spring commutator
11Friden Flexowriter — The Friden Flexowriter, or flexowriter as on its nameplate, was a teleprinter, a heavy duty electric typewriter capable of being driven not only by a human typing, but also automatically by several methods including direct attachment to a… …
12Quantum harmonic oscillator — The quantum harmonic oscillator is the quantum mechanical analogue of the classical harmonic oscillator. It is one of the most important model systems in quantum mechanics because an arbitrary potential can be approximated as a harmonic potential …
13Lucy, Lady Duff-Gordon — For the writer who lived 1821–1869, see Lucie, Lady Duff Gordon. Lucy Christiana, Lady Duff Gordon Lucile in 1919, photographed by Arnold Genthe Born 13 June 1863 London, England …
14Nortel — Networks Corporation Type Public OTC Markets Group: NRTLQ Industry Telecommunications …
15Invention of radio — Great Radio Controversy redirects here. For the album by the band Tesla, see The Great Radio Controversy. Contents 1 Physics of wireless signalling 2 Theory of electromagnetism …
16Mechanical rectifier — A mechanical rectifier is a device for converting alternating current (AC) to direct current (DC) by means of mechanically operated switches. The best known type is the commutator, which is an integral part of a DC dynamo but, before solid state… …
17Ozone — For other uses, see Ozone (disambiguation). Ozone …
18Alternating current — (green curve). The horizontal axis measures time; the vertical, current or voltage. In alternating current (AC, also ac) the movement of electric charge periodically reverses direction. In direct current (DC, also dc), the flow of electric charge …
19Color television — Title card for NBC, promoting their broadcast in RCA color . Color television is part of the history of television, the technology of television and practices associated with television s transmission of moving images in color video. In its most… …
20Mercury switch — A Single Pole, Single Throw (SPST) mercury switch on millimetre graph paper …
