🚀 go-pugleaf

    Jonas R Klein entitled a message as 'Motor controller help wan',
   on the 11-07-92  20:27 to All.
 JRK> The motors are small, and I'm using 2n2222 style transistors form
 JRK> Radio Shack, since they're cheap and easy to get, but I still need 72
 JRK> of them and a lot of wire.  Can I do this more easilly from a bipolar
 JRK> supply? How does everyone alse do it? I haven't beena able to find many
 JRK> circuits that do this.

    It is MUCH easier to control them with a split voltage
    supply.  This requires only 2 transistors (bjt or Mosfet)
    per motor, 1 NPN and 1 PNP.  The ttl can be channeled to a
    level convertor.  This will allow +-5v for control instead
    of 3.2 and .31 (ussual ttl output).

    You might be able to use the 1488 (ttl -> Rs232 level
    convertor) or a voltage comparitor.  Depends on what you are
    doing.

    The connection is like this
           EN       ~EN
           ____     ____
    +5v ___/  \_____/  \___ -5v
           npn   |  pnp
                ( )
                 |
                Gnd

    Please note that the NPN is active high input and the PNP is
    active low.  This is a complementary semetry amplifier.  If
    you don't want to use PNP you can use an npn instead.
    However this allows you to use a matched pair.  ALSO it
    means you have 3 states a nuetral and 2 oposing flow states.

    Cyberman

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