At 04:22 PM 7/28/2008, you wrote: >On Wed, 23 Jul 2008 15:22:08 -0700, Jim Lux <[EMAIL PROTECTED]> wrote: > > > > > >Based on the clocks I've taken apart, dividing the 10MHz down to 1 Hz > >is probably your best bet, rather than trying to hit 32768. However, > >I don't know of a non-programmable single chip solution that will do > >a divide by 1E7. If you want programmable chips, there's countless > >ways, some more elegant than others. > >Seems to me that all the solutions proposed so far are a bit complex, trying >to go for the 32khz frequency when that's not necessary. The quartz analog >clockworks has a one or two winding stepper motor. The SIMPLEST solution is >to drive those coils directly with the PIC output and scrap the rest of the >circuitry. Actually, it's not even that complex... it's often an electromagnet/solenoid driving a conventional escapement type clock mechanism. Why use 2 coils when you don't ever need to go backwards?
One advantage of generating 32kHz (averaged over 1 second) is that you don't have to build the power driver stage to actuate that electromagnet.. (since it's built into the single dirt-cheap chip in the clock in the first place) >With some clever fiddling, one could use one of the 8 pin PICs and that WOULD >get the solution cost down to around 50 cents :-) And, one could probably figure out a way to use the original 32kHz crystal AND run at different speeds.. _______________________________________________ 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.