What's that Lassie? You say that Stuart Wheaton fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Tue, 07 Jul 2009 19:04:38 -0400:
If you have a spring loaded ball type limiter, then you could mount a roller lever switch to trip when the ball/plate rides up.
so, just capacitively couple to the reset pin - one part, no problem.
Don't use a reed switch - use an inductive pickup - passing the magnet GENERATES a pulse, instead of switching one.
Or just put a capacitor in series with the reed switch (assuming you are using DC - which is pretty well a given connecting to a 555 timer) that will limit the duration of the pulse.
The old LM567 tone detector chip would work, too.
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