The microworld is rich in secrets. Cheerfully talk about electrons, not knowing exactly what it is. Amazing principle of uncertainty Heisenberg. Scientists, the farther, the more start to marvel at their own discoveries. Einstein’s theory is partly untenable, which means that mass does not increase with increasing speed, the speed of light is surmountable. What has recently been proven experimentally. How does a microwave oven work if nothing is known about elementary particles other than the unpredictability of behavior? Let's try to look into the world of amazing and incomprehensible phenomena.
The principle of operation of an active microwave oven
Electrons and microwave ovens
The technical characteristics of microwave ovens are different, based on a common phenomenon - the absorption of electromagnetic wave energy by water molecules. The principle of operation of the microwave remains the same. It is said that the concept was taken away by America from the defeated Nazi Germany. A few words about the work of the microwave.
In physics, the particle wave-particle theory is accepted, according to which an electromagnetic wave behaves like a particle. With decreasing frequency, effects characteristic of seas and rivers emerge: the addition of waves is not quantitative, but taking into account the phase, as a result the interference pattern will take on a bizarre look. Light behaves often like particles. Quantum - a piece of light.
Once in the laboratory, scientists decided to check: what are quanta. They took a special gun, emitting elementary particles. The sequence of experiments:
- From the gun began to fire a gap in the sheet of opaque material, behind set a sensitive screen and began to record the intensity. The result was an imprint of the original slit, which projected the rays of the gun.
Microwave microwave
- They placed two slots at a distance from each other and began to fire. The result was an interference pattern. As if there were two sea waves passing through the cracks of the breakwater. The maximums and minimums of the flux density, shown in the picture by light and dark stripes.
- When they began to try to figure out which photon passed through the gap and set up two telescopes, the interference pattern disappeared.
Scientists have put forward the theory: a particle passes through both slits simultaneously, or through a single one. As a result, the electron seems to strike itself against itself, forming a picture of interference. As for the wave theory, something similar is known. They began to say that the particle "knows" about observation. We are closer to the theory of the video commentator on YouTube, who said that the telescope takes the photon energy, therefore it is impossible to demonstrate the wave pattern. The screen is not a similar measurement tool, hence the result is different.
Magnetron in a microwave oven works due to the orderly( if it is correct to say so) movement of electrons. We do not see contradictions in experience, it is funny that scientists do not want to see further analogies with the wave. In a microwave magnetron, the process is controlled differently.
Operation of the
Microwave Regardless of the nature of the particles, it has been established that the electrons emitted by the thermal cathode in a magnetic field begin to move in a circle. To create a uniform distribution of tension, two permanent magnets are used on both sides of the washer-shaped working chamber of the magnetron.
Vacuum reigns inside so as not to interfere with the movement of elementary particles. As a result, it was invented to make something like a revolving drum, where each chamber is connected to the central channel with a narrow slit. Without thinking twice, the scientists calculated the dimensions and created a resonator for the microwave magnetron. As a result, electrons driven by the magnet and driven by electrons began to generate oscillations of various kinds. But only the frequency of the microwave resonator's resonator survived, the others quickly faded out.
A voltage of 3 kV applied to the cathode with a circuit ground on the anode of the magnetron of a microwave oven causes rotating oscillations of a given frequency in the chambers. The signal is removed through a special pin in one of many. We add that in order to make it easier for the electrons to leave the anode surface, two tricks are used:
- Wisely choose the cathode material: tungsten and thorium.
- A heating voltage( 6.3 V 50 Hz) is applied to the filament.
The microwave magnetron works in a similar way. Note that nothing is known about the nature of electrons, theoretical physicists are still struggling with the solution of the problem, practitioners have long enjoyed the result.
Food Effects of Waves
How High Frequency Oscillations Are Used in a Microwave
Oscillations leave the magnetron and immediately enter the waveguide. The dimensions of the round or rectangular section are chosen so that the attenuation is the smallest. The wave, moving at an angle to the axis of the waveguide and constantly reflecting from the upper and lower walls, reaches the working compartment. The field strength is high, foreign objects inside will lead to electrical breakdown in the form of lightning. Except as described, the output of the waveguide into the working chamber is covered with mica cloth, in use, with mica.
The specified dielectric is transparent to waves freely passing into the compartment. The size of the furnace chamber is selected based on the frequency of the magnetron. But it quickly became noticeable: if you leave the motionless body to warm, the temperature at different sites varies widely. It is clear that people do not like the fact: the first piece is hotter than the second. The phenomenon is explained by the presence of standing waves. At the nodes, the amplitude of the field oscillation is zero, at the humps is maximum. The result is a kind of interference pattern.
Explain what is happening. Energy is transferred to water molecules: an oxygen atom, two parts of hydrogen are stuck closer to one side. It turns out something like a head with two cones on the sides of the skull. The electric negative moment is in the region of the base. When the resultant is captured by the field, the molecule is carried away by the force lines. The tension of the wave is constantly changing, the design begins to rotate, collapse forward. Then back. It turns out dolls.
The oscillation speed is extremely high.
Magnetron generates at a frequency of 2.45 GHz, 2.45 billion movements occur per second. The excess kinetic energy quickly transferred to surrounding molecules is formed. Why choose the frequency of 2.45 GHz. To interfere more with cell phones and your home WiFi network? Not! Just any system has its own resonant frequency.
Reinforced many times, the wave destroys the building.
Similarly occurs with a water molecule. There are frequencies that do not cause vibrations. The 2.4 GHz connectivity region perfectly transmits energy to a pair. Water in any state of aggregation heats up shock. The principle of operation of a microwave oven is based on the fact. We add that the effect of a standing wave is blocked by a rotating table. The food is constantly moving, the various areas fall alternately in the minima, then in the maximums of the wave. That will provide uniform heating.
How
microwave modes are implemented Talked about generation, told how energy behaves inside the working chamber, revealed the process of heat transfer to food. Consider how the intensity of heating varies. The magnetron does not generate oscillations constantly, but is excited by high voltage pulses. As a result, adjusting the duty cycle or frequency, achieve acceptable modes.
Inverter microwave ovens go further. A temperature sensor in the working compartment informs the system about the state of food; as a result, the pulse repetition rate is flexibly adjusted, the mode is as smooth as possible. The principle of the sensor is based on the reception of infrared waves: the higher the frequency, the warmer the room. More precisely, one frequency is taken, but intensity is measured. As the temperature rises, the spectrum shifts up. The overall shape is a hill with a single top. The sensor itself cuts the spectrum constantly at the same frequency. At first, the mountain crawls a little on this line, but as you move to the right, it covers the place more and more. As a result, an increase in intensity is recorded. Cold food in the infrared does not radiate at all.
It is possible to turn off the inverter mode, as a result, the correct use of the microwave oven will guarantee a positive result if you have gained experience with the equipment. We hope the story turned out to be interesting, despite the general confusion in physics. Perhaps readers will solve the riddle of the observer and put the answer in the comments. And we seek to award the audience of the Nobel Prize to the responsible committee.
