Edward Weston (chemist) instruments for electric current—the modern foundation for the voltmeter, ammeter and wattmeter. In 1888 he formed the Weston Electrical Instrument Corporation which would become famous for its voltmeters, ammeters, wattmeters, ohmmeters, frequency meters, transformers, and transducers. Weston developed a method for producing a "true" permanent magnet. Weston conceived of and built a magnetic speedometer. Weston also developed the dashboard ammeter for Harley-Davidson motorcycles. Also in 1888, Weston became president of the American Institute of Electrical Engineers (AIEE) until 1889. Weston invented and patented the saturated cadmium cell in 1893. The cathode in the cell is an amalgam of cadmium with
Electrical contacts free path of electrons formula_1, ballistic conduction of electrons occurs, resulting in a phenomena known also as "Sharvin resistance" . Contact force or pressure increases the size of the a-spot which decreases the constriction resistance and the electrical contact resistance. When the size of contacting asperities becomes larger than the mean free path of electrons, Holm-type contacts become the dominant transport mechanism, resulting in a relative low contact resistance. Electrical contacts An electrical contact is an electrical circuit component found in electrical switches, relays, connectors and circuit breakers. Each contact is a piece of electrically conductive material, usually metal. When