• 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 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)
  • 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)
  • transients
  • A Zener diode connected to ground will protect against positive transients that go over the Zener's breakdown voltage, and will protect against negative transients greater than a normal forward diode drop. (wikipedia.org)
  • ground
  • In a power cord the black wire is hot, the white wire is neutral and the green wire is ground. (brown.edu)
  • 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)
  • An ideal signal ground maintains a fixed potential (zero) regardless of how much electric current flows into ground or out of ground. (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)
  • 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)
  • 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)
  • 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)
  • This allows coaxial cable runs to be installed next to metal objects such as gutters without the power losses that occur in other types of transmission lines. (wikipedia.org)
  • inductive
  • This sort of snubber is commonly used with inductive loads such as electric motors. (wikipedia.org)
  • Resonant inductive coupling is also being used in wireless power systems for portable computers, phones, and vehicles. (wikipedia.org)
  • Today resonant inductive energy transfer is regularly used for providing electric power in many commercially available medical implantable devices. (wikipedia.org)
  • Wireless electric energy transfer for experimentally powering electric automobiles and buses is a higher power application (>10 kW) of resonant inductive energy transfer. (wikipedia.org)
  • Some of these wireless resonant inductive devices operate at low milliwatt power levels and are battery powered. (wikipedia.org)
  • magnet
  • 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)
  • 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)
  • signal
  • It transforms useful input signal into light, sends it across the dielectric channel, captures light on the output side and transforms it back into electric signal. (wikipedia.org)
  • 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)
  • During experiments in 1907, Ettore Bellini and Alessandro Tosi noticed that they could cause the received signal to be re-radiated by forming a loop with multiple winds of wire. (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)
  • Fault
  • Digital fault recorder A digital fault recorder (DFR) is an IED that records information about power-system disturbances. (wikipedia.org)
  • secondary
  • WiTricity type magnetic resonance coupling systems add another set of resonant coils on the "primary" (power source) side which pair with the coils on the secondary (load bearing) side. (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)
  • braid
  • The shield might be just two braids, but it is more common now to have a thin foil shield covered by a wire braid. (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)
  • applications
  • Their only practical applications were to power early X-ray tubes, and later in some atomic particle accelerators. (wikipedia.org)
  • The need to increase the thickness of aluminium wire restricts its use in several applications, such as in small motors and automobiles. (wikipedia.org)
  • systems
  • 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)
  • It powers an endless list of laborsaving appliances and life- enhancing and support systems that have become such an assumed part of our lives that we give little thought to its potential for causing harm. (ncdcr.gov)