Electrophorus
For the genus of fish family Electrophoridae, see electric eelAn electrophorus is a simple plate capacitor used to collect static charge produced as a result of friction, devised in 18th century by Johannes Wilcke and Alessandro Volta.
The electrophorus consists of a dielectric plate on a metal surface and a metal plate with an insulating handle. First, the dielectric plate is triboelectrically charged, that is, by friction. Then, the metal plate is placed onto the dielectric plate. The metal plate charges by induction - the side facing the charged dielectric plate charges opposite to the charge of plate, while the side facing away from the dielectric charge attains the same sign of charge as the dielectric plate, thus making the metal plate electrically neutral as a whole. Then, the side facing away from the dielectric plate is momentarily grounded. Finally, the metal plate, now consisting only one sign of charge, is lifted.
