The modern pace of life dictates its own rules. There are increasingly not enough hours in the day, work is not limited to sitting in the office from 9 to 18, and visits to the gym/psychologist/all kinds of courses need to be squeezed into an already busy schedule. And no one cancels the correct diet: eating 4-5 times a day is necessary for the proper functioning of internal organs and for your own comfort. After all, how much energy is wasted every day! So, so that cooking does not take much time, you need to prepare it in advance, and then simply reheat it.
In the middle of the last century, science made a revolutionary discovery - a gadget was invented for heating food as quickly as possible. Who is the brilliant person who invented it, what were its first varieties - later in the article.
Microwave oven: who created it and when?
While using any gadget, few people think about how this device was invented. But in vain. After all, the story of when this or that gadget was invented is often very interesting. At least that's what happened with the microwave oven.
Stories about who invented it and when have become legends. But one thing is certain - back in 1945, Percy LeBaron Spencer had a hand in the creation of the microwave oven during his service at Raytheon. On October 8 this year, he patented a method for heating food using electromagnetic waves. The first machine operating on this principle was released in 1947 and bore little resemblance to modern devices: it was huge, the size of a man and weighing more than 300 kg. “Radarange” is the name the developer gave it. Interestingly, the scientist Spencer received only a small monetary reward for his brainchild, and all rights to release the gadget belonged to the company in which he was registered. Only after his death was he recognized as the one who invented and patented the microwave oven. And after a while his name was included in the Inventors Hall of Fame.
The first household microwave oven and the start of mass production
From the time the first microwave oven was invented, decades passed before its mass use. There were several reasons for this:
- High cost of equipment;
- Criticism of this gadget by scientists;
- As a consequence of the second point, there is negative PR for this device in the press.
Despite these obstacles, work to improve and optimize microwaves has been quite active. And already in 1962, the Sharp company launched the first conveyor production of microwave ovens (by the way, the modern analogue of this company’s oven is very different from its predecessors).
Due to harsh criticism, the first production versions of the unit were not particularly popular, but time passed and microwave ovens nevertheless captured the market. In 1966, a rotating rack was developed to heat food evenly. From the time when the very first microwave oven was released until 1979, another transformation occurred: a microprocessor control system for the device appeared, which made it much easier to use. Such microwave ovens began to actively enter the family life of those times.
Modern microwave oven
According to statistics, more than 12.6 million microwave ovens were sold in the United States in 2000 alone! In those days, when the microwave oven first appeared, no one could have thought that it would be so transformed and improved. A grill function will appear, as in the model, a food defrosting mode and a timer. It is these “goodies” that you should pay attention to when choosing a gadget for home. Even office premises equipped with a kitchen cannot do without a microwave oven. After all, saving time at lunch allows you to relax longer. As for control, microwave ovens are:
- mechanical;
- sensory.
Also, modern devices for heating food, unlike their predecessors, are equipped with a microwave protection system. Therefore, there is no need to worry about external radiation. For some, microwaves have even been able to replace ovens.
Half a century has passed from the moment the very first microwave ovens appeared to modern realities. During this time, this gadget has undergone total transformations both externally and internally. The table below provides a brief chronology of the development of this gadget:
| Event | |
|---|---|
| 1945 | Percy Spencer developed a technology for heating food using electromagnetic waves and patented his invention. |
| 1947 | Launch of the first microwave oven, called "Radarange". |
| 1962 | The Sharp company launched conveyor production of microwave ovens. |
| 1966 | The same company has developed a stand that rotates while the microwave is operating. |
| 1979 | Microwave ovens with a microprocessor control system were released. The entry of the gadget into the masses |
The microwave oven was released when no one expected it. And that's a fact. We must thank Percy Spencer for inventing such an ingenious way of heating food, whether by accident or design. After all, without such an irreplaceable thing in the kitchen, the life of a modern person would be much more complicated. And no matter what they say about the supposedly harmful effects of electromagnetic waves on food, no one is going to stop using the microwave oven.
Which in most cases simplifies the daily life of most people, especially those who do not like to tinker in the kitchen for a long time, and love comfort in all its details, namely - microwave oven, or as people say - microwave. In this article you will learn: what is microwave, what types of microwave ovens are there, how to choose a microwave oven, and other nuances that relate to this technique. So…
Microwave . orMicrowave ( English Microwave oven ) - a household electrical appliance designed for quick cooking or quick heating or cooking, defrosting food, and also used for industrial purposes for heating certain materials, for example, glue.
Unlike classic ovens (for example, an oven or a Russian oven), food is heated in a microwave oven not from the surface, but throughout the entire volume of the product containing polar molecules (for example, water), since radio waves penetrate deep enough into almost all food products . This reduces the heating time of the product.
The history of the discovery of the microwave oven
Like many other discoveries that have had a significant impact on people's daily lives, the discovery of the thermal effects of microwaves happened by accident. In 1942, American physicist Percy Spencer worked in the laboratory of the Raytheon company with a device that emitted ultra-high-frequency waves. Different sources describe differently the events that happened that day in the laboratory. According to one version, Spencer put his sandwich on the device, and after removing it a few minutes later, he discovered that the sandwich had warmed up to the middle. According to another version, the chocolate that Spencer had in his pocket when he was working near his installation warmed up and melted, and, struck by a lucky guess, the inventor rushed to the buffet for raw corn kernels. The popcorn brought to the installation soon began to burst with a bang...
One way or another, the effect was discovered. In 1945, Spencer received a patent for the use of microwaves for cooking, and in 1947, the first devices for cooking using microwaves appeared in the kitchens of hospitals and military canteens, where the requirements for food quality were not so high. These Raytheon products, as tall as a man, weighed 340 kg and cost $3,000 apiece.
It took a decade and a half to perfect the oven, in which food is cooked using invisible waves. In 1962, the Japanese company Sharp launched the first mass-produced microwave oven, which, however, did not initially cause a consumer stir. The same company developed a rotating table in 1966, used a microprocessor oven control system for the first time in 1979, and developed the first microwave oven with Internet access in 1999.
The experience of using millions of microwave ovens in many countries over the past decades has proven the undeniable convenience of this method of cooking - speed, efficiency, ease of use. The very mechanism of cooking food using microwaves, which we will introduce you to below, determines the preservation of the molecular structure, and therefore the taste of the products.
The principle of operation of a microwave oven, or how food is heated using a microwave
Food contains many substances: mineral salts, fats, sugar, water. To heat food using microwaves, it must contain dipole molecules, that is, molecules that have a positive electrical charge at one end and a negative one at the other. Fortunately, there are plenty of such molecules in food - these are molecules of fats and sugars, but the main thing is that the dipole is a molecule of water - the most common substance in nature.
Every piece of vegetables, meat, fish, and fruit contains millions of dipole molecules. In the absence of an electric field, the molecules are arranged randomly. 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, i.e. change polarity, as the molecules immediately turn over 180 o.
So, the microwave frequency that almost all microwave ovens use is 2450 MHz. One hertz is one vibration per second, a megahertz is one million vibrations per second. During one wave period, the field changes its direction twice: it was “plus”, became “minus”, and the original “plus” returned again. This means that the field in which our molecules are located changes polarity 4,900,000,000 times per second! Under the influence of microwave radiation, molecules tumble at a frantic frequency and literally rub against each other during revolutions. The heat released during this process is what causes the food to warm up.
Microwaves heat up food in much the same way that our palms heat up when we quickly rub them together. There is one more similarity: when we rub the skin of one hand against the skin of the other, heat penetrates deep into the muscle tissue. So are microwaves: they work only in a relatively small surface layer of food, without penetrating deeper than 1-3 cm. Therefore, heating of products occurs due to two physical mechanisms - heating of the surface layer by microwaves and subsequent penetration of heat into the depth of the product due to thermal conductivity .
This immediately follows a recommendation: if you need to cook, for example, a large piece of meat in the microwave, it is better not to turn on the oven at full power, but to work at medium power, but increase the time the piece remains in the oven. Then the heat from the outer layer will have time to penetrate deep into the meat and cook the inside of the piece well, and the outside of the piece will not burn.
For the same reasons, it is better to stir liquid foods, such as soups, periodically, removing the pan from the oven from time to time. This will help the heat penetrate deep into the soup container.
I would like to note that the radiation frequency in some industrial microwave ovens (the so-called variable frequency microwave, VFM) may vary and may not be 2450 MHz
Microwave oven device
Main components of magnetron microwave oven:
— a metal chamber with a metallized door (in which ultra-high-frequency (microwave) radiation is concentrated), where the heated products are placed;
— transformer - source of high-voltage power supply for the magnetron;
— control and switching circuits;
- direct microwave emitter - magnetron;
— a waveguide for transmitting radiation from the magnetron to the camera;
Auxiliary elements:
— rotating table - necessary for uniform heating of the product from all sides;
— circuits and circuits that provide control (timer) and safety (mode locking) of the device;
- a fan that cools the magnetron and ventilates the chamber.
Harm from a microwave oven
Actually, this is a broad question, but everyone should have their own opinion on this matter. I found a bunch of information on the Internet, both “Pros” and “Cons” of using microwave ovens. But personally, I am still inclined to believe that a microwave oven is no more dangerous, and perhaps less dangerous, than a CRT TV. Therefore, I didn’t decide to write another hundred lines. At the end of the article, you can read a couple more lines on this topic in “Myths about Microwave Ovens.”
The only thing I noticed, and that basically two “camps” of supporters and opponents agree, is that you can’t heat breast milk in a microwave oven and then feed it to a baby, because. to some extent the formula of this milk changes slightly.
By the way, on this occasion, I found a photo that shows the range of the harmful influence of a microwave oven. It shows how safe it is to have a microwave in the house.
Precautionary measures
— Microwave radiation cannot penetrate metal objects, so it is impossible to cook food in metal utensils. Metal utensils and metal utensils (spoons, forks) placed in the oven during the heating process can damage it.
— Liquids in hermetically sealed containers and whole bird eggs cannot be heated in a microwave oven - due to the strong evaporation of water, high pressure is created inside them and, as a result, they can explode. For the same reasons, it is undesirable to overheat sausage products covered with plastic film.
— When heating water in the microwave, you should also be careful - water can overheat, that is, heat above the boiling point. A superheated liquid can boil almost instantly from careless movement. This applies not only to distilled water, but also to any water that contains few suspended particles. The smoother and more uniform the inner surface of the water container, the higher the risk. If the vessel has a narrow neck, then there is a high probability that when it starts boiling, superheated water will spill out and burn your hands.
— It is undesirable to place dishes with a metal coating (“golden border”) in a microwave oven - even this thin layer of metal is strongly heated by eddy currents and this can destroy the dishes in the area of the metal coating.
Now let's turn our attention to the microwave characteristics that you need to take into account when choosing a microwave oven.
Microwave types , that is, equipped with built-in electronic scales. In such models, there is no need to indicate the weight of the products placed in the working chamber - the microwave will determine it itself.
"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 with the help of a 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 electricity 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 hold 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 for a long time at high power, 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 closed 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!
The history of the microwave oven - one of the best American inventions.
Many household and household items are taken for granted by humans. It is generally accepted that they have always helped people and few people think about the true history of this or that thing. This fully applies to a microwave oven, which today can be found in almost every apartment, catering establishment and anywhere where food preparation is involved. It has entered our lives so tightly that almost no one knows the true history of the invention of this household appliance, and yet a very interesting “legend” is associated with it.
1945 The end of the war with Nazi Germany. An employee of Raytheon, which specialized in the production of equipment for the needs of the army, Percy Spencer tested the microwave emitter he created for a military radar. The engineer, carried away by his work, decided to have a snack and, putting his hand into his pocket for the chocolate bar lying there, was surprised to find that it had melted. There was only one conclusion: the bar melted under the influence of microwave waves. Corn grains placed under radiation almost immediately became popcorn, and a chicken egg exploded. This is how the microwave oven was invented. But this is just a legend, and the true story of the invention of the microwave is completely different.
The management of Raytheon was well aware that after the end of the war, the company that produced military equipment could quickly go bankrupt. Therefore, it decided to reorient its core activities and begin producing consumer goods.
The idea for the production of microwave ovens was proposed by engineer Percy Spencer, who was researching ultrahigh-frequency waves. The company's management liked the idea, and in the fall of 1945 Spencer received a patent for an invention for heating and cooking food using microwaves.
The first microwave ovens were tested in a restaurant in Boston. They looked like huge machines, reaching a height of almost 2 meters, and weighed about 1.5 tons. Their cost was also high and reached $1000. By 1949, mass production of microwave ovens for home use began.
Next, the Japanese company Sharp took up the development of new household appliances. In the fall of 1962, the first series of new microwave ovens was released. The main problem with microwave radiation is their short length, which does not allow food to be heated evenly. The solution turned out to be very simple, and in 1966 Sharp developed and introduced a rotating plate into which food was placed to be heated.
In the 70s of the last century, microwave ovens became very popular. However, this did not prevent the spread of various myths about their harm to the human body. People were afraid of the “harmful” effects of microwaves, considering them radioactive and capable of causing various diseases. But the fears were not confirmed and microwave ovens began to become firmly established in the life of every family. Already in 1979, microwave ovens began to be equipped with a microprocessor control system. And the development of the Internet led to the fact that in 1999 the first microwave oven with access to the World Wide Web entered the market.
Today, a microwave oven is a household appliance that consists of a magnetron, a transformer and a waveguide. The magnetron is powered by a transformer and generates high-frequency waves, which are directed from it into a waveguide and, passing through a mica filter, enter directly into the chamber, where food is heated. An air fan is used to cool the constantly heating magnetron.
In the early forties of the 20th century, American physicist-researcher P. Spencer discovered during experiments that microwave radiation has a thermal effect. While working in an industrial laboratory, Spencer tested a microwave emitter. One day, as is typical for many scientists, he put a sandwich on the installation. Great was his surprise when, after a few minutes, the sandwich turned out to be heated!
Another version of the story of the discovery of the thermal effects of ultra-high-frequency waves says that the scientist carried a chocolate bar in his pocket, which melted due to the operation of the installation.
More than three years later, the scientist received a well-deserved patent for the use of microwave radiation for cooking purposes. This happened in October 1945. And by the end of the forties, the first microwave ovens appeared in US canteens. But the device was very bulky and weighed quite a lot. A wide field of activity opened up for inventors to improve the microwave oven.
Success came to Japanese designers who worked hard to refine Spencer’s invention for a decade and a half. A more modern furnace design was developed; the device received a rotating plate inside. In 1979, the first microwave oven appeared with a built-in microprocessor control system.
How does a microwave oven work?
The design of a microwave oven is simple and complex at the same time. Inside the device there is a transformer, a waveguide and a magnetron, which is a vacuum device that generates waves. To generate the required voltage, the furnace is equipped with.
The device is cooled through a fan that blows an air stream over the magnetron.
From the magnetron, microwaves go into a waveguide channel that has metal walls that can reflect radiation. After passing through the mica filter, the waves enter the furnace chamber. The internal cavity of the oven is usually made of metal and is sometimes covered with paint that imitates enamel. More expensive models are equipped with a coating made of , which is relatively easy to wash off dirt and can withstand thermal effects.
A modern microwave oven differs significantly from its prototype. It is compact, economical and multifunctional. Today, in a microwave oven you can not only heat food, but also defrost it using one of several programmable modes. There are models with a built-in grill that are popular. It is quite possible that in pursuit of consumer attention, inventors will add many more useful functions to the stove.
Every conscientious historian who has been interested in the development of technological progress knows very well that the theory of using microwaves to heat food appeared in the mid-1920s. However, Percy Spencer, an American from Massachusetts, was the first to receive a patent for a microwave oven for defrosting and heating food on October 8, 1945. This date is considered the birthday of the microwave oven. According to a widespread legend, the idea for this useful invention came to the scientist at the moment when a chocolate bar unexpectedly melted in his pocket. Surprised, Spencer began to look for the cause of the unpleasant emergency and soon realized that the reason for such incorrect behavior of the chocolate bar was the magnetron near which he was standing. As is known, this particular device generates microwave electromagnetic radiation. A worthy legend for an invention useful in the household, which was quickly adopted by military canteens and large restaurants. It should be noted that the first microwave ovens were large and heavy. With a height of about two meters, their weight reached about 340 kg. Those microwave ovens to which we are accustomed began to appear in the West only in the 1960s, and in the USSR from the second half of the 1970s. However, the modern historiography of the appearance of the first microwave ovens is not reliable. In fact, they were invented in the USSR on the eve of the Great Patriotic War.
