direct current signalling
1Current loop — This article is about the electrical signaling schemes. For the oceanic phenomenon, see Loop current. A current loop describes two different electrical signalling schemes. Contents 1 Digital 2 Analog 3 Process control use …
2Alternating 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 …
3Railway signalling — Not to be confused with Railway signal. A gantry of British semaphore signals seen from the cab of a steam locomotive Railway signalling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Being… …
4Invention 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 …
5Relay — 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… …
6Watford DC Line — 378210 at Watford Junction with a service from London Euston. Overview Type Commuter rail, Rapid transit …
7Metropolitan line — Metropolitan Colour on map Magenta Year opened 1863 Line type Sub Surface Rolling stock A Stock and S Stock 8 carriages pe …
8Clansman — For the book by Thomas Dixon, see The Clansman. Clansman The PRC 320 HF Radio Type Radio Communications System Place of …
9Milan–Bologna railway — The long steel girder bridge over the Po River at its opening in 1854 beside the temporary wooden bridge The Milan–Bologna railway is the northern part of the traditional main north south trunk line of the Italian railway network. It closely… …
10locomotive — locomotively, adv. locomotiveness, locomotivity, n. /loh keuh moh tiv/, n. 1. a self propelled, vehicular engine, powered by steam, a diesel, or electricity, for pulling or, sometimes, pushing a train or individual railroad cars. 2. an organized… …
