mains operated equipment
51Sail training — From its modern interpretations to its antecedents when maritime nations would send young naval officer candidates to sea (e.g., see Outward Bound), sail training provides an unconventional and effective way of building many useful skills on and… …
52IEC 60906-1 — is an international standard for 230 V AC domestic power plugs and sockets. It was intended to become the common mains plug and socket standard, to be used one day everywhere in Europe and other regions with 230 V mains. The… …
53Batteryless radio — Radio receivers were originally operated by battery. The term batteryless radio was initially used for the radio receivers which could be used directly by AC mains supply (mains radio).It was invented on April 8, 1925 in Canada by Edward S.… …
54Operational amplifier — A Signetics μa741 operational amplifier, one of the most successful op amps. An operational amplifier ( op amp ) is a DC coupled high gain electronic voltage amplifier with a differential input and, usually, a single ended output.[1] An op amp… …
55Appropriate technology — (AT) is technology that is designed with special consideration to the environmental, ethical, cultural, social and economical aspects of the community it is intended for. With these goals in mind, AT typically requires fewer resources, is easier… …
56Four-minute warning — For the song by Mark Owen, see Four Minute Warning (song). The four minute warning was a public alert system conceived by the British Government during the Cold War and operated between 1953 and 1992 when the system was dismantled after the cold… …
57Railway electrification in Great Britain — describes the past and present electrification systems used to supply traction current to railways and tramways in Great Britain with a chronological record of development, a list of lines using each system, and a history and a technical… …
58LED lamp — An LED lamp (LED light bulb) is a solid state lamp that uses light emitting diodes (LEDs) as the source of light. The LEDs involved may be conventional semiconductor light emitting diodes, organic LEDs (OLED), or polymer light emitting diodes… …
59USS Vigilance (AM-324) — was an , USS|Fortune|IX 146, and USS|Boreas|AF 8 to Majuro which they reached on 25 May. Vigilance departed Majuro at 0800 on the 26th to return to Hawaii, intercepted USS|Megrez|AK 126 en route, and relieved PC 548 of escorting that cargo ship… …
60Electrical grid — Power Grid redirects here. For the board game, see Power Grid (board game). For other uses, see Grid (disambiguation). General layout of electricity networks. Voltages and depictions of electrical lines are typical for Germany and other European… …
