Olin wrote:
.........
>Overall, I think this is either a power supply problem, or more likely a
>software bug where the port latch is getting set low when you don't expect
>it.
>

Exactly my feeling. Given how much current the motor takes to
operate, I find it hard to believe that pulling the base up using
the PIC - even if not all the way - would leave enough collector
current to keep the motor runnning.

Personally for such a circuit, I would probably go with an NPN or
MOSFET inverter anyway, so you would have more versatility in
choosing loads and load voltages.

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