Using high voltage equipment in the classroom can be exciting and educational for students, but most students AND teachers do not realize the real-life applications of such devices in their everyday lives. Although high voltage components are used in many of today's electronic gadgets, being able to demonstrate the principles of this electrical phenomenon can be confusing for students and may present a safety issue for the teacher if not properly used. A Leyden Jar, Wimshurst Machine and Tesla Coil demonstrate the basic fundamentals of electricity while showcasing these historically-rich devices that most students have never seen. At the most basic level, the electrical forces between electrons and protons drive the underlying concepts behind these devices, whether it is the storage of electrical charge in a Leyden Jar or the Electrical Potential Energy produced by a Tesla Coil. All of these electrical phenomena are governed by the same three basic principles:
1. Electrons are the "bits" of the atom that can be removed or added.
2. Electrons are repelled by other electrons and attracted by the protons. Or, in a simpler way… Two negatively-charged particles repel and two positively-charged particles repel while a positively-charged and negatively-charged particle attract.
3. Electrons tend to move from a greater negative concentration to a "place" where there is a lower negative concentration.
The following collection of demonstrations utilizing a Leyden Jar, Wimshurst Machine and a Tesla Coil, are designed to "spark" student interest in learning about basic concepts of electricity.
Part 1 – The Leyden Jar
Ever heard of a Leyden Jar? It's been around for over 200 years and is the forerunner of the modern day capacitor. The Leyden Jar is a device that "stores" static electricity between two electrodes on the inside and outside of a container. The gentleman who invented it tested it on himself and stated that "my whole body was shaken as though by a thunderbolt." It was invented by Pieter van Musschenbroek in 1745 in Leiden, Netherlands, which gave the invention its name. It is essentially an early form of a capacitor. In the early years of electricity research, scientists had to resort to large insulated conductors to store charge so the Leyden Jar provided a much more compact alternative and they were able to store substantial charge receiving a significant shock from the device when discharged. A large Leyden Jar was once discharged through seven hundred monks who were holding hands. They flew up into the air simultaneously!