I do have an electronics
    > background and I'm guessing that the stamp is not sourcing
    > enough current for the relay. Relay's typically take a
    > substantial amount of current to trigger. You might try
    > looking at the specs for the relay and the output pin of
    > the stamp that you are using. Probably you will have to
    > use a transistor to switch a high current to the coil of
    > the relay using the stamp as the trigger. Let me know if
    > you need more information.
    >
    >
    > On Wed, 26 Nov 2003 05:35:00 -0000
    > "jeff_alten" <jeffalten@h...> wrote:
    > >Hi, I'm trying to attach a 6vdc trigger industrial
    > >strength coil
    > >relay to an output on my basic stamp 2. It is being used
    > >to control
    > >the on/off of a 110 volts, 6 amps ac motor. But right now
    > >i'm just
    > >stuck at making sure the relay works. I'v tested the
    > >relay that I
    > >was planning to use and it works fine with a manual
    > >switch. But when
    > >I hooked it up to the stamp it won't switch states. The
    > >led attached
    > >to the same output is going from low to high, but the
    > >relay is not
    > >following, it is getting power it's just not being
    > >triggered. I
    > >don't know what I'm missing? I would appreaciate any and
    > >all
    > >suggestions...Oh and I did have it hooked up to an opto
    > >isolater 4n32
    > >but it didn't work so I began to strip it down and now
    > >I'm just as
    > >confused as ever.
    > >
    > >thanks jeff
    > >
    > >
    > >
    > >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/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 19:31
    In a message dated 11/26/2003 1:32:59 PM Eastern Standard Time,
    jeffalten@h... writes:


    > I have no idea what a darlington transistor is, are there many different
    > ones with different specks or just a couple and where would I be able to
    > find the right one for me?

    ULN2003 - seven channels - Digikey
    UILN2803 - eight channels - Digikey

    Sid


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 19:49
    I don't know if this is relevant, but I've hooked up reed relays (with
    <25ma draw) to stamp pins directly, no problems whatsoever. I designed
    some electronics for a system that did hydrogen-oxygen hydrolysis and a
    timed explosion of gas.

    On Wed, 26 Nov 2003, Jim Forkin wrote:

    > check out http://www.geocities.com/jimforkin2003/ for schematics to hook up
    > relays, lamps, etc. to stamps.
    > jim
    >
    >
    >
    Original Message
    > From: STEVE JOHNSON [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=--a2T1JCi2lf2HmJ6BxhJAt6e2ZUhjKo02XUOsnlQNPkVC73MJt0yVNxtXyQv-7BWaasYkoIuyf4nAi_]cmmdrdata@c...[/url
    > Sent: Wednesday, November 26, 2003 10:14 AM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an output pin
    >
    >
    > Hi, I'm no stamp expert but I do have an electronics
    > background and I'm guessing that the stamp is not sourcing
    > enough current for the relay. Relay's typically take a
    > substantial amount of current to trigger. You might try
    > looking at the specs for the relay and the output pin of
    > the stamp that you are using. Probably you will have to
    > use a transistor to switch a high current to the coil of
    > the relay using the stamp as the trigger. Let me know if
    > you need more information.
    >
    >
    > On Wed, 26 Nov 2003 05:35:00 -0000
    > "jeff_alten" <jeffalten@h...> wrote:
    > >Hi, I'm trying to attach a 6vdc trigger industrial
    > >strength coil
    > >relay to an output on my basic stamp 2. It is being used
    > >to control
    > >the on/off of a 110 volts, 6 amps ac motor. But right now
    > >i'm just
    > >stuck at making sure the relay works. I'v tested the
    > >relay that I
    > >was planning to use and it works fine with a manual
    > >switch. But when
    > >I hooked it up to the stamp it won't switch states. The
    > >led attached
    > >to the same output is going from low to high, but the
    > >relay is not
    > >following, it is getting power it's just not being
    > >triggered. I
    > >don't know what I'm missing? I would appreaciate any and
    > >all
    > >suggestions...Oh and I did have it hooked up to an opto
    > >isolater 4n32
    > >but it didn't work so I began to strip it down and now
    > >I'm just as
    > >confused as ever.
    > >
    > >thanks jeff
    > >
    > >
    > >
    > >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.
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    >
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    >

    Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
    Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
    email: lamont@a... WWW: http://www.serv.net
    "Do not fear mistakes, There Are None" - Miles Davis
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 20:17
    you might try using just a ttl noninverting buffer you
    can even tie multiple inputs together and outputs to
    get enough output don't forget the quenching diode
    across the realy coil good luck
    --- jeff alten <jeffalten@h...> wrote:
    > Hey steve thanks for the advice, I'm no expert in
    > either. The stamp seems
    > to only be putting out 3.52 volts and the coil does
    > need about 5 volts. I
    > tried using a tip 120 & 125, because I've used them
    > to boost the voltage
    > from a 555 but it doesn't seem to work with Basic
    > Stamp. Is there any
    > specific kind of transistor.
    > thanks, jeff
    >
    Original Message
    > From: "STEVE JOHNSON" <cmmdrdata@c...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Wednesday, November 26, 2003 9:13 AM
    > Subject: Re: [noparse][[/noparse]basicstamps] attaching a relay on an
    > output pin
    >
    >
    > > Hi, I'm no stamp expert but I do have an
    > electronics
    > > background and I'm guessing that the stamp is not
    > sourcing
    > > enough current for the relay. Relay's typically
    > take a
    > > substantial amount of current to trigger. You
    > might try
    > > looking at the specs for the relay and the output
    > pin of
    > > the stamp that you are using. Probably you will
    > have to
    > > use a transistor to switch a high current to the
    > coil of
    > > the relay using the stamp as the trigger. Let me
    > know if
    > > you need more information.
    > >
    > >
    > > On Wed, 26 Nov 2003 05:35:00 -0000
    > > "jeff_alten" <jeffalten@h...> wrote:
    > > >Hi, I'm trying to attach a 6vdc trigger
    > industrial
    > > >strength coil
    > > >relay to an output on my basic stamp 2. It is
    > being used
    > > >to control
    > > >the on/off of a 110 volts, 6 amps ac motor. But
    > right now
    > > >i'm just
    > > >stuck at making sure the relay works. I'v tested
    > the
    > > >relay that I
    > > >was planning to use and it works fine with a
    > manual
    > > >switch. But when
    > > >I hooked it up to the stamp it won't switch
    > states. The
    > > >led attached
    > > >to the same output is going from low to high, but
    > the
    > > >relay is not
    > > >following, it is getting power it's just not
    > being
    > > >triggered. I
    > > >don't know what I'm missing? I would appreaciate
    > any and
    > > >all
    > > >suggestions...Oh and I did have it hooked up to
    > an opto
    > > >isolater 4n32
    > > >but it didn't work so I began to strip it down
    > and now
    > > >I'm just as
    > > >confused as ever.
    > > >
    > > >thanks jeff
    > > >
    > > >
    > > >
    > > >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:
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  • ArchiverArchiver Posts: 46,084
    edited 2003-11-26 20:37
    You have been lucky.
  • ArchiverArchiver Posts: 46,084
    edited 2003-11-27 15:55
    In a message dated 11/26/2003 11:49:17 AM Eastern Standard Time,
    alw@a... writes:


    > A darlington will work. I personally like to use a logic level MOSFET (see
    > http://www.al-williams.com/components.htm for an IRL520). These will turn on
    > hard to ground when you put 5V on the gate and they are good to 9A (with
    > heat sinking).
    >

    Happy Thanksgiving, Al.

    I've never used a MOSFET - I don't even have one - but would like to know
    how. Is the gate like the base, the drain like the collector and the source
    like
    the emitter?

    Do MOSFETs come in arrays like the ULN2803? One of my boards has 13 relays,
    and 13 TO220 chips would take up a lot of room. If I wanted to use one to
    operate a relay, would I add a diode across the drain and the source - cathode
    to
    drain?

    Thanks

    Sid


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  • ArchiverArchiver Posts: 46,084
    edited 2003-11-27 16:04
    In a message dated 11/27/2003 8:00:52 AM Pacific Standard Time,
    Newzed@a... writes:
    I've never used a MOSFET - I don't even have one - but would like to know
    how. Is the gate like the base, the drain like the collector and the source
    like
    the emitter?
    YES


    [noparse][[/noparse]Non-text portions of this message have been removed]
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