Editing Wimshurst machine (section)

==Operation==
The two contra-rotating insulating discs have an even number of metal sectors stuck onto them. The machine is provided with four small brushes, two on each side of the machine on the neutralizer bars, plus a pair of charge-collection brushes or combs. These are typically mounted along the horizontal and contact the sectors on both front and back discs. They are usually connected to respective [[Leyden jar]]s. The neutralizer bars that momentarily connect opposite sectors together form the shape of an "X". The angle of these bars can typically be varied from 30° to the horizontal to 60°. It is essential that the neutralizer bars are angled in such a way that the sectors on the discs connect with the neutralizer bar before reaching the vertical position. For example, if a disc is rotating clockwise when viewed from the front, the neutralizer bar must be angled from top left to bottom right.

[[File:Wimshurst Machine Charge Cycle.gif|frame|center|Animation]]

Any small charge on either of the two discs suffices to begin the charging process. Suppose, therefore, that some of the sectors on the front disc ([A] lower chain) are positively charged (red) and that the front disc rotates counter-clockwise (right to left). As the charged sector (moving red square) rotates to the position of the brush on the rear neutralizer bar ([Y] down arrow tip) it induces a polarization of charge on the neutralizer bar ([Y-Y1] upper horizontal black line) attracting negative (green) charge to the sector immediately opposite it ([Y] upper square becoming green) and positive (red) charge on the sector across the disc 180 degrees away ([Y1] upper square becoming red). When this latter positive charge reaches the place where the front neutralizer bar is ([X]) it induces a negative charge on the sector on the front disc ([X] lower square becoming green) and simultaneously a positive (red) charge on the sector on the opposite side of the disc ([X1] becoming red). The positive charges are collected from both sides of the discs at [Z] and [Z] and the negative charges are collected on the other side of the discs (not labelled on the diagram).

The process repeats, with each charge on A inducing charges on B, inducing more charges on A, etc. This process, by itself, will not, however, produce the high voltages which are actually obtained because the charge induced on B will necessarily be smaller than the charge inducing it on A. The exponential increase in voltage is due to the fact that any voltage which appears on the poles of the machine generates an electric field across the machine which contributes enormously to the polarization of the neutralizer bars. Obviously, the bigger the voltage across the poles, the greater the degree of polarization and the faster the machine charges up. In the end, this positive feedback loop is more important than the charge transfer process described above which serves merely to get the process going. The energy generated by the machine is derived from the work done in separating the charges on the sectors from the charges on the polarized neutralizer bars at the time when they break contact.

The ultimate potential difference which can be achieved is limited principally by the maximum voltage which can be sustained across the sectors on the discs between the neutralizer bars (which are always at zero potential) and the poles. This distance is maximised when the neutraliser bars are as near vertical as possible. (Of course, if the bars were actually vertical, the electric field would not polarize them and the machine would cease to work.)