"Jim Thompson" /Snicker
wrote in message ...
Circuit Challenge of the Day

The following circuit...

http://analog-innovations.com/SED/Ra..._Amusement.pdf

is a ramp generator.

It is easy to see how the upper trip point circuitry causes discharge
of the ramp.

But what causes the turn-around at the bottom?

Years ago I put together a circuit for messing with random inductors, it was
based on a bistable and the "off" state was tripped by the rise to
saturation current in the driver transistor. The fun part was sensing when
the flyback voltage had peaked and was on its way back, to trip the bistable
on state.

The circuit would be easily recognisable if I could find it - it was a dead
bug/bird's nest type thing, but it seems to have vanished without trace -
I'm pretty sure I documented the development, but I can't find that either.