induction coil

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induction coil

a transformer for producing a high voltage from a low voltage. It consists of a cylindrical primary winding of few turns, a concentric secondary winding of many turns, and often a common soft-iron core

induction coil

[in′dək·shən ‚kȯil]
(electromagnetism)
A device for producing high-voltage alternating current or high-voltage pulses from low-voltage direct current, in which interruption of direct current in a primary coil, containing relatively few turns of wire, induces a high voltage in a secondary coil, containing many turns of wire wound over the primary.

Induction coil

A device for producing a high-voltage alternating current or high-voltage pulses from a low-voltage direct current. The largest modern use of the induction coil is in the ignition system of internal combustion engines, such as automobile engines. Devices of similar construction, known as vibrators, are used as rectifiers and synchronous inverters. See Ignition system

The illustration shows a typical circuit diagram for an induction coil. The primary coil, wound on the iron core, consists of only a few turns. The secondary coil, wound over the primary, consists of a large number of turns.

Induction coils of a different type are used in telephone circuits to step up the voltage from the transmitter and match the impedance of the line. The direct current in the circuit varies in magnitude at speech frequencies; therefore, no interrupter contacts are necessary. Still another type of induction coil, called a reactor, is really a one-winding transformer designed to produce a definite voltage drop for a given current. See Reactor (electricity)

References in periodicals archive ?
The ring-shaped multi-turn induction coil was produced from copper pipe in the form of a spiral.
The induction coil can be placed in or on the mould, or between the open mould halves.
The drive current is distributed between the coils to minimize any remnant field at the position of the main induction coils.
The low-resistance induction coils remain cool enough to touch.
The induction coils permit passive devices, with power being obtained through induction only when required.
INDX uses a high-frequency power supply and helical induction coils to generate heat directly within the metal barrel wall.
A selection of four different size induction coils are changed within five seconds without the need to power down the system.
based on the comparison, Chaisson asserts that if a low-permeability slip plane material is used, it can perform an important function of mitigating the conductive gases to the induction coils.
RocTool began experimenting with induction heating in 2001, at first casting induction coils into a ceramic tool with a thin (1 cm) metal skin.
Water cooling permits the use of copper coils for the induction coils, which are more efficient and several times more durable than the wrapped wire coils at less than half the cost.
Electrical induction physics demand that the refractory lining between the induction coils and the bath is as thin as possible.
Induction coils are mounted on a non-rotating shaft, close to the roller shell.