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Explosive-driven Ferromagnetic Generator
An explosive-driven ferromagnetic generator (EDFMG, explosively pumped ferromagnetic generator, EPFMG, or FMG) is a compact pulsed power generator, a device used for generation of short high-voltage high-current pulse by releasing energy stored in a permanent magnet. It is suited for delivering high-current pulses (kiloamperes) to low- impedance loads. The FMGs consist of a permanent magnet (usually a neodymium magnet), a high explosive charge, and a pickup coil. They are a kind of phase transition generators, utilizing pressure-induced magnetic phase transition effect. By adjusting the number of turns of the coil, which can be as low as a single turn, the generator can be designed for delivery of high-current low-voltage pulses or, with more turns, low-current high-voltage pulses. The shock wave generated by explosion destroys the magnetic domains in the magnet, cause loss of the magnetic field, and the very sudden change induces a high-peak electric current in the surrounding c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsed Power
Pulsed power is the science and technology of accumulating energy over a relatively long period of time and releasing it instantly, thus increasing the instantaneous power. They can be used in some applications such as food processing, water treatment, weapon, and medical applications. Overview Energy is typically stored within electrostatic fields (capacitors), magnetic fields (inductors), as mechanical energy (using large flywheels connected to special-purpose high-current alternators), or as chemical energy (high-current lead-acid batteries, or explosives). By releasing the stored energy over a very short interval (a process that is called energy compression), a huge amount of peak power can be delivered to a load. For example, if one joule of energy is stored within a capacitor and then evenly released to a load over one second, the average power delivered to the load would only be 1 watt. However, if all of the stored energy were released within one microsecond, the average po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive-driven Ferroelectric Generator
An explosive-driven ferroelectric generator (EDFEG, explosively pumped ferroelectric generator, EPFEG, or FEG) is a compact pulsed power generator, a device used for generation of short high-voltage high-current pulse. The energies available are fairly low, in the range of single joules, the voltages range in tens of kilovolts to over 100 kV, and the powers range in hundreds of kilowatts to megawatts. They are suitable for delivering pulses to high- impedance [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosively Pumped Flux Compression Generator
An explosively pumped flux compression generator (EPFCG) is a device used to generate a high-power electromagnetic pulse by compressing magnetic flux using high explosive. An EPFCG only ever generates a single pulse as the device is physically destroyed during operation. An EPFCG package that could be easily carried by a person can produce pulses in the millions of amperes and tens of terawatts. They require a starting current pulse to operate, usually supplied by capacitors. Explosively pumped flux compression generators are used to create ultrahigh magnetic fields in physics and materials science research and extremely intense pulses of electric current for pulsed power applications. They are being investigated as power sources for electronic warfare devices known as transient electromagnetic devices that generate an electromagnetic pulse without the costs, side effects, or enormous range of a nuclear electromagnetic pulse device. The first work on these generators was condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rise Time
In electronics, when describing a voltage or current step function, rise time is the time taken by a signal to change from a specified low value to a specified high value. These values may be expressed as ratiosSee for example , and . or, equivalently, as percentages with respect to a given reference value. In analog electronics and digital electronics, these percentages are commonly the 10% and 90% (or equivalently and ) of the output step height: however, other values are commonly used. For applications in control theory, according to , rise time is defined as "''the time required for the response to rise from to of its final value''", with 0% to 100% rise time common for underdamped second order systems, 5% to 95% for critically damped and 10% to 90% for overdamped ones.Precisely, states: "''The rise time is the time required for the response to rise from x% to y% of its final value. For overdamped second order systems, the 0% to 100% rise time is normally used, and for under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vector Inversion Generator
A vector inversion generator (VIG) is an electric pulse compression and voltage multiplication device, allowing shaping a slower, lower voltage pulse to a narrower, higher-voltage one. VIGs are used in military technology, e.g. some directed-energy weapons, as a secondary stage of another pulsed power source, commonly an explosive-driven ferroelectric generator. Construction Discrete component VIGs (pictured) consist of a stack of well-coupled common mode chokes interconnected with a stack of capacitors. The inductors present a high inductance to currents that are in-phase in the two windings, and a far lower inductance when the winding currents are flowing in opposite directions. The capacitors are charged with alternating polarity and when the switch (usually a triggered or free running spark gap in practice) is closed the voltage across every second capacitor rapidly inverts as a half cycle of oscillation at a frequency set by the capacitance resonating with the differential mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosively Pumped Flux Compression Generator
An explosively pumped flux compression generator (EPFCG) is a device used to generate a high-power electromagnetic pulse by compressing magnetic flux using high explosive. An EPFCG only ever generates a single pulse as the device is physically destroyed during operation. An EPFCG package that could be easily carried by a person can produce pulses in the millions of amperes and tens of terawatts. They require a starting current pulse to operate, usually supplied by capacitors. Explosively pumped flux compression generators are used to create ultrahigh magnetic fields in physics and materials science research and extremely intense pulses of electric current for pulsed power applications. They are being investigated as power sources for electronic warfare devices known as transient electromagnetic devices that generate an electromagnetic pulse without the costs, side effects, or enormous range of a nuclear electromagnetic pulse device. The first work on these generators was condu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function assigning a vector to each point of space, cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Domain
A magnetic domain is a region within a magnetic material in which the magnetization is in a uniform direction. This means that the individual magnetic moments of the atoms are aligned with one another and they point in the same direction. When cooled below a temperature called the Curie temperature, the magnetization of a piece of ferromagnetic material spontaneously divides into many small regions called magnetic domains. The magnetization within each domain points in a uniform direction, but the magnetization of different domains may point in different directions. Magnetic domain structure is responsible for the magnetic behavior of ferromagnetic materials like iron, nickel, cobalt and their alloys, and ferrimagnetic materials like ferrite. This includes the formation of permanent magnets and the attraction of ferromagnetic materials to a magnetic field. The regions separating magnetic domains are called domain walls, where the magnetization rotates coherently from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a test charge between the two points. In the International System of Units, the derived unit for voltage is named ''volt''. The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in generator, inductors, and transformers). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential such as the ground of the system is used as one of the points. A voltage can represent either a source ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Transition
In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma. A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change as a result of the change of external conditions, such as temperature or pressure. This can be a discontinuous change; for example, a liquid may become gas upon heating to its boiling point, resulting in an abrupt change in volume. The identification of the external conditions at which a transformation occurs defines the phase transition point. Types of phase transition At the phase transition point for a substance, for instance the boiling point, the two phases involved - liquid and vapor, have identic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
