- a transformer for producing high-voltage alternating current from a low-voltage direct current, consisting essentially of two concentric coils with a common soft-iron core, a primary coil with relatively few windings of heavy wire, and a secondary coil with many turns of fine wire. Excitation of the primary coil by rapidly interrupted or variable current induces high voltage in the secondary coil.
Origin of induction coil
First recorded in 1875–80
Also called Ruhmkorff coil.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for induction coil
The purpose of the induction-coil is to raise the voltage of the battery.Home-made Toys for Girls and Boys
A. Neely Hall
In so doing, you have simply had the current from the secondary of an induction-coil.ABC of Electricity
William Henry Meadowcroft
When these two wires are wound in coils, together they form an induction-coil.
Faraday, as we have seen, discovered the principle of the induction-coil.
The induction-coil may be operated by a storage battery or dynamo.
- 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 coreSometimes shortened to: coil
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- An electrical device consisting of a single coil of conductive material, often surrounding a metallic core, designed to establish a strong magnetic field around the coil. Changes in the current flow through the coil cause fluctuations in the magnetic field that induce a voltage across the coil. Induction coils have many applications, especially in circuits that tune to signals of specific frequencies, as in radios. The ability of an induction coil to induce a voltage is called inductance, and is measured in henrys. Compare capacitor.
- A type of transformer that changes a low-voltage direct current to a high-voltage alternating current. Induction coils are used for many purposes, especially as spark coils for firing spark plugs in automobile engines and starting oil burners.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.