make-and-break mechanism
51National Commission on Fiscal Responsibility and Reform — Part of a series of articles on Unit …
52List of Tesla patents — Below is a list of Tesla patents. Dr. Nikola Tesla was an inventor who obtained around 300 patents [Snezana Sarbo, [http://www.tesla symp06.org/papers/Tesla Symp06 Sarboh.pdfNikola Tesla s Patents] , Sixth International Symposium Nikola Tesla,… …
53Relay — This article is about the electrical component. For other uses, see Relay (disambiguation). Automotive style miniature relay, dust cover is taken off A relay is an electrically operated switch. Many relays use an electromagnet to operate a… …
54Electric motor — For other kinds of motors, see motor (disambiguation). For a railroad electric engine, see electric locomotive. Various electric motors. A 9 volt PP3 transistor battery is in the center foreground for size comparison. An electric motor converts… …
55Keyboard (computing) — In computing, a keyboard is an input device partially modelled after the typewriter keyboard which uses an arrangement of buttons, or keys which act as electronic switches. A keyboard typically has characters engraved or printed on the keys, and… …
56Charles Wheatstone — Wheatstone, drawn by Samuel Laurence in 1868 Born 6 …
57telegraph — telegrapher /teuh leg reuh feuhr/; esp. Brit., telegraphist, n. /tel i graf , grahf /, n. 1. an apparatus, system, or process for transmitting messages or signals to a distant place, esp. by means of an electric device consisting essentially of a …
58Urban renewal — For other uses, see Urban renewal (disambiguation). Melbourne Docklands urban renewal project, a transformation of a large disused docks into a new residential and commercial precinct for 25,000 people …
59Johann Philipp Reis — (January 7, 1834 ndash; January 14, 1874) was a self taught German scientist and inventor who in 1860 1 constructed an early telephone, today called the Reis telephone. He first publicly demonstrated it on October 26 1861.Early life and… …
60Harry DeArmond — (January 28, 1906 October 12, 1999) invented the first commercially available attachable guitar pickup in the mid 1930s. He established a working relationship with Horace Bud Rowe s company to manufacture and develop these items. The company was… …
