Stool delay flushing valve is what the principle is not the kind of electricity
Siphon is a fluid mechanics phenomenon that eliminates the need to pump and suck the liquid. The liquid at the higher position is filled with an inverted U-shaped tubular structure (called a siphon) and opens at a lower position. In this structure, the liquid potential difference between the ends of the tube can push the liquid over the highest point and discharge to the other end. Mainly by the gravity of the role of the siphon.
