What is a computer and how it works. Basic computer components

Internal combustion engines and diesel power units are driven by the energy released when the fuel / air mixture is burned. If the fuel can be pumped exclusively by a fuel pump, then there are several methods of air intake. Aspirated engines, characterized by the simplicity of the device, receive air from the environment under the influence of a natural vacuum, which is formed in the carburetor. However, they have a significant drawback, expressed in low power, which is completely eliminated in turbocharged and bi-turbo engines.

About the turbocharger

The principle of forced air injection into the combustion chamber of a diesel engine was known at the end of the 19th century, but Alfred Büchi received a patent for a turbocharger only in 1911. The invention of the turbocharger was one of the results of research on methods to increase the power of a diesel engine, of which the principle of forced injection of the combustion chamber with pre-compressed air was considered the most promising. The excess air in the combustion chamber allowed up to 99% of the fuel mixture to be burned, which provided the turbocharged engine with increased power without tangible compromises in efficiency.

How a supercharger works

The principle of operation of a turbocharger is based on the use of energy from exhaust gases. High pressure gas from the exhaust manifold passes through the turbine, spinning it up. The turbine shaft is directly connected to the rotor of the centrifugal compressor that prepares the air for the intake manifold. The turbocharger performance is directly related to the current engine power.

Biturbo engine

In the modern automotive industry, more and more attention is paid to the dynamic characteristics of vehicles. Sometimes even the advantages of turbocharged engines over atmospheric ones are not so pronounced. The fact is that the need for the presence of oxygen in the combustion chamber does not have a linear relationship with the increase in torque. Simply put, there is a certain power threshold beyond which the turbocharger's performance is not sufficient to fully exploit the potential of a diesel engine.

This disadvantage was completely eliminated with the advent of the engine with a double turbocharger. When the engine exceeds the compressor capacity threshold, a second turbocharger is activated. It has a higher performance, which, in turn, is too high for the power unit to operate at low revs. The design of the biturbo engine allows for an increase in power by burning more fuel instead of expanding the volume of the working area of \u200b\u200bthe cylinder.

Any car engine is the heart of a car. Today, manufacturers produce motors of various types and modifications. All of them are structurally different from each other, therefore, when choosing a vehicle, you need to know which unit is installed in it, its operating principle, technical characteristics, advantages and disadvantages. There are compressor, turbocharged and naturally aspirated engines.

Classification of atmospheric motors

Atmospheric - internal combustion engine, into which air enters through filters, where it mixes with fuel. The resulting mixture enters the combustion chamber, ignites and sets the pistons in motion, thanks to which all the work of the car is supported.

Internal combustion engines that convert heat energy from fuel combustion into mechanical energy of motion are divided into three groups:

• diesel;
• gas;
• gasoline.

Back in the 19th century, the first gasoline engine was created, which has undergone many changes during its existence. It has found wide application in the automotive industry along with the diesel engine. Gas is used only as an additional element to a gasoline engine.

According to the fuel supply method, all atmospheric units are classified into 2 types:

• carburetor;
• injection.

The carburetor is a component of the engine power supply system. In it, the fuel is mixed with a certain part of the air, forming an air-fuel mixture. The resulting mixture in the most acceptable amount and composition is fed into the cylinders of the engine itself.

An injector or special nozzle is an electronic-mechanical unit in a car, the task of which is to spray fuel by direct injection directly into the cylinder or into the intake manifold.

The injector outperforms the carburetor in terms of efficiency. The carburetor unit consumes more fuel, the content of harmful substances in the exhaust increases, since the fuel burns less fully. System management requires manual configuration.

Principle of operation

The notion "atmospheric" means that atmospheric pressure is involved in the combustion of fuel in the cylinders. Atmospheric plants are cumbersome and heavy, so over time, designers have found a way to improve them with compressors or turbines. Nevertheless, these engines are still in demand. They are installed on cars of any class, but most often on budget cars.

The engine runs on energygenerated by the ignition of a mixture of fuel with air filtered through an air filter. This explosive energy pushes the piston downward, causing the crankshaft to rotate. The rotational movements of the crankshaft are transmitted through the clutch and the transmission system to the rotation of the wheels.

The unit works in repeating identical cycles, each of which consists of four clock cycles:

1. Air-fuel mixture inlet.
2. Compression.
3. Ignition.
4. Exhaust gas release.

During the intake stroke, the exhaust valve is closed and the intake valve is open. The air / fuel mixture is sucked into the cylinder through the intake valve.

With the end of the downstroke, the intake stroke ends. Fuel with air is drawn into the cylinder, begins to compress more and more when the piston rises up.

When the piston completes its upward stroke, an electric current passes through the spark plug, causing a spark discharge in it, which immediately explodes the combustible mixture. The explosive energy lowers the piston, causing the crankshaft to rotate. This is the force that turns the wheels.

On completion of the downstroke, the outlet valve opens. As the piston starts to go up again, the exhaust gas is pushed out of the cylinder through the exhaust valve. The crankshaft is rotated twice as long as the piston goes through all 4 strokes.

Continuous operation of the engine is formed by the constant repetition of these strokes - this is what an atmospheric engine means.

Aspirated device

How the engine works can be seen on the example of a four-stroke atmospheric. By function, the motor parts are divided into approximately 4 groups:

1. To ensure the intake and ignition of fuel-air mixtures. This group includes the cylinder head and valve train.
2. Details for ensuring the compression of the air-fuel mixture. This group consists of pistons, piston rings, cylinder block, valve.
3. For the transmission of motor power. The group includes connecting rods, a crankshaft, bearings and flywheels, they can be bought here: /uzp.net.ua/ru/podshypnyky/.
4. Details for generating spark flashes. The group is filled with spark plugs and distributors.

The interaction of these parts of the motor ensures the main rotation of the wheels.

Cylinder head

This is the main part of the engine, located directly above the cylinder block. It is constantly exposed to high temperature and high pressure combustion gases. The part is made of sheet iron or an aluminum alloy with high-strength and high-temperature additives.

The base of the cylinder head is deepened, forming a combustion chamber together with the piston and cylinder. The efficiency of an engine is highly dependent on the shape of the combustion chamber as well as the position of the valves and spark plugs.

Valves and related parts

Modern four-stroke engines have 4 valves for each cylinder: 2 inlet and 2 outlet. To ensure efficient intake, the intake valve is larger than the exhaust valve. They are made of high temperature nickel or chrome plated steel.

Each valve has accompanying parts: a seat and a spring, which is coiled and creates close contact with the seat, preventing gas leakage. Usually, engines use one spring, but in some types, 2 pieces are installed for each valve.

When the valve is closed, the seat is in close contact with its surface to ensure the tightness of the combustion chamber.

The cylinder block forms the frame of the engine. Together with the pistons, the cylinder block plays an important role in overcoming the compression and combustion pressures. To minimize wear of parts and gas leaks, the inner surface of each cylinder is chromium-plated under high pressure.

The cylinder bore is made circular. However, the top of the cylinder and piston suffers from wear due to the high pressure and temperature. Later, the clearance between the piston rings and the cylinder increases, leading to compression losses.

Motor piston

The part moves up and down in the cylinder under the action of the pressure generated by the explosions of the fuel-air mixture. In this case, the piston rotates the crankshaft through the piston pin and the connecting rod. The cross-section of the piston is not a correct circle: the diameter towards the piston pin is made slightly smaller for thermal expansion leakage.

The piston head gets much hotter and expands more than the skirt. To compensate for the difference in thermal expansion, the piston diameter is made smaller at the top than at the bottom. The rings prevent the mixture under pressure from leaking through the gap between the cylinder and piston. Usually each piston has 3 rings.

Connecting rod assembly

It connects the piston to the crankshaft so that the vertical movement of the piston is converted into rotational movement of the crankshaft. Since the connecting rod is subject to continuous compressive and tensile forces, it must be sufficiently strong and well anchored to withstand these loads.

Crankshaft

This part converts, through the connecting rod, the linear motion of each piston into rotational motion. It consists of connecting rod journals that transmit force to the pistons and the shaft, knee journals that regulate shaft rotation, and balancing weights to ensure good, balanced shaft rotation.

The crankshaft rotates at a high speed, subject to heavy piston loads, so it must be fairly strong and secure, and well balanced both statically and dynamically.

Advantages and disadvantages

Many motorists still choose atmospheric units due to their advantages:

• the simplicity of the structure ensures ease of maintenance, the ability to eliminate the malfunction on your own and low costs;
• simple working principle;
• low oil consumption: about 200-500 g per 10 thousand km;
• oil change after 15 thousand - 20 thousand km;
• copes well with low-quality fuel;
• fast engine warm-up;
• the ability to pass over 500 thousand km without major repairs.

Of the disadvantages of the unit, the most significant in comparison with a turbocharged engine are:

• higher fuel consumption;
• lower power, dynamism and environmental friendliness.

The development of promising atmospheric engines goes in the direction of improving the working process, increasing the compression ratio and controlling the valve timing, using fuel injection into the cylinders, reducing mechanical losses and the cost of auxiliary equipment.

A personal computer is a universal technical system.

Its configuration (equipment composition) can be flexibly changed as needed.

However, there is a concept of a basic configuration that is considered typical. This kit usually comes with a computer.

The basic configuration is subject to change.

Currently, four devices are considered in the basic configuration:

• system unit;
• monitor;
• keyboard;
• mouse.

In addition to computers with a basic configuration, multimedia computers equipped with a CD-ROM device, speakers and a microphone are becoming more common.

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The system unit is the main unit within which the most important components are installed.

Devices located inside the system unit are called internal, and devices connected to it from the outside are called external.

External accessories for input, output and long-term storage of data are also called peripherals.

How the system unit works

In appearance, the system units differ in the shape of the case.

Personal computer cases are produced in horizontal (desktop) and vertical (tower) versions.

Cases with vertical design are distinguished by their dimensions:

• full-size (big tower);
• mid-size (midi tower);
• small (mini tower).

Among the cases with horizontal design, there are flat and extra flat (slim).

The choice of this or that type of case is determined by the taste and needs of computer modernization.

The most optimal case type for most users is a mini tower case.

It has small dimensions, it is convenient to place it both on the desktop and on the bedside table near the desktop or on a special holder.

It has enough space to accommodate five to seven expansion cards.

In addition to the shape, an important parameter for the case is called the form factor, which determines the requirements for the devices being placed.

Currently, mainly used cases of two form factors: AT and ATX.

The form factor of the case must be consistent with the form factor of the main (system) board of the computer, the so-called motherboard.

Personal computer cases are shipped with a power supply, and thus the power supply capacity is also one of the chassis parameters.

For mass models, a 200-250 W power supply is sufficient.

The system unit includes (fits):

• Motherboard
• ROM chip and system BIOS
• Non-volatile CMOS memory
• HDD

Motherboard

Motherboard (mother board) - the main board of a personal computer, which is a sheet of fiberglass coated with copper foil.

By etching the foil, thin copper conductors are obtained that connect the electronic components.

The motherboard contains:

• processor - the main microcircuit that performs most of the mathematical and logical operations;
• buses - sets of conductors through which signals are exchanged between the internal devices of the computer;
• random access memory (random access memory, RAM) - a set of microcircuits designed for temporary storage of data when the computer is turned on;
• ROM (read only memory) - a microcircuit designed for long-term data storage, including when the computer is turned off;
• microprocessor kit (chipset) - a set of microcircuits that control the operation of the computer's internal devices and determine the main functionality of the motherboard;
• connectors for connecting additional devices (slots).

(microprocessor, central processing unit, CPU) - the main microcircuit of the computer, in which all calculations are performed.

It is a large microcircuit that can be easily found on the motherboard.

The processor is equipped with a large copper finned heatsink cooled by a fan.

Structurally, the processor consists of cells in which data can not only be stored, but also changed.

The internal cells of the processor are called registers.

It is also important to note that data in some registers is not treated as data, but as commands that control the processing of data in other registers.

Among the processor registers there are those that, depending on their content, are capable of modifying instruction execution. Thus, by controlling the transfer of data to different registers of the processor, you can control the processing of data.

The execution of programs is based on this.

With the rest of the computer's devices, and primarily with the RAM, the processor is connected by several groups of conductors called buses.

There are three main buses: data bus, address bus and command bus.

Address bus

Intel Pentium processors (namely, they are most common in personal computers) have a 32-bit address bus, that is, it consists of 32 parallel lines. Depending on whether there is voltage on one of the lines or not, they say that one or zero is set on this line. The combination of 32 zeros and ones forms a 32-bit address that points to one of the memory cells. A processor is connected to it to copy data from a cell to one of its registers.

Data bus

This bus is used to copy data from RAM to processor registers and vice versa. In computers based on Intel Pentium processors, the data bus is 64-bit, that is, it consists of 64 lines through which 8 bytes are processed at once for processing.

Command bus

In order for a processor to process data, it needs instructions. He must know what to do with the bytes that are stored in his registers. These commands come to the processor also from the RAM, but not from the areas where the data arrays are stored, but from where the programs are stored. Commands are also represented as bytes. The simplest commands fit into one byte, but there are some that require two, three or more bytes. Most modern processors have a 32-bit instruction bus (for example, the Intel Pentium processor), although there are 64-bit processors and even 128-bit ones.

During operation, the processor serves the data in its registers, in the RAM field, as well as data in the external ports of the processor.

It interprets some of the data directly as data, some of the data as address data, and some as commands.

The totality of all possible instructions that a processor can execute on data forms the so-called processor instruction set.

The main parameters of processors are:

• operating voltage
• digit capacity
• operating clock frequency
• internal clock multiplier
• cache size

The operating voltage of the processor is provided by the motherboard, therefore different motherboards correspond to different brands of processors (they must be chosen together). As processor technology develops, the operating voltage gradually decreases.

The bit capacity of the processor shows how many bits of data it can receive and process in its registers at a time (per clock cycle).

The processor is based on the same clock principle as in a regular watch. The execution of each command takes a certain number of measures.

In a wall clock, oscillations are set by a pendulum; in manual mechanical watches, they are set by a spring pendulum; in an electronic clock for this there is an oscillatory circuit that sets the clock of a strictly defined frequency.

In a personal computer, clock pulses are set by one of the microcircuits included in the microprocessor set (chipset) located on the motherboard.

The higher the frequency of clock cycles supplied to the processor, the more commands it can execute per unit of time, the higher its performance.

The exchange of data within the processor is several times faster than the exchange with other devices, such as RAM.

In order to reduce the number of calls to the RAM, a buffer area is created inside the processor - the so-called cache memory. This is, as it were, "super-operative memory".

When the processor needs data, it first accesses the cache memory, and only if the necessary data is not there, it is called into the RAM.

Receiving a block of data from the main memory, the processor writes it simultaneously to the cache memory.

"Successful" cache hits are called cache hits.

The higher the hit rate, the larger the cache memory, so high-performance processors are equipped with an increased cache memory.

Often, the cache memory is distributed over several levels.

The first-level cache is executed in the same die as the processor itself, and has a volume of the order of tens of KB.

The L2 cache is located either in the processor die or in the same node as the processor, although it is executed on a separate die.

The L1 and L2 caches operate at a frequency consistent with the processor core frequency.

The L3 cache is executed on high-speed SRAM chips and is located on the motherboard near the processor. Its volumes can reach several MB, but it operates at the frequency of the motherboard.

Motherboard bus interfaces

The connection between all the motherboard's own and connected devices is performed by its buses and logical devices located in the microcircuits of the microprocessor set (chipset).

The architecture of these elements largely determines the performance of the computer.

Bus interfaces

ISA (Industry Standard Architecture) is an obsolete system bus of IBM PC-compatible computers.

EISA (Extended Industry Standard Architecture) - Extension of the ISA standard. It features an enlarged connector and increased performance (up to 32 MB / s). Like ISA, this standard is now considered obsolete.

PCI (Peripheral Component Interconnect - literally: the interconnection of peripheral components) - I / O bus for connecting peripheral devices to the computer's motherboard.

AGP (Accelerated Graphics Port) - Developed in 1997 by Intel, a specialized 32-bit system bus for a video card. The main task of the developers was to increase performance and reduce the cost of a video card by reducing the amount of built-in video memory.

USB (Universal Serial Bus - universal serial bus) - This standard defines the way a computer interacts with peripheral equipment. It allows you to connect up to 256 different serial devices. Devices can be switched on in chains (each next device is connected to the previous one). The USB bus performance is relatively low, up to 1.5 Mbit / s, but for devices such as keyboard, mouse, modem, joystick, and the like, this is sufficient. The convenience of the bus is that it practically eliminates conflicts between different equipment, allows you to connect and disconnect devices in "hot mode" (without turning off the computer) and allows you to combine several computers into a simple local network without the use of special hardware and software.

The parameters of the microprocessor kit (chipset) to the greatest extent determine the properties and functions of the motherboard.

Currently, most motherboard chipsets are produced on the basis of two microcircuits, called "Northbridge" and "Southbridge".

The North Bridge controls the interconnection of four devices: processor, RAM, AGP port and PCI bus. Therefore, it is also called a four-port controller.

The South Bridge is also called a functional controller. It functions as a hard and floppy disk controller, ISA-PCI bridge, keyboard, mouse, USB bus controller, and the like.

(RAM - Random Access Memory) is an array of crystal cells capable of storing data.

There are many different types of random access memory, but in terms of the physical principle of operation, a distinction is made between dynamic memory (DRAM) and static memory (SRAM).

Dynamic memory (DRAM) cells can be represented as microcapacitors capable of storing charge on their plates.

This is the most common and economically available type of memory.

The disadvantages of this type are associated, firstly, with the fact that both during charging and discharging of capacitors, transient processes are inevitable, that is, data recording is relatively slow.

The second important drawback is associated with the fact that the charges of the cells tend to dissipate in space, and very quickly.

If the RAM is not constantly "recharged", data loss occurs in a few hundredths of a second.

To combat this phenomenon, the computer constantly regenerates (refreshes, recharges) the RAM cells.

The regeneration is carried out several tens of times per second and causes an unproductive consumption of the resources of the computing system.

Static memory cells (SRAM) can be thought of as electronic microelements - triggers consisting of several transistors.

The trigger does not store the charge, but the state (on / off), therefore this type of memory provides higher performance, although it is technologically more complicated and, accordingly, more expensive.

Dynamic memory chips are used as the main RAM of a computer.

Static memory chips are used as auxiliary memory (called cache memory) designed to optimize processor performance.

Each memory cell has its own address, which is expressed as a number.

One addressable location contains eight binary locations in which 8 bits can be stored, that is, one data byte.

Thus, the address of any memory cell can be expressed in four bytes.

RAM in a computer is located on standard panels called modules.

The RAM modules are inserted into the corresponding connectors on the motherboard.

Structurally, the memory modules have two versions - single-row (SIMM-modules) and double-row (DIMM-modules).

The main characteristics of RAM modules are memory size and access time.

Access time shows how long it takes to access memory cells - the shorter the better. Access times are measured in billionths of a second (nanoseconds, ns).

ROM chip and system BIOS

At the moment the computer is turned on, there is nothing in its RAM - neither data nor programs, since RAM cannot store anything without recharging the cells for more than hundredths of a second, but the processor needs commands, including at the first moment after turning on.

Therefore, immediately after switching on, the start address is set on the processor address bus.

This happens in hardware, without the participation of programs (always the same).

The processor addresses the set address for its first command and then begins to work according to programs.

This source address cannot point to RAM, which has nothing in it yet.

It points to another type of memory - read only memory (ROM).

The ROM chip is capable of storing information for a long time, even when the computer is turned off.

Programs in ROM are called "hardcoded" - they are written there at the stage of manufacturing a microcircuit.

The set of programs located in the ROM forms the basic input-output system (BIOS - Basic Input Output System).

The main purpose of the programs in this package is to check the composition and operability of the computer system and to provide interaction with the keyboard, monitor, hard disk and floppy disk drive.

The programs included in the BIOS allow us to observe on the screen diagnostic messages accompanying the computer startup, as well as interfere with the startup process using the keyboard.

Non-volatile CMOS memory

The operation of standard devices, such as a keyboard, can be supported by programs included in the BIOS, but such means cannot provide work with all possible devices.

For example, BIOS manufacturers know absolutely nothing about the parameters of our hard and floppy disks, they do not know either the composition or properties of an arbitrary computing system.

In order to start working with other hardware, the programs included in the BIOS need to know where to find the desired parameters.

For obvious reasons, they cannot be stored either in RAM or in permanent storage.

Especially for this, the motherboard has a "non-volatile memory" microcircuit called CMOS by manufacturing technology.

It differs from RAM in that its contents are not erased when the computer is turned off, and it differs from ROM in that data can be entered and changed into it independently, in accordance with what equipment is included in the system.

This microcircuit is constantly powered by a small battery located on the motherboard.

The charge of this battery is enough so that the microcircuit does not lose data, even if the computer will not be turned on for several years.

The CMOS chip stores data about floppy and hard disks, about the processor, about some other devices on the motherboard.

The fact that the computer clearly keeps track of the time and calendar (even when turned off) is also due to the fact that the system clock is constantly stored (and changed) in the CMOS.

Thus, the programs written in the BIOS read data on the composition of the computer's hardware from the CMOS chip, after which they can access the hard disk, and, if necessary, the flexible one, and transfer control to those programs that are written there.

HDD

HDD - the main device for long-term storage of large amounts of data and programs.

In fact, it is not a single disc, but a group of coaxial discs that are magnetically coated and rotate at high speed.

Thus, this "disc" has not two surfaces, as a normal flat disc should have, but 2n surfaces, where n is the number of individual discs in a group.

Above each surface is a read-write head.

At high rotational speeds of the disks (90 r / s), an aerodynamic cushion is formed in the gap between the head and the surface, and the head hovers above the magnetic surface at a height of several thousandths of a millimeter.

When the current flowing through the head changes, the strength of the dynamic magnetic field in the gap changes, which causes changes in the stationary magnetic field of the ferromagnetic particles that form the coating of the disc. This is how the data is written to the magnetic disc.

The read operation takes place in reverse order.

The magnetized particles of the coating, passing at high speed near the head, induce an EMF of self-induction in it.

The electromagnetic signals generated by this are amplified and transmitted for processing.

The hard disk is controlled by a special hardware-logical device - the hard disk controller.

Currently, the functions of disk controllers are performed by microcircuits included in the microprocessor kit (chipset), although some types of high-performance hard disk controllers are still shipped on a separate board.

The main parameters of hard drives are capacity and performance.

It can be stored on a hard disk for years, but sometimes it needs to be transferred from one computer to another.

Despite its name, hard drives are fragile devices that are sensitive to overload, shock and shock.

Theoretically, it is possible to transfer information from one workplace to another by transferring a hard disk, and in some cases this is done, but nevertheless, this technique is considered untechnological, since it requires special accuracy and certain qualifications.

For the rapid transfer of small amounts of information, so-called floppy disks (floppy disks) are used, which are inserted into a special drive - a floppy drive.

The drive inlet is located on the front panel of the system unit.

Since 1984, 5.25-inch high-density (1.2 MB) floppy disks have been produced.

5.25-inch drives are not used these days, and the corresponding drives have not been shipped in the basic configuration of personal computers after 1994.

3.5-inch floppy disks have been produced since 1980.

Today, 3.5-inch high-density disks are considered standard. They have a capacity of 1440 KB (1.4 MB) and are marked with HD (high density) letters.

On the underside, the flexible disk has a central hub, which is gripped by the drive spindle and rotated.

The magnetic surface is covered with a sliding shutter to protect it from moisture, dirt and dust.

If the floppy disk contains valuable data, it can be protected from erasure and overwriting by sliding the security latch to create an open hole.

Floppy disks are considered unreliable storage media.

Dust, dirt, moisture, temperature fluctuations, and external electromagnetic fields are very common causes of partial or complete loss of data stored on a floppy disk.

Therefore, using floppy disks as the main storage medium is unacceptable.

They are used only for transporting information or as an additional (backup) storage medium.

CD-ROM drive

The abbreviation CD-ROM (Compact Disc Read-Only Memory) is translated into Russian as a read-only storage device based on a CD.

The principle of operation of this device is to read numerical data using a laser beam reflected from the surface of the disk.

Digital CD recording differs from magnetic disc recording at a very high density, and a standard CD can store approximately 650 MB of data.

Large amounts of data are characteristic of multimedia information (graphics, music, video), therefore CD-ROM drives are referred to as multimedia hardware.

Software products distributed on laser discs are called multimedia publications.

Today multimedia publications are gaining an ever stronger place among other traditional types of publications.

For example, there are books, albums, encyclopedias and even periodicals (electronic journals) published on CD-ROM.

The main disadvantage of standard CD-ROM drives is the inability to write data, but in parallel with them there are both CD-R (Compact Disk Recorder) and CD-RW rewritable devices.

The main parameter for CD-ROM drives is the read speed.

Currently, the most widespread are CD-ROM readers with a performance of 32x-50x. Modern samples of write-once devices have a performance of 4x-8x, and re-write devices - up to 4x.

The modern magnetic compass used by tourists, hunters, and even rescue workers is perhaps the simplest compass known today.

Looking at such equipment and its functionality, the following conclusion can be drawn. The main thing is to remember the rules for using the elements that make up the final product when constructing something new, and to really assess the possibility of their use in the conditions for which the new equipment is intended. And then, contrary to all the laws of physics, new teapots with a "low" spout and compasses mounted in knives will begin to appear.

If we talk about compasses in general, then it should be noted that mankind has invented many different types of compasses, differing not only in appearance, but also in the principle of operation, and therefore in the internal structure. Many of them are much more complicated than the models considered. And among magnetic ones, too, everything is not always simple: what is the device of a marine (ship) compass with its system of counteracting magnetic deviations, which makes it possible to reduce the influence of large masses of iron on the compass needle, minimizing its deviation.

We have considered only the magnetic compass, since it is it that is most applicable to the conditions of tourism, and can also be constructed independently from improvised means in the event of an unforeseen emergency that occurred far from civilization. Understanding the material presented will allow a person to choose the model that is optimal for his needs, and, if necessary, to fix it.

What is a temple? How is a temple different from a chapel and a church? Why should we go to church? How does an Orthodox church work?

Temple, church, chapel: what are the differences

Temple (from Old Russian "mansion", "khramina") - an architectural structure (building) intended for the performance of divine services and religious rites.

The Christian temple is also called the "church". The word "church" itself comes from the Greek. Κυριακη (οικια) - (house) of the Lord.

Photo - Yuri Shaposhnik

The main church of a city or monastery is usually called a cathedral. Although local tradition may not be too strict about this rule. So, for example, in St. Petersburg there are three cathedrals: St. Isaac's, Kazan and Smolny (not counting the cathedrals of city monasteries), and in the Holy Trinity Sergius Lavra there are two cathedrals: Assumption and Trinity.

The church where the chair of the ruling bishop (bishop) is located is called the cathedral.

In an Orthodox church, the altar part, where the throne is located, and the meal - a room for worshipers, must be distinguished. In the altar of the church, on the throne, the sacrament of the Eucharist is celebrated.

In Orthodoxy, it is customary to call a chapel a small building (structure) intended for prayer. As a rule, chapels are erected in memory of events that are important to the heart of a believer. The difference between the chapel and the temple is that the chapel has no throne and the Liturgy is not celebrated there.

Temple history

The current liturgical charter prescribes that services should be performed mainly in the church. As for the very name of the temple, templum, it came into use around the 4th century, earlier the pagans called their places where they gathered for prayer. We, Christians, call a temple a special building dedicated to God, in which believers gather to receive the grace of God through the sacrament of Communion and other sacraments, to offer prayers to God that have a public character. Since in the temple the believers gather, who constitute the Church of Christ, the temple is also called “the church,” a word derived from the Greek “kyriakon” which means “the house of the Lord”.

Consecration of the Cathedral of the Archangel Michael, founded in 1070. The Radziwill Chronicle

Christian temples, as special church buildings, began to appear among Christians in a significant number only after the end of persecution by the pagans, that is, from the 4th century. But even before that, temples had already begun to be built, at least from the 3rd century. Christians of the first Jerusalem community still attended the Old Testament temple, but to celebrate the Eucharist they gathered separately from the Jews “in their homes” (Acts 2:46). In the era of persecution of Christianity by the pagans, the catacombs were the main places of worship for Christians. This was the name of the special dungeons dug for the burial of the dead. The custom of burying the dead in the catacombs was quite common in pre-Christian antiquity, both in the east and in the west. Burial places, according to Roman law, were recognized as inviolable. Roman law also allowed for the free existence of burial societies, no matter what religion they held: they enjoyed the right of assembly in the burial places of their members and could even have their own altars there for the administration of their cults. Hence, it is clear that the first Christians widely used these rights, as a result of which the main places of their liturgical meetings, or the first temples of antiquity, were the catacombs. These catacombs have survived to this day in different places. Of greatest interest to us are the best-preserved catacombs in the vicinity of Rome, the so-called "Catacombs of Callista." This is a whole network of intertwining underground corridors with more or less extensive rooms scattered here and there among them, like rooms called "cubicles." In this labyrinth, without the help of an experienced guide, it is very easy to get confused, especially since these corridors are sometimes located on several floors, and you can unnoticeably go from one floor to another. Niches are carved along the corridors, in which the deceased were walled up. Cubicles were family crypts, and even larger rooms of the "crypt" were the very temples in which Christians celebrated their divine services in times of persecution. The tomb of the martyr was usually installed in them: it served as the throne on which the Eucharist was celebrated. This is the origin of the custom of placing in the newly consecrated church the holy relics inside the throne and in the antimension, without which the Divine Liturgy cannot be celebrated. Along the sides of this throne or tomb were places for the bishop and presbyters. The largest rooms of the catacombs are called “chapels” or “churches. “In them it is already easy to distinguish many of the components of our modern church.

Temple in Scripture

The Old Testament Temple in Jerusalem transformed the Church of the New Testament, into which all nations must enter to worship God in spirit and in truth (John 4:24). In New Testament Scripture, the theme of the temple found its most striking light in the Gospel of Luke.

The gospel from Luke begins with a description of a significant event that took place in the temple of Jerusalem, namely, with a description of the appearance of the Archangel Gabriel to the elder Zechariah. The mention of the Archangel Gabriel is associated with Daniel's prophecy of seventy weeks, that is, with the number 490. This means that 490 days will pass, including 6 months before the Annunciation to the Virgin Mary, 9 months before the Nativity of Christ, that is, 15 months, equal to 450 days, and 40 days before the Meeting of the Lord, and in the same temple the Messiah Christ, the Savior of the world, promised by the prophets will appear.

In the Gospel of Luke, Simeon the God-Receiver in the Jerusalem temple proclaims to the world “light for the enlightenment of the Gentiles” (Luke 2:32), that is, light for the enlightenment of nations. Here is Anna the prophetess, a widow of 84 years old, “who did not leave the church, serving God day and night by fasting and prayer” (Luke 2:37), and who showed in her godly life a bright prototype of many Orthodox Russian old women, bearers of genuine church piety against the general gloomy background of blind religious apostasy under the conditions of a harsh theomachic regime.

In the Gospel of Luke we find the only testimony of the childhood of the Lord Jesus Christ in the entire canon of the New Testament. This precious testimony of the evangelist Luke has as its subject an event that took place in the temple. Saint Luke narrates that every year Joseph and Mary went to Jerusalem for the feast of Easter and that one day the 12-year-old boy Jesus remained in Jerusalem. Joseph and Mary on the third day “found Him in the temple, sitting among the teachers” (Luke 2:46).

In response to their bewilderment, the Divine Child uttered mysterious words full of incomprehensible meaning: “Why did you seek Me? Or did you not know what should be in me in what belongs to my Father? " (Luke 2:49). The Gospel of Luke ends with a description of the Ascension of Christ into heaven and the return of the apostles to Jerusalem, indicating the fact that they "were always in the temple, glorifying and blessing God" (Luke 24:53).

The theme of the temple has its continuation in the book of Acts of the Holy Apostles, which begins with a description of the Ascension of Christ the Savior and the Descent of the Holy Spirit on the disciples of Christ, indicating that "all ... the believers were together ... and every day with one accord remained in the temple" (Acts 2 : 44-46). The testimony of the book of Acts is valuable in that it relates to the illumination of the historical aspect of the life of the Church of Christ. In the New Testament, the temple is a focus, a visible manifestation and concrete manifestation of the life of the One Holy Catholic and Apostolic Church, the actual embodiment of the conciliar religious experience of the people of God.

Why go to church?

We need to comprehend for ourselves what the Church is in general . The question of a worldly person, for whom the Church is something incomprehensible, alien, abstracted, far from his real life, therefore he does not enter it. The Apostle Paul answers it in a way that no one else has been able to answer in the entire history of mankind: "The Church is the body of Christ," while adding - "the pillar and confirmation of the truth." And then he adds that we are all “get away from the part,” that is, members of this organism, particles, cells, one might say. Here you already feel some very deep mystery, it can no longer be something abstract - an organism, body, blood, soul, work of the whole body and subordination, co-organization of these cells. We come to the question of the attitude to faith in God of the worldly man and the church. The Church is not so much a legal institution and a public organization, but, first of all, it is what the Apostle Paul speaks about - a kind of mysterious phenomenon, a community of people, the Body of Christ.

A person cannot be alone. It should belong to some direction, philosophy, views, worldview, and if at some time the feeling of freedom, inner choice, it - especially in youth - is interesting for a person, then life experience shows that a person cannot achieve anything in life alone, he needs to have some kind of circle, some kind of social community. In my opinion, such a worldly approach to a “personal” God outside the church is purely individualistic, it is just a human illusion, it is impossible. Man belongs to humanity. And that part of humanity that believes that Christ was resurrected, and testifies to this - this is the Church. "You will be my witnesses," says Christ to the apostles, "even to the ends of the earth." The Orthodox Church carries out this testimony, and did it during the persecution, and this tradition has been preserved by generations of people in different circumstances.

In Orthodoxy, in the church there is a very important thing - there is reality, there is sobriety. A person constantly looks into himself and not with his own vision explores something in himself and in the life around him, but asks for help and participation in his life by the grace of God, which, as it were, shines through his whole life. And here the authority of tradition, the thousand-year experience of the church, becomes very important. The experience is living, effective and working in us through the grace of the Holy Spirit. This gives different fruits and other results.

The device of an Orthodox church

The internal location of churches has been determined since ancient times by the goals of Christian worship and a symbolic view of their meaning. Like any expedient building, a Christian church had to satisfy the purposes for which it was intended: firstly, it had to have a comfortable space for the priests who performed divine services, and secondly, a room where the believers would stand, that is, already baptized Christians; and, thirdly, there should have been a special room for the catechumens, that is, not yet baptized, but only preparing to receive baptism, and those who repent. In accordance with this, as in the Old Testament temple there were three departments "the holy of holies," "the sanctuary" and the "courtyard," so the Christian temple from ancient times was divided into three parts: the altar, the middle part of the temple, or actually the "church," and the narthex.

Altar

The most important part of a Christian church is the altar. Name altar
comes from the Latin alta ara - an exalted altar. According to the custom of the ancient
The altar of the church was always placed in a semicircle on the eastern side of the temple.
Christians have assimilated to the East the highest symbolic meaning. There was paradise in the east,
in the east our salvation is done. In the east, the material sun rises, giving
life to all living on earth, in the east the Sun of Truth also rose, giving
eternal life to humanity. The East has always been recognized as a symbol of goodness, in
the opposite of the west, which was considered a symbol of evil, the realm of the unclean
perfume. The Lord Jesus Christ Himself is personified by the image of the East: “East is the name
him, "(Zech. 6:12; Ps. 67:34)," East from on high "(Luke 1:78), and St. prophet
Malachi calls Him "the Sun of righteousness" (4: 2). This is why Christians in prayer
always and are facing east (see St. Basil the Great Canon 90).
The custom of Roman Catholics and Protestants to turn altars to the west was established on
west not earlier than the 13th century. The altar (in Greek "vima," or "hieration") means a high place, in addition, it also marks an earthly paradise,
where the ancestors lived, the places from where the Lord walked to preach, Zion
the upper room where the Lord established the Sacrament of Communion.

The altar is a place for some
priests who, like heavenly disembodied forces, serve before
the throne of the King of Glory. Laymen are not allowed to enter the altar (69 right., 6th universe.
Cathedral, 44 avenue Laod. Cathedral). Only clerks who help can enter the altar
when performing a divine service. Women are unconditionally prohibited from entering the altar.
Only in convents is it allowed for a tonsured nun to enter the altar
for cleaning the altar and serving. The altar, as its very name indicates (from
Latin words alta ara, which means "high altar" (is built above
other parts of the temple in steps, two, and sometimes more. so, he
becomes more visible to worshipers and clearly justifies its symbolic
the meaning of the "mountain world." The one entering the altar is obliged to put three bows to the ground in
weekdays and feasts of the Mother of God, and on Sundays and Lord's
Holidays three bows.

The Holy See

The main accessory of the altar is
the holy throne, in Greek "meal," as it is sometimes called
Church Slavonic in our liturgical books. In the first centuries of Christianity in
underground churches of the catacombs the throne served as the tomb of the martyr, if necessary
in the form of an elongated quadrangle and adjacent to the altar wall. IN
the ancient above-ground churches, the thrones began to be arranged almost square, on
one or four stands: they were made of wood in the form of an ordinary
tables, but then they began to be made of precious metals, sometimes they arranged
thrones are stone, marble. The throne marks the heavenly throne of God, on
where the Lord Almighty Himself is mysteriously present.
It is also referred to as
"Altar" (in Greek "fisiastirion"), because on it
a Bloodless Sacrifice for peace is offered. The throne also depicts the tomb of Christ,
for the Body of Christ rests on him. The rectangular shape of the throne symbolically
depicts that a sacrifice is made on it for all four parts of the world, that
all the ends of the earth are called to partake of the Body and Blood of Christ.

According to the double meaning of the throne, he wears two robes,
the lower white clothes, which is called "shrachitsa" (in Greek "katasarkion" "priloty") and depicts a shroud with which the Body was entwined
Savior, and the upper "india" (from the Greek "endio" "dress") from the precious
shiny garment that depicts the glory of the throne of the Lord. At consecration
of the temple, the lower garment of the srachitsa is entwined with a string (rope), which
Himself the bond of the Lord, with which He was bound when He was led to the judgment of the chief priests
Anna and Caiaphas (John 18:24). The rope is tied around the throne so that from all
on four sides of it, a cross is obtained, symbolizing the cross with which
the malice of the Jews brought the Lord down into the grave, and which served to victory over sin and
hell.

Antimension

The most important belonging to the throne is the antimension (from
Greek "anti" "instead of" and Latin mensa "mensa" "table, throne"), or
"Instead of the throne." Currently, antimension is a silk wrap with
depicting the position of the Lord Jesus Christ in the grave, four Evangelists and
instruments of suffering of Christ the Savior, inside which, in a special bag with a reverse
hand, embedded particles of St. relics. The history of antimension goes back to early times
Christianity. The first Christians had the custom of celebrating the Eucharist on tombs.
martyrs. When Christians from the 4th century were able to build freely
aboveground temples, they, by virtue of the already rooted custom, began to transfer to these
temples from different places of the relics of St. martyrs. But since the number of temples is all
increasing, it was already difficult to get whole relics for each temple. Then
began to put under the throne only at least a particle of St. relics. Hence it leads its
the beginning of our antimension. He is, in essence, a portable throne.
Evangelists who went to distant lands to preach the Gospel,
emperors who went on campaigns with clergy and marching churches should
were to take with them marching thrones, which were the antimenses.
A number of news
about antimensions, with this name, we have already from the 8th century, and ourselves
antimensions that have come down to us in the form of material monuments date back to 12
century. The ancient Russian antimensions that have survived to us were prepared from
canvas, had an inscription and an image of a cross. The inscriptions indicate that the antimension
replaces the consecrated throne; the name of the bishop who consecrated
"This throne," its destination (for which church) and the signature of the relics ("here
power "). Since the 17th century, more complex images appear on antimensions, like
position in the Savior's tomb, and the canvas is replaced by silk. Initially, every
the throne consecrated by the bishop was invested by St. relics (in a metal ark
under the throne or in a recess in the upper throne board). Such thrones are not
needed antimensions. Temples that were not consecrated by bishops were consecrated
through the antimenses sent by the bishops with St. relics. As a result, some temples
had thrones with St. relics, but did not have antimensions; others had thrones without
St. relics, but had antimensions. So it was in the Russian Church in the first time after
adoption of Christianity. But over time, first in the Greek, and then in
Russian Church, antimensions began to be placed on the thrones, consecrated
bishops, but so far without St. relics. Since 1675, a custom has been established in the Russian Church
lay antimensions with St. relics in all churches, even those consecrated by bishops.
The antimension given by the bishop to the priest became, as it were, a visible sign of authority
a priest to celebrate the Divine Liturgy, being subordinate to the bishop,
who issued this antimension.

The antimension lies on the throne, folded in four.
Inside it is "lip," or in Greek "musa." She marks that
lip, which, having drunk bile and otstom, brought to the mouth of the Lord, who hung on
cross, and serves to wipe off the particles of the Body of Christ and the particles taken out in honor
saints, living and dead, when immersed in St. the cup at the end of the Liturgy.

Antimense, folded in four, is wrapped in a special silk dress,
which is slightly larger than it, and is called "iliton" from the Greek
"Ileo," which means "I wrap up." Iliton depicts the shroud with which
the povit was the Lord after His birth, and at the same time that shroud in which
His Body was wrapped at His burial in the tomb.

The ark

To store the Holy Mysteries, an ark is now placed on the throne itself, or
the kivot, also called the tabernacle. It is made like the tomb of the Lord
or in the form of a church. St. myrrh.

Ciborium

Above the throne in ancient temples, it was arranged, as Latin writers call it
ciborium, in Greek ciborium, or in Slavic canopy, a kind of canopy,
supported by four columns. The canopy also visited the old Russian churches. She
symbolizes itself, as it were, the sky, spread over the earth, on which
a sacrifice is offered for the sins of the world. At the same time, canopy means “immaterial
God's tabernacle, "that is, the glory of God and the grace that He Himself is covered with,
dress with light, like a garment, and sit on the exalted throne of your glory.

Under the ciborium above the middle of the throne hung a peristerium vessel in the form
dove, in which were kept spare Holy Gifts in case of communion of the sick and for
Presanctified Liturgies. Currently, this image of a dove in some places
survived, but it lost its original practical meaning: the dove
this one no longer serves as a vessel for storing the Holy Mysteries, but only as a symbol of St.
Spirit.

Paten

Discos - (Greek for "deep dish") is a round metal dish, usually golden
or silver, on a stand, in the form of a leg, on which the "Lamb" relies, then
there is that part of the prosphora, which at the Liturgy is transformed into the Body of Christ, and
also other particles removed from the prosphora at the beginning of the Liturgy. Paten
symbolizes the manger in which the newborn God-child was placed, and
at the same time the tomb of Christ.

Chalice

Chalice or bowl (from the Greek "potirion" drinking vessel). This is the vessel from which the believers partake of the Body and Blood of Christ, and which resembles the cup from which the Lord first introduced His disciples at the Last Supper. At the beginning of the Liturgy in this cup
wine is poured with the addition of a small amount of water (so that the wine does not lose its characteristic taste), which is transformed at the Liturgy into the true Blood of Christ. This cup also resembles the "cup of suffering" of the Savior.

Zvezditsa

The star (in Greek "astir, asteriskos") consists of two arcs,
connected to each other crosswise. Recalling the star that led the Magi to
Bethlehem, the starlet is placed on the diskos so that the patrons do not touch
particles located on the disk and did not mix them.