Van de Graaff Generator
Voltages of hundreds of thousands of volts can be generated with a demonstration model Van de Graaff generator. Though startling, discharges from the Van de Graaff do not represent a serious shock hazard since the currents attainable are so small.
A pulley drives an insulating belt by a sharply pointed metal comb which has been given a positive charge by a power supply. Electrons are removed from the belt, leaving it positively charged. A similar comb at the top allows the net positive charge* to spread to the dome.
|A favorite demonstration with the Van de Graaf is to make someone's hair stand on end.