Humans have been cooking since stone age and have used variety of sources to cook foods. The basic idea of cooking has always been the same and that is heat the food to kill the bacteria and make the food more tasty to eat. For this we have used different heating sources from raw fire using wood to gas and electric stoves. Now the latest technology is induction cooktop which is far more efficient than any other cooking source. If you buy a good induction cooktop, you will never regret and also save lot of money in long term. We have already discussed benefits of induction cooktop in the previous article. In this post we will be discussing "How induction cooktop works".
How Induction cooktop works
Before you can understand induction cooking, you need to understand induction. An induction burner consists of a ceramic plate with an electromagnetic coil beneath it. Induction cooktops use one of the odd quirks of electromagnetism: if you put certain materials into a rapidly alternating magnetic field, the material absorbs the energy and heats up. Some cooking techniques available when cooking over a flame are not applicable. And the first thing you need to know is that "induction" is a shortened way of saying "electromagnetic induction." In a nutshell, induction means generating electricity using magnetism.
- When you turn on the burner, an electric current runs through the coil, generating a fluctuating magnetic field, but no heat on the burner itself.However, once you set an iron or stainless steel pan on the burner, the magnetic field induces many smaller electric currents in the pan's metal.
- That's because the field creates electrical currents inside the material, and the resistance of the material converts this electrical energy into heat, which is transferred to the food inside the pan.
- Persons with implanted cardiac pacemakers or other electronic medical implants are usually instructed to avoid sources of magnetic fields; the medical literature seems to suggest that proximity to induction cooking surfaces is safe, but individuals with such implants should always check first with their cardiologists.
- It stems from the simple fact that electricity and magnetism aren't separate, unconnected things (as we originally learn in school) but two different aspects of the same underlying phenomenon: electromagnetism.
- The intermolecular friction and heat made by the IGBT result from a process called hysteresis.
- Nowadays there are also so-called "zoneless" induction cooktops (every maker has its own trademarked term for "zoneless', but that's the common term). It rather seems, at this point, as if the mountain has labored to birth a mouse.
Radio receivers near the induction-cooking unit may pick up some electromagnetic interference. Induction cooktops also produce less waste heat. Both hysteresis and eddy currents generate heat in the cookware. The original promise of zoneless was a surface on which you could put down any size or shape of cooking vessel in any location or orientation and have everything work. The magnetic field induces eddy currents (small circular electric currents) inside the metal cookware, these currents create heat within the pot or pan. This is useful if you're working with sensitive, expensive food that needs to be cooked carefully and kept cold beforehand, such as langoustines or truffles, or if you want to work near the cooktop but not actually cook like you would with caviar. Attempts to determine which process plays the more important role have been known to cause screaming arguments between induction-cooktop engineers. In fact, even that, when once one comes to think it through, is not so very exciting except as it may involve cooking vessels of unusual sizes or shapes—the few things (griddle, grill, fish pan) that don't function well, or at all, on standard circular heating elements; for most pots and pans, having fixed-location heating elements is just not an issue. Since the pan itself is creating the heat for cooking and it conducts heat very well, hot spots are eliminated.
An alternating current is the kind of electricity flowing through power lines and home wiring, as opposed to a direct current, which we get from batteries. An electromagnetic field is generated from the coil in a short distance from the surface of cooking, which is enough to reach the pot’s base. When you switch on the power supply of the cooktop, an electric current passes through the coil. The food cooks through the transfer of heat from the cookware. The pots heat up because the changing magnetic field causes small electrical currents to be set up in the material of the pot.
An electric current is induced by the magnetic field and creates forces into the cookware’s base within this field. The electric current passing through the coil produces a magnetic field in all directions around the coil, including directly above it (where pots and pans are placed). Note that until this point, no heat is generated, as the magnetic field being produced doesn’t produce any heat unless a third object – the cooking pan – is introduced into the mix. Because the currents heat the pot or pan (made of ferromagnetic materials) and not the cooking surface, the surface remains relatively cool, warmed only by contact with the hot pan. As the currents move in the material the molecules in the pot offer resistance to the current and heats up. The flow of this current is resisted in the metal of cookware and heat up.
The key to induction cooktops is that the pots and pans you use must be made from a magnetic material to work with this system. Magnetic materials in the pot such as iron can be made magnetic when a magnetic field is nearby. The induction cooktop will induce the electrons in a magnetic material to move, creating an electric current in that magnetic material. But the magnetic field from induction cookers is changing direction very rapidly. That current generates heat in the pot. Changing the direction of the magnetic field means working to change the magnetic field of the pot, which causes the pot to heat up more.