What is the name for what is basically an induction coil whereby the voltage of an alternating current can be increased or decreased without changing the frequency?
Induction coil Induction coil An induction coil or "spark coil" (archaically known as an inductorium or Ruhmkorff coil after Heinrich Ruhmkorff) 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
Induction heating induction heating increasingly popular. Induction heating can also be applied to molds, offering more even mold temperature and improved product quality. The basic setup is an AC power supply that provides electricity with low voltage but very high current and high frequency. The workpiece to heat is placed inside an air coil driven by the power supply, usually in combination with a resonant tank capacitor to increase the reactive power. The alternating magnetic field induces eddy currents in the workpiece. The frequency of the inductive current determines the depth that the induced eddy currents penetrate into the workpiece. In the