Hi If you dig into the data sheets on modern watch driver IC's they get pretty crazy with the drive waveforms. They do a PWM / switcher like sequence on each drive pulse and look at the current in the coil. The objective is to just barely put in enough power to supply the torque required.
Bob On May 19, 2011, at 7:35 AM, Chuck Harris wrote: > An actual quartz analog wristwatch wouldn't do something so mundane as > to use a 50uf capacitor to drive the coils. They do this: > > DRIVER-A---------------------COIL-----+ > ......................................| > DRIVER-B------------------------------+ > > > And feed the drivers with these waveforms: > > 1.5V..........+-+.............+-+.............+-+...... > ..............|.|.............|.|.............|.|...... > A-------------+ +-------------+ +-------------+ +---... > > 1.5V..+-+.............+-+.............+-+.............. > ......|.|.............|.|.............|.|.............. > B-----+ +-------------+ +-------------+ +-----------... > > Where the pulses alternately come from A and B every second. > > If you use a PIC to drive the clock, the driver is easy to program in > software. > > -Chuck Harris > > iov...@inwind.it wrote: >> I understand now why most analog wristwatches do tick every two seconds when >> the battery is low. I believed the logic used this trick to signal low >> battery. >> >> Antonio I8IOV > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
