page_title: Induction coil
hierarchical_section_title: Induction coil
caption_attribution_description: Deutsch: Zur Erzeugung kräftiger Induktionsströme benutzt man Funkeninduktoren; große Geräte wurden nach dem Erfinder auch Rühmkorff genannt. Im Innern befindet sich eine primäre Spule, die aus gut isoliertem dickem Draht gewickelt ist und einen Eisenkern enthält. Sie ist umgeben von der sekundären Spule, die aus sehr vielen, oft mehrere Kilometer langen Wicklungen dünnen Drahtes besteht. Der Strom geht von der Stromquelle zum Stromwender, von dort einerseits zur Primärspule, andererseits zum Wagnerschen Hammer. Wird der Strom eingeschaltet, erzeugt der Wagnersche Hammer fortwährend entstehende und verschwindende Kraftlinien in der Sekundärspule. Die erzeugten Induktionsströme entladen sich als Funken zwischen den Elektroden über dem Gerät. Die Induktionsströme sind Wechselströme da der Öffnungs- und der Schließungsstrom entgegengesetzte Richtung haben. English: Induction coil (also called "spark coil" or "Rühmkorff coil"), used in science education probably around 1900, on display in the Schulhistorische Sammlung (School Historical Museum), Bremerhaven, Germany. It generates high voltage from low voltage direct current (D). Inside the cylinder is the primary winding, consisting of relatively few turns of thick wire, wrapped around an iron core. It can be seen sticking out of both ends of the coil. Around this is wound the secondary winding, consisting of many turns of fine wire. At the left end of the core is a vibrating contact called an "interrupter", which repeatedly breaks the current in the primary circuit to provide the flux changes necessary for induction. When operating, the high voltage from the secondary is applied to the spark gap at the top, creating a stream of sparks
context_page_description: An induction coil or "spark coil" is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply. To create the flux changes necessary to induce voltage in the secondary coil, the direct current in the primary coil is repeatedly interrupted by a vibrating mechanical contact called an interrupter. Invented in 1836 by Nicholas Callan, with additional research by Charles Grafton Page and others, the induction coil was the first type of transformer. It was widely used in x-ray machines, spark-gap radio transmitters, arc lighting and quack medical electrotherapy devices from the 1880s to the 1920s. Today its only common use is as the ignition coils in internal combustion engines and in physics education to demonstrate induction.
context_section_description: An induction coil or "spark coil" (archaically known as an inductorium or Ruhmkorff coil after Heinrich Rühmkorff) is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply.  To create the flux changes necessary to induce voltage in the secondary coil, the direct current in the primary coil is repeatedly interrupted by a vibrating mechanical contact called an interrupter.  Invented in 1836 by Nicholas Callan, with additional research by Charles Grafton Page and others, the induction coil was the first type of transformer.  It was widely used in x-ray machines, spark-gap radio transmitters,  arc lighting and quack medical electrotherapy devices from the 1880s to the 1920s.  Today its only common use is as the ignition coils in internal combustion engines and in physics education to demonstrate induction.
caption: Antique induction coil used in schools, from around 1900, Bremerhaven, Germany
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