Dissectible Van de Graaff - Physics Demonstrations - Dissectible Van de Graaff | Physics Undergraduate Labs

The sphere accumulates voltages exceeding 100 kV. Current is limited to microamperes (not lethal) but shocks are painful. Always discharge with a grounded conductor before touching. Students with pacemakers should maintain distance.

Purpose

A Van de Graaff generator with transparent column and removable sphere reveals the internal belt, rollers, and discharge combs. Students observe how charge is transported mechanically and transferred via corona discharge at the combs.

Large polished chrome sphere on a red insulating column with a discharge wand visible to the right

Close-up of lower section showing motor, gold fabric belt on rollers, lower discharge comb, and wiring on a black base with clear plastic shielding

Full Van de Graaff generator on a wheeled cart: chrome sphere on top, two parallel red insulating columns, motor and base on a wooden platform with casters

Figure 1: Dissectible Van de Graaff generator sphere and upper column. The sphere lifts off to reveal the upper roller and comb.

Figure 2: Lower section showing motor, belt, lower roller, and adjustable discharge comb enclosed in clear plastic shielding.

Figure 3: Full apparatus on wheeled cart showing the complete assembly from motor base through insulating columns to collecting sphere.

Safety Warnings

Danger: High Voltage Discharge Hazard

Purpose