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Unipolar Motor
A unipolar motor (also called homopolar motor) is a direct current (DC) motor typically with slip-rings on each end of a cylindrical rotor and field magnets or a DC field winding generating a magnetic field on the stator. The rotor has typically not a winding but just straight connections in axial direction between the slip-rings (e.g. a copper tube encasing the rotor or rods embedded in the rotor). The field is uniformly perpendicular to the cylindrical rotor surface and does not change polarity over the 360-degree perimeter of the cylindrical part of the rotor. That means if the field is considered entering the rotor between the slip-rings it must leave the rotor though the rotor's end surfaces. It is not important that the magnetic field is generated from the stator; a similar field may be generated from the rotor with the same effect (the magnetic fields would not rotate with the rotor). Unipolar motors and generators are rarely built any more because of advancing technology. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homopolar Motor
A homopolar motor is a direct current electric motor with two magnetic poles, the conductors of which always cut unidirectional lines of magnetic flux by rotating a conductor around a fixed axis so that the conductor is at right angles to a static magnetic field. The resulting force being continuous in one direction, the homopolar motor needs no commutator but still requires slip rings. The name ''homopolar'' indicates that the electrical polarity of the conductor and the magnetic field poles do not change (i.e., that it does not require commutation). Run in reverse, the device is known as a homopolar generator and generates a voltage difference from rotary motion. History The homopolar motor was the first electrical motor to be built. Its operation was demonstrated by Michael Faraday in 1821 at the Royal Institution in London. In 1821, soon after the Danish physicist and chemist Hans Christian Ørsted discovered the phenomenon of electromagnetism, Humphry Davy and B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Current
Direct current (DC) is one-directional electric current, flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor (material), conductor such as a wire, but can also flow through semiconductors, electrical insulation, insulators, or even through a vacuum as in electron beam, electron or ion beams. The electric current flows in a constant direction, distinguishing it from alternating current (AC). A archaism, term formerly used for this type of current was galvanic current. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', as when they modify ''Electric current, current'' or ''voltage''. Direct current may be converted from an alternating current supply by use of a rectifier, which contains Electronics, electronic elements (usually) or electromechanical elements (historically) that allow current to flow only in one direction. Direct current may be converted into alt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Motor
An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to generate Laplace force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy. Electric motors can be powered by direct current (DC) sources, such as from batteries or rectifiers, or by alternating current (AC) sources, such as a power grid, Inverter (electrical), inverters or electrical generators. Electric motors may also be classified by considerations such as power source type, construction, application and type of motion output. They can be brushed motor, brushed or brushless motor, brushless, single-phase electric power, single-phase, two-phase electric power, two-phase, or three-phase electric p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassette Player
A cassette deck is a type of tape machine for playing and recording audio cassettes that does not have a built-in power amplifier or speakers, and serves primarily as a Transport (recording), transport. It can be a part of an automotive entertainment system, a part of a portable audio system or a part of a home High fidelity#Modularity, component system. In the latter case, it is also called a component cassette deck or just a component deck. History Roots The first consumer tape recorder to employ a tape reel permanently housed in a small removable cartridge was the RCA tape cartridge, which appeared in 1958 as a predecessor to the cassette format. At that time, reel-to-reel recorders and players were commonly used by enthusiasts but required large individual reels and tapes which had to be threaded by hand, making them less accessible to the casual consumer. Both RCA and Bell Sound attempted to commercialize the cartridge format, but a few factors stalled adoption, inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DC Motors
DC most often refers to: * Washington, D.C. (District of Columbia), the capital of the United States * DC Comics, an American comic book publisher * Direct current, electric current which flows in only one direction DC, D.C., D/C, Dc, or dc may refer to: Places * Bogotá, Distrito Capital, the capital city of Colombia * Dubai City Science, technology and mathematics * dC, decicoulomb, a tenth of a Coulomb, the SI unit of electric charge * New Zealand DC class locomotive * Methylphosphonyl dichloride, a chemical weapons precursor * A don't care term, in digital logic Biology and medicine * Dendritic cell, a class of immune cell * Doctor of Chiropractic, a qualification in alternative medicine Computing * dc (computer program), a command-line based calculator on Unix-derived systems * DC coefficient, in a discrete cosine transform * Data center, a physical location housing computing-related gear * Device context, part of the legacy Microsoft Windows graphics API ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
