> > 0.5Hz. The remains of the clock can still be used - drive the
> > coil with two PIC pins, reciprocating style, at 1.5V. I've made
> > a few novelty/special purpose clocks this way
> 
> Have you done any tests to see how fast you're able to drive the
> clock mechanics before there are problems?

Yes, but it was a while ago and I don't recall the exact speed. ISTR
it was about 4Hz. You can't make the second hand whizz around
(hehehe....whizz) because the linkage is weakly magnetic. The coil
is driven reciprocatingly. The alternating polarity of the resulting
magnetic field flips a magnetised cog 180deg, which moves the second
hand and thence to the rest of the gear box. It's not hard to stop the
second hand with a finger as the coupling between the coil and cog
is weak. Think of it as a very very very wussy AC or stepper motor
with a very very very light aluminium second hand as the load. Maybe
with some coil tinkering it could be made to go faster

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