The background of my request is an OT story. Just to mention briefly, I already have an ordinary (non-radio-controlled) clock machine which turns a miniature torsion balance in a sealed glass vessel. It runs on a single AA battery. No extreme accuracy needed. I wont to modify the rate to sidereal, and might have to replicate the setup too. I figure that the solution I should pursue is getting the "odd" crystals. Now it is clear to me that I have to explore two options, a) contacting a crystal manufacturer, b) modifying 32768 crystals. Thanks, Antonio
[email protected] wrote: > >> does anybody out there have any ideas as where to find a 32859Hz crystal (1/ >> 2 that value would be better) to be used to replace 32768 crystals in >> ordinary clocks? I think that 32768 crystals cannot be dragged that much. >> I've already read the JimLux article somewhere on the web, but I would be >> pleased finding a simpler solution. Also, I already have computer programs >> that show sidereal time. > >I think it depends upon what you mean by "ordinary clocks". > >Most of the recent wall clocks I've seen are battery powered (single AA) and >resynchronize nightly via WWVB. > >If you want sidereal time, you won't have anything to synchronize to. What >sort of accuracy are you interested in? If you want reasonable accuracy, you >will need an external signal. (You can provide power over the same cable.) > >My straw man would be to send 32859Hz down coax or twisted pair and feed it >into the xtal-in pin on the clock chip. I'm not sure how to set the time. >You can cut the lead to the antenna to make sure it doesn't sync to WWVB. > >You can make 32859Hz from a PIC (or any micro you like) running off any handy >frequency. Given that this is time-nuts, I'd suggest 10 MHz from a GPSDO. > >It might be simpler to dump the 32KHz and WWVB chip and drive the motor >directly from a 1 PPS signal. Just use a sidereal second rather than a >normal second. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
