• conductors
  • High-voltage overhead conductors are not covered by insulation. (wikipedia.org)
  • In telecommunications and professional audio, a balanced line or balanced signal pair is a transmission line consisting of two conductors of the same type, each of which have equal impedances along their lengths and equal impedances to ground and to other circuits. (wikipedia.org)
  • The shield (screen) of the data cable is typically connected to the grounded equipment chassis of both A and B, forming a closed loop with the ground conductors of the power cords, which are connected through the building utility ground wire. (wikipedia.org)
  • These conductors originate at the power-system device, are installed in trenches or overhead cable trays, and are then terminated on panels within the RTU. (wikipedia.org)
  • Roughly half of all copper mined is used to manufacture electrical wire and cable conductors. (wikipedia.org)
  • In 1913, the International Electrotechnical Commission defined the conductivity of commercially pure copper in its International Annealed Copper Standard, as 100% IACS = 58.0 MS/m at 20 °C, decreasing by 0.393%/°C. Because commercial purity has improved over the last century, copper conductors used in building wire often slightly exceed the 100% IACS standard. (wikipedia.org)
  • m at 20 °C. The high cost of silver combined with its low tensile strength limits its use to special applications, such as joint plating and sliding contact surfaces, and plating for the conductors in high-quality coaxial cables used at frequencies above 30 MHz Tensile strength measures the force required to pull an object such as rope, wire, or a structural beam to the point where it breaks. (wikipedia.org)
  • conductive
  • The working group attempted to distinguish between the terms stray voltage and contact voltage as follows: Stray voltage is defined as "A voltage resulting from the normal delivery and/or use of electricity (usually smaller than 10 volts) that may be present between two conductive surfaces that can be simultaneously contacted by members of the general public and/or their animals. (wikipedia.org)
  • Contact voltage is defined as "A voltage resulting from abnormal power system conditions that may be present between two conductive surfaces that can be simultaneously contacted by members of the general public and/or their animals. (wikipedia.org)
  • In mains powered equipment, exposed metal parts are connected to ground so that if, due to any fault conditions, a "Line" supply voltage connection occurs to any such conductive parts, the current flow will then be such that any protective equipment installed for either overload or "leakage" protection will operate and disconnect the "Line" voltage. (wikipedia.org)
  • Several electrically conductive metals are less dense than copper, but require larger cross sections to carry the same current and may not be usable when limited space is a major requirement. (wikipedia.org)
  • stray
  • Transmission of a signal over a balanced line reduces the influence of noise or interference due to external stray electric fields. (wikipedia.org)
  • In the vicinity of electric power wiring there will always be stray magnetic fields oscillating at the utility frequency, 50 or 60 hertz. (wikipedia.org)
  • Stray voltage is the occurrence of electrical potential between two objects that ideally should not have any voltage difference between them. (wikipedia.org)
  • Stray voltage is any case of undesirable elevated electrical potential, but more precise terminology gives an indication of the source of the voltage. (wikipedia.org)
  • In 2005, the Institute of Electrical and Electronics Engineers (IEEE) convened Working Group 1695 in an attempt to lay down definitions and guidelines for mitigating the various phenomena referred to as stray voltage. (wikipedia.org)
  • Stray voltage is not related to power system faults, and is generally not considered hazardous. (wikipedia.org)
  • In spite of the above definitions, the term stray voltage continues to be used by both utility workers and the general public for all occurrences of unwanted excess electricity. (wikipedia.org)
  • For example, at the annual "Jodie S. Lane Stray Voltage Detection, Mitigation & Prevention Conference", held at the Con Edison headquarters in New York City in April 2009, which attracted the presidents of most major utilities from throughout the United States and Canada, the utility leaders continued to use stray voltage for all occurrences of unwanted excess electricity. (wikipedia.org)
  • It would seem that stray voltage is now the common term for all unwanted voltage leakage as it categorises the fault as part of normal operation, therein limiting liability. (wikipedia.org)
  • In the coverage of the growing concern regarding the role of public utilities in electrical safety in the urban environment that her death triggered, both the media and the New York state regulatory agency used stray voltage was for neutral-to-earth voltage (NEV), but conceded that the notoriety of the Jodie S. Lane incident had caused stray voltage to be a term that is well recognized by the public. (wikipedia.org)
  • At that point, the regulator used stray voltage for any ""voltage conditions on electric facilities that should not ordinarily exist. (wikipedia.org)
  • clarification needed] Since that time, the term "stray voltage" has had at least two very different definitions. (wikipedia.org)
  • The term "stray voltage" is commonly used for all unwanted electrical leakage, by both the general public and many electrical utility professionals. (wikipedia.org)
  • generates
  • The unit of inductance in the SI system is the henry (H), named after American scientist Joseph Henry, which is the amount of inductance which generates a voltage of one volt when the current is changing at a rate of one ampere per second. (wikipedia.org)
  • transmit
  • The term "power system" describes the collection of devices that make up the physical systems that generate, transmit, and distribute power. (wikipedia.org)
  • The gap between the transmit and receive coils was designed to be less than 10 cm when powered. (wikipedia.org)
  • generate
  • In a generator, alternator, or dynamo the armature windings generate the electric current, which provides power to an external circuit. (wikipedia.org)
  • Electric motors are used to produce linear or rotary force (torque), and should be distinguished from devices such as magnetic solenoids and loudspeakers that convert electricity into motion but do not generate usable mechanical powers, which are respectively referred to as actuators and transducers. (wikipedia.org)
  • generators
  • A wide area synchronous grid, also known as an "interconnection" in North America, directly connects a large number of generators delivering AC power with the same relative frequency to a large number of consumers. (wikipedia.org)
  • Such generators generated very high voltage and low current. (wikipedia.org)
  • In certain applications, such as in regenerative braking with traction motors in the transportation industry, electric motors can also be used in reverse as generators to convert mechanical energy into electric power. (wikipedia.org)
  • capacitor
  • If a capacitor or inductor is added to a DC circuit, the resulting circuit is not, strictly speaking, a DC circuit. (wikipedia.org)
  • The voltage across a capacitor cannot change instantaneously, so a decreasing transient current will flow through it for a small fraction of a second, allowing the voltage across the switch to increase more slowly when the switch is opened. (wikipedia.org)
  • opposite
  • A movable switch could connect opposite pairs of these wires to form a dipole, and by rotating the switch the operator could hunt for the strongest signal. (wikipedia.org)
  • In Faraday's experiment, he wrapped two wires around opposite sides of an iron ring. (wikipedia.org)
  • transmission
  • Most transmission lines are high-voltage three-phase alternating current (AC), although single phase AC is sometimes used in railway electrification systems. (wikipedia.org)
  • Underground power transmission has a significantly higher installation cost and greater operational limitations, but reduced maintenance costs. (wikipedia.org)
  • If the demand for power exceeds supply, the imbalance can cause generation plant(s) and transmission equipment to automatically disconnect or shut down to prevent damage. (wikipedia.org)
  • Electric transmission networks are interconnected into regional, national, and even continent wide networks to reduce the risk of such a failure by providing multiple redundant, alternative routes for power to flow should such shut downs occur. (wikipedia.org)
  • This proved insufficient, however, with the growth of electric power transmission which tended to use the same routes. (wikipedia.org)
  • In the mid-1950s, high-voltage direct current transmission was developed, and is now an option instead of long-distance high voltage alternating current systems. (wikipedia.org)
  • In some applications such as aerial electric power transmission cables, copper is rarely used. (wikipedia.org)
  • Specific technologies include: WiTricity Rezence Qi wireless power transfer eCoupled Wireless Resonant Energy Link (WREL) Other applications include: Data transmission such as with passive RFID tags (for example in a passport) and contactless smart cards. (wikipedia.org)
  • quantities
  • Very large quantities of direct-current power are used in production of aluminum and other electrochemical processes. (wikipedia.org)
  • Electricity (as well as heat) was originally understood to be a kind of fluid, and the names of certain electric quantities (such as current) are derived from hydraulic equivalents. (wikipedia.org)
  • high
  • High-voltage direct-current (HVDC) technology is used for greater efficiency over very long distances (typically hundreds of miles). (wikipedia.org)
  • These were initially set up to power arc lighting (a popular type of street lighting) running on very high voltage (usually higher than 3000 volt) direct current or alternating current. (wikipedia.org)
  • In high-speed cases, where the switching is faster than 10 nanoseconds, such as in certain switching power regulators, "fast", "ultrafast", or Schottky diodes may be required. (wikipedia.org)
  • This is particularly likely if the floated system is near high voltage power lines. (wikipedia.org)
  • High voltage (one million volt) sources for X-ray production. (wikipedia.org)
  • These medical devices are designed for high efficiency using low power electronics while efficiently accommodating some misalignment and dynamic twisting of the coils. (wikipedia.org)
  • High power levels are required for rapid recharging and high energy transfer efficiency is required both for operational economy and to avoid negative environmental impact of the system. (wikipedia.org)
  • railways
  • To finance electrification at the beginning of the 20th century, American financier Charles Yerkes took it over and made it part of his Underground Electric Railways Company of London (UERL) group. (wikipedia.org)
  • ground
  • This can be caused, for example, in a signal circuit referenced to ground, if enough current is flowing in the ground to cause two points to be at different potentials. (wikipedia.org)
  • Wiring practices that protect against ground loops include ensuring that all vulnerable signal circuits are referenced to one point as ground, so that no potential differences can occur. (wikipedia.org)
  • Two circuits share a common path to ground. (wikipedia.org)
  • Suppose you wish to measure a 0.5V potential difference between two wires that are both approximtely 100V above Earth ground. (wikipedia.org)
  • To reduce the danger of electric shocks, the chassis of the instruments are usually connected separately to Earth ground. (wikipedia.org)
  • Floating grounds can be dangerous if they are caused by failure to properly ground equipment that was designed to require grounding, because the chassis can be at a very different potential from that of any nearby organisms, who then get an electric shock upon touching it. (wikipedia.org)
  • If the ground voltage difference is small, it tends to only cause hum and clicks. (wikipedia.org)
  • This is done to prevent harm resulting to the user from coming in contact with any such dangerous voltage in a situation where the user may, at the same time, also come in contact with an object at ground/earth potential. (wikipedia.org)
  • In electronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential. (wikipedia.org)
  • It was then discovered, probably by the German scientist Carl August Steinheil in 1836-1837, that the ground could be used as the return path to complete the circuit, making the return wire unnecessary. (wikipedia.org)
  • For longwave use, the two crossed antennae could be easily built by running four wires from a single mast to the ground to form triangular shapes. (wikipedia.org)
  • 1832
  • When French instrument maker Hippolyte Pixii built the first dynamo electric generator in 1832, he found that as the magnet used passed the loops of wire each half turn, it caused the flow of electricity to reverse, generating an alternating current. (wikipedia.org)
  • The first commutator DC electric motor capable of turning machinery was invented by the British scientist William Sturgeon in 1832. (wikipedia.org)
  • interference
  • The geometry of the cable ensures that magnetic fields will causes equal interference of both legs of the balanced circuit. (wikipedia.org)
  • A telephone line running alongside a power line for many miles will inevitably have more interference induced in one leg than the other since one of them will be nearer to the power line. (wikipedia.org)
  • coils
  • The magnetic field of the dynamo or alternator can be provided by either wire windings called field coils or permanent magnets. (wikipedia.org)
  • Using two loop antennae arranged at right angles and two sets of these small wire coils arranged the same way, the directional properties of the original radio signal were re-created. (wikipedia.org)
  • systems
  • The term DC is used to refer to power systems that use only one polarity of voltage or current, and to refer to the constant, zero-frequency, or slowly varying local mean value of a voltage or current. (wikipedia.org)
  • Monitoring and control of power delivery systems in the substation and on the pole reduce the occurrence of outages and shorten the duration of outages that do occur. (wikipedia.org)
  • Various resonant coupling systems in use or are under development for short range (up to 2 meters) wireless electricity systems to power laptops, tablets, smartphones, robot vacuums, implanted medical devices, and vehicles like electric cars, SCMaglev trains and automated guided vehicles. (wikipedia.org)
  • However, this type of system radiates most of its energy into empty space, unlike modern wireless power systems which waste very little energy. (wikipedia.org)
  • applications
  • Their only practical applications were to power early X-ray tubes, and later in some atomic particle accelerators. (wikipedia.org)
  • The largest of electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. (wikipedia.org)