Related Research Articles
An electromagnetic coil is an electrical conductor such as a wire in the shape of a coil, spiral or helix. Electromagnetic coils are used in electrical engineering, in applications where electric currents interact with magnetic fields, in devices such as electric motors, generators, inductors, electromagnets, transformers, and sensor coils. Either an electric current is passed through the wire of the coil to generate a magnetic field, or conversely an external time-varying magnetic field through the interior of the coil generates an EMF (voltage) in the conductor.
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil around a core.
A transformer is a passive electrical device that transfers electrical energy from one electrical circuit to one or more circuits. A varying current in any one coil of the transformer produces a varying magnetic flux, which, in turn, induces a varying electromotive force across any other coils wound around the same core. Electrical energy can be transferred between the coils, without a metallic connection between the two circuits. Faraday's law of induction discovered in 1831 described the induced voltage effect in any coil due to changing magnetic flux encircled by the coil.
An electric motor is an electrical 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 wire winding to generate force in the form of rotation of a shaft. Electric motors can be powered by direct current (DC) sources, such as from batteries, motor vehicles or rectifiers, or by alternating current (AC) sources, such as a power grid, inverters or electrical generators. An electric generator is mechanically identical to an electric motor, but operates in the reverse direction, converting mechanical energy into electrical energy.
Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. It was part of a family of related technologies which bridged the gap between vacuum tubes and semiconductors by exploiting the magnetic properties of materials to perform switching and amplification. Such memory is often just called core memory, or, informally, core.
In electricity generation, a generator is a device that converts motive power into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids.
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole, denoting the centre of the coil. The magnetic field disappears when the current is turned off. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet.
A solenoid is a type of electromagnet, the purpose of which is to generate a controlled magnetic field through a coil wound into a tightly packed helix. The coil can be arranged to produce a uniform magnetic field in a volume of space when an electric current is passed through it. The term solenoid was coined in 1823 by André-Marie Ampère to designate a helical coil.
Twistor memory is a form of computer memory formed by wrapping magnetic tape around a current-carrying wire. Operationally, twistor was very similar to core memory. Twistor could also be used to make ROM memories, including a re-programmable form known as piggyback twistor. Both forms were able to be manufactured using automated processes, which was expected to lead to much lower production costs than core-based systems.
The shaded-pole motor is the original type of AC single-phase induction motor, dating back to at least as early as 1890. A shaded-pole motor is a small squirrel-cage motor in which the auxiliary winding is composed of a copper ring or bar surrounding a portion of each pole. When single phase AC supply is given to the stator winding, due to shading provided to the poles, a rotating magnetic field is generated. This auxiliary single-turn winding is called a shading coil. Currents induced in this coil by the magnetic field create a second electrical phase by delaying the phase of magnetic flux change for that pole enough to provide a 2-phase rotating magnetic field. The direction of rotation is from the unshaded side to the shaded (ring) side of the pole. Since the phase angle between the shaded and unshaded sections is small, shaded-pole motors produce only a small starting torque relative to torque at full speed. Shaded-pole motors of the asymmetrical type shown are only reversible by disassembly and flipping over the stator, though some similar looking motors have small, switch-shortable auxiliary windings of thin wire instead of thick copper bars and can reverse electrically. Another method of electrical reversing involves four coils.
A voice coil is the coil of wire attached to the apex of a loudspeaker cone. It provides the motive force to the cone by the reaction of a magnetic field to the current passing through it. The term is also used for voice coil linear motors, such as those used to move the heads inside hard disk drives, which produce a larger force and move a longer distance but work on the same principle.
A magnetic core is a piece of magnetic material with a high magnetic permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, generators, inductors, magnetic recording heads, and magnetic assemblies. It is made of ferromagnetic metal such as iron, or ferrimagnetic compounds such as ferrites. The high permeability, relative to the surrounding air, causes the magnetic field lines to be concentrated in the core material. The magnetic field is often created by a current-carrying coil of wire around the core.
A solenoid valve is an electromechanically operated valve.
In electrical engineering, an armature is the component of an electric machine which carries alternating current. The armature windings conduct AC even on DC machines, due to the commutator action or due to electronic commutation, as in brushless DC motors. The armature can be on either the rotor or the stator, depending on the type of electric machine.
An inductive sensor is a device that uses the principle of electromagnetic induction to detect or measure objects. An inductor develops a magnetic field when a current flows through it; alternatively, a current will flow through a circuit containing an inductor when the magnetic field through it changes. This effect can be used to detect metallic objects that interact with a magnetic field. Non-metallic substances such as liquids or some kinds of dirt do not interact with the magnetic field, so an inductive sensor can operate in wet or dirty conditions.
The NCR 315 Data Processing System, released in January 1962 by NCR, is an obsolete second-generation computer. All printed circuit boards use resistor–transistor logic (RTL) to create the various logic elements. It uses 12-bit slab memory structure using magnetic core memory. The instructions can use a memory slab as either two 6-bit alphanumeric characters or as three 4-bit BCD digits. Basic memory is 5000 "slabs" of handmade core memory, which is expandable to a maximum of 40,000 slabs in four refrigerator-size cabinets. The main processor includes three cabinets and a console section that houses the power supply, keyboard, output writer, and a panel with lights that indicate the current status of the program counter, registers, arithmetic accumulator, and system errors. Input/Output is by direct parallel connections to each type of peripheral through a two-cable bundle with 1-inch-thick cables. Some devices like magnetic tape and the CRAM are daisy-chained to allow multiple drives to be connected.
The NCR Century 100 was NCR's first all integrated circuit computer built in 1968. All logic gates were created by wire-wrapping NAND gates together to form flip-flops and other complex circuits. The console of the system had only 18 lights and switches and allowed entry of a boot routine, or changes to loaded programs or data in memory. A typewriter console was also available.
The rotor is a moving component of an electromagnetic system in the electric motor, electric generator, or alternator. Its rotation is due to the interaction between the windings and magnetic fields which produces a torque around the rotor's axis.
A microcoil is a tiny electrical conductor such as a wire in the shape of a spiral or helix which could be a solenoid or a planar structure. One field where these are found is nuclear magnetic resonance (NMR) spectroscopy, where it identifies radio frequency (RF) coils that are smaller than 1 mm.
In electrical engineering, coil winding is the manufacture of electromagnetic coils. Coils are used as components of circuits, and to provide the magnetic field of motors, transformers, and generators, and in the manufacture of loudspeakers and microphones. The shape and dimensions of a winding are designed to fulfill the particular purpose. Parameters such as inductance, Q factor, insulation strength, and strength of the desired magnetic field greatly influence the design of coil windings. Coil winding can be structured into several groups regarding the type and geometry of the wound coil. Mass production of electromagnetic coils relies on automated machinery.
References
Citations
- ↑ Higashi 1966, p. 461.
- ↑ Higashi 1966, pp. 459-461.
Bibliography
- Higashi, Paul (August 1966). "A Thin-Film Rod Memory for the NCR 315 RMC Computer" (PDF). IEEE Transactions on Electronic Computers. EC-15 (4): 459–467. doi:10.1109/PGEC.1966.264353.
- Behrendt, D. (September 1967). "Rod Memory Array Production Design". IEEE Transactions on Parts, Materials and Packaging. 3 (3): 77–81. doi:10.1109/TPMP.1967.1135727.