School of Physics Lecture Demonstration Manual

El-10 Electric Pinwheel

Published: Tuesday 14 March 2006 - Updated: Thursday 31 March 2011


To demonstrate a simple electrostatic motor.



Click on pictures to enlarge.

Van De Graaf pinwheel

Pinwheel Diagram


The pinwheel is placed on top of the Van de Graaff dome. On starting the generator the wheel rotates, and on a good day a bluish light together with a hissing sound emanates from the points.

The air is ionised in the high electrical field of the points. The ions and the points have the same sign of charge and thus repel each other.

Safety notes

Electrical safety 


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