In glass-ceramic stoves with a regular burner (spiral, strip or halogen, whatever), the heat travels this way: first it gets hot a heating element burners, then the heating zone of the glass-ceramic coating of the stove, and the bottom of the cookware is heated from the surface of the glass. Induction cooker- essentially this is an electric kitchen stove that heats metal utensils with induced eddy currents created by a high-frequency magnetic field with a frequency of 20-100 kHz.
An induction cooker is an electric cooker with glass-ceramic induction burners. The difference from all other types of stoves is the principle of heat generation.
Induction heating technology is different in that heat arises in the very bottom of the cookware. No time required to heat up the burner - The dishes are heated immediately at the specified power. This brings induction hobs very close to gas hobs in terms of convenience.
An induction cooker heats up quickly and consumes significantly less energy.
Where can I buy. Induction cookers are sold in the section of stoves and ovens in Ozone, also see in the section of the manufacturer Oursson (in this section there are only induction cookers, without conventional ones).
The device of an induction cooker.
Under the glass cover of the plate there is a copper coil through which high-frequency electric current flows. According to Faraday's laws, the magnetic field of this current, penetrating the bottom of the dish, induces electric currents. The bottom of the pan is not a long wire, but a disk, so the currents in it go in a circle and do not flow in a string. Therefore, eddy electric currents spinning in the bottom of the pan heat the bottom, and with it the food.
The bottom of the cookware must be made of a material with clearly defined ferromagnetic properties. Majority modern dishes exactly like that. Modern induction cookers automatically recognize suitable cookware and only in this case turn on the magnetic field. Induction hobs are able to recognize cookware with a ferromagnetic bottom on their surface: without it they will not turn on. In order for the burner to turn on, you usually need to cover at least 70% of its area with dishes. Induction panels can even adjust the diameter of the eddy current generation zone. The panel sensors will adjust the diameter of the heating zone to the diameter of the cookware, if it is within the limits allowed for a given burner, so you can put something small on it that is smaller in diameter than the burner itself.
Induction hob.
General rule is this: if the cookware has a layer of ferromagnetic metal (for example, steel) in the bottom, not separated from the burner by anything other than dielectrics (for example, enamel), then this cookware is suitable for an induction cooker, regardless of what materials and how thick they lie above the ferromagnetic layer (the magnetic field practically does not penetrate above it).
Cookware suitable for induction cookers:
- from of stainless steel with ferromagnetic bottom;
- aluminum cookware with ferromagnetic bottom;
- cast iron cookware.
Cookware made of copper, aluminum, heat-resistant glass and other non-magnetic materials are NOT suitable for induction cookers. HOWEVER, progress does not stand still: induction cookers are now appearing that can use any metal utensils, and also devices appear that allow you to cook a product in copper and aluminum utensils on an induction stove.
Traditional enameled iron (steel) cookware works great on induction cooktops. However, if the pan does not have a modern, flat bottom, but an old version, with an elevation in the central part, a noticeable hum or squeak may appear during operation due to vibrations of this elevation, similar to the diaphragm of a loudspeaker.
It's great to cook in woks on these stoves: the induction cooker perfectly heats the WOK pan, which, as you know, requires high heat.
Instant heating allows you to boil water very quickly, for example.
The efficiency of such plates is about 90%(in contrast to 60-70% for electric stoves using resistive heating elements, and 30-60% for gas ones). Savings and high efficiency arise due to the absence of leakage of heat flows past the dishes from hot resistive heating elements or gases.
In this case, no heat transfer occurs through the glass ceramics: the stove remains cool, as if they were not cooking on it! If the glass of the burner is warm, it is only because it was heated from the bottom of the pan, and not vice versa!
Induction cookers can a short time(usually up to 10 minutes) transfer the power of one burner to the adjacent one, paired with it. The function is called Booster, intense heating, and all modern induction cookers are equipped with it.
So that the burners can share power with each other, they are grouped in pairs (therefore there are no 3 or 5 burner induction hobs, always an even number, or one). Each pair has a leader - the main burner, and a slave - the dependent burner. For two people, let’s say, 3600 W of power is allocated. In nominal mode, the main burner consumes 3000 W. But if you turn on the Booster function, the burner will temporarily take another 600 W from the dependent burner and produce 3600 W of total power. Useful when very high heat is needed. Naturally, single-burner stoves do not have this, but there is one powerful burner, it alone will produce 3500 W.
When you remove the cookware, the induction cooker immediately turns off. On electric stoves with a classic resistive heating element, the burner is constantly heated, regardless of whether there is food on it or not. As a result, additional energy consumption and heating of the air in the room.
This effect allows you to reduce the cost of air conditioning, which is especially important in the summer. For a summer residence, an induction cooker is indispensable: it is much more economical in terms of electricity, plus it is not hot in the room in the summer when food is being prepared! Heat radiation comes only from the product or cookware on the stove, and the rest of the surface of the induction cooker remains cold. The release of heat, fumes and harmful gases into the atmosphere is reduced.
Cleaning induction equipment also saves time and effort: an induction stove cools down in 6 minutes, a gas stove cools down in 25 minutes, and an electric stove cools down in only 50 minutes.
Modern models of Electrolux electric hobs are equipped with a large set of various functions, which can significantly expand the capabilities of your kitchen, as well as provide greater comfort during the cooking process. One of these useful additional options is Stop&Go, thanks to which you can pause cooking and then return to the set parameters with one touch. Today, most surface models are equipped with this function, and this is the secret of such popularity.
Request stop
Many housewives have encountered a situation where it became necessary to leave the kitchen while cooking. Of course, this is not always convenient and can result in a burnt or overcooked dish. Modern manufacturers took into account the wishes of housewives and introduced a convenient and useful Stop&Go function into their hobs. Now you can easily stop the cooking process, leave the kitchen for a while, and when you return, resume the program with the same parameters.
As a rule, the control of such an option is represented by two or three touch buttons, which are responsible for setting the minimum power level of one or more burners. This allows you to leave your work area on low heat without worrying about your roast burning or your soup boiling over. Returning to the control panel, you restore the previous operating mode with one click of a button. Electrolux models also provide a number of other, no less useful options, including:
- burner turn-off timer, which can be programmed for the desired time and continue doing other things;
- residual heat indication warning that work zone has not cooled down yet;
- intensive heating (Boost), increasing the power of the burners;
- fast boiling, allowing you to effectively boil a large volume of liquid;
- recognition of dishes and the ability to expand the heating zone;
- locking the control panel “child lock”.
Do you want to purchase high-quality, functional household appliances for the kitchen? Check out model range Electrolux electric hobs, the range of which is presented in the catalog of our online store. Such a surface is guaranteed to provide greater comfort during the cooking process, and also thanks to stylish design will complement perfectly kitchen interior. For more information, please contact our experienced consultants.
Just a couple of decades ago, it was impossible to imagine that on one part of a switched-on stove burner there could be a raw egg, and on the other - fried eggs (Fig. 1). Only illusionists could demonstrate such tricks. The advent of electric stoves with induction heating made the incredible obvious...
Rice. 1. Amazing properties of an induction hob
Thanks Faraday
The phenomenon of electromagnetic induction was discovered by Michael Faraday in 1831. Probably, the first experiments of the brilliant Englishman, which demonstrated the appearance of an induced current in a conductor located next to another current conductor, without direct contact between them, “through the air,” also seemed to many a circus trick . It would take decades for electromagnetic induction became fully operational in transformers and electric motors, becoming the basis of the world of electricity.
The first induction hob was proposed by AEG back in 1987, but at first it did not find widespread use, both because of the high cost and because of the wary attitude of consumers towards the new heating principle. The distribution of induction kitchen appliances went through professional channels: catering business placed high demands on the quality and speed of food preparation, and the costs of purchasing such expensive equipment were justified here.
And the costs were indeed considerable: the first induction hobs were several times more expensive than glass-ceramic hobs, despite the fact that they used the same glass. However, subsequently, induction appliances were significantly improved, and today their price is only slightly higher than the price of glass-ceramic hobs.
Induction panels are making their first successful steps on the Russian market, entering the product range of almost all leading manufacturers of built-in kitchen appliances.
Energy from the bottom of the cookware
In glass-ceramic stoves with a conventional burner (spiral, strip or halogen), heat travels the following way: first, the heating element of the burner heats up, then the heating zone of the glass-ceramic coating of the stove, and the bottom of the cookware is heated from the glass surface (Fig. 2a). Induction heating technology is different in that heat occurs at the very bottom of the cookware (Fig. 2b). Where does it come from?
Rice. 2. The difference between conventional (a) and induction (b) heating methods
Under the glass cover of the plate there is a copper coil through which a high-frequency electric current flows (Fig. 3). According to the laws discovered by Faraday, the magnetic field of this current, penetrating the bottom of the dish, induces in it - you guessed it - electric currents. The bottom of the pan is not a long wire, but a disk, so the currents in it move in a circle, and do not flow “in line”. These eddy electric currents spinning in the bottom of the pan heat the bottom, and with it the food (Fig. 4).
Rice. 3. Induction hob
Rice. 4. Induction heating principle
There is only one condition that must literally be strictly observed: in order for the induction hob to work, the bottom of the cookware must be made of a material with clearly defined ferromagnetic properties. Each of us tested materials for the presence of such properties in childhood, when we received a magnet in our hands: it did not stick to some objects, but to others it stuck very readily: these were ferromagnetic materials. Under high magnification, one could see areas of natural magnetization (domains) in a section of such material. In an alternating magnetic field, the direction of magnetization of these areas often changes, due to which heat is released in the bottom of the cookware: energy magnetic field turns into thermal (Fig. 5).
Rice. 5. Domain structure of the ferromagnetic bottom of the cookware
In this case, no heat transfer occurs through the glass ceramics. If the glass remains warm at the end of cooking, it is only because it was heated from the bottom of the pan, and not vice versa. Can be done interesting experience, placing a sheet of paper between the glass and the dishes: the fried eggs will fry, but the paper will not burn (Fig. 6). The most spectacular version of this experiment, which is shown by some demonstrators household appliances, performed with a banknote. Try it yourself!
Rice. 6. Experiment with a sheet of paper
What kind of cookware is suitable for an induction cooker? Naturally, only one whose bottom has ferromagnetic properties, for example:
— stainless steel cookware with a ferromagnetic bottom;
— aluminum cookware with a ferromagnetic bottom;
- cast iron cookware.
But dishes made of copper, aluminum, heat-resistant glass and other non-magnetic materials are useless for such a stove.
Pros of induction
Thanks to the shortest conversion path electrical energy In thermal induction cookers have a number of advantages over their competitors: they heat up quickly and consume less energy.
Induction cookers can do things that they can’t do at all. ordinary slabs. For example, for a short time (usually up to 10 minutes) “transfer” the power of one burner to the adjacent one. All modern induction cookers are equipped with this function, called “Booster”. It is also called the intensive heating function.
In order for the burners to “share” power with each other, they are grouped in pairs (by the way, this is why there are no 3- or 5-burner induction hobs). Each pair has a leader - the so-called main burner, and a slave - the dependent burner. For two of them, say, 3600 W of power is allocated. In nominal mode, the main burner consumes 3000 W. But if the housewife turns on the “Booster” function, then the burner will temporarily take away another 600 W from the dependent burner and produce all 3600 W of total power. In Fig. 7, such a pair is, in particular, the front left (main) and rear right (dependent) burners.
Rice. 7. Booster function (AEG-Electrolux)
Induction hobs from a number of manufacturers (for example, AEG-Electrolux) are equipped with fairly powerful burners, so that a dependent burner, which was operating, say, at a power of 1400 W, can give 800 W to its main partner, and in the meantime continue to work on the remaining 600 W.
Another example of a powerful induction hob is the vario-panel VI 411 from Gaggenau (Fig. 8). This product of the “domino” format has only one burner, but it does not need the “Booster” mode: the burner itself, without any partner, produces power up to 3500 W, which allows you to use a Chinese WOK frying pan on it, which, as you know, requires a strong heat. That's what induction can do! Replace gas burner high power is no joke.
Rice. 8. Vario panel VI 411 (Gaggenau)
Induction hobs are able to recognize the presence of cookware with a ferromagnetic bottom on their surface: without such cookware, they simply will not turn on. In order for the burner to turn on, it is usually necessary to cover at least 70% of its area with dishes, and it is not so much the overlap area that is important, but the amount of ferromagnetic material above the burner. For example, on Teka hobs, the “U” indicator light comes on if the cookware installed on the hob has a diameter of less than 80 mm (Fig. 9).
Rice. 9. Pot indicator (Teka)
Induction panels can even adjust the diameter of the eddy current generation zone. The panel sensors will “adjust” the diameter of the heating zone to the diameter of the cookware, if it is within the limits acceptable for a given burner (Fig. 10).
Rice. 10. Automatic adjustment of the burner to the diameter of the cookware (Teka)
Starting point
The simplest glass-ceramic hob has four round heating zones. On the control panel of a standard hob there are buttons (or switches) for the power of the burners and, as a rule, indicators of residual heat. The most common improvement to the simplest configuration of heating zones is the appearance of burners with a variable heating zone. This can be either a “concentric” zone, in which it is possible to increase the diameter of the burner, or an oval heating zone, which is connected when an additional sector is connected to a round burner. In this case, a button for turning on the additional heating zone appears on the control panel. If we add to these burners the “Automatic Boiling” system, implemented by almost every manufacturer, such a panel could be called a reasonable minimum, which should be guided by when choosing a hob. Automatic boiling allows you to temporarily switch the burner to intensive heating mode. The time during which the hotplate will remain on maximum power, depends on the initial (and final) power level. If the heating is initially set to “6” and the automatic boiling is turned on, this leads to the fact that the burner operates for some time at a power of “9”, and then switches to “6”. If you set the power to “4” and turn on the automatic boiling, the burner operates at power “9” for several minutes, and then switches to “4”. The initial power value is selected empirically! It would seem that working with such a system is not very convenient, because milk can “run away” if you do not guess the operating time at maximum power. However, as practice shows, with constant use of this system you will quickly understand what power level should be set in which case.
ADVICE.
If your hob has automatic boiling, but you have not used it yet, try starting with the minimum settings entry level power. If you find that you have to activate the automatic boiler several times before the water in the pan boils, try starting with more next time. high level. Little by little you will find best option and you will use it.
Be careful and careful!
Even the most modern hob remains a rather dangerous electrical appliance, so manufacturers pay a lot of attention to the safety of its use. If you are not always sure that you have turned off all electrical appliances when leaving home, when buying a new stove, pay attention to panels with a safety shutdown function. The hob can turn off when it reaches a certain (sufficiently high) temperature (so-called overheating protection) or after several hours (provided that no one touched the control panel during this time). As a rule, the time after which a complete shutdown occurs depends on the installed heating power. Many panels are equipped with an overflow protection system. In most cases, the hob switches off completely if liquid overflows from the pan and gets onto the control panel. In some cases, blocking occurs when liquid gets on the surface itself. However, keep in mind that this function will not be able to prevent the liquid from boiling over. If your children like to “stick their noses everywhere,” it makes sense to purchase a panel with a temporary control panel lock. When you press a certain key, the control panel “freezes” in the state it was in. To “defrost” the panel, you must press and hold this button again for a few seconds. To some extent, a button can be considered protection against unwanted use general inclusion panels. Temporary blocking may also have a brand name, for example Stop+Go in AEG hobs, StopSensor in Siemens. There are other ways to prevent unwanted activation of the hob. Siemens, for example, offers removable magnetic handles for electromechanical switches in its panels. If you remove them, there will simply be nothing to turn on the panel. By the way, this original solution You will also like it when cleaning the panel: the space under the handles is accessible, and the handles themselves can be cleaned separately. Another option that can be used to ensure the safety of your family is to purchase a cooktop with controls located on the side of the cooking zones, rather than on the lower, more accessible part.
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Convenience you don't notice
The well-known wisdom “Know where the light is, you will understand where the darkness is” perfectly illustrates the owner’s feeling from working with a panel with many additional functions. Indeed, convenient functions fit so seamlessly and organically into your usual kitchen activities and are so intuitive that you usually notice their value only when you start using a model devoid of one or another option. For example, the stove can “sense” the presence of cookware on a burner and its size, independently turning on or off additional heating zones on burners with variable shapes. Most manufacturers call this function “Auto-Focus”, but you may also come across other names, for example, Sensor Control from AEG. Note also that the burner goes into standby mode as soon as you remove the pan from it, without wasting electricity. In some AEG and Miele models, thanks to a special hole for steam outlet, it is possible to organize the release of air upward, directly into the hood, which, of course, has a beneficial effect on the freshness of the air in the kitchen. Quite curious is the zone for keeping the dish heated, which is present mainly on expensive wide (more than 80 cm) panels. This zone (usually rectangular in shape) allows you to heat food directly in the plate. It will also help to preheat the plates, since it is better to place the freshly prepared dish in a warm bowl when serving so that it does not change the taste and smell. No less necessary on the hob and minimum size burners, for example, for making Turkish coffee. Until recently, in most stoves the minimum diameter of the burner was 14.5 cm, but now many manufacturers supply hobs with a burner with a diameter of 12 cm. Some (AEG, Ariston and Siemens/Bosch) have gone further and offered a heating zone with a diameter of 10 cm. AEG This miniature heating zone is called an Espresso burner; other manufacturers do not give it a special name. The leader in terms of minimum burner diameter is held by SMEG, whose hobs have a 9-centimeter burner. However, it is set to induction panels, which means that it will not be possible to make coffee in a copper pot (made of non-magnetic material).
Automatic cooking
A number of additional functions are designed to automate the cooking process. Most of these are systems that control cooking temperature and time, i.e. various systems maintaining constant temperature and timers. In some cases, you can even record a cooking recipe in the stove's memory. A classic example of a temperature sensor is the infrared sensor (IR sensor), which has long been used in Siemens hobs. In the new model range it was named KochSensor. The sensor is installed in the corner of the panel and remotely measures the temperature on the surface of the pan. Once the surface temperature of the pan has reached the selected value, the automation ensures that it remains constant, lowering or increasing the heating power. To make this possible, the pan must be covered with dark enamel or a special strip glued to it. However, you receive a set of suitable cookware and several thermal tapes when purchasing such a panel. The same function in Bosch panels is called ThermoControl. BratSensor (ThermoControl in Bosch panels) will help automate the frying process on Siemens panels. This function allows you to automatically control the frying process in a special frying pan, accurately informing you when the set temperature is reached with an optical or acoustic signal. You don’t need to stand near the stove to further control the process; you just need to select one of three frying modes – Min, Med or Max. The special frying pan comes with a panel equipped with a BratSensor. Timers were a rarity on cooktops not long ago. Today, many leading manufacturers (AEG, Miele, De Dietrich) equip all their models with timers. Using the sleep timer, you can enter the cooking time for each burner. It can be turned on at any time (even after the cooking process has started). At the end of the countdown, the corresponding burner will turn off, accompanied by a sound signal. You can automate the cooking process to an even greater extent using the “memory recording” function of the cookers. Bosch panels and Siemens. It will allow you to store the most frequently used actions in memory and run them automatically at any time. In this case, each heating zone has its own program. Each such program can consist of five different sequences of changing time and power parameters. The memory recording function is recommended, for example, for preparing milk porridge or eggs in the morning, potatoes or jam.
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Easy to manage - successfully managed
How convenient and well designed the control panel is hob, the user’s attitude towards a particular model largely depends. From our point of view, the optimal option is when all controls and indication of operating modes are concentrated in one place on the surface, and not scattered on different sides of the panel closer to the heating zones they control. In addition, the control seems more convenient, in which each burner has its own power adjustments and additional modes.
Many functions – varied menu
Only if the hob has wide possibilities, you can demand extraordinary creative results from the chef. If you need to bring more water to a boil in the shortest possible time, you can use the Booster function. It allows you to combine the power of two burners into one for a short time. In this case, the power can increase by about one and a half times. The Booster function is usually included in the arsenal of induction hobs, but is also found in HiLight hobs in models in the upper price range.