Well, tidal power plants exist. If you want a smaller device that will work in principle, hang a ball on a spring from the ceiling. When the moon passes overhead, the ball will go up. Then it’s up to you to translate that to rotary motion. The effect will be tiny though, so you’ll need a really lossless spring, a really stable building, and maybe a vacuum filled room :-)
As for Foucault’s pendulum, which works based on rotation of the Earth (not tides), I don’t think you can extract energy from such things even in principle.
Well, tidal power plants exist. If you want a smaller device that will work in principle, hang a ball on a spring from the ceiling. When the moon passes overhead, the ball will go up. Then it’s up to you to translate that to rotary motion. The effect will be tiny though, so you’ll need a really lossless spring, a really stable building, and maybe a vacuum filled room :-)
As for Foucault’s pendulum, which works based on rotation of the Earth (not tides), I don’t think you can extract energy from such things even in principle.