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thermostat

(Encyclopedia)thermostat, automatic device that regulates temperature in an enclosed area by controlling heating or refrigerating systems. It is commonly connected to one of these systems, turning it on or off in o...

relay

(Encyclopedia)relay, electromechanical switch operated by a flow of electricity in one circuit and controlling the flow of electricity in another circuit. A relay consists basically of an electromagnet with a soft ...

transformer

(Encyclopedia)transformer, electrical device used to transfer an alternating current or voltage from one electric circuit to another by means of electromagnetic induction. The simplest type of transformer consists ...

ignition

(Encyclopedia)CE5 Ignition system ignition, apparatus for igniting a combustible mixture. The German engineer Nikolaus A. Otto, in his first gas engine, used flame ignition; another method was heating a metal t...

microelectronics

(Encyclopedia)microelectronics, branch of electronic technology devoted to the design and development of extremely small electronic devices that consume very little electric power. Although the term is sometimes us...

Sprague, Frank Julian

(Encyclopedia)Sprague, Frank Julian sprāg [key], 1857–1934, American electrical engineer, b. Milford, Conn., grad. Annapolis, 1878. He was an assistant to Thomas Edison in 1883 and independently created a superi...

superconductivity

(Encyclopedia)superconductivity, abnormally high electrical conductivity of certain substances. The phenomenon was discovered in 1911 by Heike Kamerlingh Onnes, who found that the resistance of mercury dropped sudd...

Farmer, Moses Gerrish

(Encyclopedia)Farmer, Moses Gerrish, 1820–93, American inventor, b. Boscawen, N.H. He helped build and maintain some of the pioneer telegraph lines of Massachusetts and experimented in multiple telegraphy. He exh...

Eggleston, Edward

(Encyclopedia)Eggleston, Edward, 1837–1902, American author, Methodist clergyman, b. Vevay, Ind., educated in frontier schools. Before 1870 he was a Bible agent, a farm worker, a circuit rider in Minnesota and In...

Johnson, Herschel Vespasian

(Encyclopedia)Johnson, Herschel Vespasian, 1812–80, U.S. political leader, b. Burke co., Ga. Admitted to the bar in 1834, he filled (1848–49) an unexpired Senate term before serving as circuit court judge (1849...