How does the induction cooker or cooking surface work?
If we all at school well taught physics, then the principle of the induction cooker would not cause any questions or concerns. But most of us safely forgot school lessons, and therefore new technologies and the principle of their operation often cause doubts and generate many speculations and myths. In fact, everything is not scary and quite simple.
1What is induction?
- 1.1Compared with the usual cooker - it is profitable
- 2Is it not harmful?
3Disadvantages of induction hobs
- 3.1Video: choose the hob
What is induction?
The work of the induction plate is based on the phenomenon of electromagnetic induction, discovered in 1831 by M. Faraday. Without getting into the jungle, the main principle can be formulated as follows: an alternating magnetic field becomes the source of an induction current, or a changing electric field.
In the kitchen stove, the phenomenon discovered by Faraday is as follows:
- Under the surface of a glass or glass-ceramic panel is a coil made of copper wire.
- When a coil of electric current passes through the turns, it converts it into an alternating electromagnetic field, which in turn creates an induction current.
- A pan with a magnetic bottom set on top becomes not just a pan, but a conductor with a closed loop.
- The vortex induction current produced by the plate drives the electrons of the ferromagnetic material of the bottom of the dishes.
- When electrons move, heat is released, which heats the pan - and its contents start to boil. Or grill, if it's not a pan, but a frying pan.
Compared with the usual cooker - it is profitable
In conventional plates, electric and gas, the heat source works much less efficiently. When cooking food on a gas burner or electric stove, heating up cookware consumes 30 to 60% of the heat, and the rest is spent on heating the environment, and not the dishes.
The principle of the induction panel reduces unproductive losses to a minimum: the bottom of the glass is heated immediately.
The very surface of the glass panel, unlike traditional electric stoves, heats only from contact with the heated bottom of the pan, so it never heats up to high temperatures.
Is it not harmful?
No, there is absolutely no harm from the induction plate. The magnetic field appearing in the operating induction plate is small. The principle of its action is such that even in the bottom of the dishes it penetrates only to the most superficial layer. No changes, except those caused by the action of temperature, in the cooked food do not take place at any level. Products contact only with the heated bottom, and more with nothing.
In addition, the design is such that the coil simply does not turn on if there are no dishes of the correct diameter and of a suitable material on the surface of the plate above it. On good models, special sensors will also recognize the degree of filling of dishes and will not allow the plate to turn on under an empty pan.
The diameter of the dishes when using a plate of this type should also be of a certain diameter. As a rule, it should be at least 12 cm or at least half the diameter of the burner. That is, if you drop a coin, fork, or put a silver saltcellar on the surface of the burner - nothing will happen, the hob simply does not turn on.
This selectivity makes use of the induction cooker safer and more economical. The hob does not work for a minute, the sensors will disconnect the current, even if you just lift the pan from the surface. Its surface does not heat up to more than 50-60 ° C - no one will burn, and food falling on the working plate will not become a source of fire and the smell of burning.
From this point of view, it is much more dangerous to use both electric and gas devices.
But there are disadvantages to "induction" all the same. What to do, in the world there is still no perfection.
Disadvantages of induction hobs
- Cooking induction panel belongs to the segment of expensive equipment. Although some electric stoves of the "Lux" class are quite comparable in value to induction ones.
- Induction hobs, designed for connection to a 220 V network, have increased requirements for the cross section of the input cable, since their power can reach 6 and more kW. Installation of such an electric stove may require the alteration of the wiring, and this will entail additional costs.
- Need special dishes. Theoretically, any one, whose bottom is made of ferromagnetic material, will do. In practice, conventional pots of enamelled steel are not very convenient to use, since they often have a thin bottom. The best dishes for the induction panel should have a thick magnetic bottom. Favorite pots made of non-magnetic stainless steel, heat-resistant glass or anodized aluminum will have to be donated to someone who still uses ordinary plates.
Most induction panels can not be installed directly above other devices, in the design of which there are metal elements. In some of the most advanced models this problem is solved, but they are worth it, respectively.
Depending on the design of the induction hob, it can be connected to either a 380 V or 220 V network. Most of the plates supplied to our country are rated at 220 V, which is not the case with panels imported from abroad. The fact is that the 380 V standard is a common thing for European apartments, so the manufacturer makes the wiring of individual plate heaters to different phases. This makes it possible to reduce the load on the wiring and to eliminate the skew of phases on the lowering network transformers. In our case, all the burners are obtained from two wires. At the same time, the load on the network also increases, which requires the use of wiring, as well as accounting and automation devices designed for a current of more than 25 amperes. I must say that in the event that you hit the plate, designed for a three-phase connection, there is no reason to despair - as a rule, such equipment can easily be changed to work in the ordinary single-phase network.