The Van de Graaff Generator is our most popular way of demonstrating electrostatic phenomena in the classroom. Don Lynch has created a new animation to help illustrate how this beloved device works.
The Van de Graaff generator uses essentially similar triboelectric phenomena to the classic charging by friction demonstrations we often use at the beginning of any class on electricity, and that you have probably performed by accident on dry winter days in carpeted rooms. A grounded comb at the bottom exchanges charges with the moving belt, then this surplus of charge is deposited through the upper comb on the large conductive dome. The individual identical charges repel each other, so they become distributed across the entire outer surface of the dome.
You can find this animation, along with a growing collection of others, on our Teaching Aids page!
(And always remember: It’s Van de Graaff, with two F’s. With one F, it’s the band. Don’t mix them up!)