The first electric motors were simple electrostatic devices described in experiments by Scottish monk Andrew Gordon and American experimenter Benjamin Franklin in the 1740s. The theoretical principle behind them, AmpÃ¨re's force law, was discovered by AndrÃ©-Marie AmpÃ¨re in 1820. The law described the production of mechanical force by the interactions of an electric current and a magnetic field. The conversion of electrical energy into mechanical energy by electromagnetic means was demonstrated by English scientist Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury, on which a permanent magnet (PM) was placed. When a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire. This motor is often demonstrated in physics experiments, substituting brine for (toxic) mercury. Though Barlow's wheel was an early refinement to this Faraday demonstration, these and similar homopolar motors remained unsuited to practical application until late in the century.
Copyright © 2016-2018 Animalia Life | All rights reserved