Algodoo

The analogy of electricity and water is explaining how an alternating electric voltage can be achieved by means of an orange cylinder and a flywheel, which steers valves. In electricity the cylinder stands for a capacitor, the flywheel for a coil, and the height of the water in the capacitor for the electric voltage.

There is no motor driving the flywheel, it gets its energy purely
from the water in the upper pool.

Due to lots of water, this scene may be a bit slow, as the pc has to calculate so many moving and interacting particles. If your computer is slow, then reduce the width of the water-pool to 1/4 at the same height of water.