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bs2 vin vdd & fun fun fun!! — Parallax Forums

bs2 vin vdd & fun fun fun!!

ArchiverArchiver Posts: 46,084
edited 2003-07-30 20:05 in General Discussion
The VDD pin acts as an output for
the BS2 voltage, if you are using
the BS2 on-module regulator.

It acts as a +5 volt input, if you
are using an on-board regulator.

If you put +12 on it, I believe you
are bypassing ALL regulators.

I believe the Stamp processor is max
rated at 5.5 volts DC. I would
assume 12 Volts would smoke it.

Please tell us what really happened,
it would be very educational.

BTW, I once accidentally wired a
TTL chip backwards (put 5 volts
on ground, and 0 volts on VCC).
It glowed for a bit.
It didn't work afterwards.
I highly discourage this practice.

--- In
basicstamps@yahoogroups.com, "[noparse][[/noparse].......................................
..]" <manwithapipe@y...> wrote:
> hello all...
>
> what, if any, are the consequences of applying say 12v (the max) to
> VDD as opposed to VIN to power your stamp project. are the
> consequences disastrous? or will it regulate as well?
>
> manny

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-07-30 15:21
    Manny,

    Very bad idea. When you do this you are bypassing the voltage regulator. I
    had a student smoke a Stamp that way.

    Jonathan

    www.madlabs.info

    Original Message
    From: "[noparse][[/noparse].........................................]" <manwithapipe@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, July 29, 2003 10:48 PM
    Subject: [noparse][[/noparse]basicstamps] bs2 vin vdd & fun fun fun!!


    > hello all...
    >
    > what, if any, are the consequences of applying say 12v (the max) to
    > VDD as opposed to VIN to power your stamp project. are the
    > consequences disastrous? or will it regulate as well?
    >
    > manny
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
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    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-30 18:49
    >in a late night wiring accident I put the jumper on the wrong pin.
    >Turned on the supply & ........................................*pop*
    >http://groups.yahoo.com/group/basicstamps/files/dead-stamp.gif

    At least you have a sense of humor about it! The good folks at
    Parallax might be sympathetic to the plight of the midnight burnout,
    in terms of repair/replacement/exchange.

    If you have a setup prone to that sort of thing (like mine, a table
    covered with a spaghetti plate of jumper cables and clip leads),
    protection on the i/o pins and the power pins could save some
    $$&*!xx^(#.
    -- I/O pins with resistors, ~220 ohm.
    -- Reset pin with its capacitor.
    -- Vdd and Vin with a fuse/diode combo:

    power ---oFUSEo---o
    Vdd
    250ma |
    | 1N4734 zener 5.6v 1W
    `--|<---Vss


    same thing for Vin, except use a 1N4001 instead of the zener.
    Reversing the battery or applying 12 volts to Vdd would blow the
    fuse before the voltage rises to a destructive level.

    -- Tracy
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-30 20:05
    In a message dated 7/30/2003 11:09:36 AM Pacific Daylight Time,
    tracy@e... writes:

    > If you have a setup prone to that sort of thing (like mine, a table
    > covered with a spaghetti plate of jumper cables and clip leads),
    > protection on the i/o pins and the power pins could save some

    spaghetti plate of jumper cables and clip leads??.......you are not
    alone!!!!!!!!!!!!!


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