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Overvoltage
In electrical engineering, overvoltage is the raising of voltage beyond the design limit of a circuit or circuit element. The conditions may be hazardous. Depending on its duration, the overvoltage event can be transient—a voltage spike—or permanent, leading to a power surge. Explanation Electronic and electrical devices are designed to operate at a certain maximum supply voltage, and considerable damage can be caused by voltage that is higher than that for which the devices are rated. For example, an electric light bulb has a wire in it that at the given rated voltage will carry a current just large enough for the wire to get very hot (giving off light and heat), but not hot enough for it to melt. The amount of current in a circuit depends on the voltage supplied: if the voltage is too high, then the wire may melt and the light bulb burn out. Similarly other electrical devices may stop working, or may even burst into flames if an overvoltage is delivered to the circ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightning
Lightning is a natural phenomenon consisting of electrostatic discharges occurring through the atmosphere between two electrically charged regions. One or both regions are within the atmosphere, with the second region sometimes occurring on the land, ground. Following the lightning, the regions become partially or wholly electrically neutralized. Lightning involves a near-instantaneous release of energy on a scale averaging between 200 megajoules and 7 gigajoules. The air around the lightning flash rapidly heats to temperatures of about . There is an emission of electromagnetic radiation across a wide range of wavelengths, some visible as a bright flash. Lightning also causes thunder, a sound from the shock wave which develops as heated gases in the vicinity of the discharge experience a sudden increase in pressure. The most common occurrence of a lightning event is known as a thunderstorm, though they can also commonly occur in other types of energetic weather systems, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage Spike
In electrical engineering, spikes are fast, short duration electrical transients in voltage (voltage spikes), current (current spikes), or transferred energy (energy spikes) in an electrical circuit. Fast, short duration electrical transients ( overvoltages) in the electric potential of a circuit are typically caused by * Lightning strikes * Power outages * Tripped circuit breakers * Short circuits * Power transitions in other large equipment on the same power line * Malfunctions caused by the power company * Electromagnetic pulses (EMP) with electromagnetic energy distributed typically up to the 100 kHz and 1 MHz frequency range. * Inductive spikes In the design of critical infrastructure and military hardware, one concern is of pulses produced by nuclear explosions, whose nuclear electromagnetic pulses distribute large energies in frequencies from 1 kHz into the gigahertz range through the atmosphere. The effect of a voltage spike is to produce a correspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Flare
A solar flare is a relatively intense, localized emission of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other eruptive solar phenomena. The occurrence of solar flares varies with the 11-year solar cycle. Solar flares are thought to occur when stored magnetic energy in the Sun's atmosphere accelerates charged particles in the surrounding plasma. This results in the emission of electromagnetic radiation across the electromagnetic spectrum. The typical time profile of these emissions features three identifiable phases: a ''precursor phase'', an ''impulsive phase'' when particle acceleration dominates, and a ''gradual phase'' in which hot plasma injected into the corona by the flare cools by a combination of radiation and conduction of energy back down to the lower atmosphere. The extreme ultraviolet and X-ray radiation from solar flares is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Generator
A diesel generator (DG) (also known as a diesel genset) is the combination of a diesel engine with an electric generator (often an alternator) to generate electrical energy. This is a specific case of an engine generator. A diesel compression-ignition engine is usually designed to run on diesel fuel, but some types are adapted for other liquid fuels or natural gas (CNG). Diesel generating sets are used in places without connection to a power grid or as an emergency power supply if the grid fails, as well as for more complex applications such as peak-lopping, grid support, and export to the power grid. Diesel generator size is crucial to minimize low load or power shortages. Sizing is complicated by the characteristics of modern electronics, specifically non-linear loads. Its size ranges around 50 MW and above, an open cycle gas turbine is more efficient at full load than an array of diesel engines, and far more compact, with comparable capital costs; but for regular pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Explosion
A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, though to date all fusion-based weapons have used a fission device to initiate fusion, and a pure fusion weapon remains a hypothetical device. Nuclear explosions are used in nuclear weapons and nuclear testing. Nuclear explosions are extremely destructive compared to conventional (chemical) explosives, because of the vastly greater energy density of nuclear fuel compared to chemical explosives. They are often associated with mushroom clouds, since any large atmospheric explosion can create such a cloud. Nuclear explosions produce high levels of ionizing radiation and Nuclear fallout, radioactive debris that is harmful to humans and can cause moderate to severe skin burns, eye damage, radiation sickness, radiation-induced cancer and possible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitor
In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the '' condenser microphone''. It is a passive electronic component with two terminals. The utility of a capacitor depends on its capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed specifically to add capacitance to some part of the circuit. The physical form and construction of practical capacitors vary widely and many types of capacitor are in common use. Most capacitors contain at least two electrical conductors, often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconductin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Pulse
An electromagnetic pulse (EMP), also referred to as a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. The origin of an EMP can be natural or artificial, and can occur as an electromagnetic field, as an electric field, as a magnetic field, or as a conducted electric current. The electromagnetic interference caused by an EMP can disrupt communications and damage electronic equipment. An EMP such as a lightning strike can physically damage objects such as buildings and aircraft. The management of EMP effects is a branch of electromagnetic compatibility (EMC) engineering. The first recorded damage from an electromagnetic pulse came with the solar storm of August 1859, or the Carrington Event. In modern warfare, weapons delivering a high energy EMP are designed to disrupt communications equipment, computers needed to operate modern warplanes, or even put the entire electrical network of a target country out of commission. General characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a distinct military uniform. They may consist of one or more military branches such as an army, navy, air force, space force, marines, or coast guard. The main task of a military is usually defined as defence of their state and its interests against external armed threats. In broad usage, the terms "armed forces" and "military" are often synonymous, although in technical usage a distinction is sometimes made in which a country's armed forces may include other paramilitary forces such as armed police. Beyond warfare, the military may be employed in additional sanctioned and non-sanctioned functions within the state, including internal security threats, crowd control, promotion of political agendas, emergency services and reconstruct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero Cross Circuit
Zero-crossing control (or burst-fire control) is an approach for electrical control circuits that starts operation with the AC load voltage at close to 0 volts in the AC cycle. This is in relation to solid-state relays, such as TRIACs and silicon controlled rectifiers. The purpose of the circuit is to start the TRIAC conducting very near the time point when the load voltage is crossing zero (at the beginning or the middle of each AC cycle represented by a sine wave), so that the output voltage begins as a complete sine-wave half-cycle. In other words, if the controlling input signal is applied at any point during the AC output wave other than very close to the zero-voltage point of that wave, the output of the switching device will "wait" to switch on until the output AC wave reaches its next zero point. This is useful when sudden turn-on in the middle of a sine-wave half-cycle could cause undesirable effects like high-frequency spikes, for which the circuit or the environment is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
