[mastax]

You could use a mechanical 60 to 50Hz converter. Basically a motor connected to a generator. They tend to be very expensive but maybe there are options.

If I were making something for this problem I would make an AC-DC-AC converter with a PLL to divide the 60Hz input frequency to 50Hz to control the inverter.

[spicyjpeg]

> If I were making something for this problem I would make an AC-DC-AC converter with a PLL to divide the 60Hz input frequency to 50Hz to control the inverter.

This is the best way to do it, especially if the synchronous motor inside the clock is actually fed with a lower voltage from a transformer (which seems to be common in old radio clocks as they needed a transformer anyway to power the radio circuitry). If that is the case, it should be possible to bypass the transformer entirely and build a converter that operates entirely on low voltage; some quick searching suggests that this exact kind of project has already been done before in fact [1].

[1]: https://mitxela.com/projects/phase-locked_inverter

[ilyt]

> If I were making something for this problem I would make an AC-DC-AC converter with a PLL to divide the 60Hz input frequency to 50Hz to control the inverter.

I'd put a $3 breakout board with any microcontroller and quartz... why would you want to sync to power network in the first place ?

[nomel]

> why would you want to sync to power network in the first place

It's very stable, because it was used/ok to use for time. Well, it was until very recently [1].

[1] https://www.usatoday.com/story/money/economy/2018/05/17/cloc...

[BenjiWiebe]

Iirc, the power grid frequency is adjusted over the long term to give excellent long term stability. A crystal will drift.