What is induction | how induction cook stove works?
Principal of Electromagnetic induction:
Before learning Induction stoves we should firstly know what is Electromagnetic induction.Electromagnetic induction is produced by of an electromotive-motive force (EMF)when magnetic field is passed around an electric conductor and changed continuously or when conductor is moving continuously in constant magnetic field , therefore, the creation of current by moving an electric
conductor through a static magnetic field. Electromagnetic interference is also called electric current and electromagnetic induction and may also be called magnetic induction, as the principle remains the same whether the even if process is carried out through electromagnet or static magnet.
To know more about electromagnetic induction click here
How does an induction stove work?
An induction stove consists of a ceramic plate with an electromagnetic coil made up of copper beneath it. When electricity (alternating current) is supplied, an electric current runs through the coil, generating a fluctuating magnetic field, but no heat on the burner itself. This large eddy current flowing through resistance of pot generates resistive heating on pot. An induction cooktop is simply an electromagnet you can
cook with.
Most of the induction pots are made up of ferrous metals that is cast or some stainless steel.Iron of pot concentrates the current to produce the heat.if thickness of pot is less, current will not be concentrated and no heat will be generated and if pot is thick enough to concentrate the current, heat will be generated as much of the energy is converted to heat.This heat is then used to cook the food.
Thus, in induction stove there is nothing like burner and flame, which makes it even more safer in use.When power is supplied to the coil placed inside induction stove, magnetic field is generated just above of it which in turn produces heat by passing through the resistive metal pot.Position of the pot above affects the working as if the pot is placed at the corner of the stove then only half or less magnetic field lines will pass through resistive pot and hence will stop working or may give less heating.Distance of pot from stove will make the same effect as described above.
Type of current required for induction stove:
A simple direct electric current (which flows in the same direction) produces a constant magnetic field.According to lows of electromagnetism fluctuating magnetism is produced only by a constantly changing electric current. So an alternating current which is always fluctuating will only be capable of producing fluctuating magnetic field. Click here to know difference between AC and DC
When magnetic field lines passes through the resistance or pan this creates current to flow through them and this is not the kind of current which flows through the wire but swirling electric current with high energy which is called as eddy current.This eddy current is responsible for generating heat.
Design measures:
An induction cooker is consist of a conductor coil placed below the ceramic plate.Much of the current is lost due to the self resistance of coil wire and to reduce the skin effect and consequent heat generation in the coil, it is made from litz wire, which is a bundle of many smaller insulated wires in parallel. The coil has many turns, while the bottom of the pot effectively forms a single shorted turn. This forms a transformer that steps down the voltage and steps up the current. The resistance of the pot, as viewed from the primary coil, appears larger. In turn, most of the energy becomes heat in the high-resistance steel, while the driving coil stays cool.
Often a thermostat is present to measure the temperature of the pan. This helps prevent the pan from severely overheating if accidentally heated empty or boiled dry, but also can allow the induction cooker to maintain a target temperature.
