a pulse of alternating polarity every minute.
Motherclock, or german "Mutteruhr" is a arduino based Master Clock or german "Hauptuhr". It generates a short pulse of alternating polarity to drive so called slave clocks or german "Nebenuhr".
https://en.wikipedia.org/wiki/Master_clock
With a DC/DC converter it uses minimal power, the highly accurate DS3231 RTC to keep time, and a Arduino Nano Every as a Brain.
Schematic: https://github.com/designer2k2/Mutteruhr/blob/main/MotherClock/Motherclock%20Schematic.pdf
The actual clock drive is a transistor h-bridge, parts can be either SMD or THT.
2 Buttons and a DIL switch is on it to make settings while the clock operates.
A small mosfet can be used to switch some LED´s on/off