Induction cooker: principle of operation, features, choice of dishes

Induction cooker - a cooking surface for cooking, which remains cold until the dishes with a magnetic bottom are placed on it. It is absolutely safe and allows you to save on electricity. How is the induction cooker arranged and working, we will consider further.

How is the induction cooker arranged and working?

The hob is usually made of glass ceramic or other dielectric and non-magnetic composite material. Under the surface of the induction cooker there are inductors made of metal with good electrical conductivity in the form of a cylinder. They look as follows:

When an alternating current of high frequency begins to pass through the inductors, an alternating (pulsating) magnetic field arises. This field extends beyond the coil, including above the surface of the plate. If a plate with magnetic properties (iron) is on the plate, an alternating magnetic field excites a current flow in it. This current, passing through the conductor, experiences resistance to its movement, which heats the object on the stove.

This phenomenon (currents induced by a magnetic field in a material falling into the magnetic field) is called electromagnetic induction (the effect was discovered by British scientist Michael Faraday in 1831). Therefore, stoves whose work is based on this effect are called induction.

A diagram of the induction cooker is presented below:

The oscillation frequency of the magnetic field is from 20 to 60 kilohertz. The highest sound that can distinguish the ear of an ordinary person is 16 kilohertz. The efficiency of the induction cooker is very high - from 80% to 90%, depending on the model. This means that getting the same dishes as on a regular stove, you will spend much less energy.

It should be noted that the surface of the plate during operation is heated not from a magnetic field, but only from an object on the plate. If you touch the stove during operation, the surface will be at room temperature. The exception is the area under the pan (pan). This zone is heated from the bottom of the dishes. But if you remove the dishes, the heating will stop immediately (there is simply nothing to warm up), and the hob will cool to ambient temperature in just a few seconds.

Even non-heat-resistant materials in contact with the stove will not melt and do not catch fire, including because even at high temperature after removing the kitchen utensils from the surface, its temperature drops very quickly. Therefore, a plastic bottle with baby formula or a disposable plate will never burn to the stove.

Each induction furnace model has a built-in timer. With its help, you can both extremely precisely adjust the cooking mode, and simply limit the amount of energy spent on heating dishes. In many models there is a “boiling control” function, that is, the temperature sensor determines when the dish has reached a temperature of 100 degrees, the set time allows it to boil, after which the oven turns off.

The digital indicator on the control panel can indicate several parameters:

• temperature for each burner (optional);
• power consumption;
• clock;
• cooking time on each burner.

There are models of cooking surfaces, where some of the hobs are induction, and some are conventional electric hobs. All this is under the common glass-ceramic surface. If there are several induction hobs, they can work as one, heating a large pan or a whole pan together, and the temperature is distributed evenly on the bottom of the container.

It is proposed to visually see how the induction cooker works in the following video:

Features of induction cooker

What features are noted with such a device of the plate, we will highlight below:

• There is no harm from cooking on such stoves and cannot be - neither in the process of cooking, nor in eating food. This is due to the fact that there is no powerful radiation affecting the physicochemical composition of food.

• The manufacturability of the furnace is much higher than that of a conventional electric or gas furnace. That is why induction furnaces are still more expensive.
• One of the main positive aspects when working with such a stove is that there is absolutely no smell of burning in your kitchen. On the electric stove, the spiral, the body and the grill are heated (approximately the same with the gas stove), and on all heated parts get dust, oil and food particles that burn out and give off the corresponding "Aroma". And on the "induction" there is simply nothing to burn.
• Such furnaces are equipped with temperature sensors that clearly withstand the specified temperature conditions. Thus, you can program the cooking process literally every minute, which cannot be achieved on a conventional gas or electric stove.
• Due to the fact that energy is used exclusively to increase and maintain the temperature of food, your kitchen maintains a comfortable atmosphere. During cooking, you do not overcome the heat and stuffiness, you do not need to turn on the air conditioner again.

• The control of most induction furnaces is touch-sensitive. A simple set of several buttons, however, gives you much more options than an electric or gas stove.
• The stove can give you sound signals. If you set it up in a certain way, it will “call” you when the oil starts to boil in the pan, or the kettle prepares to whistle.
• Almost all induction furnaces are equipped with an additional emergency temperature sensor that monitors the surface temperature. When the temperature reaches, for example, 250 degrees Celsius, an automatic shutdown will occur. So you can not be afraid that you left the kettle on the stove turned on - smart electronics will insure you when all the water boils.
• Induction furnaces are also distinguished by the fact that they maintain the set temperature much more accurately than in gas or electric stoves. This is because, due to the absence of temperature interference for the thermocouple of the plate from gas flows or heating elements, its accuracy is much higher.
• You can put kitchen towels directly on the surface during cooking so that splashes of water and oil do not even fall on the hob;
• Even if food particles fell or spilled onto the stove during cooking, they will not burn and can be easily removed, because they will stop heating up.
• If you put pots, pans and a kettle on all burners at the same time, then the total power of the stove will be artificially reduced - in order to reduce the load on the electronics in the plate and on the wiring in your the house. This is a programmed function. For example, the total power of the stove is 3 kilowatts. But if you use all the burners, only 2.5 kilowatts will be spent.

The features, pros and cons of the induction cooker can be found in the following video:

Where to install?

A huge plus of the induction burner is that it can be built into almost any place on the surface of the kitchen countertops, if only there is enough space. However, some points to consider:

1. It is undesirable that metal pipes, corners or other conductive structures are close to such a furnace - this is not dangerous, but it can negatively affect the operation of the furnace.
2. There should be enough space for ventilation, since the electronics inside the induction unit require good cooling.
3. Do not over-seal the location of all kitchen units. An induction furnace saves a lot of space, but you should not place it closer than 50 centimeters from the refrigerator, microwave and other electrical appliances. It's not even about the metal walls. The mutual influence of magnetic fields, electromagnetic radiation and high temperature can be unpredictable.

What cookware to choose for cooking on an induction stove?

The induction furnace simply does not turn on and does not start the heating process if the item of kitchen utensils placed on it:

• not a current conductor;
• is too good a conductor;
• has a diameter of less than 12 centimeters (approximately 5 inches);
• has a temperature above a certain maximum (usually 100 degrees Celsius).

It should be understood that any materials containing ferromagnets can be heated on an induction stove, even if the materials themselves are not magnetic. For example, stainless steel or cast iron does not have pronounced magnetic properties, but they still contain iron - the material that gave the name the property “ferromagnet”. Therefore, both stainless steel and cast iron are perfectly heated under the influence of the eddy currents of the induction furnace.

On specialized cookware for induction heatingput a special sign - several vertical loops and the inscription «Induction».

Usually they are made of "white" cast iron.

The bottom of the vessel for heating by magnetic fields must be iron-containing - cast iron, steel or stainless. The thickness of the bottom should be at least 2 millimeters thick. Expensive and high-quality products have a bottom about a centimeter thick and some innovative non-stick coating (for example, titanium-ceramic).

For tanks with a too small bottom (Turks, stewpan), there are special iron coasters-circles, which are perfectly heated on an induction furnace and transfer heat to small tanks.

Conventional iron enameled containers are also quite suitable, although if the bottom is thin and concave, they can make unpleasant sounds. But due to the very fast warming up of the capacity, you will not have to endure these sounds for long.

Some non-specialized types of cookware may warm up unevenly. For example, the center of the pan may be hot, and at the walls the temperature will be fifty degrees lower. This can only be fixed by changing the dishes.

Another disadvantage of ordinary dishes is a damaged or loose bottom. A frying pan coated from below with a layer of soot after a gas oven, when used on an induction burner starts to emit unpleasant odors, sounds and even lets out smoke, because now the temperature does not rise outside, but from the inside. In addition, a deformed bottom may scratch the surface of the plate.

Naturally, kitchenware made of glass, ceramics, plastic, and other materials not containing metals is not suitable for induction furnaces. Also, copper, aluminum and other kitchen utensils made of materials that conduct electricity well are not suitable. The fact is that for fast heating by magnetic fields it is required that the conductor be bad. Then the eddy currents, experiencing great resistance, cause the dishes to heat up, and from increased temperature the resistance increases even more.

What can not be done with an induction furnace?

In order not to cause malfunctions in the work of such a cooking surface, it is worth considering the following restrictions:

• Do not work with an induction cooker for those who have a pacemaker built-in, since a magnetic field can adversely affect the implant. At a distance of half a meter from the stove, the field is almost indistinguishable, but it is better not to risk it.
• Do not allow contact of credit cards, documents and other items with the magnetic field of the induction cooker. The same applies to mobile cards, mobile phones and other electronic devices.
• Do not use aluminum foil - it gets too hot under the influence of induction currents and can cause a fire. The same applies to foil packaging - chocolate bars, sweets, milk bags, others similar items, including decorative foil ribbons for gifts, balloons and so Further.

Why does not it work?

If the induction cooker does not work at all, you can find the cause of the breakdown as follows:

1. Check the power cord. Most often, it breaks off at the plate body or at the outlet. If contact occurs when the cord is moved, it appears, then it disappears - the problem is localized, it is necessary to repair the cord.
2. Try removing the plug and plugging it into another outlet — perhaps this is the case.
3. Make sure the power button on the back of the stove is pressed (close to where the power cord is located). Sometimes children or pets manage to click on it and unplug the oven.

If everything is fine outside, you have to open the countertop. First, just inspect the filling of the plate visually - whether any obviously unusual places are imperceptible. Here we check:

• fuse;
• terminals and wire connections (you can tighten the screws tighter, just for prevention);

Further, it is most reasonable to check the elements experiencing the greatest energy and thermal load. Usually they are mounted on a certain radiator. It:

• diode bridge;
• power transistor;
• power transformer.

Then it remains to check the controller chip and transistors through which the controller signals go. If checking all of the above items has not identified the cause of the problem, you will have to contact a specialized workshop.

Video: Induction cooker against gas and electric

The following video reveals in a practical way which type of slab is better:

Induction cookers and surfaces are almost ideal cooking appliances. They are safe, economical, beautiful, convenient, compact, and are also adjustable over a wide range. The food is cooked and heated very quickly. For it to last a long time, it is worth carefully approaching the installation, operation and maintenance.