Induction cooking is a kind of electric cooking that involves using magnetic coils to heat up cookware placed over the induction unit, without the coil getting hot. Due to their speed and efficiency in cooking as compared to gas or regular electric cook-tops, induction cook-tops have grown in popularity in commercial kitchens. Without actually placing your hand over a possibly scorching electric hob, it can be hard to determine whether or not the surface is hot. But did you know that you can actually place your hand, palm face down, over a cooker top on which an egg is cooking without getting burned? How?
The principle of induction cooking
There is a coil below each cooking zone of your induction hob through which flows a medium frequency alternating current (between 20 and 100 kHz). This produces a magnetic field with the same frequency that passes freely through the ceramic cover of your induction hob, piercing into the pan you have placed over the cooking zone. A circular current is created by the magnetic field in the base of the pan, which is electrically conductive. This process is known as induction. The material used to make the base of the pan allows for the highest possible heat loss of the circular current at the frequency being used. Ferromagnetic materials are usually used here, where the alternating field is pushed into the external layer of the base, which in turn produces intense heat by increasing resistance of the material against the current.
Leakage currents
The pan you’ve placed over the cooking zone combine with the induction coil to form a capacitor. The saucepan is charged electrically when you switch the induction coil on. In case you touch the pan, a small current may flow through your body. This is known as a leakage current.
General output
Home appliances usually come with 4 cooking zones with several outputs, varying between 1200 and 3600 watts. The overall output of integrated units is around 7500 Watts. If you are looking to heat water rapidly or start the cooking process quickly, you can operate the cooking zones for a short while at increased output (power or booster function).
Regulating heating power
You can regulate heating power using different methods, all of which involve playing with the properties of magnetic fields.
- Using the frequency of alternating current: There is an electrical oscillating circuit integrated into your induction hob that transmits the maximum current at booming frequency. In case the frequency diverges from this resonant frequency, both output and current are reduced.
- Using pulse amplitude modulation: You can regulate output by turning the magnetic field on and off intermittently at lower settings. You can use one pulse per 2 seconds, with the length of the pulse being determined by the selected output.
- Radiation risks
Induction hobs produce very low frequency radiation, reminiscent to that of microwave radio frequency, and have been shown to diminish to nothing at distances of a couple inches to around one foot away from the source.
Normally, you’ll not be close enough to the induction hob to draw any radiation.
Cardiac implant concerns
Studies have proven that pacemakers do not interfere with the induction cooking unit of an induction hob. However, problems may occur if the implanted pacemaker is left sided and unipolar, and the bloke is standing close to the cook-top where a saucepan is not seated concentrically on the coil.
Summing up
Induction cooking is a relatively superior and efficient cooking method. For general safety purposes, it is advisable to use the right pan size that can cover the coil completely. Stick to flat bottomed pans, which will sit straight over the cook-top. In addition, avoid using metal spoons when cooking, as these may facilitate current flow through your body.
Also read: Can Exercise Bikes Generate Electricity?