«Kelvin water dropper is a type of electrostatic generator.
It was invented in 1867 by William Thomson, better known as Lord Kelvin.
This is a very simple device that can generate voltage of up to 10,000 Volt.
The water dropper is built using two pairs of metal buckets located on top one another and connected crosswise by wires. The upper pair is connected to the metal tube that is hung above the buckets and has water dropping from it. The bottom of the upper metal buckets is partially removed so that the water drops could also reach the bottom buckets.
The water used in this apparatus is non-distilled, as the distilled water is a dielectric.
This generator works based on the regenerative feedback principle.
Two metal tubes create an electric field that polarizes the upper bucket. That’s why, due to the electrostatic induction, the drops on the left and on the right have different charges.
The drops fall into the buckets that correspond to their charge and this increase the charge of the buckets creating an even stronger electric field around the tubes and intensifying charge separation in the upper bucket.
That’s how Kelvin water dropper converts the potential energy of the water in the upper bucket into the electric energy between the two bottom ones.
The efficiency of this process is, however, very low.»