A generator which produces an electric charge by friction or electrostatic induction.
- 1663 Otto von Guericke constructs a primitive form of frictional electric mahine.
- 1746 Watson′s machine had a large wheel turning several glass globes with a sword and a gun barrel suspended from silk cords for its prime conductors.
- 1746 The collector, consisting of a series of metal points, was added to the machine by Benjamin Wilson.
- ~1750 Litzendorf substituted a glass ball for the sulphur ball of Guericke.
- 1768 Jesse Ramsden constructed a widely used version of a plate electrical generator.
- by 1784 Martin van Marum constructed a machine that could produce voltage with either polarity.
- 1785 N. Rouland constructed a silk belted machine which rubbed two grounded hare fur covered tubes.
- 1787 Edward Nairne developed an electrostatic generator for medical purposes.
- 1830′s Georg Ohm possessed a machine similar to the van Marum machine for his research.
- 1840 Armstrong hydroelectric machine was developed and used steam as a charge carrier.
- 1929 The Van de Graaff generator was developed at MIT and the first model was demonstrated in October.
- 1931 A version able to produce 1,000,000 volts was described in a patent disclosure.
See also: Electrostatic.