The microwave oven works using a simple fact: the 2.4 GHz radiation is shock absorbed by water. A food product( even a cookie) contains moisture. Meat, vegetables, fruit 60-90 percent are formed by life-giving moisture. It is clear that by passing 2.4 GHz radiation through food, it is possible to heat the contained water to a decent level. The device will allow you to make a microwave oven. WiFi took a close frequency, personal computer users do not fry: radiation is dosed. Some transmitters require permission before use. Otherwise, wait for the consequences, the most innocent is the increase in body temperature. The reproductive function and the immune system suffer.
Inside an
Microwave Oven A magnetron operates at the heart of the microwave. It emits waves that heat the product. How much power the device works with. Like most electrical household appliances, consumption does not depend much on what happens to the object of labor. The temperature of the magnetron is not monitored. Not so obvious to take the first look. The power of the gas burner drops for two reasons:
- The loss of the pan grows simultaneously with the temperature.
- Heating efficiency decreases with increasing heat.
Power is taken from the source, converted, handed to the place of destination. No matter how hot the dish is, it gets a fixed amount of watts every time. The microwave oven is controlled by a mechanical programmer. The new generation of devices is equipped with an infrared sensor that measures the temperature of food, which flexibly regulates the porosity of packs of pulses feeding the magnetron. Cooking conditions are maintained accurately, stably, the power of the microwave oven varies, determined by the needs of the recipe. Of course, the consumption of the outlet does not remain the same.
Consider the device of a magnetron. A vacuum chamber of sophisticated shape, the walls of which form the resonators of the selected wavelength( 2.4 GHz).The initial vibrations are formed by emptiness. The universe is not ideal, the microworld is full of fluctuations that generate different frequency processes. Thanks to the resonators of growth receive oscillations that fit into the desired wavelength. Others fade. To make the electrons easier to leave the cathode, the element is heated with an alternating voltage of 6.3 V( approximate value), the potential difference is applied in units of kilovolts relative to the positive electrode. It turns out demonstrated enormous power.
I had to hear the reasons for the existence of a certain voltage: oscillations are formed without reaching the anode. It turns out supposedly perpetual motion, can heat, give energy. It is pertinent to remind the masters of theorists that if the loop no longer takes energy, the output current will become zero. No electrons will fall on the anode, there is no heating. Consequently, conjectures are good when you need to find the ideal mode of the device, saving energy. The meaning is deep, the idea of electrons hovering in a spiral that does not reach the anode looks curious: the selection of the energy of the Universe at an arbitrary point in space.
The principle of operation of a microwave oven fully exploits the outlet current, feeding the magnetron to heat the food. Waves are removed by a loop located in the resonator. They are transmitted to the waveguide, which creates the conditions for the propagation of a 2.4 GHz wave with minimal losses. One open end of the waveguide touches the working chamber, covered with a mica plate, the second one is blocked. The connection loop pin sticks out exactly in the middle, at a distance from the bounding wall, avoiding to interfere with the waves reflected in the direction of the working chamber. An important aspect, you can find the position of the pin, when the total radiated field is zero. The energy will be formed in the channel antiphase, there is no heating of the food.
High-frequency oscillations, forming an interference pattern, add up, taking into account the phase difference, are quantitatively equal to 180 degrees( anti-phase) - a complete zero is obtained. Visually observed, correctly adding the radiation of two lasers( coherent radiation is necessary).The lessons of physics of secondary schools, universities often demonstrate similar. Occurs with a microwave. The field pattern is changeable. Inside the waveguide, the radiation is more or less constantly going out into the working chamber, the place of the dislocation of the plate changes the process of superposition. The interference pattern is determined by the size of the dishes, the type of food. Power, presented by the technical characteristics of microwave ovens, partially reaches edible.
A lot of energy is extinguished by the wrong addition of phases, a fixed number disappears through the door. Total efficiency is determined by exposing bowls filled with water, warm from one temperature to another, trying to understand, evaluate the result. Practically, the conditions did not even stand close to the experience. We aim readers' attention: the microwave oven is an imperfect device. The efficiency is below 100%, the damage can be considerable, if the screen is broken. Check - a separate question.
Practice shows: the metal mesh of the door transmits microwave radiation from a cell phone. The frequency is slightly different. .. Let's try a laptop and Wi-Fi.
- Turn off the device, take the plug out of the network.
- Put inside a laptop with a working network.
- Close the door.
- Watch the signal strength.
catches? Protection is not effective enough. Keep the microwave away at a respectful distance. The case of the device is earthed normally, according to generally accepted standards. We believe readers have worked to comply with the instructions:
- The parameters of microwave ovens were evaluated in the laboratory.
- The field was measured with the instrument in operation.
- The level must not exceed the norm.
The problem is simple: the issue of radiation, the dosage is poorly understood, measurements can be trusted with a stretch. People working in enterprises with radiation receive a surcharge for harm. The question is delicate, the device came from the USA.Buy a better cooker. ..
The microwave oven is good to warm up quickly. Baby bottles of milk put in the camera. Would not use the principle of the microwave for this purpose. Decide for yourself what to do. In Switzerland, conducted experiments to substantiate our point of view. The opposite is supported by advertising, the strength of the industrial lobby, the lack of knowledge of the issue.
Working the microwave oven
A lot of good things you learned about microwave ovens, it is interesting to know how the units work. Inside the usual surge protector from which the transformer ultimately feeds. Output windings are two. One is quite symbolic, represented by a pair of turns of insulated wire. From here it turns out 6 volts of power supply of the cathode filament of the magnetron of the microwave oven. Other windings are wound with wire with lacquer insulation, they look more impressive. The voltage of the secondary part is 1-2 kV.Then follows a rectifier, formed by a high-voltage diode, of impressive capacitor size. The diode is locked, the charging process is in progress, on the other half-wave the cathode will be under double voltage. The potential will be 2-4 kV.
The pulses feed the magnetron, which gives energy to the working chamber. Work is controlled by a mechanical programmer. Similar, more difficult, is in washing machines. The device microwave does not require complex operations. Inside, a set of cams defining the mode of operation of the grill, the fact of switching on the magnetron, the power of microwaves is regulated by periods of work / inactivity. Inside there is a timer switched on and off by a transformer. The process is accompanied by the usual circuit-opening circuit. To eliminate the spark, the circuit is complemented by a relay, which in the initial period of time does not allow current to the transformer, waits until the control gate voltage rises. The element takes a blow, much depends on the quality performance.
As a result, the transformer is included in the circuit, turns off. The magnetron functions synchronously. This is how the microwave works. Modern models in the temperature measurement mode use an inverter circuit, the transformer is powered by the generated pulses with the desired parameters. The sensor turns off, the device returns to its original state.
In the story of how a microwave oven is arranged, one cannot keep silent about the abundance of internal microswitches that control whether the door is closed. From the empty inclusion( without food) there is no protection! Microwave requires control.
This is interesting! High voltage lines generate air ionization. Usually, the atmosphere is filled with an excess of positive particles harmful to health. The main enemies were kinescopes. Today's plasma, liquid crystal displays behave more modestly.
