Video: Watch this demo
Description: This is a high voltage Van de Graff generator (~400,000V) used for many electricity demos.
If you put two grounding sources close together, you can change the frequency of discharges thus creating more powerful discharges.
- Van de Graff machine.
- Discharge wand.
- (Optional) Metal discharge dome.
- Connect the Van de Graff to a table that has a three prong cord (grounding prong); else you may get zapped when turning it off.
- With the machine off, set the machine to about half speed.
- Connect the discharge wand (and any other things that are to be grounded) to the black grounding jack on the machine.
- When the professor is done, discharge the metal dome for safety.
- Turn on the Van de Graff while holding the discharge wand in the other hand.
- Bring the discharge wand near the machine to observe discharges.
- To turn it off, hold the discharge wand up to the dome and turn it off.
- When the machine has stopped, discharge the dome once more.
Due to the high voltage, keep away from sensitive electronics.
Never have a student touch the Van de Graff who has any electronics in their body such as a pacemaker.
Note: As with most electrostatic demonstrations, they work best under 50% humidity.