AN2383 datasheet(6/39 Pages) STMICROELECTRONICS

6 / 39 page

Induction heating basics

AN2383

6/39

Doc ID 12433 Rev 3

Induction heating basics

Put simply, an induction cooking element (what on a gas stove would be called a "burner") is

a special kind of transformer. When a good-sized piece of magnetically conducting material

such as, for example, a cast-iron frying pan, is placed in the magnetic field created by the

cooking element, the field transfers ("induces") energy into the metal. That transferred

energy causes the metal - the cooking vessel - to become hot.

By controlling the intensity of the magnetic field, we can control the amount of heat being

generated in the cooking vessel and we can change that amount instantaneously.

Induction cooking has several advantages over traditional methods of cooking:

●

Speed: conductive heat transfer to the food is very direct because the cookware is

heated uniformly and from within. Induction cooking is even faster than gas cooking

●

Safety: there are no open flames. This reduces the chances of fire and the cold stove

top is also more child safe

●

Efficiency: around 90%. Heat is generated directly in the pot, while for electric and gas

the efficiency is around 65% and 55% respectively due to heat transfer loss.

Induction cooking functions based on the principle of the series L-C resonant circuit, where

the inductance L is the cooking element itself.

By changing the switching frequency of the high voltage half-bridge driver, the alternating

current flowing through the cooking element changes its value. The intensity of the magnetic

field and therefore the heating energy can be controlled this way.

AN2383 Datasheet(PDF) 6 Page - STMicroelectronics