Colin wrote:
> Spehro Pefhany wrote:
> > hmmm... you sure it isn't something more like this?
> 
> Well, it is sort of.
> 
> Not sure how I got my base measurements mixed up compounded by my 
> search for a 2A marking for SOT3 BJT which led me to Digikeys 
> incorrect reverse base layout. Why I accepted them rather than my 
> meter readings I can't explain.
> 
> I've now attached the correct drawing which resolves the mystery.

It does ???

This circuit makes no sense at all -- there's no way to supply current to
the NPN base. Or, for that matter, to the PNP emitter. Plus, the LED is
backwards (I think).

I was ignoring this thread until this morning, when Spehro's circuit
caught my eye -- it has enough interesting features that I'm thinking
about using it in the next EQ quiz.

-- Dave Tweed
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