Basic Electricity

The Minds That Discovered Electricity

Thomas Alva Edison (1847-1931). Born in Milan, Ohio. In 1882 he designed the first hydoelectric plant in Appleton, Wisconsin. In 1887 he and Sir Joseph Wilson Swan produced the Edison electric lamps. After his invention of the incandescent light with Joseph Swan, Edison invented the flourescent light, or more commonly known as the light bulb. In October of 1879, Thomas Alva Edison "quietly" made his own sensational breakthrough. After testing over two thousand materials, he tried making a filament out of some lamp-chimney soot that he happened to have rolled up between his fingers. He carefully fastened the ends of this fragile black "hair" to a pair of positive and negative posts (electrodes) inside a clear glass tube. After sealing the tube, he used the most advanced method available to suction out as many combustible oxygen molecules as possible. Next, he sent a charge of (DC) electric current surging through the hair-like strand and watched, rather routinely, as its temperature quickly rose to over 4000 degrees. With great astonishment, he observed that - unlike almost every other filament he had previously tested - this one did not soon begin to flicker and disintegrate, but continued to "burn" with a relatively pleasant and steady light.

Next, Edison tried the experiment using a piece of #40 (fine) sewing machine thread that he had oven-baked to a crisp, or “carbonized.” Presto! The instant he turned on the current, the scorched thread fused into a thin and intensely bright coil of light that filled the room with a mellow dawn-like glow. For the next 14 hours, he and an assistant marveled at the particularly beautiful yellow-orange color that was radiating from the incandescing cotton. Long before the "burning" thread turned white-hot, sputtered, and broke apart, Edison had become convinced that he finally held the key to producing the most practical and socially acceptable form of "artificial" lighting in existence.

Count Alessandro Volta (1745-1827). Born in Como, Italy. An Italian physicist, known for his pioneering work in electricity. In 1774 he became professor of physics at the Royal School in Como, and in the following year he devised the electrophorus, an instrument that produced charges of static electricity. In 1776-77 he applied himself to chemistry, studying atmospheric electricity and devising

experiments such as the ignition of gases by an electric spark in a closed vessel. By 1800 he had developed the so-called voltaic pile, a forerunner of the electric battery, which produced a steady stream of electricity. From studying earlier experiments he believed that dissimilar metals in contact with each other would create electricity, so he stacked discs of copper, zinc,and cardboard (soaked in salt water) until he had a tall pile.

When he touched the top and bottom discs of the stack at the same time, Volta had a shocking experience. He had built the first battery, which was called a voltaic pile. He published his findings in 1800. The "volt," a measurement of electrical current, is named after the count.

James Prescott Joule (1818 - 1889). Born in Salford, England. A physicist, he shared in discovering the law of the conservation of energy. Two German physicists, Hermann von Helmholtz and Julius von Mayer, and English physicist Lord Kelvin, also worked on the law of physics. The law states that energy used up in one form reappears in another and is never lost. In 1840, he stated a law, now called Joule's Law, that heat is produced in an electrical conductor. The unit of work or energy, the joule, is named in his honor.

Georg Simon Ohm (1787 - 1854). Born in Erlangen, Germany, his later work as a physicist resulted in the 1827 discovery of the mathematical law of electric-current called "Ohm's Law." The ohm, a unit of electrical resistance, is equal to that of a conductor in which a current of one ampere is produced by a potential of one volt across its terminals.

Michael Faraday (1791 - 1867). Born in Londan France. Early in his life he became interested in the concept of energy, or more specifically, force. Because of his early reading and experiments with the idea of force, he was able to make important discoveries in electricity later in life. He eventually became a chemist and physicist. He isolated benzene (a clear, colorless, flammable liquid derived from petroleum and used to manufacture motor fuels). He performed experiments demonstrating discovery of electromagnetic induction. This discovery paved the way for changing mechanical energy into electrical energy.

Lewis Howard Latimer (1848 - 1928). Born in Chelsea, Massachusetts. As a young man, Lewis Latimer learned mechanical drawing while working for a Boston patent office. In 1880, he was hired by Hiram Maxim of the U.S. Electric Lighting

Company to help develop a commercially viable electric lamp. In 1882, Latimer invented a device for efficiently manufacturing the carbon filaments used in electric lamps and shared a patent for the &quotMaxim electric lamp". He also patented a threaded wooden socket for light bulbs and supervised the installation of electric street lights in New York City, Philadelphia, Montreal, and London. In 1884, Latimer became an engineer at the Edison Electric Light Company where he had the distinction of being the only African American member of "Edison's Pioneers" - Thomas Edison's team of inventors. While working for Edison, Latimer wrote Incandescent Electric Lighting, the first engineering handbook on lighting systems. Although today's incandescent light bulbs use filaments made of tungsten rather than carbon, Latimer's work helped to make possible the widespread use of electric lights.

Nikola Tesla (1856 - 1943). Born in Croatian, Europe. An electrical engineer who invented fluorescent lighting, the Tesla induction motor, the Tesla coil, and developed the alternating current (AC) electrical supply system. In 1885 George Westinghouse, head of the Westinghouse Electric Company, bought the patent rights to Tesla's system of dynamos, transformers and motors. Westinghouse used Tesla's alternating current system to light the World's Columbian Exposition of 1893 in Chicago. The Tesla coil, invented in 1891, is still used in radio and television sets and other electronic equipment. Tesla is considered one of the outstanding intellects who paved the way for many of the technological developments of modern times.

Charles Coulomb (1736-1806). Born in Paris, France. With the start of the French revolution Charles Coulomb fled Paris, returning in 1795 when he was appointed to the Institute de France. Laterhe became the Inspector-General of Public Instruction. Experiments in mechanical resistance led him to one of two Coulomb's laws, this one relating the amount of friction to the normal pressure. The second, however, is the law for which he is most famous "Coulomb's Law for electrostatic charges" in which he observed that the force between charges is as the reciprocal of the square of the distance between them. The SI unit of charge, the Coulomb, is named in his honor.

Ben Franklin (1706-1790). Born in Boston, Massachusetts. Ben’s interest in electricity came long before he flew the kite. Ben didn’t just fly the kite when lightning was striking just to see what would happen. When lightning struck the kite, he actually ahd a theory behind what was going to happen. Ben sort of suspected that lightning in nature was electrical current, so flying the kite with a key on the end was a test to see if he was right.

His famous kite flight took place on June 1752, and led him to develop many terms that we still use today when we talk about electricity: conductor, condenser, charge, discharge, uncharge, negative, minus, plus, electric shock, and electrician.

Ben, after this experiment clearly understood how powerful and dangerous lightning could be. So he invented the lightning rod to protect buildings and houses from electrical shock.