You can use a resistor to lower the voltage and plug in a stepper motor and there is your clock.
When the idea was initially proposed quartz generators were also a bit more expensive so using the grid to synchronize was not a bad idea at all.
Even today it's not the worst idea since it's being kept very close to 50hz. Close enough that you can safely operate an alarm clock from it without being off to far by the end of the day.
You wouldn't use a resistor to lower the voltage, because then you have most of the power being dissipated in the resistor rather than the stepper motor. Much easier to just use a transformer or a 240V-rated stepper motor.
Well, normally you wouldn't draw power over that resistor, I was thinking more in the direction of using the power line as a "sense" pin for the stepper and power was provided properly via a transformer.
You can use a resistor to lower the voltage and plug in a stepper motor and there is your clock.
When the idea was initially proposed quartz generators were also a bit more expensive so using the grid to synchronize was not a bad idea at all.
Even today it's not the worst idea since it's being kept very close to 50hz. Close enough that you can safely operate an alarm clock from it without being off to far by the end of the day.