“Reinvigorating a handsome old clock and making it super-accurate, without any internet. Uses a Raspberry Pi Pico, a radio antenna and a couple of components to emulate a signal from a Mother clock.
The DCF77 signal is a radio signal that carries information from some Atomic Clocks. The signal covers most of Europe and is accurate to within a second over about 300,000 years (the DCF77 signal has been broadcasting the time since 1973 and in 2021 it was agreed to be continued for at least 10 more years).
(The United States uses WWVB, United Kingdom uses MSF and Japan uses JJY. You could easily adapt the code to any of those signals)
- Old ‘nebenuhr’ clock with secondary mechanism (a mechanism that is controlled by pulses from the mother-clock)
- A ferrite receiver (for the DCF77 signal)
- A microcontroller (Raspberry Pi Pico)
- Real time clock (RTC) (backup for any radio signal issues)
- H bridge (LN298), for the polarity switch that triggers the clock mechanism
- Step-up module to send correct voltage pulse to the clock (replaces the dc power supply used in the video)”