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Single-wire earth return (SWER) or single-wire ground return is a single-wire transmission line which supplies single-phase electric power from an electrical grid to remote areas at lowest cost. The earth (or sometimes a body of water) is used as the return path for the current, to avoid the need for a second wire (or neutral wire ) to act as a ...
Earth-return telegraph is the system whereby the return path for the electric current of a telegraph circuit is provided by connection to the earth through an earth electrode. Using earth return saves a great deal of money on installation costs since it halves the amount of wire that is required, with a corresponding saving on the labour ...
A transmission line is drawn as two black wires. At a distance x into the line, there is current I(x) travelling through each wire, and there is a voltage difference V(x) between the wires. If the current and voltage come from a single wave (with no reflection), then V(x) / I(x) = Z 0, where Z 0 is the characteristic impedance of the line.
Earth return or ground return is an electric circuit using the earth for one conductor. It may refer to: Earth-return telegraph; Single-wire earth return, an electric power distribution system; Simplex signaling, an earth return signalling system used in telephony
The single-wire transmission line is not the same as the single-wire earth return system, which is not covered in this article. The latter system relies on a return current through the ground, using the earth as a second conductor between ground terminal electrodes. In a single-wire transmission line there is no second conductor of any form.
Presidents Eisenhower, Kennedy, Johnson, and Nixon used an Air Force One plane known as SAM 970. The first jet-powered presidential aircraft featured an office and a safe for the nuclear codes.
Important examples of these single-wire systems were the Morse telegraph (1837) and the Cooke & Wheatstone single-needle telegraph (1843). In such systems the cost of a return conductor was fully 50 per cent of the cable costs. It was discovered that a return conductor could be replaced with a return path through the Earth using grounding ...
SF 6 is a far superior dielectric to air and, in recent times, its use has been extended to produce far more compact switching equipment (known as switchgear) and transformers. [ 20 ] [ 21 ] Many important developments also came from extending innovations in the ICT field to the power engineering field.