Relay and Transformer

With this set up when the button is pushed the capacitors are just charging on the positive portion of the sine wave, then discharge on the negative portion of it. Then when you let go of the button the capacitors just discharge through the secondary, and this flow of electrons( the secondary basically acts as a short) charges the capacitors on the opposite side, then they discharge again and recharge, and continue to do this. They will eventually stop however, each time they discharge they are losing some energy through the lines, and from the secondary, which is acting as an inductor(as well as a short basically) and this inductor produces a magnetic field. The magnetic field absorbs some of this energy.

The only thing this circuit could be used for is to show how the capacitors act when an ac voltage is applied, and when they are charged and they can charge and discharge through the inductor. Also forgot to say this in the last comment, when the capacitors discharge through the inductor (secondary of the transformer) the inductor holds the energy in it magnetic field, then as the voltage starts to decrease its magnetic field starts to collapse and it induces a current. That current flows back into the capacitors charging them up, and the cycle repeats.