That which is an electrical device. General information about modern household electrical appliances. place: microwave

It is difficult to imagine our life without reliable assistants - electrical appliances. With their help, bread is baked and food is prepared, food is stored and the room is cleaned. Without electrical appliances, we would not be able to quickly transmit and receive information, for example, get acquainted with technical achievements, sports and film news, weather forecasts. They help to process a variety of materials, illuminate the premises and streets, and perform many other useful jobs. Look at Figure 183 and explain what electrical appliances are shown on it, what they are for. What is common between them and what is the difference? What kind of devices does your family use?

Rice. 183. Use of electrical appliances in everyday life

Yes! Common to all household electrical appliances is that they run on electrical energy. Appliances that operate on electrical energy and are used in everyday life to facilitate the performance of certain work, create comfortable conditions for work and rest, are called household electrical appliances.

In the lessons of labor training and in the future in everyday life you will use, or maybe already use a variety of similar electrical appliances. To do this, you need to know the purpose of such devices, the principle of their operation and, most importantly, the rules for their safe use. Regardless of the purpose, in every household electrical appliance there is an element that consumes electrical energy to power its working part. For example: in an electric drill, electric energy drives a motor, on the shaft of which a drill is fixed, in an electric jigsaw - a nail file, in a meat grinder - knives, in a washing machine - a drum with linen, etc. Since such devices work due to the consumed electric energy , they are all called consumers.

Depending on the purpose, principle of operation and design, household electrical appliances are divided into types and types. The most common types according to the principle of operation are the following: electric lighting, electric heating, electromechanical.

Each type can have several types. For example: the type of device is electric lighting devices, and its types are: floor lamp, sconce, chandelier, table lamp. Another group is heating electrical appliances, and their types: electric stove, electric iron, electric coffee maker, etc.

Electromechanical include electric meat grinders, food processors, sewing and washing machines, screwdrivers, electric drills and much more (Fig. 184). With long-term use of household electrical appliances, various types of problems may occur. The most common ones are: self-loosening clamping screws, which are used to fasten the conductive cores of electrical cartridges, plugs, sockets; breaking wires; failure of electrical and mechanical parts of devices, etc. As a result, sparking may occur, heating of wires, melting of insulation can occur, resulting in a fire, failure of electrical devices (Fig. 185).

Rice. 184. Types of household electrical appliances

Rice. 185. Possible malfunctions of electrical equipment

The use of faulty electrical appliances can lead to electric shock to a person and, as a result, lead to serious consequences for health. To prevent this, the following safety rules must be observed:

1. Before using the appliance, carefully read the instructions that come with each appliance.
2. Use the appliance only with the permission and in the presence of adults.
3. It is forbidden to touch the levers, buttons of the equipment placed in the workshop, and turn them on.
4. Do not check for voltage in an electrical circuit by touching bare wires with your fingers.
5. In case of any minor effects of electric current on the body (tingling, warming) and if there is a sign of damage to the electrical wiring, the smell of a melting insulating sheath of wires, the appearance of smoke, turn off the source of electric current and immediately inform the teacher, and when doing work at home - adult family members.
6. When using electrical appliances, make sure that the current-carrying wires are not taut and not twisted.
7. To prevent electric shock to a person, when turning on electrical appliances in the electric current network, it is forbidden to hold on to the metal pipes of water heating, the wall of the building, the body of another person (Fig. 186).
8. It is forbidden to hold or pull the electric plug from the socket with a cord (Fig. 187).
9. In order to avoid electric shock, it is forbidden to touch bare wires with your hands, to perform any work with consumers connected to the electric current network or other power sources (Fig. 188).
10. If an electric shock has occurred to another person, it is necessary to put a rubber mat or dry wood stand under your feet and with one hand pull the victim by the collar or other part of dry clothing from the electrical current-carrying network (Fig. 189).
11. In case of falling into the zone of falling electric wires, it is necessary to urgently get out of it, not jumping, but in small steps, moving the feet without taking them off the road, as shown in Figure 190.

Rice. 186. Possible cases of electric shock to a person

Rice. 187. Incorrect pulling of the plug from the socket

Rice. 189. Way of release of the victim

Rice. 190. Exit from the electric wire fall zone

New terms

electrical engineering, sources of electrical energy, consumers of electrical energy, household electrical appliances.

Basic concepts

• Sconce- wall lamp or lamp holder.
• Chandelier- a pendant lamp with several light sources.
• Floor lamp- lamp on a high stand.

Fixing the material

1. What types and types of household electrical appliances are divided into?
2. What is common and what is the difference between the types and types of electrical appliances?
3. What safety rules must be observed when using household electrical appliances?

Test tasks

1. Why is it necessary to save electrical energy?

And to avoid the failure of household appliances
B to reduce energy costs
In order to reduce the cost of natural resources for its production

2. What household appliances are powered by electricity?

A chandelier
B hair dryer
The grinder

3. The use of faulty electrical appliances may result in

And the excessive consumption of electrical energy
B electric shock
Failure of an electrical device

4. Why can't you touch bare wires?

And the electrical device will fail
B power supply will be cut off
You can get an electric shock

Household electrical appliances

The simplest device for heating water is a boiler. Boilers are available in various sizes, different capacities, designed for different rated voltages, but the principle of operation is the same for all.

The main element of the device is a heating element - a tube with a diameter of 5-10 mm, the working part of which is twisted into a spiral with a diameter of 30 to 100 mm. The lining of the heating element is made of steel, copper, brass, food-grade aluminum. To protect the electric wire, there is a rubber or plastic limiter at the junction of the heating element and the wire. The design of the boiler is such that it can be hung over the edge of the dish.

All other household appliances designed for heating water are made with built-in heating elements. An electric kettle, an electric samovar, in addition, have a thermal switch that protects the device from overheating.

Teng is also used in the device of electric water heaters designed to heat running water. the heating element is built into a metal tank covered with a plastic case. The heaters also have a heating power regulator, a pressure regulator, a temperature regulator.

Devices for food processing can be divided into two large groups. The first includes devices for food processing, such as electric meat grinders, electric coffee grinders, electric potato graters, electric juicers, mixers.

The second group includes appliances for cooking, which are electric stoves (electric stove), electric pots, electric frying pans, electric ovens, electric coffee makers, electric grills, electric barbecues, electric waffle irons. toasters, microwave ovens.

Food processors make it easier to work in the kitchen, allowing you to do less heavy mechanical work, thereby speeding up the cooking process and saving effort.

For the preparation of minced meat or fish, electric meat grinders are designed, which are auger and cutter. Screw electric meat grinders have the same device as a manual meat grinder, with the exception that the rotation of the screw, which feeds parts of the product to the rotating knife, is carried out by an electric motor.

A cutter meat grinder works on the same principle as a coffee grinder: at the bottom of the container in which the product is placed, there is a rotating knife that grinds the product to mincemeat.

The design of both types of meat grinders is extremely simple and is an electric motor that rotates the screw or cutter knife on an axial principle. To protect the motor from overload, the meat grinders are equipped with a mechanical protective device. The cutter meat grinder has a lock that makes it impossible to operate the device without a lid. The design of the meat grinder can be provided with a time relay, a device for storing attachments, a device for winding the cord. Attachments and interchangeable knives must be sold in the kit.

There are two types of electric coffee grinders. Impact grinders are a small cutter that also has a lock that makes it impossible to work without a lid. An electric motor drives a two-bladed knife located at the bottom of the grinding tank.

The design of an impact type coffee grinder is even simpler than a cutter meat grinder. It does not have a timer, a mechanical safety device, or other devices. On the case there is only a button that closes the network.

A burr-type electric coffee grinder grinds coffee beans (as well as other bulk products, by the way) using discs, cylinders, cones and other elements that act as millstones. The most common design of this device has two disc millstones - a movable and a fixed one. Grains are poured into the working mechanism through a special funnel. The ground product enters the hopper, from where it can be removed by opening the lid.

This coffee grinder is more convenient, because at the same power with an impact coffee grinder it has a grinding degree regulator that sets the distance between the burrs, four times more product is placed in it (125 g versus 30 g in an impact coffee grinder), it also provides cord storage device.

The electric potato maker is designed for cooking potato mass. This operation can be performed on a juicer, but the mass in this case is heterogeneous. The potato grater is an electric motor on which a grating disc is fixed. The potatoes are loaded into the hopper, while the grater disc grinds it, and the potato mass, having passed through the holes of the cutting elements, goes into the receiving dishes.

The same principle applies to a juicer designed to extract juice from fruits and vegetables. The juicer also has a grating disc that grinds the product. After that, the crushed mass enters the centrifuge, during the rotation of which juice is released. From time to time the centrifuge is cleaned by the ejector.

Potato graters and juicers have a simple design that allows you to make repairs yourself. As a rule, problems with these devices occur due to the fact that the gap between the grater disc and the plastic parts of the housing increases due to their wear. In this case, it is recommended to disassemble the device, replace worn parts, and then assemble and adjust the device.

A mixer also belongs to the devices for processing products. This device is an electric motor in a plastic case that rotates two axes, on which various nozzles are put on. The mixer has step speed control for processing different products.

If the device is made in a desktop version and has a device for squeezing juice from citrus fruits, a reclining mixer operating in a special container, as well as other additional devices, it is commonly called a food processor.

Of all the cooking appliances, the electric stove is one of the easiest household appliances to handle food. It is a metal stand on which there is a ceramic base with grooves in which the spiral fits. The tile sometimes has a step heating regulator.

However, tiles with an open spiral can be found less and less, as the open spiral is increasingly being replaced by heating elements. This can be explained by the fact that during the cooking process, you can spoil the spiral by spilling milk or water on it. Secondly, since the spiral is open, the possibility of an electric shock is likely.

Tenovye electric tiles in this sense are more reliable. The metal tube protects the heating element from harmful effects and also protects against electric shock. The rest of the hot plate remains the same: it has a step-by-step heating power regulator with the corresponding designations in degrees Celsius.

An electric stove works on the same principle as a heating element, with the exception that it has an oven. On the front panel there are position switches for heating power, an oven backlight switch, and a thermostat signal lamp.

The heating elements recline for cleaning pallets, there is a block in the stove, which excludes the simultaneous inclusion of the oven and burners. The stove has a lid.

An electric pan is also produced with a heating element. It has an aluminum or steel case, a thermostat that allows you to adjust the water temperature within 65-95 ° C, a thermal switch that turns off the device when the water boils away or is turned on without water in the network.

The device is similar for the electric frying pan. Under the base it has a tubular heater, which allows you to heat the work surface up to 185°C in 6 minutes. As in other devices that use heating elements, the frying pan has a thermostat designed to adjust the heating of the working surface in the range from 100 to 275 ° C. Electric pots are available for cooking under high pressure (pressure cookers) and for steaming food (steamers).

Electric ovens are designed for baking flour products, for preparing stews from meat, fish and vegetables. The heating element of the electric oven transfers heat evenly over the entire working surface. Some models have a sight glass on top.

The body of the electric furnace is made of aluminum alloy, the heating element, which is a nichrome spiral with beads put on it, is located in the lid. The heating element can also be tubular.

The maximum oven temperature is 240°C. The design of the stove allows you to use it as an oven, frying pan, brazier, double boiler. The lid is made in the form of a frying pan and can be used for cooking.

An electric coffee maker can be vacuum, compression, percolation, filtration. In a vacuum coffee maker, coffee is prepared by passing pressurized hot water or steam through a layer of ground coffee. Due to the vacuum, coffee enters the water vessel.

In a compression coffee maker, coffee is brewed by passing pressurized water or steam through a layer of ground coffee. In a percolating coffee maker, water or steam passes repeatedly through the layer of ground coffee.

In a filter coffee maker, coffee is prepared by passing water or steam once through a layer of ground coffee located in the filter (dispenser grid).

All coffee makers have a temperature limiter that turns off the household appliance in case of overheating. The coffee container is installed on the food warmer, which heats the coffee to the desired temperature.

A heating element is installed in the coffee maker. The steam formed as a result of heating water exits through the tube and enters the dispenser, where the ground coffee is located, passes through the dispenser and drains into the beverage container.

An electric grill is a household appliance for heating food using infrared radiation. A tubular heater or tungsten filament in a quartz glass tube is located under the dome. Devices for fixing food are attached to the side walls. The drive that rotates the fasteners can be manual or automatic. The electric grill can be both open and closed.

Electric grills are equipped with thermostats that allow heating the device from 190 to 250 ° C. Some models have a front glazed door, lighting, a timer.

According to the same principle as the electric grill, an electric barbecue is arranged. Electric grills are available in two versions: vertical and horizontal. The electric motor rotates the skewers at a speed of 0.5-5 revolutions per minute. In electric grills and electric barbecue grills, a signal light is not installed, since the heating element glows during operation.

A heating element or a tungsten filament in a quartz glass tube also acts as a heating element. In electric grills and electric grills, the temperature of the emitter is at least 700 ° C, the heating element heats up in 5 minutes, the tungsten filament in the quartz glass tube - in 1.5 minutes.

The electric waffle iron is a form, the heating of the working surfaces of which is carried out by heating thermoelements located in special recesses.

Under the lower heating plate there is a bimetallic thermostat, which disconnects the device from the mains at temperatures above 200°C. Also under the bottom plate there is a fuse designed to turn off the device in case of failure of the bimetallic thermostat. The fuse can only be reused after it has been soldered with a soldering iron.

Electric toasters are designed to toast slices of bread using an infrared emitter (tungsten filament in a quartz glass tube). Depending on the model, they may have an automatic shutdown with a timer or a manual shutdown.

Models differ in the number and size of toasting chambers, in time and uniformity of toasting, the possibility of removing crumbs, and in power consumption.

In devices with manual shutdown, slices of bread are placed in special niches, from where they are then removed manually. Frying can be done on one or both sides. In appliances with automatic shut-off, toasting is carried out for a certain time, the switch-off occurs automatically, and the slices of bread are pushed outward by spring pushers.

An electric roaster is also built on the same principle - a household appliance designed for making sandwiches. Just like electric toasters, the heating element is a tungsten filament in a quartz glass tube. Switching off the device can be manual or automatic.

For uniform heating, the electric roaster has several heating elements at the top and bottom. With the help of a step heating power regulator, it is possible to turn on the heating elements selectively, i.e. top or bottom, or all at once.

The electric roaster (as well as the electric toaster) has a timer with which you can set the heating time. Since the infrared emitter heats up very quickly (maximum 1.5 minutes), the time switch is designed for 6 minutes of operation.

Of all household cooking devices, the most complex is the microwave oven. If other household appliances are easy enough to fix, since most problems occur due to mechanical damage, the microwave oven has a more complex device, stuffed with electronics, and therefore it is best to repair it in a workshop.

The microwave oven uses the property of the electromagnetic field to evenly heat the entire volume of the chamber, regardless of the contact of the workpiece with the coolant, the thermal inertia of the heater. The microwave field is completely converted into heat, which allows for uniform and fast heating of products.

Unlike methods when heating is performed due to the contact of the product with the coolant, microwave heating generates heat due to the displacement of charged particles when the product is exposed to an electromagnetic field. Due to intermolecular friction, heat is generated.

Regardless of the model of this household appliance, it has the following devices: a power source that converts the mains voltage for a microwave generator (a high-frequency voltage rectifier or a transformer with a voltage regulator); magnetron - an electrovacuum device that generates pulsed and continuous microwave oscillations (microwave generator); a device for transmitting microwave energy to the heating chamber; a heating chamber with appropriate electrodynamic properties for the distribution of microwave energy throughout the volume; – sealing devices preventing leakage of microwave energy.

The microwave oven must have a time switch to adjust the duration of heating. As a rule, on modern models of microwave ovens there is a control panel with a touch drive.

The device has a frame made by cold stamping and welding. The lining of the furnace is made of cold-rolled steel, painted with enamel. Removable elements are attached to the frame with screws. In front there is a chamber door that opens down or to the side, the door can have a transparent window made of quartz glass in order to be able to observe the cooking process. The case has ventilation holes for cooling the magnetron and the working chamber.

A house cannot be comfortable if it is cold. The recommended air temperature in the apartment should be 16-25°C. In living quarters, the air temperature should be 18-22°C, in bedrooms 14-17°C.

In everyday life, such heating devices as convectors, radiators, infrared heaters of directional radiation are used.

Convector-type heaters use the convection movement of warm air. Cold air, passing through the heater, is heated by a metal coil and should not have a temperature of 85 ° C at the outlet.

In convector-type heating devices, adjustable resistances are installed so that you can set the heating power, as well as bimetallic thermostats that turn off the device in case of overheating. The heating element in most cases is a spiral, sometimes located in a glass tube. The body of the convector is designed to reflect heat.

Radiator-type heating devices are designed so that heat transfer occurs from the working surface. They rarely install heating power regulators, as well as thermostats, since the electric radiator has insufficient power and is more often used as an additional means for heating the room.

Electric radiators are divided into dry (having no intermediate carrier), oil-filled, sectional and panel. By execution, electric radiators can be wall and floor.

Infrared heaters of directional radiation are a reflector with a heater placed at the focus. With the help of a reflector, directional heat transfer is formed. The body can be made from any material. Maximum heating temperature - 900°C, power - up to 2 kW.

Infrared heaters are distinguished by the type of heating element, which can be closed or open, as well as by the shape of the reflector, which can be spherical, parabolic, cylindrical.

As a heater, spirals in quartz tubes, double spirals on ceramic bases and high-resistance wire wound on a ceramic rod are used. The spiral is necessarily covered with an oxide film, which eliminates interturn short circuit.

To increase the effect of heat transfer, the surface of the reflector made of aluminum is polished and anodized, reflectors made of other metals are chrome-plated or nickel-plated.

Depending on the complexity of the design, the infrared heater can have a step-by-step power switch,

As a rule, the reason for the breakdown of heating devices is commonplace. This is either the wear of the heating element, or the wear of the insulation on the wire, or other mechanical damage. Knowing the principle of the thermal action of electricity, the heating device is easy to repair on your own.

First of all, refrigerators are divided according to the methods of obtaining cold: compression, absorption, thermoelectric. They are also divided according to the volume and number of freezers, according to the version: floor, wall, block, etc.

Compression-type refrigerators are a cabinet with a refrigeration unit, as well as elements of automation and electrical equipment. The refrigeration unit generates cold with the help of a special substance, which is commonly called a refrigerant.

The refrigerant is a substance that passes at low temperatures into a vapor state. It should have moderate boiling pressure, high thermal conductivity, as low a solidification point as possible, and as high a critical temperature as possible. In addition, it must be harmless to the body and not cause metal corrosion. That is why the most common refrigerants are freons and ammonia.

The refrigeration unit of a household refrigerator is a motor-compressor, an evaporator, a condenser, a piping system, and a filter-drier. As a rule, the compressor is located below, the condenser is on the back wall, the evaporator forms a small freezer compartment in the upper part of the chamber.

The compressor circulates the refrigerant in the system. The compressor is driven by an electric motor. The principle of operation of the compressor is as follows: an electric motor drives a piston that moves a valve. This creates a vacuum, and part of the refrigerant enters the suction chamber through the suction valve. With further movement of the valve, pressure is created, from which the suction valve closes, and the refrigerant leaves the suction chamber into the pipeline. This is a general principle of operation for any compressor, regardless of the version.

The electric motor of the refrigerator works cyclically, i.e. periodically turns on and off. The shorter the intervals, the lower the temperature of the freezers, the greater the energy consumption, and vice versa. The frequency of operation of the electric motor is provided by a temperature sensor-relay, which maintains a certain temperature in the freezers.

The refrigerator condenser is a heat exchanger through which the refrigerant gives off heat to the environment. Cooling occurs due to air, and therefore the condenser coil is usually made with metal fins that enhance cooling. Capacitors are usually made of copper or aluminum, as these metals are characterized by high thermal conductivity. The refrigerant, being cooled, passes into a liquid state and enters the evaporator.

In the evaporator, the refrigerant absorbs heat from the refrigerated chamber. As a rule, in the refrigerator it is located above the freezer. Evaporators have channels of various configurations and differ in the way they are attached to the freezer.

The supply of liquid refrigerant from the condenser to the evaporator is carried out by a capillary tube, which has a low permeability and, by connecting the parts of the installation with high and low pressure, creates a pressure difference between the condenser and the evaporator, passing a limited amount of liquid refrigerant.

The filter is located at the entrance to the capillary tube to prevent clogging with solid particles. It is a metal case filled with bronze balls with a diameter of 0.3 mm or having a brass mesh inside.

To clean the working environment from moisture and acids, various adsorbents are used, which are filled with filter driers. Synthetic zeolites, mineral adsorbents (silica gel, almulugel, etc.) are used as filtering material. Due to the crystal structure, synthetic zeolites adsorb moisture well and almost completely absorb refrigerant and engine oil.

A filter that adsorbs moisture that may freeze in the capillary tube is called a desiccant cartridge, which is installed before entering the capillary tube, and therefore is often combined with a filter drier. The drying cartridge is also filled with synthetic zeolite. Sometimes methyl alcohol is used instead of a drying cartridge. In this case, moisture is not removed from the system, its freezing point is simply lowered. The amount of methyl alcohol is 1-2% of the amount of refrigerant. However, methyl alcohol is not used if the capacitor is made of aluminum, since the interaction of substances leads to the destruction of aluminum and the leakage of refrigerant.

In general, the process of operation of the compression cooling unit is as follows. Freon vapor is sucked out of the evaporator by the compressor, which at the same time cools the motor winding. The refrigerant vapor compressed in the compressor enters the condenser, where it is cooled and passes into a liquid state. Liquid freon enters through the filter and capillary tube into the evaporator. There, under the influence of low pressure (98 kPa), it begins to boil, taking heat from the freezer. From the evaporator, the freon vapor re-enters the compressor. The electric motor is turned on and off by a start-up relay, which in turn is turned on by a relay sensor that automatically maintains the temperature.

Another type of refrigerators - absorption. They are intended for short-term storage of perishable products and obtaining edible ice. Cooling occurs due to the process of absorption - absorption by a liquid or solid absorber of refrigerant vapor formed in the evaporator. The refrigerant is ammonia, the absorbent is water bidistillate, the inhibitor is sodium bichromate, and the gas is hydrogen.

The system is filled with a water-ammonia solution and hydrogen. Hydrogen is inert and therefore does not react with ammonia. A water-ammonia solution is heated in the generator, as a result of which water-ammonia steam is released, which rises through the rectifier. As a result of the fact that water has a higher condensing temperature, pure ammonia vapor enters the condenser.

In this case, ammonia vapor displaces hydrogen and condenses under a pressure of 1500-2000 kPa, equal to the pressure inside the entire system. Cooling is carried out due to the design of the condenser, as well as the cold vapor-gas mixture leaving the evaporator.

In the evaporator, liquid ammonia evaporates, absorbing heat. Vapor removal from the evaporator is carried out by circulating the refrigerant in a closed system. Ammonia vapor is absorbed in the absorber with an ammonia-water solution, from where it is then returned to the generator to continue moving. The heater is a nichrome wire spiral inserted into a metal sleeve with porcelain bushings strung on it, the free space is filled with quartz sand.

Absorption refrigeration units can have a manual or automatic temperature control system. In the first case, a manual step power regulator is used, in the second, a thermostat is used that turns off and on the heating element to maintain a constant temperature.

The advantage of absorption refrigerators can be considered silent operation, while compression refrigerators make a specific sound due to the movement of the valve in the compressor. Also, the advantages of absorption plants include the simplicity of design, the absence of valves and moving parts.

However, due to the fact that the heater in the absorption refrigerator must be constantly turned on, more energy is consumed, and therefore the use of the absorption refrigerator is more expensive.

Among other things, refrigerators of both types often have additional devices that perform various functions: to maintain a certain humidity in freezers; cooling drinks and dispensing them without opening the door; signaling of operating modes; automatic door closing; fixing a certain opening angle of the door, excluding a hit against a wall or a central heating battery.

Unlike refrigerators, freezers are designed for deeper freezing at a temperature that prevents the formation of large ice crystals, as well as for storing food at a lower temperature. The freezer is a compression unit in which, unlike a conventional refrigerator, the compressor does not work intermittently, but constantly. Between the evaporator and the compressor suction pipe there is a refrigerant after-boiler (which has not had time to dissolve in the evaporator), which allows to increase the efficiency. The zeolite dryer is double-sided, which makes it possible to perform double-sided evacuation of the unit when it is filled with refrigerant.

Unlike a refrigerator, where the evaporator is positioned so that it is more convenient to divide the interior space into a freezer and a storage compartment, in a freezer, the evaporator is located so that the entire compartment is cooled evenly, so there is no separate freezer, it has only a few shelves for placing products.

Repair of refrigerators should be carried out in the workshop, since it is impossible to repair the refrigeration unit on your own, this requires special repair equipment. As a result of the repair, it is necessary to carry out diagnostics, remove the refrigerant, unsolder the joints, flush and dry the components, assemble, check for leaks, evacuate and fill with refrigerant, run in. You understand that at home such complex work is simply impossible to perform. All you can do yourself is fix the door hook, replace the insulating strip on the door, change the light bulb.

In the event of a refrigerant leak, safety precautions should be taken as the refrigerant is flammable. You should be careful not to get it on your hands, face, eyes.

Unlike compression and absorption type cooling units, thermoelectric refrigerators do not have a refrigerant, they operate only on electricity.

Thermoelectric cooling occurs as follows. Electric current passes through a thermopile composed of two types of semiconductor heating elements: one is cooled, the other is heated.

As you already know, all materials can be divided into two groups: conductors of electric current and dielectrics. In addition, there are materials that occupy an intermediate position between conductors and dielectrics. Unlike metals (conductors), they have a greater resistance to electric current, but less than that of dielectrics.

Any conductor heats up when an electric current passes through it. This is also true for semiconductors, however, if the resistance of the conductor increases when the conductor is heated, then the reverse occurs when the semiconductor is heated: the more the semiconductor heats up, the less resistance it has. Also, current flows through a semiconductor in only one direction.

These properties of semiconductors (copper oxide, selenium, silicon, germanium, etc.) allow them to be used in cooling conditions of thermoelectric action.

Some thermoelements of the refrigerator are made of an alloy of lead and tellurium, others are made of an alloy of tellurium and antimony. Thermoelements can also be made from bismuth and selenium alloys.

Semiconductors are interconnected in series using metal plates. When an electric current passes through them, some heat up a little, while others cool. Heating semiconductors are located outside the cooling chamber, cooling - inside. The refrigerator also has a fan to keep the temperature cooler.

Thermoelectric refrigerators are rarely used in everyday life, as they are inferior in quality to compression and absorption refrigeration units. The refrigerator can be used as a car refrigerator, as it is designed for short-term cooling of food - no more than 48 hours. As a rule, its body is designed so that the device can be used as an armrest.

The refrigerator can operate both from DC 12 V and from AC 127 and 220 V. Many models do not have an AC rectifier. This is due to the fact that the device has the most compact design in order to be convenient to use in a car. If you need to turn on the device through a network with a voltage of 127 or 220 V, you should use a charger-rectifier connected to the cord plug.

Washing machines are semi-automatic, in which the washing and spinning processes are controlled by the operator, as well as automatic, in which the processes are carried out in accordance with a given program.

The semi-automatic washing machine is a sheet steel body containing a washing tub and a centrifuge. The surface is covered with nitro enamel or anodized, the tank and the centrifuge have separate covers, the body is closed with a removable cover. For ease of use, there are handles and rollers on the body. On the back wall there is a niche for laying a rolled cord.

The washing tank is made of stainless sheet steel covered with vitreous enamel and has a cylindrical shape or is made in the form of a cube with rounded edges, with an inclined bottom, at the bottom of which there is a drain.

The activator is installed in the wall of the washing tub or at the bottom. It is located in a recess, which prevents the linen from getting into the gap between the tank and the activator.

The activator is an electrically driven paddle disk. Tightness is created by rubber gaskets. The activator rotates at a speed of 475 to 750 rpm. Its operating time is regulated by a mechanical time relay.

The centrifuge is a basket made of aluminum, powered by an electric drive. The rotation speed during the spin cycle is 2600-3270 rpm. To start the electric motor, there is a capacitor in the circuit; a thermal relay is installed to protect the windings from burnout. Electric motors for the activator and centrifuge are installed separately, four types of insulation are used to protect against electric shock. The running time of the centrifuge is also controlled by a mechanical time switch.

The solution is drained using a centrifugal pump, the drive is carried out by the shaft of the activator electric motor. Productivity is from 18 to 30 liters per minute.

Automatic washing machines, which are also called drum-type machines, front-loading machines, perform all operations according to a given program. Washing and spinning take place in the same drum, which allows the use of electronics that fully automate the washing process.

Water filling and draining, metered injection of detergents, locking, washing in heated water, rinsing, spinning are automatically performed. Processes can also be adjusted according to the degree of soiling of the laundry, as well as its wear resistance.

The washing tank is mounted on springs that reduce vibration, and has a drum inside, which is driven by an electric motor with a belt drive, and several speeds (for washing and spinning). Water is supplied from a cold water supply network - heating with a tubular heater. The water is drained by a pump. Commands are entered from the control panel.

Vacuum cleaners perform all the work that is associated with rarefied air: cleaning carpets and floors, cleaning clothes, whitewashing. The principle of operation of the vacuum cleaner is that air is sucked in by the unit through special filters.

Vacuum cleaners are floor and manual. Floor vacuum cleaners have a steady design on running rollers. Handheld vacuum cleaners are a portable case with a handle. Hand vacuum cleaners can be hose or car vacuum cleaners. In the direction of the air flow, vacuum cleaners are direct-flow and vortex.

The design of any vacuum cleaner necessarily has a dust collector, which can be made in the form of a replaceable paper bag or a device for pressing dust. As a rule, the dust collector has cap locks so that it is easy to remove the filter (dust collector).

Also, the vacuum cleaner must have an automatic shutdown device when the dust container is full or a full signal. Filling the dust container creates an obstacle to the operation of the air suction unit, which may not be able to withstand the load.

Since the vacuum cleaner has a longer cord than other devices, it must be provided with an automatic cord winder.

A corrugated air duct in a stretchable nylon braid must have a length of at least 2 m for floor vacuum cleaners and at least 1 m for manual vacuum cleaners. The extension tube is made of aluminum and must be 1 m long (for floor vacuum cleaners).

The vacuum cleaner must have a set of nozzle brushes that are designed to clean various surfaces and are made of horsehair, spinal bristles. The body is made of polyethylene, polyvinyl chloride, polystyrene.

The most important part of a vacuum cleaner is the electric motor, which converts electrical energy into mechanical energy. An electric motor drives a bladed propeller, which creates a rarefaction of air. The air suction unit can be made in different ways, depending on the design of the vacuum cleaner (reducer, clutch, belt, etc.)

The vacuum cleaner must have holes for the exit and entry of air, to which a corrugated hose can be connected. Some models of vacuum cleaners have a power regulator. Some vacuum cleaners have a special housing to reduce noise. For vacuum cleaners that do not have a noise-reducing housing, the noise level should not exceed 80 decibels.

Electric polishers designed for rubbing floors can be of two types - with and without a vacuum cleaner. The floor polisher has a rod that freely rotates in a vertical plane, which is held in this position with a special lock.

The ventilation device is located so that during operation, air flows cool the working units. Replaceable paper bags are used as a dust collector. The polisher has three brushes, which are driven by an electric motor. In addition to brushes, polishing washers are included in the kit. The brushes and the ventilation device are turned on at the same time.

The design of the floor polisher is very simple and no special tools are required for its repair, so repairs can be done independently.

The simplest device that circulates air in a residential area is a fan. Depending on the purpose, the fan can supply or extract air, as well as blow or mix. More complex are fan heaters, which are designed for heat transfer due to forced convection. Humidifiers create the desired humidity. Ionizers increase the amount of negative ions in the air, the carrier of which is oxygen.

Air purifiers and air conditioners are the most complex and complex devices that perform several operations: they ventilate the room, create the desired level of humidity, heat and cool the air, and purify it from fine particles.

All these devices can be combined under the general name devices for improving the microclimate. The composition of the air in any room in the absence of normal ventilation deteriorates due to pollution with dust, aerosols, combustion products, and carcinogens.

This leads to the need for ventilation devices that would provide good air circulation, the most accessible of which is a fan.

The fan is a bladed propeller driven by an electric motor. According to the design version, the fans can be desktop, wall, floor, ceiling. The fan can be universal if the design allows it to be installed in different ways.

Fans are also usually distinguished by the presence of protective devices. A fan without a guard has an open bladed propeller. Such devices are usually available in desktop, wall and ceiling versions.

The open-type guarded fan has a bladed propeller covered with a metal frame. This type of barrier is mainly used for floor fans (floor lamp type).

A closed-type fan with a guard is a bladed propeller recessed into the fan housing and covered with a grille. This type of protective fence is used exclusively in exhaust devices. It is also generally accepted that exhaust fans operate according to the tangential principle (turbine).

Table and floor fans usually have multiple speeds. Speed ​​control can be smooth or stepped. Two-speed fans have two buttons that turn on different speeds, multi-speed floor lamp fans have a panel on which speed switching buttons are displayed.

Table and floor type fans must also have a device for directing the air flow. The inclination of the propeller vertically is performed non-automatically using a special fixing screw (handle). Automatic circular change of air direction is carried out by a rotary mechanism, which can be stopped by pressing a button on the control panel or by pressing a sleeve on the body.

Ceiling-type fans are slightly different in design. If all the fans discussed above are axial in principle, then the ceiling fan is centrifugal.

The fan is suspended from the ceiling with a rod, at the end of which there is an electric motor. The wings are attached to the motor with screws. Switching the fan on and off, as well as speed control, is carried out by a regulator mounted on the wall.

Comfort fans may have the following additional devices: a mechanism for automatic cord retraction; height adjustment device; timer.

The design of almost all fans is very simple, designed for ease of use, it is possible to carry out self-repair without the use of special tools.

Fan heaters, as well as conventional fans, can be floor, table, wall, universal. Heating is provided by forced convection. The fan has heating elements behind which the fan itself is located. The heating element is a tungsten filament in a quartz glass tube.

Almost all fan heaters are equipped with a closed-type protective enclosure, which is necessary in accordance with fire safety requirements.

Fan heaters can be single-speed, two-speed and multi-speed. Adjustment can be smooth or stepped. In addition, there is a heating controller. In most cases, it is a multi-channel switch to turn on all or some of the heating elements, although a smooth adjustment of the heating power is also possible. To protect the device from overheating, a bimetallic thermal switch is installed. The signal lamp may not be used if it is possible to determine from the operation of the heating elements whether the heating is turned on or not.

Fan heaters of increased comfort have a device for automatic cord winding, as well as a compartment for its laying, a signal lamp, a handle for transferring the device.

Humidifiers are used to create the desired level of humidity, as well as to spray aromatic aqueous solutions and medicines in the room. At the same time, the humidifier increases the number of negative ions in the air, as a result of which the air is cleaned of dust and smoke.

The device has a water tank, a centrifugal fan, and a mesh through which the spray occurs. During operation, water rises along the walls of the tank, entering the fan, which throws it onto the grid; it enters the air in the form of mist or fine spray.

Humidifiers are available in wall, table and floor versions. The device may have a smooth or stepped water spray control or may be unadjustable.

The design of the humidifier is simple, no special tools are required for repair, so repairs can be done by yourself. However, it should be remembered that the device works with water, as well as aqueous solutions that are conductors of electricity, therefore, special attention should be paid to insulation, if necessary (for example, when checking the device), take the necessary safety measures.

Ionizers are designed to increase the amount of negative ions in the air. As already mentioned, the carrier of negative ions is oxygen. The feeling of fresh air depends on the amount of negative ions. However, their lifetime is short, since they come into contact with fine particles (dust), losing their polarity. The air becomes heavy, stuffy.

Household ionizers are based on various voltage multiplication schemes. The device has two contacts between which a corona charge passes, which ionizes the air. Negatively charged electrons propagate at high speed due to a special reflective contact.

The ionizer should not be left switched on for a long time. According to the recommendations of experts, he should work at a distance of 1 m from a person for 15-30 minutes.

As a rule, the main source of air pollution is the kitchen, especially the gas stove. Combustion products, dust come into contact with negatively charged ions, while the air becomes heavy, it has a lot of extraneous odors. That is why kitchens use devices for recirculating air purification from various contaminants.

The principle of operation of the air purifier is similar to the action of a gas mask, in which the purification of air from toxic substances is carried out due to the work of the human lungs. Air purifiers are equipped with special supply and exhaust fans.

It is customary to install an air cleaner above a gas stove at a distance of 60-90 cm, since it is the main source of air pollution by combustion products. Therefore, air cleaners are produced in standard sizes, corresponding to the dimensions of gas and electric stoves. Among other things, the device is equipped with a backlight in case of insufficient natural light.

The purifier works according to the following principle: behind the filter there is a fan that provides air flow. Passing through the filter, the air is purified.

The design of the purifier allows you to replace the filter yourself. The filter is designed to clean the air from the products of incomplete gas combustion and is a replaceable cassette with a sorbent (for example, activated carbon or aluminosilicate ball catalysts). The filter needs to be changed every 6-12 months.

The purifier can also be designed for air sterilization due to the operation of a bactericidal mercury-quartz lamp, which can operate all the time the device is in operation. It is recommended to turn on the air cleaner from the beginning of cooking and turn it off when finished.

The fan has at least two operating modes: nominal and boosted. The device is controlled from the front panel, which has all the necessary keys, as well as signal lamps.

The fact that the air purifier is usually installed in the kitchen above the gas stove does not mean that the air purifier cannot be used in other rooms where, for some reason, air pollution is possible.

In this case, instead of an air cleaner, an air conditioner is installed, which, in addition to cleaning the air, also heats or cools it, and ensures air circulation at the desired level.

In principle, the air conditioner is derived from all the devices described above for improving the microclimate. It has a fan that circulates the air, heating elements and a cooling unit that maintain the desired temperature in the room, the air is cleaned using a filter like the one used in the air purifier. In addition, air conditioners have electronics that automate the execution of operations, as well as remote control for the convenience of using this household device.

The air conditioner consists of two compartments, one of which is outdoors, the other indoors. The compartments can be made in one housing, or they can be made separately and connected with a corrugated hose.

In most air conditioners, a compressor-type cooling unit is installed, as it is more reliable in operation and less energy-intensive than an absorption unit. The difference lies only in the reduced size (compared to a refrigerator or freezer) of the unit, as well as its special location in the air conditioner housing, due to the design features of this device. The compressor, condenser and dryer are located in the outdoor compartment, since these parts of the installation require cooling. The evaporator is located in the inner compartment and cools the air.

The air conditioner can be provided with an air heating function, for which heating elements made of tungsten filament in a quartz glass tube are installed in the inner compartment. As a rule, air conditioners with a common body do not have an air heating function, since it is difficult to combine a cooling unit with heating elements in one body.

Air filters, as well as in air cleaners, are made in the form of replaceable cassettes filled with a sorbent. However, it has to be changed more often, since the kitchen air cleaner only works during cooking, and the air conditioner is designed to work around the clock.

The air conditioner fan is axial, having at least two modes of operation: nominal and forced. The fan can operate when the cooling unit, heating elements are switched on or switched on separately in the ventilation mode.

The air conditioner is also equipped with bimetallic thermal switches that turn off the device in case of violation of the corresponding temperature regimes.

Separately, it should be said about the electronics that are used in air conditioners. Since the performance of some operations depends on the performance of others (for example, three ways to turn on the fan, as mentioned above), as well as the incompatibility of some operations (heating and cooling), it is necessary to automate the control of the device, otherwise the control panel will be too cumbersome, in it will be difficult for her to understand. It would also be difficult to control the air conditioner using any mechanical means (switches, regulators), so over time, more and more air conditioners began to be equipped with special electronic control circuits that facilitate the use of the device.

Since the air conditioner in most cases is located in the window, in the ventilation shaft, therefore it is inconvenient to place the control of the device on the case, it is easier to use remote control.

From the remote control, powered by AA batteries, you can perform all the operations to control the device. In addition to simply turning on ventilation, heating and cooling, adjusting air circulation, you can use the remote control to set a program that would constantly maintain the desired temperature in the room throughout the day, you can program the air conditioner to turn on and off at certain intervals.

In everyday life, many devices for individual use are used - electric shavers, hair dryers, massagers, etc. All of them are small in size, most of them are hand-made. These devices cannot be classified as converting electricity into thermal or mechanical energy, since the devices have different purposes and the only thing that can unite them is individual use.

First of all, it should be said about devices that produce "soft heat" designed to heat the human body. As a heater, a spiral of nichrome or constantine wire is used, woven into asbestos fabric and sewn into a low-stretch fabric. An elastic carbon-graphite cord is sometimes used as a heater. The maximum heating temperature does not exceed 70°C.

The device has a step-by-step heating power regulator, as well as an emergency thermal switch. The advantages of such heating devices include the fact that they are reliable, not afraid of bending, have reinforced electrical insulation that can withstand a voltage of 375 V.

The most common household appliances for individual use can rightfully be considered a hair dryer and an electric shaver, which are in every home. The hair dryer is designed for drying, combing and styling hair.

This device can be called a manual fan heater. The maximum heating temperature is 60°C, moderate heating 50°C, low heating 40°C. Heating control can be stepwise or smooth. The heating element is made of nichrome or constantine wire twisted into a spiral. The heating element also performs the function of lowering the mains voltage. To protect the device from overheating, it is equipped with a thermal switch that turns off the device and turns it on after cooling.

The fan is driven by a DC electric motor. The air passes through the slots in the housing and exits into the divider. To rectify the alternating current, a diode rectifier is installed, the electric motor is located in a case made of polystyrene, polyvinyl chloride or other dielectric material. Complete with a hair dryer, various nozzles are sold that are screwed onto the body.

Electric shavers work from a network with a voltage of 127, 220 V, or from autonomous DC power supplies with a voltage of up to 12 V. The razor can have a universal connection to the network and autonomous power sources. The movement of the knives in the razor is reciprocating or rotational. Almost all razors come with a cutting block. As engines in razors, magnetic vibrators and collector electric motors are used.

The magnetic vibrator is used in razors with reciprocating blades, as well as in clippers. The principle of operation of the magnetic vibrator is as follows. The excitation winding magnetizes the rotor, as a result of which the stator and rotor cores turn out to be opposite poles facing each other. The rotor is attracted to the stator core. The alternating current has a frequency of 50 Hz per minute, and therefore there is a constant change in polarity, as a result of which the rotor oscillates at a speed of 6000 times per minute.

As already explained in the book, a collector-type motor is a stator and a rotor with windings that rotate due to a magnetic vortex flow. The motor windings are designed for several phases, and therefore a collector-type switch is connected to the stator and rotor. This type of razor has a small DC motor that drives the floating round blades.

Various massagers designed for sports and therapeutic muscle massage can also be attributed to devices for individual use. Just like a reciprocating electric shaver, massagers use a motor with a magnetic vibrator.

The massager has a plastic case; for various types of massage, a set of nozzles is sold in the kit. Funnel-shaped, spongy, ball nozzles, rubber drummer are intended for cosmetic massage. The mushroom nozzle is designed to massage the ligaments and tendons. Instead of nozzles, a massager with a magnetic vibrator can have a massage belt. In this case, the principle of operation of the device does not change.

As mentioned above, the magnetic vibrator operates at a speed of 6000 vibrations per minute at a voltage of 220 V at a frequency of 50 Hz. This is a fairly high speed, which sometimes has to be adjusted, so most massagers are equipped with a step frequency controller. The amplitude of the electric current is changed using a solenoid coil.

The massager can also be pneumovacuum. The compressor piston is driven by an electric motor. During the operation of the compressor in various vacuum nozzles, air pressure and rarefaction are alternately created, due to which the massage is carried out. In addition to the electric current frequency regulator, the massager is also equipped with an air supply regulator.

The number of nozzles for a pneumovacuum massager is less than for a massager working on a magnetic vibrator: a funnel-shaped and ball nozzle, a rubber drummer.

Even if you are not very good with electricity and technology, you still need to keep tools at home in case of repairs. Tools can be mechanical or electrical. The electric ones include a drill, a puncher, a sharpener, an electric jigsaw, a grinder, an electric planer and others. As a rule, electricity is used in tools to generate mechanical energy, but there are also tools that generate thermal energy: a soldering iron, a heater.

The number one tool can rightfully be considered a drill, since not a single repair can do without its participation. The drill is an electric motor that rotates a cam clamp, into which drills for wood and metal, nozzles for mixing solutions, and other nozzles can be inserted.

There is a button on the handle of the drill that closes the circuit. The maximum speed is 1200 rpm. If this speed is suitable for drilling holes, then it is completely unsuitable for using a drill as a screwdriver. Therefore, the drill has a smooth speed controller, which is located on the button that closes the network, in the form of a small control ring.

The drill also has a switch that allows you to change the direction of rotation, as well as actuate the percussion mechanism. The drill must have mechanical overload protection for the motor.

A type of drill can be considered a screwdriver. It differs from a drill only in that the electric motor rotates at a slower speed required to drive screws. The screwdriver has both a button that closes the network, and a direction switch, and an impact mechanism, but does not have a connecting cord.

Since this device has to be used in order to sheathe the roof, as well as in cases where the power source is not available, the screwdriver operates on 9 and 12 V batteries. The battery is charged from a 220 V power source for several hours and has an electric capacity, allowing you to work for several hours. The battery is made in the form of a small attachment to the screwdriver handle, which is the most convenient technical solution: the battery, due to its weight, acts as a counterweight, so you can use a screwdriver to tighten very tight screws with almost no hand effort.

It looks like a drill and other device designed to drill holes in concrete and stone walls. The hammer drill, like the drill, has an electric motor that rotates the clamp for various nozzles. The same power regulator, rotation direction switch and impact mechanism. The difference from the drill is that the hammer drill is slightly larger, the electric motor rotates the cam clamp at a speed of 300-400 rpm. The clamp is slightly larger in size, a special drill is inserted into it for working on concrete and brick - a drill. Some models of hammer drills have a side handle that allows you to apply more force during drilling.

An electric grinder is an electric motor, to the axis of which a carborundum disk is attached to sharpen the tool. The sharpener can be made in two versions - stationary and manual.

The stationary sharpener has an electric motor that simultaneously rotates two grinding wheels, protected by a metal visor that closes the discs from unwanted contact with the work surface, and also traps sparks that can be fire hazardous.

A manual sharpener is an electric motor located vertically, on the axis of which a grinding wheel is put on. The circuit is closed with a button on the plastic case. The case has rubber feet that give the tool stability and dampen vibration. Some models have a compartment for a connecting cord.

The jigsaw is designed for wood and metal work. The electric motor is located in a plastic housing mounted on a sled that slides over the surface to be treated. The knife is attached perpendicular to the surface of the sled and passes through their horseshoe cutout.

Closing the network occurs when you press a button that can be held with your finger or secured by moving forward. An electric motor drives a crank mechanism that transmits translational motion to the web. By moving the tool on a sled along the drawn line, you can cut wood and metal very accurately. Included with the tool must be blades for wood for longitudinal and transverse sawing, as well as blades for metal.

A wood sander can have various designs. Grinding can be done by vibration generated by an electric motor, or by the rotation of a ring of sandpaper driven by rotating cylinders.

A vibration-powered grinder is an electric motor mounted vertically, with an axis brought down, to which a mechanism is attached that transmits rotational movement to the base. The grinder has a plastic case with handles for which you should hold the tool during operation.

Sandpaper is attached to the base, which has a rubber gasket, using two clamps. Some models of grinders (especially foreign-made) have a replaceable dust collector. In this case, the base and sandpaper have several holes with a diameter of 10 mm through which dust is collected. There is no fan in this type of grinder, dust is collected in the dust collector due to the temperature difference and vortex flows during the operation of the device.

The grinder may have two rotating cylinders at the base, on which a ring of sandpaper of the appropriate width is put on. The rotating cylinders are mounted on shock absorbers, which dampen vibration and also allow the load to be applied to the workpiece more smoothly.

The options for grinders described above, as well as a jigsaw, may have a power button that can be held or fixed by moving forward. As a rule, grinders do not have speed controllers, and they also do not have mechanical protective devices, since, unlike a drill, a hammer drill and a jigsaw, no serious mechanical obstacles are created to the operation of an electric motor.

Metal grinding is performed by rotating the grinding wheel. The grinder ("grinder") has a cone-shaped body, at the end of which there is a rotating disk, partially covered with a protective fence. The body has a side handle to hold the tool during operation, a keyboard-type switch, a body half made of polystyrene and metal (so that sparks do not burn through the polystyrene).

Almost any tool can be made electric. An example would be an electric planer. Outwardly, this is an ordinary planer, only instead of the block into which the cutter is inserted, a drum is installed.

The drum has fasteners for a replaceable cutter and is driven by an electric motor. The rotation speed is 2000 rpm, depending on how far the cutter protrudes, the electric planer can replace the sherhebel, planer, jointer.

Tools that convert electricity into thermal energy are much smaller, the most common is a soldering iron. Heating can be continuous, forced or pulsed. The stem can be seed or non-replaceable.

The most commonly used soldering iron with continuous heating. The soldering rod condenses heat, the heating temperature is sufficient to work with solder. The forced heating soldering iron has two heaters, one of which warms up, and the other maintains the temperature. The impulse heating soldering iron has a small rod, made in the form of a loop, heated by induction.

Soldering iron rods are made of copper with the addition of zinc, lithium, zirconium and can be straight or curved with the letter "L". Some models of soldering irons have a thermostat.

According to the method of heating, soldering irons are wire or induction. In wire soldering irons, the heating element is wound around the rod in several layers and insulated with mica or mica.

Induction heaters are connected to the break of the short-circuited winding of the transformer located in the housing. Sometimes the heating element is located inside the rod, which allows you to achieve stronger heating.

The tools that use the thermal effect of electricity include a heater, or, more simply, a heat fan.

The heater is used to dry the room, if the humidity level is high and does not allow for some types of finishing work, as well as to dry certain areas of the room for faster work.

The principle of operation of a heat fan has already been explained above, so it makes no sense to describe the principle of operation of a heater. It should only be said that the air heater has the only control tool - a multi-channel switch, which allows you to selectively turn on the heating elements, as well as the fan.

Unfortunately, it is impossible to consider in detail all the variety of household appliances within one book, so we did not consider some household appliances, confining ourselves to explaining the general principle on which they work.

All of them have a relatively simple design, and they can be repaired independently without the use of special tools.

We also did not consider some models of household appliances that can already be considered obsolete. For example, a washing machine with a manual spin of linen. These have not been on sale for a long time, although somewhere such washing machines are probably still preserved.

Also, we did not consider some features of imported equipment, which is distinguished by an exquisite design, many different necessary and not very improvements. Foreign manufacturers of household appliances use the same technologies as domestic ones, and therefore attention was paid only to the basic principles of operation of household appliances, and, if necessary, there were listed possible improvements that could be applied.

When describing the device of certain household appliances, more detailed attention was not paid to the features of the execution of some components and assemblies, since this information is needed more by a specialist than by a user, and therefore we did not delve into the features of the technical solutions of a particular device in order to remain understood .

The current level of production development has made it possible to equip our homes with a completely new generation of household appliances. Electric helpers such as vacuum cleaners, floor polishers, dishwashers and washing machines make household chores easier. With the help of some models of household electric vacuum cleaners, it is not only possible to reduce the time spent on cleaning the apartment by 2.5-3 times, but also successfully whitewash the ceiling, walls, and humidify the air in the room. And washing dishes with a dishwasher will save up to 12-15% of the time, and also helps to use water and detergents more efficiently.

In addition, washing dishes in a car is more hygienic than manual washing, and in terms of physical phenomena, the technology of washing dishes in a car is similar to washing clothes. Modern washing machines with the possibility of programming leave the housewives more free time, they allow you to automatically fill and drain water, heat it to a predetermined temperature, soak clothes, enter the right amount of detergent, wash, rinse and wring out. However, there are some difficulties with connecting machines of this type to the electrical and water networks.

Modern refrigerators have become more spacious, easily and quickly freeze food, and have special compartments for different types of food. Refrigerators according to the principle of producing "cold" can be divided into two types: absorption and compression. Absorption refrigerators have exceptional consumer characteristics: they are silent in operation, reliable in operation, and relatively easy to repair.

However, their significant drawback is that during operation they consume 3 times more electricity than compression-type refrigerators. The principle of operation of absorption-type refrigerators is based on the fact that when a concentrated aqueous solution of the refrigerant is heated, it evaporates, while taking heat from the refrigeration chamber. Up to 1,400 kWh of electricity is needed to ensure the operation of an absorption refrigerator during the year. During the same time, a compression refrigerator consumes about 400 kWh.

The refrigeration unit of a compression refrigerator forms a closed system filled with refrigerant. The compressor sucks the refrigerant vapor from the evaporator and thus creates a low pressure in it. The refrigerant vapors in the compressor are compressed and fed to the condenser, where, after cooling, they turn into a liquid, which again enters the evaporator, and turns into vapor in it.

Kitchen equipment sets are increasingly complemented by microwave ovens, electric coffee makers, mixers, juicers, meat grinders, etc. For cooking, household electric heaters such as floor (and desktop) electric stoves, electric frying pans, electric kettles, electric pots, electric barbecues are increasingly used.

The electric stove is the most versatile cooking appliance. This is a permanently installed appliance, equipped with burners and a frying cabinet. Cooking is carried out on burners in stove-top dishes, in an electric oven - baking flour products, frying, stewing vegetables and meat. The burner of the electric stove acts as a heater. Three types of burners are used in electric stoves: cast iron, tubular, pyroceramic.

The shape of the working surface of the burner is usually round, and the diameter can be 90, 100, 110, 145, 180 and 220 mm. The most common burners with a diameter of 145 mm and 180 mm, and the burners with a diameter of 90, 100 and 110 mm are intended for coffee pots. Based on the maximum power of the heating elements, the burners are divided into two groups: normal heating (heating up to operating temperature 10-12 minutes for cast iron burners and 4-5 minutes for tubular burners), accelerated heating (heating up to operating temperature 3-6 minutes for cast iron burners and 1-3 minutes for tubular burners).

Accelerated heating burners, depending on the design, are divided into express burners and automatic ones. An express burner is a burner with accelerated heating to the operating temperature due to additionally installed power. Express burners are usually made of cast iron. An automatic burner is an accelerated heating burner that provides automatic carrying out of various technological processes with an independent transition from the heating mode to the specified thermal mode.

Burners are equipped with devices that allow you to adjust either the power consumption from 100-350 W (at the minimum setting), or the temperature of the working surface in the range of 100-500 ° C. Cast iron burners have two or three spiral grooves into which filler and heating elements are placed. The filler of the burners is an electrical insulating mass prepared on the basis of talc or periclase. In terms of thermal and electrical insulating properties, the fillers are almost the same, but the talc-based filler has a lower mechanical strength.

Tubular burners are made of one-, two- or three-tubular heating elements (TEH), bent in the form of one or more turns of the Archimedes spiral. To improve the thermal contact of the dishes with the heating element, its working surface is made flat. To increase the efficiency, a reflector made of stainless steel is installed under the heating element.

Pyroceramic burners are a heating element covered on top with pyroceramic material: technical glass-ceramic or other material. The oven oven of an electric stove allows to use advantages of electric heating at cooking to the fullest extent.

The metal muffle is thermally insulated with fiberglass or mineral wool. The thermal insulation layer is covered with aluminum foil, which in this case acts as a reflector. An air gap separates the aluminum foil and the side walls of the electric stove. The muffle is attached to the front wall, forming a loading window, which is closed by a door. A viewing glass is mounted in the oven door, which allows you to observe the progress of the technological process. The temperature is controlled by a thermostat.

Microwave ovens are widely used today, in which a completely different method of heat treatment of products is used than in gas or electric stoves. Microwave ovens use the energy of ultra-high frequency electromagnetic oscillations, or microwave waves, generated by a magnetron. Products cooked in microwave ovens do not burn, completely retain vitamins, do not dehydrate and do not fry, and the cooking process itself is much faster than, for example, on a gas stove. At the same time, the microwave oven does not heat up, does not emit any combustion products, the air in the kitchen remains fresh and clean. In addition, cooking in a microwave oven allows you to significantly reduce the use of fats, which is often an important condition for dietary nutrition.

When using microwave ovens, precautions must be taken: it is not recommended to use sealed dishes for cooking food; plastic bags must be opened or pierced before cooking food in them. It is forbidden to use metal utensils, foil, newsprint, as well as paper napkins containing synthetic materials.

When preparing or heating liquid dishes and products, it is necessary to mix them. Foods with skins, such as potatoes or tomatoes, should be pricked before microwave cooking.

Of course, mastering the art of cooking delicious food in a microwave oven requires experience. Therefore, you need to be creative in your work. When cooking, a heat-resistant glass pan is used. Its capacity can be 0.5 -2.5 liters. This pan is made specifically for use in the microwave. In addition, for cooking in microwave ovens, you can use makitra (ceramic pot) and sitall plates.

Increasingly, infrared radiation is being used for the thermal processing of products. Its use reduces the duration of heat treatment processes, energy costs, technological losses of the product. The essence of the infrared method of heating food products lies in the fact that the energy imparted to the product by radiation is released in the form of heat not only in the surface layer of the product, but also inside it, as a result of which the processing time of the product is reduced by 40-50% for meat and by 30 % for fish, and the biological value of the product does not deteriorate. Electric grills, electric barbecue grills, electric toasters are specialized devices for cooking with product heating using infrared radiation. The use of infrared radiation for heat treatment of the product allows to reduce the duration of heat treatment of the product, to carry out the process without the use of fats, which is important for dietary nutrition, while obtaining a product with improved taste.

Capacitive devices for heating liquids include electric juice cookers, electric steam cookers, electric fryers and general-purpose electric pots (express pots, rice cookers, slow cookers). Household electric pans are widely used due to their ease of use, economy and high quality of the prepared product.

Electric meat grinders, coffee mills or electric coffee grinders, electric coffee makers, electric juicers, electric beaters and mixers are widely used to process products.

Electrical appliances have also become widespread in everyday life for direct heating of water, both without its accumulation, and for heating containers with water. In such devices, water is brought to a temperature of 60-100 ° C. These are portable appliances for heating and boiling small amounts of water, such as electric kettles, electric samovars, electric jugs, instantaneous electric water heaters and capacitive (non-flowing) electric water heaters.

In principle, all devices of this purpose are arranged in the same way, the difference exists only in the design features and functional purpose of each of them. Various kinds of electric kettles, samovars, coffee pots have a container for heated water, in the lower part of which there is a heating element - a tubular electric heater of one form or another. Tubular electric heaters are sealed, usually have a very high degree of protection, reliable, safe in operation. A tubular electric heater is a thin-walled metal tube in which a coil of wire with a very high resistivity is placed. Particular care should be taken with household appliances that use tubular electric heaters, since a malfunction associated with the failure of this electric heater makes it impossible to repair the entire appliance.

First of all, it should not be forgotten that appliances intended for heating water can only be connected to the mains when they are filled with water by at least one third of their volume, otherwise the heating element may burn out.

Do not pour out all the water from the electric kettle completely until it has cooled down or while it is plugged in, and you should not pour or top up cold water into a heated kettle, as the spiral may fail because of this.

Electric heaters for heating residential premises have become widespread relatively recently. They have certain advantages over other types of heating, as they are simple and safe to operate, compact and hygienic, and when used, it is easy to automate the microclimate control of each room. Today in world practice there are three types of electric heating: full, additional and combined. With full heating, all heat losses of the building are compensated by electric heaters, with combined heating, the main part of heat losses is covered by centralized heating systems, and additional electric heating is a type of combined heating and is used in the off-season, when central heating does not work, or when the outside temperature drops below the calculated in addition to the central one.

With the development of technology, the problem of air purification becomes more and more acute. The solution to this problem includes three main areas: the fight against sources of pollution, ventilation and improvement of the environment, and air purification using air conditioners.

Household over-stove electric air cleaners help prevent contamination of walls, ceilings, curtains, furniture with greasy particles, soot that form during cooking, as well as reduce the amount of harmful products of incomplete gas combustion and the unpleasant smell of burnt food.

To create favorable conditions in residential premises, household air conditioners are used, which reduce or increase the air temperature in rooms, dry the air and purify it from dust. The air conditioner can automatically maintain the set temperature, ventilate the room, change the speed and direction of the air flow, as well as air exchange with the environment.

Electric irons and dryers have become familiar. Modern irons are equipped with thermostats that automatically maintain the temperature on the iron soleplate necessary for ironing certain types of fabrics, as well as steam humidifiers that allow you to iron fabrics without pre-moistening. In addition, the iron can be weighted and also have a spray arm.

It is recommended to clean the iron at least once every 1.5-2 years in order to eliminate the thin fibers of the fabric that get inside the iron through the cracks between the body and the sole. These fibers can clog the contacts of the thermostat and burn on the sole, forming a burning smell. When disassembling the iron, it is recommended to tighten all the nuts inside the iron and clean the thermostat contacts, which can be done by stretching a small strip of fine-grained sandpaper between them. Brown plaque, which often appears on the working surface of the iron, can be removed by wiping it with a damp cloth sprinkled with baking soda, and the iron can be protected from contamination by treating its working surface with paraffin: grated paraffin is poured into a double layer of material and ironed with a slightly heated iron.

And there are also special electrical appliances with a very cozy name: “soft heat appliances”. Their purpose is to communicate heat to the human body. These are electric blankets, electric blankets, electric bandages, heating pads. All of them have the form of traditional household items, and flexible heating elements are placed inside the devices. To prevent burns, the devices are equipped with thermal switches that limit the surface temperature of the product.

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• Household appliances of time, A. I. Naberezhnykh, V. V. Yarabaev. The history of the development of clocks from ancient to the latest molecular and atomic devices is outlined. Designs of mechanical, electronic-mechanical and electronic watches are given, as well as ...

Whether this is good or bad is hard to say, but, in any case, inevitable: any woman spends a lot of time in the kitchen. And if there are children in the family, or someone from the household is on a diet or special diet, then cooking duties become almost the main part of the hostess's routine. Maternity.ru will tell you about the 10 most useful kitchen appliances, the use of which makes life easier and reduces the time spent in the kitchen.

Let's make a reservation right away that every woman is a chef in her own kitchen, so we all have different “technological” preferences. Someone prefers to get by with a minimum, someone respects the most fashionable and advanced novelties and rushes to get them as soon as they appear on sale. The rating is based on Internet surveys, and you may rank devices differently in terms of importance and usefulness.

10th place: food processor

This device replaces graters, knives, a mixer, a blender, it cuts vegetables and fruits, beats eggs, kneads the dough - in general, an excellent assistant to the hostess in the kitchen. Critics remind that the combine takes up quite a lot of space and requires careful maintenance: after each use, you have to disassemble it and rinse every large and small part. In general, both critics and supporters agree that the combine is justified if the family is large, and you have to cook food often and in large quantities.

9th place: multicooker

In fact, this is an electric pot with a wide range of possibilities: you can cook soups, cereals, pilaf and even pastries (cakes) in it. Cons - takes up a lot of space, requires careful maintenance, still cannot cook complex dishes. Pros - food does not burn, food is cooked at the optimum temperature. The most important advantage of the multicooker is its “independence”: the hostess can do other things while the food is being prepared, which saves a lot of time. In advanced, more expensive versions, there are quite a few modes and functions, there is the possibility of delayed cooking and keeping the finished dish hot.

8th place: juicer

More and more families are switching to a healthy lifestyle, including proper nutrition. Probably, the growing popularity of juicers is connected with this fact. There are two main types: for everyday use and industrial-type juicers (for harvesting for the winter). The main advantage of the supporters of this device is its ability to quickly and the quality of squeezing fresh juices, which are much more useful than packaged juices.

7th place: bread maker

This device is quite expensive, but supporters consider the price justified. Most bread makers are able not only to bake fresh bread on their own (from kneading to baking), but also know how to knead the dough for dumplings and dumplings, as well as cook jam. Housewives get the opportunity to experiment with the composition of bread (add bran, cereals, cornmeal, etc.). And most importantly - the bread turns out delicious, and its composition is precisely known.

6th place: microwave

This device conquered us with its ability to quickly heat food, but it is capable of a lot: you can cook in a microwave oven (even baking in some models), as well as defrost food. Types of microwave ovens: "solo" (only microwaves), "solo + grill" (microwaves and grilling function). Advanced, more expensive versions of ovens are multifunctional - they have convection heating, they are able to process food with steam.

5th place: mixer

A modern kitchen is indispensable without a mixer. Mixers are submersible (manual) and stationary with a bowl (for small volumes, these can be used in "manual" mode, unfastening the moving part). This device has many attachments - whisks for beating, mixing products, hooks for kneading dough, blender nozzles (with chopper knives), chopper glasses. It is possible to set different speed modes, which helps to get different results. Advanced, more expensive versions of mixers have noise minimization systems, protection systems against scratches on dishes, splash protection systems.

4th place: electric kettle

The device is certainly not new, but modern electric kettles have become more powerful, thanks to disc heaters, they boil and heat water faster. "Smart" models are able to maintain a constant water temperature and turn on the timer.

3rd place: meat grinder

Meat grinders are mechanical and electric. Our mothers and grandmothers also used mechanical ones, and electric ones are becoming increasingly popular, as they take on the main work. Meat grinders quickly, efficiently and differently process meat (up to 4.5 kg per minute). They have self-sharpening knives, different nozzles not only for minced meat of different consistency, but also for homemade sausages, homemade sausages. Modern meat grinders are easily disassembled (sometimes automatically), have compartments for storing small parts, and are compact. Advanced, more expensive versions of meat grinders are combined with food processors (there are choppers for slicing and shredding, graters for products - vegetables and fruits), as well as juicers.

2nd place: cooker

Cookers may be gas or electric (including electric stoves and hobs), or may or may not have a built-in oven. They don’t argue about tastes, besides, in some situations, the installation of electric stoves is due to the situation (for example, in multi-storey buildings). The advantage of gas stoves is efficiency, the advantage of electric stoves is the absence of open fire. In most cases (and this, of course, is more convenient and expands the culinary possibilities), the stoves are combined with ovens (gas or electric). Electric ovens have more options: multiple heating modes, convection heating (the best option for various pastries), built-in grill, etc. They can also be combined with a double boiler or microwave oven. Many modern stoves and ovens have a built-in programming function, timers, various cooking modes (languishing, gentle stewing, fermentation, defrosting, etc.), as well as quick cooling systems.

1st place: refrigerator

This is the most energy-intensive appliance in the kitchen and - according to the unanimous recognition of the housewives - the most useful. The meat in it remains frozen, vegetables - fresh, and drinks - chilled. Modern refrigerators are optimized for storing different products, in different modes, have built-in LCD screens with various indicators, and are combined with freezers (top, bottom or side-by-side). Shelves in refrigerators are adjustable in height, drawers and baskets are fully extended, there are containers for storing certain products, compartments with humidity control (for fruits and herbs). Energy-saving models of refrigerators are labeled Energy Star.

Popular with hostesses are also:

- coffee maker

This is a compact, easy to use and relatively inexpensive (compared to a coffee machine, for example) device. Instant coffee doesn't have the same rich, full-bodied flavor as brewed coffee, but a coffee maker brews coffee quickly and on its own. Removable parts are easy to clean; in advanced, more expensive versions, you can set the mode to keep coffee hot; they also have a so-called "anti-drip" system, often supplemented with coffee grinders.

- toaster

This device is very popular in the West, but, according to experts, has not taken root in Russia. Many housewives believe that it is unreasonable to occupy a limited kitchen space with appliances that can perform only one function - toast and dry bread. Supporters of toasters claim that it helps to diversify the menu, and is also good for health (nutritionists recommend eating dried bread). All toasters have thermostats - they regulate the degree of toasting of bread; advanced, more expensive options can warm up buns, croissants, and make toast from frozen bread.

- kitchen scales

Many housewives cook intuitively or “by eye”, but kitchen scales are relevant for complex dishes and pastries. Modern electronic scales are supplemented with the functions of storing weight, sequential weighing of ingredients, calculating the volume of the weighed liquid, and the tare compensation function (products are weighed without taking into account the weight of the bowl).

- blender

This appliance is often built into other kitchen appliances (such as a food processor) and has similar functions and the same attachments as a mixer, so housewives tend to choose one.

- aerogrill

A fashionable appliance among lovers of fried foods. Allows you to fry in a relatively harmless way, with a minimum of fat.

- freezer

It is considered necessary by those housewives who freeze a large amount of food (fresh fruits and vegetables) for the winter.

- Dishwasher

A dishwasher is the dream of mothers of large families, but this dream is not cheap and takes up quite a lot of space.

What kitchen appliances do you find the most useful?