Leyden jar

The Leyden jar, also Kleistian bottle or bottle condensation is the oldest design of a capacitor. On the inside and outside of a glass vessel ( such as a bottle ) are attached metal pads; the glass represents the insulator dar. Leyden jars have a high dielectric strength and are used primarily as a high- voltage capacitors.

Discovery

The principle of the Leyden jar was independently on 11 October 1745 the dean Ewald Georg von Kleist of Pomerania ( Pomeranian ) and 1746 by the physicist Pieter van Musschenbroek discovered in Leiden, as they in laboratory tests with corresponding arrangements of glass and metal parts of electrical shock were given.

From various documents also Andreas Cunaeus (1712-1788) is mentioned as a co-inventor and friend Musschenbroek, others put Musschenbroek by the appended in brackets name Cunaeus falsely with this same.

Construction

Four Leyden jars in Museum Boerhaave, Leiden

Build a Leyden jar

Elements of a Leyden jar

Kleist had a nail stuck in experiments in a water-filled bottle and connected to an electrical machine. Later, when you pull out the nail, he received a powerful electric shock. Musschenbroek had a similar experience. Various scholars repeated the experiment and varied the arrangement. Johann Heinrich Winckler moved the ladder from the middle to the inner wall of the bottle, surrounded them with a sheath made of metal and experimented with various liquids such as water, melted butter and wine. Your final form was the Leyden jar in 1748 by two London doctors William Watson and John Bevis. They both gave up the liquid and lined the walls of the bottle inside and out with tinfoil. The Danziger physicist Daniel Gralath joined for the first time several Leyden jars in a row and was able to increase the effect.

The first applications

When the then-popular public demonstrations of electricity and the Kleistian shock was presented, in which a human chain a blow from a Leyden jar was added, whereby the subjects fell into convulsions. Georg Christoph Lichtenberg wrote in a physics textbook about this:

" In Paris it was believed to have been found several years ago that the shock always in a ' frigidis et impotentibus ' cease. The Count of Artois, who heard of it, called to the eunuchs of the opera; and the observation was found wrong. In this way, the electrical machine has come to honor one day to adorn as a useful tool in the assembly halls of Consistories and marriage courts. "

Physical

For sizing and calculation of electric capacity, see capacitor.

Michael Faraday pointed out that there is no difference in principle between a charged conductive part and a Leyden jar: If a metal part insulating held in the air, for example, positively charged, there arises in the environment, such as the walls of a room, negative electrostatic induction charge. The walls of the room then in a sense form the outer assignment of the bottle, the intermediate air, the very thick, insulating layer. The Leyden jar differs only by the greater electrical capacity from simple ladder. She is in typical Leyden jars (glass with electrolytically deposited copper coatings ) in demonstration experiments 10-9 to 10-8 farads.