Spehro wrote:
> Since I'm going to be seeing Bob Pease tomorrow it reminds me of the
> following trick - not applicable to this case because the available
> current is very low, microamps. Also you need +12V or so.

That one I thought about too but discarded it immediately because of the
10K contrast pot which would kill the voltage on the spot (the available
current is about 2 x 10^-8A (20 nA) at -0.4V. And you don't need 12V. You
can do it with 5V with transistors with Vber < 5V like UHF antenna
amplifier transistors. An interesting exercise would be to plot the
available current vs. injected current. Who knows maybe a 2N3055 with
200mA into the inverted BE can supply more than I thought ;-).

Peter

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