The Everyday Dude
A podcast for the everyday dude where we talk about anything and everything that pertains to the everyday dude from sports to cooking, camping to technology. You name it, we'…
Do you know how Van de Graaff generators work? Let's turn it on.
July 24, 2017
Turn it off and the charge stays on the dome.
To understand what is going on, let's look inside.
There is only a motor, powering a pulley, connected to a belt, almost touched by a copper comb.
The pulley is made of a special plastic. Let's fade away all but a few (exaggerated) plastic atoms.
The pulley's plastic atoms will transfer electrons to the inside of the belt (it's just "static electricity").
The inside of the belt becomes more and more negative.
But now let's go back and figure out what the bottom copper comb does.
Electrons jump from the comb trying to reach the increasingly positive pulley.
But these electrons cannot penetrate the belt and are carried away.
This is an electron's worst nightmare as both sides of the belt are now negative!
But as they reach the top, the outer electrons can jump onto a second comb ...
and then spread out on the metal dome.
So the Van de Graaff uses the motor's work pushing electrons upward to build up "electrostatic energy."
This podcast is drawn from the Virtual Lab presentations of
WeCanFigureThisOut.org. The copyrighted material of this site
was developed under funding from National Science Foundation
CCLI, NIRT, MRSEC and NUE programs. This project is led by John C. Bean
All of the scenes together
You must Log In or Sign Up in order to subscribe.