Who invented the induction cooker and what is its detailed principle?

The first household induction cooker was born in Germany in 1957

Its working principle:

Induction cooker is a new type of stove in the kitchenware market. It breaks the traditional open flame cooking method and uses the heating principle of magnetic field induced current (also called eddy current). The induction cooker generates an alternating magnetic field through the components of the electronic circuit board. When an iron-containing pot is placed on the bottom of the stove, the pot That is, the alternating magnetic field lines are cut to generate alternating current (ie eddy current) in the metal part of the bottom of the pot. The eddy current causes the iron molecules of the pot to move irregularly at high speed. The molecules collide and rub with each other to generate heat energy (therefore: the heat source of induction cooker cooking comes from The heat is transferred to the bottom of the pot instead of the induction cooker itself, so the thermal efficiency is nearly 1 times higher than that of all cookware.) The appliance itself heats up at a high speed and is used to heat and cook food, thereby achieving the purpose of cooking. It has the advantages of fast heating, high thermal efficiency, no open flame, no smoke, no harmful gas, no thermal radiation to the surrounding environment, small size, good safety and beautiful appearance, and can complete most cooking tasks in the family. Therefore, in some countries where induction cookers are more popular, they are known as the "God of Cooking" and "Green Stoves".

[Working process] Since the induction cooker generates heat by directly inducing the magnetic field at the bottom of the pot to generate eddy currents, magnetically sensitive iron should be selected as the cookware, because iron can fully absorb the magnetic field and has a shielding effect. Very good, this reduces a lot of magnetic radiation, so iron pots are safer than cooking utensils made of any other material. In addition, iron is a substance beneficial to human health and an essential element that the human body needs to absorb for a long time.

Working process

When a loop coil is supplied with current, its effect is equivalent to a magnet bar. Therefore, there is a magnetic field N-S pole generated on the coil surface, that is, there is magnetic flux passing through it. If the power source used is alternating current, the magnetic poles of the coil and the magnetic flux passing through the return surface will change.

When a conductive metal surface is placed above the loop coil, the metal surface will induce current (ie, eddy current). The eddy current causes the iron molecules of the pot to move irregularly at high speed, and the molecules collide and rub against each other. Generate heat energy

The greater the current induced, the higher the heat generated and the shorter the time required to cook food. To make the induced current larger, the change in magnetic flux passing through the metal surface will be larger, and of course the magnetic field intensity will be stronger. As a result, the coil originally supplied with alternating current needs more turns to be wound together. Because it uses high-intensity magnetic field induction, no current is generated on the stove surface, so the stove surface will not generate high temperatures when cooking food. It is a relatively safe cooking appliance.