Induction heating of soldering irons is a technology where the soldering tip is not heated by a heating element, but by a non-contact electromagnetic field. There is a coil in the handle through which a high frequency alternating current flows, creating a rapidly changing magnetic field. When a tip made of conductive and magnetic material is inserted into it, eddy currents are induced. The material's resistance to these currents generates heat directly inside the tip, so it heats itself from the inside, not by heat transfer from the outside. Temperature control is provided by a physical property of the tip called the Curie point - at this temperature the material loses its magnetic properties and stops heating. Once the temperature drops slightly, the material becomes magnetic again and heating resumes. This results in a stable working temperature. To change the temperature, the tip must be replaced with another tip designed for a different temperature. The result is rapid heating from a cold state and the ability to deliver heat output immediately on contact with the joint.
