You are really late to this party. Current comptition is how many diffenent types of clocks can be driven with PoE&NTP -- know someone trying to do Nixie with it.
Sent from my iPhone > On Oct 14, 2015, at 09:42, Nick Sayer via time-nuts <[email protected]> > wrote: > > >> On Oct 14, 2015, at 4:42 AM, billriches <[email protected]> wrote: >> >> Not milisecond time distribution but time related! >> >> In the early half of the 1900s Western Union was in the time business. They >> would rent businesses such as banks, office buildings, etc clocks for a few >> dollars a month. These were pendulum wall clocks that had 2 #6 dry cell >> batteries inside that would wind them every hour or so. The clocks were >> connected to the WU telegraph line and for a minute before and after the >> top of the hour all traffic on the circuit would stop. Exactly at the top >> of the hour they would push a pulse of 50 ? volts or so over the line and it >> would reset the clock to the top of the hour. > > The WU standard time service goes back further than the turn of the 20th > century. It started in 1870. > > I’ve always wanted to get my hands on one of those clocks and come up with a > circuit to recreate the synchronization signal for it, probably with a > Raspberry Pi running ntpd and a big ol’ MOSFET. The problem is that at this > point, those clocks are quite expensive once they’re reconditioned. > > My understanding (perhaps incorrect) was that the sync pulse was once daily > and, as you said, would cause the hands to “snap” to 12. The trailing edge of > the pulse was synchronized and would release the clock to operate normally. > > That they had something as accurate and widespread as it was so early is > astonishing. > _______________________________________________ > 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. _______________________________________________ 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.
