How does a microwave oven work?

The first person to discover the possibility of microwave radiation to heat food was an engineer from the USA, Percy Spencer. It was he who patented the microwave oven.

Judging by the stories of eyewitnesses, the idea of ​​​​creating it came to his mind when he stood near the magnetron for several hours and found a piece of chocolate melted in his pocket.

The device is capable of heating food without heat energy and is thus more like a radio transmitter than a familiar stove. The main operating element is microwave microwaves - this is one of the forms of electromagnetic energy, like light and radiomagnetic waves.

At the speed of light, they propagate towards an object in the form of ultra-high-frequency waves, the length of which ranges from 0.01 to 1 m.

REFERENCE! Microwaves are also used in civil radar, radio navigation, satellite television, mobile communications, etc. Microwaves in the natural environment are emitted by the sun and are measured by certain instruments.

Microwave oven device

How does a microwave oven work? An oven with a control panel, a waveguide, a rotating stand, a transformer, a capacitor and a magnetron are the main elements of building a microwave oven.

The operating diagram of a microwave oven is as follows: from the control panel, electric current enters the transformer, then into the capacitor, where the power is increased and transferred to the magnetron.

IMPORTANT! A high voltage (about 3-4 kW) is applied to the filament so that its antenna can emit fairly strong microwave waves.

An electromagnetic field with a frequency of 2450 MHz interacting with water molecules in food is converted by a waveguide contained in any microwave oven.

Thermal fuses or thermal relays serve to ensure the safety of the device and prevent it from overheating.

The principle of operation of the fuse is very simple. In the place where it is necessary to control the temperature, its aluminum body is attached using a special flange connection. This ensures maximum thermal contact. The metal plate located inside the thermostat is fundamentally set to a specific temperature.

Microwave ovens are also equipped with fans that suck in air from outside, and then distribute it inside the cabinet through a blower with a ventilation system. The fan motor is a conventional single-phase AC asynchronous motor.

IMPORTANT! To avoid turning on an open microwave, a system of three microswitches is provided. One of them turns off the magnetron. The next one turns on the backlight. And the third is designed to notify the control unit about the door opening.

The main functions of the control unit include:

• regulation of device power;
• automatic shutdown after the programmed period.

How does a microwave oven work?

Since the microwaves produced by the oven act specifically on water molecules.In other words, all that is needed is a small amount of water in the food placed in the chamber.

The increase in temperature of food in the oven under the influence of microwaves is similar to the process when our hands warm up when we rub them vigorously. The similarity is also that when one palm rubs against the surface of the other, heat seeps into the soft tissue. Microwaves work on the same principle, namely on a small surface (1–3 cm), without penetrating deep into the object.

The emitted microwaves come into contact with water molecules, causing them to move faster and warm up the food. There are millions of molecules in a drop of water, and when a microbeam hits them, it penetrates the food to a depth of 2.5 cm, causing them to wobble under the influence of an electromagnetic field. During this friction, heat is released.

This means foods with a high liquid content heat up faster.

IMPORTANT! Scientists are still arguing about how harmful a microwave is and how it affects the quality of food. However, the World Health Organization states that microwave ovens do not harm either humans or the food consumed.

How additional microwave functions work

Almost all modern ovens have a grill mode. When not only the chamber is heated inside, but also heat is supplied using a special awning - a curved metal device located at the top of the chamber. They are called heating elements - from “thermal electric heater”.

In modern ovens, in addition to the grill mode, there is a convection mode. When the chamber is effectively blown from the grill heating element to the food. The system is a circulator. Convective heat transfer, as applied to a furnace, is the transfer of heat using air molecules.Using a fan is usually called convection mode.

Modern models have a number of recipes and cooking methods built into the computer.