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Javelin Stamp heating issue — Parallax Forums

Javelin Stamp heating issue

ArchiverArchiver Posts: 46,084
edited 2003-03-13 12:22 in General Discussion
Hi,

I'm not sure if there is a specific group for Javelin stamps, but I
didn't find one listed on the parallax website.

I just bought a javelin stamp starter kit 2 days ago and it works
fine so far except for a heating issue. When I touch the address
latch chip on the stamp, it feels really really hot (after even 2
minutes of use). I'm using a 9V DC (proper polarity) power supply
that's rated at 500mA. I built a simple test circuit (flashing LEDs)
which uses very little current and I'm only flashing at 5 Hz, so I
doubt I'm overloading the CPU.


Is the stamp supposed to get this hot? If not, how can I start
troubleshooting? If so, can anyone recommend cooling devices/products?

thanks,
-sridhar

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-03-13 06:43
    Hi,

    There is a Javelin discussion group.
    Go to the parallax website.
    Select from products menu: javelin stamp -> discussion.

    If you don't power external circuitry from the javelins VDD pin,
    No chip should get really hot. Check your circuitry for
    Heavy loads or possible shorts.

    Regards peter

    Oorspronkelijk bericht
    Van: i_hate_stupid_alias_names [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=k3Ye5KHPYgBSvS405gZNWIVj5YcIcuTQHc8-XYGTHgD8bG_Qf6VWpdAjpq6HwqZeCq05V7jqlpcdSlOam6GLdA]isthereanidiot@y...[/url
    Verzonden: donderdag 13 maart 2003 03:39
    Aan: basicstamps@yahoogroups.com
    Onderwerp: [noparse][[/noparse]basicstamps] Javelin Stamp heating issue

    Hi,

    I'm not sure if there is a specific group for Javelin stamps, but I
    didn't find one listed on the parallax website.

    I just bought a javelin stamp starter kit 2 days ago and it works
    fine so far except for a heating issue. When I touch the address
    latch chip on the stamp, it feels really really hot (after even 2
    minutes of use). I'm using a 9V DC (proper polarity) power supply
    that's rated at 500mA. I built a simple test circuit (flashing LEDs)
    which uses very little current and I'm only flashing at 5 Hz, so I
    doubt I'm overloading the CPU.


    Is the stamp supposed to get this hot? If not, how can I start
    troubleshooting? If so, can anyone recommend cooling devices/products?

    thanks,
    -sridhar


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  • ArchiverArchiver Posts: 46,084
    edited 2003-03-13 10:30
    I posted there too (about an hour after I posted here). No reply
    yet :-).

    Meanwhile, I tested the circuit with NO external circuit attached.
    just powered it up. it's been 5 minutes and the chip feels hot.

    How hot is the chip supposed to get? I'd estimate mine's reaching
    around 70-80 C because I can barely touch it for more than 3 seconds.
    And my hands are perfectly clean so I'm sure there are no conductive
    elements on it shorting anything out.

    I'll try to hookup and a thermometer and measure the actual temp.


    thanks for the help so far,
    -sridhar

    --- In basicstamps@yahoogroups.com, "peter verkaik"
    <peterverkaik@b...> wrote:
    > Hi,
    >
    > There is a Javelin discussion group.
    > Go to the parallax website.
    > Select from products menu: javelin stamp -> discussion.
    >
    > If you don't power external circuitry from the javelins VDD pin,
    > No chip should get really hot. Check your circuitry for
    > Heavy loads or possible shorts.
    >
    > Regards peter
    >
    >
    >
    Oorspronkelijk bericht
    > Van: i_hate_stupid_alias_names [noparse][[/noparse]mailto:isthereanidiot@y...]
    > Verzonden: donderdag 13 maart 2003 03:39
    > Aan: basicstamps@yahoogroups.com
    > Onderwerp: [noparse][[/noparse]basicstamps] Javelin Stamp heating issue
    >
    > Hi,
    >
    > I'm not sure if there is a specific group for Javelin stamps, but I
    > didn't find one listed on the parallax website.
    >
    > I just bought a javelin stamp starter kit 2 days ago and it works
    > fine so far except for a heating issue. When I touch the address
    > latch chip on the stamp, it feels really really hot (after even 2
    > minutes of use). I'm using a 9V DC (proper polarity) power supply
    > that's rated at 500mA. I built a simple test circuit (flashing LEDs)
    > which uses very little current and I'm only flashing at 5 Hz, so I
    > doubt I'm overloading the CPU.
    >
    >
    > Is the stamp supposed to get this hot? If not, how can I start
    > troubleshooting? If so, can anyone recommend cooling
    devices/products?
    >
    > thanks,
    > -sridhar
    >
    >
    > 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 2003-03-13 12:22
    Are you sure it isn't the voltage regulator IC that is getting hot?
    The 9v DC power supply may be providing more like 12v-15v and not 9v like
    you think. IF possible try a 6v DC power supply (provides more like 7-9v)
    and see what happens.
    Original Message
    From: i_hate_stupid_alias_names [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ritcq2nBPoxMo21hv44zgYetIS_W6Tcgbq30MbJtcPgPkzXsOdthdsIchrY20wZ88s4AGTkvBRt1LKolM28a]isthereanidiot@y...[/url
    Sent: Thursday, March 13, 2003 4:30 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: Javelin Stamp heating issue


    I posted there too (about an hour after I posted here). No reply
    yet :-).

    Meanwhile, I tested the circuit with NO external circuit attached.
    just powered it up. it's been 5 minutes and the chip feels hot.

    How hot is the chip supposed to get? I'd estimate mine's reaching
    around 70-80 C because I can barely touch it for more than 3 seconds.
    And my hands are perfectly clean so I'm sure there are no conductive
    elements on it shorting anything out.

    I'll try to hookup and a thermometer and measure the actual temp.


    thanks for the help so far,
    -sridhar

    --- In basicstamps@yahoogroups.com, "peter verkaik"
    <peterverkaik@b...> wrote:
    > Hi,
    >
    > There is a Javelin discussion group.
    > Go to the parallax website.
    > Select from products menu: javelin stamp -> discussion.
    >
    > If you don't power external circuitry from the javelins VDD pin,
    > No chip should get really hot. Check your circuitry for
    > Heavy loads or possible shorts.
    >
    > Regards peter
    >
    >
    >
    Oorspronkelijk bericht
    > Van: i_hate_stupid_alias_names [noparse][[/noparse]mailto:isthereanidiot@y...]
    > Verzonden: donderdag 13 maart 2003 03:39
    > Aan: basicstamps@yahoogroups.com
    > Onderwerp: [noparse][[/noparse]basicstamps] Javelin Stamp heating issue
    >
    > Hi,
    >
    > I'm not sure if there is a specific group for Javelin stamps, but I
    > didn't find one listed on the parallax website.
    >
    > I just bought a javelin stamp starter kit 2 days ago and it works
    > fine so far except for a heating issue. When I touch the address
    > latch chip on the stamp, it feels really really hot (after even 2
    > minutes of use). I'm using a 9V DC (proper polarity) power supply
    > that's rated at 500mA. I built a simple test circuit (flashing LEDs)
    > which uses very little current and I'm only flashing at 5 Hz, so I
    > doubt I'm overloading the CPU.
    >
    >
    > Is the stamp supposed to get this hot? If not, how can I start
    > troubleshooting? If so, can anyone recommend cooling
    devices/products?
    >
    > thanks,
    > -sridhar
    >
    >
    > 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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