Wolf CT30I/S Instructions Manual page 17

Induction Cooktop (CTI) Series
Induction Cooktop (CTI) Series
PRINCIPLES OF INDUCTION
Introduction
There are two techniques of glass-ceramic heating:
• Infrared
• Induction
The difference is only obvious once the cooking zones are turned on. Induction has no visible indication of opera-
tion. The Infrared is provided with radiant or halogen sources that transmit heat by radiation or conduction.
Induction Cooktops produce a magnetic field which passes through the glass ceramic to the pan. When Ferro mag-
netic cookware is used, this magnetic field excites the molecules in the pan, causing them to vibrate at a very high
frequencies, producing heat. The principle of heating by induction is a natural phenomenon discovered in the 19th
century by several physicists, among them Leön Foucault. He discovered the induced currents that are named eddy
currents. Eddy currents are caused by a conductor (such as a pot or pan) intersecting a varying magnetic field (cre-
ated by the inductor hob). These currents transform electromagnetic energy into heat. The glass surface then
remains relatively cool and the cooking response time is very quick. The flexibility of the quick response time and
increased safety due to the glass staying cool are not the only advantages to the induction cooktop. The energy effi-
ciency of an induction cooktop is up to 90% and cleaning is easy due to the glass cooking surface staying cool.
Induced "Eddy" Currents
Operational Principles
An induction cooktop operates thanks to the electromagnetic properties of most containers used on the traditional
cooktop. You can compare this cooktop with a transformer of which the secondary winding would be shorted. A sig-
nificant internal current arises and causes quick heating. The saucepan can be compared with a shorted set of con-
centric coils whose internal resistance is not zero.
From the function keys, you can control the electrical power supply to the transformer primary winding that generates
a magnetic field. This field induces currents at the bottom of the container placed on the cooking zone. These
induced currents immediately heat the container, which transmits the produced heat to the food contained inside.
Cooking is performed practically without any loss of energy.
TRANSFORMER
Magnetic Conductor
Secondary Winding
Primary Winding
Magnetic Conductor
Magnetic Field
Induction Coil
Principles of Induction.
Gap
Electronic Circuit
+
-
1
2
3
4
5
6
INDUCTION UNIT
1
2
3 Glass-Ceramic Plate
4 Inductor (Element)
5
6
3-3
Electronic Control
Saucepan
Saucepan
Ferrite
Magnetic Field
#821684 - Revision B - March, 2013