>> On the consumer side, your microwave, coffee machine and even bedside clock will
> I'd be very surprised. It's cheaper to build in a 32.768kHz crystal for timekeeping than try to access the grid frequency from the isolated low-voltage circuit.
IIRC, the grid frequency is usually more accurate. Probably because it's carefully monitored and managed by the power authorities like the OP describes. If you build a clock with its own frequency reference, than any error will accumulate and have to be monitored and managed by the user.
> I'd be very surprised. It's cheaper to build in a 32.768kHz crystal for timekeeping than try to access the grid frequency from the isolated low-voltage circuit.
IIRC, the grid frequency is usually more accurate. Probably because it's carefully monitored and managed by the power authorities like the OP describes. If you build a clock with its own frequency reference, than any error will accumulate and have to be monitored and managed by the user.