For those who have tried it, induction cooking provides an experience similar to that of cooking on gas, but without the dangers cooking with gas poses. However, induction heating requires a significantly more complex control circuit than alternative electrical heating approaches, such as ceramic hobs that can simply use a thermostat. As well as being used for hob-based cooking, induction heating is integrated into rice cookers, hot plates, and even milk frothers.
Induction heating works in a similar way to a transformer. A coil is energized but, rather than generating current flow in another coil, it causes current to flow in a cooking vessel. The Eddy currents generated result in Joule heating due to the resistance of the material used, typically something magnetic such as iron or magnetic stainless steel. Single-ended parallel resonance (SEPR) circuits are a common approach, using an IGBT switch with integrated forward diode for control.
Toshiba has continuously developed its IGBT process technology to optimize them for the demands of induction heating applications. The latest device, the GT20N135SRA offers improvements in the collector saturation current limiting the short-circuit current during start-up conditions. Its turn-off operation has also been optimized to reduce radiated emissions, resulting in lower emissions that provid around 10 dB more margin at 30 MHz during EMC testing.
To learn more about the use cases for the GT20N135SRA in induction heating applications, take a look at our latest white paper here: