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BS and Rare Earth Magnets — Parallax Forums

BS and Rare Earth Magnets

ArchiverArchiver Posts: 46,084
edited 2003-07-30 21:00 in General Discussion
I have an application(circuit and battery) that is very small and
would like to be able to stick up anywhere with a magnet(from an old
hard drive). Question- will the magnet cause problems for a micro
(like the BS) if yes and I go to a more simple route(i.e.
MOSFET,transistor,...), will the same problems apply?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-07-29 21:59
    In a message dated 7/29/2003 4:57:05 PM Eastern Standard Time,
    iphillips@s... writes:


    > I have an application(circuit and battery) that is very small and
    > would like to be able to stick up anywhere with a magnet(from an old
    > hard drive). Question- will the magnet cause problems for a micro
    > (like the BS) if yes and I go to a more simple route(i.e.
    > MOSFET,transistor,...), will the same problems apply?
    >
    >

    I wouldn't want to take the chance. Have you tried Mounting Foam Tape from
    your local drug store? Very, very strong - I use it in countless applications.
    Sid Weaver
    W4EKQ
    Port Richey, FL


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-29 22:14
    I thought about that but really wanted the ability to move stuff around
    a lot.
    Ian


    Original Message
    From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=a5wdb7RikNZl6ZYH0VQG-W9SxZkholNiLfH8YdQRU6hO4_3SiW2yAJICNv-LnNY4kTwfi2QISV4]Newzed@a...[/url
    Sent: July 29, 2003 4:59 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] BS and Rare Earth Magnets

    In a message dated 7/29/2003 4:57:05 PM Eastern Standard Time,
    iphillips@s... writes:


    > I have an application(circuit and battery) that is very small and
    > would like to be able to stick up anywhere with a magnet(from an old
    > hard drive). Question- will the magnet cause problems for a micro
    > (like the BS) if yes and I go to a more simple route(i.e.
    > MOSFET,transistor,...), will the same problems apply?
    >
    >

    I wouldn't want to take the chance. Have you tried Mounting Foam Tape
    from
    your local drug store? Very, very strong - I use it in countless
    applications.
    Sid Weaver
    W4EKQ
    Port Richey, FL


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


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  • ArchiverArchiver Posts: 46,084
    edited 2003-07-29 22:47
    it doesn't seem like a magnet (albeit a rather powerful one) could do much
    damage to the stamp or associated circuitry, except from a mechanical point
    of view. You would have problems with anything that depended on magnetic
    fields, ofcourse, and I suppose delicate structures that could be ripped
    away by a powerful magnetic field (I've heard that people have to be checked
    with metal detectors before they can enter an MRI gadget). if your're
    concerned, and still want to use the magnet, you could probably rig up a
    shield with mu-metal from an old CRT shield, or possibly just a regular
    piece of steel.

    just my 2.5c.


    d...

    >
    Original Message
    > From: Ian Phillips [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=R0N91TbV2vLLy8Boa9A5WbattfL48kp05w7tpt0NR5BSi6S3SLrHBaXolhP0gXCkL8XgXV_BZhkOqIUpM6wu]iphillips@s...[/url
    > Sent: Tuesday, July 29, 2003 2:15 PM
    > To: basicstamps@yahoogroups.com
    > Subject: RE: [noparse][[/noparse]basicstamps] BS and Rare Earth Magnets
    >
    >
    > I thought about that but really wanted the ability to move stuff around
    > a lot.
    > Ian
    >
    >
    >
    Original Message
    > From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=flZD1A5sHTb1wTLGODBqgVEMPhqyD_hnp498qUmcWB9pjO7ODXJYaW57apAkuonX-ULapr9ENDA]Newzed@a...[/url
    > Sent: July 29, 2003 4:59 PM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] BS and Rare Earth Magnets
    >
    > In a message dated 7/29/2003 4:57:05 PM Eastern Standard Time,
    > iphillips@s... writes:
    >
    >
    > > I have an application(circuit and battery) that is very small and
    > > would like to be able to stick up anywhere with a magnet(from an old
    > > hard drive). Question- will the magnet cause problems for a micro
    > > (like the BS) if yes and I go to a more simple route(i.e.
    > > MOSFET,transistor,...), will the same problems apply?
    > >
    > >
    >
    > I wouldn't want to take the chance. Have you tried Mounting Foam Tape
    > from
    > your local drug store? Very, very strong - I use it in countless
    > applications.
    > Sid Weaver
    > W4EKQ
    > Port Richey, FL
    >
    >
    > [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:
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    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-29 23:24
    My 2 cents: It shouldn't be a problem.
    All of the BS2's operation is based on
    CMOS logic and PIC processing -- there is
    no magnetic material (like a hard disk or
    floppy disk) involved. I assume you'll
    have a 9-volt battery involved -- also
    not a problem.

    I believe MOSFET and transistors are also
    pretty inert, magnetically.

    I'm sure if I'm wrong on this, I'll hear
    about it!

    --- In basicstamps@yahoogroups.com, "iphillipsca" <iphillips@s...>
    wrote:
    > I have an application(circuit and battery) that is very small and
    > would like to be able to stick up anywhere with a magnet(from an
    old
    > hard drive). Question- will the magnet cause problems for a micro
    > (like the BS) if yes and I go to a more simple route(i.e.
    > MOSFET,transistor,...), will the same problems apply?
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-29 23:25
    Also, Velcro can be used...

    --- In basicstamps@yahoogroups.com, "Ian Phillips" <iphillips@s...>
    wrote:
    > I thought about that but really wanted the ability to move stuff
    around
    > a lot.
    > Ian
    >
    >
    >
    Original Message
    > From: Newzed@a... [noparse][[/noparse]mailto:Newzed@a...]
    > Sent: July 29, 2003 4:59 PM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] BS and Rare Earth Magnets
    >
    > In a message dated 7/29/2003 4:57:05 PM Eastern Standard Time,
    > iphillips@s... writes:
    >
    >
    > > I have an application(circuit and battery) that is very small and
    > > would like to be able to stick up anywhere with a magnet(from an
    old
    > > hard drive). Question- will the magnet cause problems for a micro
    > > (like the BS) if yes and I go to a more simple route(i.e.
    > > MOSFET,transistor,...), will the same problems apply?
    > >
    > >
    >
    > I wouldn't want to take the chance. Have you tried Mounting Foam
    Tape
    > from
    > your local drug store? Very, very strong - I use it in countless
    > applications.
    > Sid Weaver
    > W4EKQ
    > Port Richey, FL
    >
    >
    > [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 2003-07-29 23:30
    For Allen.Lane

    I have a very strong rare earth magnet. I pass it over a couple of spare
    chips and there was an attaction between the chips and the magnet. Not SNAP ! -

    just a gentle pull. There is something magnetizable in the chip - maybe its
    the pins.


    Sid Weaver
    W4EKQ
    Port Richey, FL


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-30 00:35
    Attach a stand-off, or small block of wood, between the magnet and the
    circuit to diminish the magnetic susceptibility at the circuit location.
    I've done this with a hall sensor on one end of a nylon standoff and a
    button magnet at the other, to make a movable stand. The hall sensor
    detects another close magnet, but is insensitive to the button magnet.

    Dennis

    Original Message
    From: iphillipsca [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=IR8wkKCAzes-Ta0imHI_WOcZ67kDSET9a0EIzdNW_zboJOJ0bgW1NjP1Yti-6gDCMONT3GNF9sO48Up4ck94idk]iphillips@s...[/url
    Sent: Tuesday, July 29, 2003 1:54 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] BS and Rare Earth Magnets


    I have an application(circuit and battery) that is very small and
    would like to be able to stick up anywhere with a magnet(from an old
    hard drive). Question- will the magnet cause problems for a micro (like
    the BS) if yes and I go to a more simple route(i.e.
    MOSFET,transistor,...), will the same problems apply?


    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/
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-30 13:53
    Interesting! Sure, there may be some
    magnetically active compounds in the DIPs.
    The point of my earlier post was that there
    is no operation in the chips that depends
    on these magnetic properties.

    When you store data in an eeprom or a
    microprocessor's memory, it's
    stored as a charge on a gate -- not as
    magnetic domains aligned a certain way
    on a piece of magnetic media.

    Thus your magnet wouldn't 'erase' the
    chip -- as it definitely would 'erase'
    a piece of VCR tape.


    --- In basicstamps@yahoogroups.com, Newzed@a... wrote:
    > For Allen.Lane
    >
    > I have a very strong rare earth magnet. I pass it over a couple of
    spare
    > chips and there was an attaction between the chips and the magnet.
    Not SNAP ! -
    > just a gentle pull. There is something magnetizable in the chip -
    maybe its
    > the pins.
    >
    >
    > Sid Weaver
    > W4EKQ
    > Port Richey, FL
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-30 16:22
    I'm guessing, though, that a static discharge could probably Muck up these chips
    (the SNAP!).

    That's a concern with any IC though....so those precautions would be good to
    take!

    sb

    Original Message
    From: Newzed@a...
    Date: Tuesday, July 29, 2003 3:30 pm
    Subject: Re: [noparse][[/noparse]basicstamps] Re: BS and Rare Earth Magnets

    > For Allen.Lane
    >
    > I have a very strong rare earth magnet. I pass it over a couple
    > of spare
    > chips and there was an attaction between the chips and the magnet.
    > Not SNAP ! -
    > just a gentle pull. There is something magnetizable in the chip -
    > maybe its
    > the pins.
    >
    >
    > Sid Weaver
    > W4EKQ
    > Port Richey, FL
    >
    >
    > [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 2003-07-30 20:55
    I would not think it would cause a problem since you are not moving the
    conductor with respect to the field. I tend to use Velcro as it is light
    and cheap or double stick foam tape. Inductors would have some different
    effects in a strong magnetic field depending on orientation, core material
    etc but I doubt the stamp itself would be having problems because of this.
    Larry


    At 08:53 PM 7/29/03 +0000, you wrote:
    >I have an application(circuit and battery) that is very small and
    >would like to be able to stick up anywhere with a magnet(from an old
    >hard drive). Question- will the magnet cause problems for a micro
    >(like the BS) if yes and I go to a more simple route(i.e.
    >MOSFET,transistor,...), will the same problems apply?
    >
    >
    >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 2003-07-30 21:00
    The lead frame is probably Kovar and may be magnetic as well as the pins.
    Shouldn't be a problem magnetized other than it would attract ferrous
    materials so you could get a short circuit if conductive filings are sucked
    into the wrong areas.
    Larry


    At 06:30 PM 7/29/03 -0400, you wrote:
    >For Allen.Lane
    >
    >I have a very strong rare earth magnet. I pass it over a couple of spare
    >chips and there was an attaction between the chips and the magnet. Not
    >SNAP ! -
    >just a gentle pull. There is something magnetizable in the chip - maybe its
    >the pins.
    >
    >
    >Sid Weaver
    >W4EKQ
    >Port Richey, FL
    >
    >
    >[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/
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