A powerful and dangerous microwave weapon is hidden in the microwave oven. Design and principle of operation of a microwave oven Properties of microwave waves

"Plate of Crusty", otherwise called "Crisp", allows you to fry food on it like in a frying pan. It is made of special metal and heats up to 200°C.

The “Dual emission” function declared by the manufacturer means that the radiation source is bifurcated. This separation contributes to more uniform heating of the products and increases the efficiency of the oven.
Sometimes microwave ovens are equipped with a dialogue mode, with which even a child can cook. A leading question is displayed on the display, and you only need to answer it for the next one to appear. Some models voice-duplicate messages displayed on an electronic display.

Electronic cookbook - this feature will greatly ease your wallet during the purchase and your life after the “smart” microwave oven is delivered home. Even a child can cook using this collection of recipes; you just need to understand how to use it. However, in our computer age, children are much better friends with electronics than adults.

In modern microwave ovens, there is a dialog mode when recommendations for the housewife are displayed on the display.

Safety

Safety from radiation, electric shock, mechanical and thermal injuries is confirmed by certification according to international standards. Despite the criminal liability of developers and manufacturers of microwave ovens for your safety, installation and operation rules must be strictly followed.

You are protected from microwave radiation by a metal casing and structural traps around the perimeter of the door. The magnetron and transformer inside the microwave are fan cooled to prevent overheating. When the magnetron is turned on, the door is locked so that it cannot be opened. When the door is opened or the temperature of the chamber wall or stove casing rises, special sensors instantly turn off the magnetron. Experts say that the level of radiation even in the immediate vicinity of a microwave oven is several times lower than permissible and decreases sharply with distance.

High power consumption is another reason for increased danger. If your home's electrical system has a third ground wire, conventional shock protection will provide maximum safety.

It is strictly prohibited to use water or gas pipes as a grounding wire. This could lead to the death of your loved ones or neighbors.

If there is no grounding, try to prevent the possibility of simultaneous contact with the microwave oven body and water or gas pipes. Your safety can be increased by installing an RCD (Residual Current Device).

To protect against children, the microwave oven is switched on. Nevertheless, the possibility of children playing dangerous pranks with oven buttons and control knobs must be excluded.

Inventory technology in microwave ovens

Very often, the desire of consumers to purchase a large-volume microwave oven is faced with the impossibility of placing the desired oven in a small kitchen due to the very impressive dimensions of the oven. In addition to the actual volume of the working chamber, there are also technical elements that ensure the functioning of the microwave oven and, unfortunately, take up a lot of space. Inverter stoves were called upon to solve the problem.

Inverter technology can significantly reduce the volume required to house technical components by replacing the conventional magnetron with more compact components, resulting in an increase in the usable volume of the chamber.

The use of inverter technology for microwave ovens is based on the principle of direct control of the output power level (as opposed to classical magnetrons, which always operate at maximum power, and power regulation is achieved by their pulsed operating mode). The advantages of inverters, in addition to smaller dimensions, also include more rational use of energy, speeding up cooking processes (heating, defrosting) and reducing energy consumption.

Currently, inverter technology is used mainly in Panasonic microwave ovens (in which it was first used), but there is no doubt that inverter technology has a great future.

Myths about microwave ovens

— Many people adhere to the belief that an iron plate can cause a high-power microwave to explode. In fact, in the worst case, it will cause damage to the magnetron due to arcing.

— If you keep a microwave oven on at high power for a long time, its powerful electromagnetic radiation can damage all electrical appliances within a radius of several meters. In fact, electromagnetic radiation outside the working chamber is no greater than from the back wall of the computer system unit, although close to it it can still interfere with the reception of a signal at a close frequency. Some oven models may interfere with Wi-Max, Wi-Fi and Bluetooth.

— A microwave oven can cause allergies... to electromagnetic waves.

— That for the first time a microwave oven, called “Radiomissor,” was allegedly developed by German scientists during the Second World War, it was even allegedly used in the active German army to heat food, but allegedly turned out to be unsafe and was abandoned (Russian sites with in this case they refer to foreign ones, and foreign ones - to Russian studies, allegedly conducted in the non-existent Russian cities of Kinsk and Rajasthan).

—Microwaves are radioactive or make foods radioactive. This is incorrect: microwaves are classified as non-ionizing radiation. They do not have any radioactive effect on substances, biological tissues and food.

— Microwaves change the molecular structure of food or make food carcinogenic. This is also incorrect. The operating principle of microwaves is different from that of X-rays or ionizing radiation, and they cannot make foods carcinogenic. In contrast, because microwave cooking requires very little fat, the finished meal contains less burnt fat with its molecular structure altered by cooking. Therefore, cooking food using microwaves is healthier and does not pose any danger to humans.

— Microwave ovens emit dangerous radiation. This is not true. Although direct exposure to microwaves can cause thermal damage to tissue, there is absolutely no risk when using a working microwave oven. The design of the oven provides strict measures to prevent radiation from escaping outside: there are duplicate devices for blocking the microwave source when the oven door is opened, and the door itself prevents microwaves from escaping outside the cavity. Neither the housing, nor any other part of the oven, nor food products placed in the oven accumulate electromagnetic radiation in the microwave range. As soon as the oven is turned off, the emission of microwaves stops.

Those who are afraid to even come close to a microwave oven need to know that microwaves attenuate very quickly in the atmosphere. To illustrate, we give the following example: the microwave radiation power allowed by Western standards at a distance of 5 cm from a new, just purchased stove is 5 milliwatts per square centimeter. Already at a distance of half a meter from the microwave, the radiation becomes 100 times weaker.

As a consequence of such strong attenuation, the contribution of microwaves to the general background of electromagnetic radiation surrounding us is no higher than, say, from, say, from, in front of which we are ready to sit for hours without any fear, or a mobile phone, which we so often hold to our temple. Just don't lean your elbow on a running microwave or lean your face against the door trying to see what's going on in the cavity. It is enough to move away from the stove at arm's length, and you can feel completely safe.

Utensils for microwave oven

The choice of utensils for the microwave oven should be taken very seriously. The fact is that if you don’t understand this issue, it can lead to several troubles:

- you can harm your health;
- you can damage the microwave;
- you may lose the dishes themselves;
- you can ruin the product itself.

Choosing material

Dishes for microwave ovens can be fireproof or heat-resistant. The first can withstand temperatures of 250-300°C, the second - only up to 140°C. Both types of dishes can be made of glass, porcelain, ceramics, plastic, but the properties of these materials will be different. Refractory materials are subjected to special hardening; as a result, the resulting containers can be used even on electric and gas burners. Heat-resistant materials - ordinary table glass and ceramics (as well as some types of food plastics).

Let us dwell on the issue of choosing material in a little more detail.

— Glass– one of the most common materials of cookware suitable for cooking in a microwave oven. It is not recommended to use thin-walled dishes in the microwave - although stable, such glass can burst when exposed to high temperatures. The best choice in this case would be bowls, bowls or dishes made of thick frosted or transparent glass: you can conveniently place pieces of food in them.

— Porcelain. Porcelain dishes are very convenient for portion-wise heating of food: just place the plate intended for serving in the microwave - and in a few minutes you will get a hot lunch. If you buy plates without wide sides and a small diameter, you can place several pieces in the microwave at once, thereby providing lunch for the whole family. Porcelain cups can be used to heat drinks.

— Ceramics, faience. Dishes made from this material are suitable for the microwave oven if they are covered with glaze on all sides (when purchasing, be sure to read the labeling on the product - it should indicate that it is acceptable for use in the microwave). You need to carefully ensure that the top layer of glaze does not crack or fall off - otherwise the dishes will not be able to withstand the high temperature. Ceramic dishes, plates and bowls are not the best choice for the microwave: they are not transparent enough for microwaves and get very hot. However, you can use such dishes for preparing omelettes or meat dishes: on a very hot surface you can even get a beautiful golden crust, like in a regular frying pan. If desired, you can use ordinary tableware for cooking; many types are microwave safe.

— Paper- a very convenient and fairly safe material for use in a microwave oven, provided that the cooking time is not long and the food does not contain a large amount of fat or moisture (otherwise they will saturate the paper too much). However, avoid dyed paper as it may stain your food when exposed to heat. Paper towels can be used to wrap food and place it in baking pans.

— Plastic has become quite widespread, but many still prefer to use plastic containers exclusively for storing and carrying food. Meanwhile, only plastic dishes can be placed in the microwave immediately after removal from the refrigerator (if they are used as “storage” for food) - they can withstand such changes. Plastic food storage containers marked “Thermoplast” or “Duroplast” can be an excellent solution for office workers who prefer to carry home-cooked food from home and heat it up at work.

The shape of the container also matters. By choosing the right cookware settings, you can regulate the cooking time and quality. So, food takes longer to cook in deep dishes than in shallow ones. The round shape will ensure the most even heating of the food. Beware of dishes with sloped edges - the food will burn around the perimeter, but the inside will still be completely raw.

Foil It is permissible to use only for wrapping protruding parts of food. If you use too much foil, arcing may occur.

Important! When choosing dishes for a microwave oven, immediately purchase a lid of a suitable size (of course, also made of a suitable material). Covering food will retain more moisture and cook faster. This way you can use special materials for better cooking - wax paper, paper napkins, transparent film. Typically, recipes (if you use them and don't improvise them) will tell you how to wrap the food to get the best results.

Thus, choosing the right utensils for a microwave oven will not only allow you to get a guaranteed result, but also improve the taste of the dish, as well as reduce its cooking time.

How to care for your microwave oven

— You need to wash the walls of the chamber with special detergents for microwave ovens, abrasive detergents - only stainless steel.

— If the camera is too dirty, put a glass of water in it and boil for 1 minute. The dirt will liquefy and wash off easily.

— Do not leave the inside of the microwave oven dirty, because... If the area where the door touches when closing becomes dirty, the door may not seal tightly, causing microwaves to leak out.

1. If your electrical network experiences frequent power surges, get a voltage stabilizer or an uninterruptible power supply (UPS), because When there are changes, especially in microwave ovens with LCD displays and touch controls, it is these components that fail.

2. When purchasing a microwave, it is better to immediately purchase microwave care products, because... These products are most often sold only in specialized stores, and when caring for a product, it is best to use them.

3. When purchasing, pay attention to the warranty card, because If the store where you purchased the product does not cooperate with a specific service center of the microwave manufacturer, in the event of a possible breakdown, they may begin to “send” you from one place to another in search of the truth.

4. When purchasing, pay attention to the tray, which is mainly made of glass. Sometimes he may get stabbed, or with other unpleasant surprises.

5. When purchasing, always, I repeat once again, always open and look at the appearance of the product. The words of the seller, who in a hurry says that the goods have already been checked, and leave everything in it well for others, because often some representatives of the selling company are too lazy to fulfill their duties.

6. Be sure to check the package contents when purchasing. There are times when something is missing.

Video about choosing a microwave oven

Do you want a good mood? Watch a humorous video about a “talking” microwave

Well, that seems to be all. I wish you a pleasant shopping experience and may you get exactly the microwave oven that is right for you!

How exactly does a microwave oven work? What causes food, water and other substances to heat up, while the air or glass in the microwave barely heats up? How to properly handle a microwave oven so as not to damage it and the food you are preparing? You will find answers to these questions in our article!

How does a microwave oven work?

The correct full name of a microwave oven is an oven with ultra-high frequency currents (microwave). Inside it (behind the dashboard) there is a special device for emitting radio waves - a magnetron, which can be seen from the diagram:

When a magnetron operates, the electromagnetic vibrations it emits at a certain frequency cause the dipole molecules inside the furnace to vibrate at the same frequency. The most common dipole molecule in nature is a water molecule (in foods there are also fats and sugars). At the molecular level, high vibration frequency translates into increased temperature, so any food with a high water content will heat up quickly. If there are very few or no water molecules inside the products (or materials), almost no heating occurs.

The depth of penetration of microwaves is small - 2-3 centimeters, but the surface of the prepared dish is easily penetrated by microwave waves, and deep down they encounter resistance from water molecules, so the product is actually heated from the inside.

Any conductive materials inside the microwave will become hot. Different ability to conduct current in our case means different heating rates.

To ensure that food is heated evenly, several approaches are used:

• Heat-resistant glass disc at the bottom of the microwave oven. It rotates with the dish, exposing all its sides to the magnetron radiation.
• Microwave. They are fed through a special waveguide (wide tube) from the magnetron to a rotating reflector, usually located in the upper part of the microwave oven. In such microwaves you can heat stationary dishes of large size and weight.

There are also so-called inverter microwave ovens. They differ from conventional models in that the magnetron operates continuously, but with reduced power consumption. This is achieved by using a so-called inverter (DC to AC converter) in the furnace instead of a traditional transformer.

In inverter ovens, vitamins are better preserved and the surface structure of the dish is less destroyed, but there is no fundamental difference.

In many models of microwave ovens, the magnetron is covered with a special translucent plate. It is transparent to microwave rays, but does not allow steam, grease splashes and other foreign substances to enter the microwave through the hole in the shielding. Do not remove this plate, and if it is required for cleaning from grease, then after complete drying, be sure to return it to its place.

Find everything about cleaning a microwave oven in this article:.

Despite popular belief, microwave radiation does not kill germs. At least this has not been scientifically proven. On the other hand, the combined effect of high temperature and microwaves on water molecules inside bacteria and viruses reduces their number many times over within a few minutes, and your immune system copes with those that remain on its own.

Microwave operating frequency

Most magnetrons emit waves at a frequency of 2450 MHz (megahertz, or millions of vibrations per second). These are waves of decimeter length (12.25 cm long). Some industrial installations, for example in the USA, operate at 915 MHz. Forced vibrations of water molecules are not resonant vibrations, since for them the resonant frequency is an order of magnitude higher - 22.24 GHz (gigahertz, or billions of vibrations per second).

There is no need to be afraid of harmful radiation from a microwave. The first mass production of microwave ovens was made in Japan by Sharp in 1962. Many years have passed since then, tens of millions of Japanese have been heating food in microwave ovens for decades, and the average life expectancy of the Japanese is the envy of the whole world.

At a distance of half a meter from the microwave oven, the impact of microwaves weakens 100 times, so if you are afraid of getting radiation, it is enough to stay at arm's length from the microwave.

You can find more information about the effects of microwave ovens on humans. Only scientific facts!

How does a microwave grill work?

A grill allows you to microwave food using regular heat rather than microwaves. It is she who creates an appetizing crust on dishes, which does not appear during conventional microwave processing.

The grill spiral is located at the top of the oven and comes in two types:

• heating elements(thermal electric heaters). A heating element is a metal tube, inside of which there is a thin spiral made of an alloy of nickel and chromium. Current passes through the coil and it heats up.
• Quartz. A quartz grill is also a heating element, but instead of a metal tube there is a glass shell, and between the spiral and the tube there is insulating quartz sand.

Conventional metal heating elements can often be adjusted - moved to the back wall or lowered, but the glass surface of a quartz grill is easier to clean (grease and carbon deposits do not eat into the glass as they do into metal).

There are designs of microwave ovens with grill and convection. Convection is simply blowing hot air over your food as it cooks. For such airflow, a fan is installed in the microwave, blowing heated air from the grill spiral towards the dish.

Most microwave oven models allow you to use both heating elements and microwaves at the same time. However, be aware that this combination can cause a lot of heat in the outlet and wires in your premises.

Read the following article about the principles of choosing a microwave oven to suit your needs:.

Instructions for using a microwave oven

To properly handle your microwave, you need to carefully approach all points - from choosing dishes to properly turning it off after use.

What kind of cookware should I use?

The best material for heating in the microwave is heat-resistant glassware. Porcelain and other ceramic products, paper (cardboard) are also well suited. Microwaves pass through them very easily and hardly heat them up. But you should avoid dishes made from the following materials:

• Plastic. It transmits microwave radiation well, but due to toxic components in manufacturing (for example, polystyrene foam) it can pose a danger to your health.
• Metal. They conduct electricity without allowing microwaves to pass through. So you won’t be able to cook or simply reheat a dish in an aluminum pan or cast iron pot. Metal simply will not allow electromagnetic waves to reach the food, and it will remain cold. In this case, the metal itself will, of course, heat up, and the food can also heat up from its heat. But this can lead to damage to the microwave oven, and you will have to wait a long time for the dish to cook. Read the instructions for repairing microwave ovens.

Some materials may contain metals, and this can be difficult to guess in advance. For example, this is crystal. So it is worth reading carefully on the label what materials were used in the production of a particular cookware.

• Melamine. This is a light and beautiful material for dishes, similar to porcelain, but it cannot be placed in a microwave oven. The fact is that when heated, it releases toxins that are dangerous to your health.

As for the shape of the cookware, it can be any, but not with a narrow neck, since it can be dangerous when used for heating in the microwave. The fact is that some liquids are heated to the boiling point, but violent mixing inside the volume does not occur. But when you take such a jug or flask out of the microwave oven, the liquid will instantly boil, boiling foam will pour out of the container, and you can get burned. For example, distilled water and some purified vegetable oils behave this way under certain conditions.

Correct handling of products

Initially, it is worth determining exactly what cannot be defrosted in the microwave:

• Butter. If you put it in the microwave and leave it for a long time, it will not only melt, but also boil, staining the entire oven from the inside. This happens because inside the oil there is not only the oil itself, but also water. It boils at 100 degrees, and oil at about 120. So the water can turn into steam even before the butter melts, and the water vapor will spread the oil throughout the stove.

About the same thing can happen with other products that sometimes need to be melted, for example, chocolate, so it is better to do this not in the microwave, but by steaming it.

• Products with a dense shell. For example, these are eggs, tomatoes, whole poultry liver. When heated, some of the water does not just gradually heat up, but immediately turns into steam. If you heat food for a long time, then even more steam is generated from direct heating. This steam has nowhere to escape, so the pressure inside the container increases and leads to an explosion.
• Hermetically sealed container. For example, canned food and bottles. The reason is the same as in the previous paragraphs - there is a high probability of an explosion.

• Before microwave heating, sausages tightly packed in a casing must be pierced with a fork to create holes for steam to escape, otherwise it will turn the sausages from the inside.
• In eggs and other foods, you need to destroy all the outer and inner shells, for example, make an omelet or cut the liver.
• To cook eggs and other products in the microwave, special saucepans with shielding are used. Water is poured into it, it is heated by microwave waves, but electromagnetic radiation does not reach the eggs - they are covered by a screen.
• If you place a small dish in the microwave, you should add a regular glass of water to it. This way you will avoid overheating of the magnetron.
• It is better to salt any liquid dishes in the microwave in advance, and not after cooking. This way you will save time and energy. The fact is that distilled (unsalted) water heats up and boils in the microwave, but longer than regular water.
• A very frozen product (meat, for example) will take quite a long time to defrost in the microwave, and you need to turn on the microwave oven at minimum power. The reason is that ice molecules are not water molecules, microwave waves do not loosen them so intensely. In addition, ice molecules form a fairly rigid structure and are not as easy to “rock” as water molecules.

Dry bread is often recommended to be “softened” in the microwave, but it can catch fire with prolonged exposure and maximum microwave power. The same can happen even with popcorn designed to be cooked in the microwave. Therefore, you need to be vigilant when placing such foods in the microwave.

On/off rules

You cannot turn on an empty microwave, especially at full power:

1. Inside the oven, all the walls (and even the door) are a special metallized screen that reflects microwaves back into the microwave. The only place where there is no screen is the hole for the exit of electromagnetic waves from the magnetron.
2. When there is food on the tray, the microwaves use their energy to heat the food. If there is nothing to absorb energy, microwave radiation is reflected from the walls of the shielding surfaces, and the wave density increases more and more.
3. Microwave radiation falls back into the magnetron, and if it is made of metal, it will simply overheat and may fail.

It is believed that after heating a dish in a microwave oven, it is better to let it stand for 3-5 minutes. Then the so-called “free radicals”, that is, parts of molecules that have broken apart under the influence of microwaves, have time to be neutralized.

Video: How does a microwave oven work?

All of the above about the principle of operation of the device is well illustrated in the following video:

After reading our article, you began to understand much better the principle of operation of a microwave oven. Now you know what it can do better than a conventional oven and electric stove, and what it cannot do, and what actions are generally unacceptable when working with a microwave.

The operating principle of a microwave oven is based on the process of converting an electromagnetic microwave field. The electromagnetic field is converted into heat and heats the product placed in the chamber in a non-contact manner. This is the main difference between a microwave oven and other devices - electric ovens, gas ovens, etc.

In microwave ovens, heating occurs directly within the product being heated, which is why the process takes just a few minutes. And in traditional stoves, heat is directed to the surface of the object, and spreads further depending on the thermal conductivity properties of the product. Of course, this method is less effective than microwave waves, and also requires much more knowledge in the field of cooking.

Even with the passage of time and the development of technology, the structure of a microwave oven remains unchanged. Yes, the design improved and became more comfortable, functionality developed, and new ways to adjust time and power appeared. But the principle of operation has not changed to this day.

Many people confuse concepts such as “microwave oven” and “microwave oven,” but these are just different names for the same device.

Just ten years ago, microwaves were considered an unaffordable luxury and a simple addition to the kitchen interior. The reason for this was the high cost of such devices, and not everyone could afford such an innovation. But over time, it became clear that this is not a luxury, but a necessity, especially in times of urbanization and the constant race for money.

What causes heating?

The operating principle of a microwave oven is based on an element called a magnetron. This concept is widely known to anyone familiar with the world of radar devices. It was thanks to the magnetron that humanity received the most effective and easy-to-use device for cooking and heating food. This is one of the most striking examples of how the developments of heavy industry began to be applied in everyday life with stunning success.

The structure of a microwave oven can be briefly described in these words: a magnetron generates microwave energy, which is converted into heat. The power sources for these elements are special anode-filament transformers-stabilizers, which are the reason for such a high price for microwaves. These stabilizers are the most expensive and important element of the furnace.

While studying the operating principle of a microwave oven, we will pay special attention to the design of the magnetic circuit equipped with magnetic shunts. This device makes it possible to change the increased voltage within only two percent, in conditions of network voltage fluctuations of 10%. The magnetic core and the significant inductive dissipation force of the high-voltage winding are the main attractions of the microwave oven transformer. In words, everything seems quite complicated, but in reality such a device has proven to be simple and extremely effective.

But at the first stages of development, the creators were faced with such a problem as increased noise when the stove was operating. Excessive noise has always been a problem for many household appliances, but manufacturers easily avoided this pitfall. To reduce the noise level, some parts of the magnetic circuit are connected by welding.

The standard microwave body is a rectangular chamber, which plays a significant role in heating. The generated waves are not simply directed towards the heated object - they are reflected from the walls of the housing.

An additional element that makes it possible to ensure high-quality and uniform heating is a rotating saucer in the chamber. By rotating, it allows the waves to evenly impact the surface. The principle of operation is such that the generated waves are by no means uniform - they can be with beams, nodes, etc. The magnetron transmits power to the emitter through a rectangular waveguide.

The door is an important element of the microwave oven

In the production of a microwave oven, the greatest attention is paid to the door. Everyone knows that in every microwave oven the door plays the role of a kind of fuse - as soon as it opens, the operation of the oven stops. The door structure is quite complex, as it is directly related to the level of safety during operation. The operating principle of the door is as follows:

• The ideal shape of the door and body is necessary so that the gap is minimal. The door protects the environment from microwave radiation and therefore must be constructed with the utmost responsibility.
• The perimeter of the door is equipped with a high-frequency choke valve, which is responsible for reducing microwave radiation to the required levels.
• The production process uses a special type of plastic that helps absorb radiation.

The control panel is nothing complicated. Usually these are two knobs that regulate the power and cooking time. The timer can be either mechanical or in the form of an electronic dial.

These days, many modern models are equipped with panels with a choice of different modes, but in fact these are just minor additions - the basic principle of operation does not change.

Over the years of microwave ovens' existence, much has been said about their detrimental effects on health. In fact, microwave ovens do not emit radioactive radiation, and even allow you to cook healthier food, preserving up to 75% of vitamins in food (which cannot be said about traditional cooking methods). If you follow safety precautions, there will be no harm to your health from the microwave.

Good afternoon, dear Khabrovsk residents.

This post will be about the undocumented functions of the microwave oven. I'll show you how many useful things you can do if you use a slightly modified microwave in an unconventional way.

The microwave contains a generator of microwave waves of enormous power.

I open the case

In this video I want to show what this voltage can do:

Antenna for magnetron

Now all the radiation is directed in the right direction. Just in case, I decided to test the effectiveness of this antenna. I took a lot of small neon bulbs and laid them out on a plane. When I brought the antenna with the magnetron on, I saw that the lights were lighting up exactly where needed:

Unusual experiences

Using non-ionizing radiation from a magnetron, plasma can be obtained. In an incandescent lamp brought to the magnetron, a brightly glowing yellow ball, sometimes with a purple tint, like ball lightning, lights up. If you do not turn off the magnetron in time, the light bulb will explode. Even an ordinary paper clip turns into an antenna under the influence of microwaves. An EMF of sufficient strength is induced on it to ignite an arc and melt this paper clip. Fluorescent and housekeeper lamps light up at a fairly large distance and glow right in your hands without wires! And in a neon lamp, electromagnetic waves become visible:

I want to reassure you, my readers, that none of my neighbors suffered from my experiments. All the closest neighbors fled the city as soon as fighting began in Lugansk.

Safety precautions

Unusual uses of the magnetron

These are not all possible applications that I have tested. Experiments continue and soon I will write an even more unusual post. Still, I want to point out that using a microwave like this is dangerous! Therefore, it is better to do this in cases of extreme necessity and while observing safety rules when working with microwaves.

That's all for me, be careful when working with high voltage and microwaves.

History of invention.

The invention of the microwave oven is an invention in a completely new way cooking.

In the 30s of the 20th century, work was carried out simultaneously in different countries to obtain powerful radio waves microwave range. These radio waves were primarily used in radars. Quite by accident, in 1932, employees of a laboratory in the United States fried two sausages without fire, placing them near a powerful microwave generator.

In 1945, the American engineer Spencer experimented with a magnetron - a radio tube that generates radio waves in the microwave range. Spencer took a few grains of corn and placed them near the magnetron, after a few minutes the grains turned out to be popcorn. He did the same with a raw egg.

A raw egg, left cold on the outside, boiled almost instantly in the middle under the influence of electromagnetic waves.

In October 1945, Spencer's company received a patent for the microwave oven and began producing devices called "radar ovens" - large cabinets filled with radio tubes, transformers and cooling fans. The space where the food had to be placed was no larger than a regular kitchen oven. We used these microwave ovens to defrost strategic food stocks.

In 1952, the Japanese bought a patent and started producing microwave ovens for the home.

And fifteen years later, our domestic microwave ovens appeared in stores.

Gradually, microwave ovens became combined and were equipped grill, convector, “crisp” and other additional functions, with the help of which cooking has been simplified, and the taste is equal to dishes prepared in the traditional way.. A microwave can cook food in five different ways: simple microwaves; grill radiation; microwave and grill at the same time; grill using convection; Microwave with convection.

Where do microwaves come from?

Household microwave ovens use microwaves with a frequency of 2450 MHz. This frequency is established for microwave ovens by special international agreements, so as not to cause interference operation of radars and other devices using microwaves.

The radiation source is a high voltage vacuum device - magnetron. A high voltage must be applied to the magnetron filament - about 3–4 kV. The mains supply voltage (220 V) is not enough for the magnetron, and it is powered through a special high voltage transformer.

The magnetron power is approximately 700–850 W. To cool the magnetron, there is a fan next to it that continuously blows air over it. The fan provides forced convection of air in the oven cavity while simultaneously heating it, which promotes uniform baking of products.

Microwaves from the magnetron enter the furnace through a waveguide - a channel with metal walls that reflect microwave radiation.

Complex design has a microwave door. It should provide visibility (what is happening inside) and prevent microwaves from escaping outside. This is a multilayer “pie” made of glass or plastic plates.

Between the plates there must be a mesh of perforated metal sheet. The metal reflects microwaves back into the oven cavity, and small perforation holes (less than 3mm) do not allow microwave radiation to pass through. A seal made of dielectric material is mounted around the perimeter of the door.

For microwave cooking completely unsuitable metal utensils. Microwave do not penetrate metal, they are reflected from it. This may cause electric discharge (arc) and cause damage to the oven. Besides, reflected microwaves can pass through glass doors, which is unsafe for health

How do microwaves heat food?

To heat food using microwaves, it must be present dipole molecules, that is, those that have a positive electrical charge at one end and a negative one at the other. There are many such molecules in food - these are molecules of fats, sugars and water. In an electric field, they line up strictly in the direction of the field lines, “plus” in one direction, “minus” in the other. As soon as the field changes direction to the opposite direction, the molecules immediately turn over at 180°. The wave field in which these molecules are located changes polarity 4,900,000,000 times per second!

Under the influence of microwave radiation, molecules rotate at a frantic frequency and rub against each other. The heat released during this process is what causes the food to warm up. Heating of products occurs due to the heating of the surface layer by microwaves and further penetration of heat into the depths of the food due to thermal conductivity.

Water boils in the microwave not like in a teapot, where heat is supplied to the water only from below. Microwave heating comes from all sides. In the microwave, the water will reach boiling temperature, but there will be no bubbles. But when you take the glass out of the oven, shaking it at the same time, the water in the glass will belatedly begin to boil, and the boiling water can scald your hands.

If you want to bring water to a boil in a glass or other tall, narrow vessel, be sure to drop a teaspoon into it before placing the glass in the oven.

What should you not do?

You cannot turn on an empty oven, without a single object that would absorb microwaves. Without encountering any obstacles on their way, microwaves will be reflected repeatedly from the inner walls of the oven cavity, and the concentrated radiation energy can disable the oven. As a minimum load, you need to put at least a glass of water in it.

Are microwaves dangerous?

Microwaves do not have any radioactive effect on biological tissues or food.

Microwave cooking requires very little fat, so microwaved food healthier and does not pose any danger to humans.

The design of the furnace includes strict measures to prevent radiation from escaping outside. Although direct exposure to microwaves can cause burns, there is a risk when using a working microwave properly completely absent.

Microwaves decay very quickly in the atmosphere. And already at a distance of half a meter from the microwave, the radiation becomes 100 times weaker. It is enough to move away from the stove at arm's length, and you can feel in complete safety.

Bon appetit everyone!

Magazine "Science and Life"