School of Physics Lecture Demonstration Manual

El-15 Whimshurst Machine

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


To demonstrate the Whimshurst electrostatic generator



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Whimshurst Machine Pic


Whimshurst Machine


The Whimshurst electrostatic generator is essentially a system of electrophorus plates which operate in a continuous fashion accumulating large amounts of positive and negative charge.Assuming a small amount of positive charge on a disk on one plate A an opposite negative charge is induced on the nearest metal disk on the contra-rotating second plate.The connecting rods transfer an induced positive charge to disks on a diametrically opposite position of Plate A. As the plates rotate the second plate B moves to a position where it induces a positive charge on the disk opposite it on plate A via the second set of connecting rods. With continuous rotation positive charges accumulate at position A and negative charges at B.

Safety notes

Electrical safety 

Sharps Safety 


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