A Van de Graaff generator is a device designed to create static electricity and make it available for experimentation. There are two kinds of generators; one that uses a high-voltage power supply for charging and one that uses belts and rollers for charging. The Van de Graaff generators available through MEEC are made up of:
A motor; two rollers; a belt; two brush assemblies; and an output terminal (usually a metal or aluminum sphere).
When the motor is turned on, the lower roller (charger) begins turning the belt. Since the belt is made of rubber and the lower roller is covered in silicon tape, the lower roller begins to build a negative charge and the belt builds a positive charge. You can understand why this charge imbalance occurs by looking at the triboelectric series: Silicon is more negative than rubber; therefore, the lower roller is capturing electrons from the belt as it passes over the roller.
There is a generator at both the AV Library and the Victorville Library.