Question:
There is an automatic clock that works with energy that is produced through the body movement, may I carry it on Shabbos? Wouldn´t there be an issue of mavier or hotzaa, or any other melocho? There is also a clock that works with solar energy? may I carry it on Shabbos? Wouldn´t there be the same issue?
Answer:
As long as the watch is currently working, it may be worn on Shabbos. A solar watch should not intentionally be placed in the sun, but may be worn normally.
Sources:
See here.
