How a Microwave Oven Works

Introduction

A microwave oven is actually a metal cage inside which it generates microwaves, which heat the material. Microwaves are electromagnetic waves. That is, these are disturbances of the magnetic field and electric field, like the waves. The electric and magnetic fields keep changing direction, 2 and a half billion times per second. Indeed, the molecules are sensitive to the electric field, and particularly water molecules, which are present in almost any food (Bitton, p. 17).

A little experiment may help to convince you: a plastic bag rub against your sweater (this electrically charged and establishes the electrical unclamp around), and approach it with a trickle of water flowing from the tap, without touching the water, of course. You should see the stream of water is diverted! That's a sign that water is sensitive to the electric field (Möllmann, p. 38-44).

So the water molecules are excited and move about in all directions by an electric field that varies with great frequency. However, more molecules are agitated, the more they are hot, by the temperature. That is how the microwaves heat the food (Bitton, p. 17).

How does Microwave Oven Work

The electrical energy in the form of an alternating voltage (high and low voltage) is converted into voltage through a transformer truck, a diode and a capacitor. The current coming from the step-up transformer used to power the magnetron (Möllmann, p. 38-44).

Magnetron

The magnetron consists of an anode cylinder, consisting of cavities, they are in the axis of a cathode heater. The more holes the higher the yield is high.

The anode and cathode are separated by a space called the interaction space which is under vacuum. These cavities called "resonant cavity" can have different forms depending on the magnetron considered. There are also two magnets that are attached perpendicular to the axis of the tube (Möllmann, p. 38-44).

An electric field is continuously applied between the anode and cathode. This field has a value of the order of several kilovolts for an interaction space of a few millimeters. The electrons released by the cathode are accelerated by the electric field continuously (Bitton, p. 17). In the absence of magnets, the electrons would go directly to the anode; the combination of the two fields creates a rotating electron cloud between the anode and cathode. These charges interact with the resonant cavities of the anode block which becomes the carrier of electromagnetic oscillations. The dimensions of these cavities are calculated so that the waves have a frequency of 2450 MHz. Some of these waves are fed into the waveguide through various means of coupling. The waveguide transmits them in the oven and they will help cook the food (Bitton, p. 17).

Power

A magnetron of 1000 W (output) requires about 2500 V at 0.6A for power. The current schema is an assembly-type anode to ground, simplifying the insulation. The food is very simple, with a single power transformer for the filament and the THT and relief with alternating mono-diode and a filter capacitor. The high voltage ...