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


An induc­tion hob is a cook­ing hob that stays cold until a pan with a mag­net­ic bot­tom is placed on it. It is absolute­ly safe and allows you to save on elec­tric­i­ty. How the induc­tion cook­er is arranged and works, we will con­sid­er fur­ther.

How does an induction cooker work?

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

The structure of the induction cooker

When an alter­nat­ing cur­rent of high fre­quen­cy begins to pass through the induc­tors, an alter­nat­ing (pul­sat­ing) mag­net­ic field aris­es. This field goes beyond the coil, includ­ing above the sur­face of the plate. If a mate­r­i­al 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 that has fall­en into the zone of a mag­net­ic field) is called elec­tro­mag­net­ic induc­tion (the effect was dis­cov­ered by the British sci­en­tist Michael Fara­day in 1831). There­fore, stoves, the work of which is based on this effect, are called induc­tion.

The scheme of the induc­tion cook­er is pre­sent­ed below:

Simplified diagram of the induction cooker

The oscil­la­tion fre­quen­cy of the mag­net­ic field is from 20 to 60 kilo­hertz. The high­est sound that the ear of an ordi­nary per­son can dis­tin­guish 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 con­ven­tion­al stove, you will spend much less ener­gy.

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

Induc­tion cook­ers are much safer than any oth­ers — there is no chance of get­ting burned by care­less­ly putting your hand on the stove. It also reduces the like­li­hood of fire — a rag or paper that has fall­en on the hob will nev­er ignite.

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

Induction cooker

Each induc­tion oven mod­el has a built-in timer. With it, you can both extreme­ly fine­ly adjust the cook­ing mode, and sim­ply lim­it the amount of ener­gy spent on heat­ing dish­es. Many mod­els have 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);
  • con­sumed pow­er;
  • watch;
  • cook­ing time for each burn­er.

In the event of an emer­gency shut­down of the oven, the indi­ca­tor will also dis­play rel­e­vant infor­ma­tion on the sen­sor so that you are not lost in guess­ing what hap­pened.

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

To clear­ly see how the induc­tion cook­er works, it is pro­posed in the fol­low­ing video:

Features of the induction cooker

What fea­tures are not­ed with such a plate device, we high­light fur­ther:

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

It is still not worth approach­ing the top of the stove dur­ing oper­a­tion — the effect of a rapid­ly oscil­lat­ing mag­net­ic field on the human body is not well under­stood.

  • 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 using such a stove is that there is absolute­ly no smell of burn­ing in your kitchen. On an elec­tric stove, a spi­ral, a body and a grate are heat­ed (about the same with a gas stove), and dust, oil and food par­ti­cles get on all heat­ed parts, which 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 regime. Thus, you can pro­gram the cook­ing process lit­er­al­ly every minute, which is impos­si­ble to achieve on a con­ven­tion­al gas or elec­tric stove.
  • By using ener­gy sole­ly to raise and main­tain the tem­per­a­ture of the food, your kitchen main­tains a com­fort­able atmos­phere. While cook­ing, you do not over­come the heat and stuffi­ness, you do not need to turn on the air con­di­tion­er once again.

Cooking food on an induction stove

  • The con­trol of most induc­tion fur­naces is touch. A sim­ple set of a few but­tons, how­ev­er, gives you a lot more options than an elec­tric or gas stove.
  • The oven may beep­ing you. If you set it up in a cer­tain way, it will “call” you when the oil boils in the pan, or the ket­tle is about 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 — smart elec­tron­ics will insure you when all the water boils away.
  • Induc­tion ovens 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 ther­moele­ment of the plate from gas flows or heat­ing ele­ments, its accu­ra­cy is much high­er.
  • You can put kitchen tow­els on the sur­face dur­ing cook­ing so that splash­es of water and oil do not even fall on the hob;
  • Even if food par­ti­cles fall or spill on the stove dur­ing cook­ing, they will not burn and can be eas­i­ly removed as they 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 stove and on the wiring in your house. This is a pro­grammed fea­ture. For exam­ple, the total pow­er of the stove is 3 kilo­watts. But if you use all the burn­ers, only 2.5 kilo­watts will be con­sumed.

You can learn about the fea­tures, pros and cons of the induc­tion cook­er from the fol­low­ing video:

It is bet­ter to con­nect the induc­tion cook­er with a sep­a­rate cable from the elec­tri­cal pan­el so that there are no prob­lems with the wiring. Ground­ing is an inte­gral part of the cor­rect con­nec­tion of the induc­tion hob.

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 work­top, as long as there is enough space. How­ev­er, some points should be tak­en into account:

  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 adverse­ly affect the oper­a­tion of the fur­nace.
  2. There must be enough space for ven­ti­la­tion, as the elec­tron­ics inside the induc­tion oven require good cool­ing.
  3. Do not over­ly com­pact the loca­tion of all kitchen units. An induc­tion oven saves a lot of space, but you should not place it clos­er than 50 cen­time­ters from a 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.

After instal­la­tion, it is unde­sir­able to leave the glass-ceram­ic coat­ing with­out care. For him, it is bet­ter to buy a spe­cial tool con­tain­ing sil­i­cone. This will give your stove a sophis­ti­cat­ed shine and a well-groomed look.

What cookware to choose for cooking on an induction hob?

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

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

The com­plex of mag­net­ic field and tem­per­a­ture sen­sors is respon­si­ble for the above con­di­tions. Elec­tron­ics even knows how to reg­u­late the pow­er, which is dis­trib­uted depend­ing on the size of the dish­es. As a result, you again save elec­tric­i­ty.

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

On spe­cial­ized dish­es for induc­tion heat­ing, they put a spe­cial sign — sev­er­al ver­ti­cal loops and the inscrip­tion Induc­tion”.

Designation on the dishes for the induction oven

They are usu­al­ly made from “white” cast iron.

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

For con­tain­ers with a too small bot­tom (turks, stew­pans), there are spe­cial iron cir­cle coast­ers that heat up per­fect­ly on an induc­tion oven and trans­fer heat to small con­tain­ers.

Ordi­nary enam­eled iron con­tain­ers are also quite suit­able, although if the bot­tom is thin and con­cave, they can make unpleas­ant sounds. But due to the very rapid heat­ing of the con­tain­er, you will not have to endure these sounds for long.

In gen­er­al, the main sign of suit­abil­i­ty for an increase in tem­per­a­ture from fluc­tu­a­tions in the mag­net­ic field is this: if the mag­net is attract­ed to the dish­es, such dish­es are suit­able; if they are not attract­ed, they are not suit­able.

Some non-spe­cial­ized types of cook­ware may heat uneven­ly. For exam­ple, the cen­ter of the pan may be hot, and the tem­per­a­ture near the walls will be fifty degrees low­er. The only way to fix this is to replace the dish­es.

Anoth­er dis­ad­van­tage of con­ven­tion­al dish­es is a dam­aged or loose bot­tom. A fry­ing pan cov­ered from below with a lay­er of soot after a gas oven, when used on an induc­tion burn­er, begins to emit unpleas­ant odors, sounds and even smokes, because now the tem­per­a­ture is ris­ing not from the out­side, but from the inside. In addi­tion, a deformed bot­tom may scratch the sur­face of the plate.

Nat­u­ral­ly, kitchen uten­sils made of glass, ceram­ics, plas­tic, and oth­er mate­ri­als that do not con­tain met­als are not suit­able for induc­tion ovens. Also not suit­able are cop­per, alu­minum and oth­er kitchen uten­sils made of mate­ri­als that con­duct elec­tric­i­ty well. The fact is that for rapid 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 an increased tem­per­a­ture, the resis­tance increas­es even more.

What can not be done with an induction oven?

In order not to inde­pen­dent­ly cause mal­func­tions in the oper­a­tion of such a hob, it is worth con­sid­er­ing the fol­low­ing restric­tions:

  • Those who have a built-in pace­mak­er should not work with the induc­tion cook­er, as the mag­net­ic field may adverse­ly affect the implant. At a dis­tance of half a meter from the stove, the field is almost indis­tin­guish­able, but it’s bet­ter not to risk it.
  • Do not allow cred­it cards, doc­u­ments and oth­er objects to come into con­tact 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 heats up too much under the influ­ence of induc­tion cur­rents and can cause a fire. The same applies to foil pack­ag­ing — choco­late bars, sweets, milk bags, and oth­er sim­i­lar items, includ­ing dec­o­ra­tive foil rib­bons for gifts, bal­loons, and so on.

Induction cooker

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 at the body of the stove or at the out­let. If, when the cord is moved, the con­tact appears, then dis­ap­pears — the prob­lem is local­ized, it is nec­es­sary to repair the cord.
  2. Try remov­ing the plug and insert­ing it into anoth­er out­let — per­haps this is the issue.
  3. Make sure the stove pow­er but­ton on the back of the stove is pushed in (near the pow­er cord entry). Some­times chil­dren or pets man­age to press it and unplug the oven from the mains.

If every­thing is fine out­side, you will have to open the coun­ter­top. First, just inspect the fill­ing of the plate visu­al­ly — is it imper­cep­ti­ble to see if there are any obvi­ous­ly unusu­al places. Here we check:

  • fuse;
  • ter­mi­nals and wire con­nec­tions (you can tight­en the screws more tight­ly, 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.

After that, it remains to check the con­troller chip and the tran­sis­tors through which the con­troller sig­nals go. If check­ing all of the above ele­ments did not reveal the cause of the prob­lem, you will have to con­tact a spe­cial­ized work­shop.

In order not to have an unnec­es­sary headache with the repair of expen­sive equip­ment, install an over­volt­age pro­tec­tion device in advance and con­nect the equip­ment through it.

Video: Induction cooker vs gas and electric

In the fol­low­ing video, in a prac­ti­cal way, which type of stove is bet­ter:

Induc­tion hobs and sur­faces are almost ide­al cook­ing appli­ances. They are safe, eco­nom­i­cal, beau­ti­ful, com­fort­able, com­pact, and adjustable over a wide range. Food cooks and heats up very quick­ly. In order for it to serve for a long time, it is worth­while to care­ful­ly approach the instal­la­tion, oper­a­tion and main­te­nance.





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