An induction coil is used in two widely different industries for a relatively similar purpose. In the automotive industry, an induction coil is the ignition or spark coil. An ignition coil takes the voltage from the vehicle’s battery and amplifies it to a few thousand volts. A spark plug uses that high voltage to make a spark that burns fuel. In the industrial heating, melting and hardening equipment, the coil is one of the most important parts of an induction furnace. An alternating current and computerized control and timer system make an induction furnace the perfect technology for modifying metal.
An induction coil assembly has two insulated copper wire coils, called windings. An induction coil is made of copper tubing and typically is water cooled. Both ends of the winding are connected to a high or medium frequency alternating current source. These alternating current causes eddy currents that actually heats the metal. Size and shape of the coil is depends on size and shape of the parts that want to heat.
Small size of the parts need higher frequency and bigger size of the parts need medium frequency. The metal to be melted or hardened gets placed inside the hollow core. Heating begins immediately when current is applied to the primary coil. Depending on the material’s thickness, melting can occur quickly or take some time totally related to how much material needs to be heated or melted. Sensors monitor the metal’s temperature and a computer monitors and controls the current flow to apply the exact current needed to heat the metal to the exact temperature to harden heat or melt it.