Practical electronics with circuits. Isolate, tricks for beginners, diagrams with numbers

Content:

Each electrical circuit consists of many elements, which, in turn, also include various parts in their design. The most striking example is Appliances. Even an ordinary iron consists of a heating element, a temperature regulator, a control light, a fuse, a wire and a plug. Other electrical appliances have an even more complex design, supplemented by various relays, circuit breakers, electric motors, transformers and many other details. An electrical connection is created between them, ensuring the full interaction of all elements and the fulfillment by each device of its intended purpose.

In this regard, the question very often arises of how to learn to read electrical circuits, where all components are displayed in the form of conventional graphic symbols. This problem is of great importance for those who regularly encounter electrical installations. Proper reading of the diagrams makes it possible to understand how the elements interact with each other and how all work processes proceed.

Types of electrical circuits

In order to correctly use electrical circuits, you need to familiarize yourself with the basic concepts and definitions that affect this area in advance.

Any diagram is made in the form of a graphic image or drawing, which, together with the equipment, displays all the connecting links of the electrical circuit. Exist different kinds electrical circuits, differing in their intended purpose. Their list includes primary and secondary circuits, signaling, protection, control systems and others. In addition, there are and are widely used fundamental and, full-line and deployed. Each of them has its own specific features.

Primary circuits include circuits through which the main technological voltages are supplied directly from sources to consumers or receivers of electricity. Primary chains generate, transform, transmit and distribute electrical energy. They consist of a main circuit and circuits that provide their own needs. Main circuit circuits generate, convert and distribute the main flow of electricity. Auxiliary circuits ensure the operation of the main electrical equipment. Through them, the voltage is supplied to the electric motors of the installations, to the lighting system and to other areas.

Secondary are those circuits in which the applied voltage does not exceed 1 kilowatt. They provide the functions of automation, control, protection, dispatching service. Through the secondary circuits, control, measurement and metering of electricity is carried out. Knowing these properties will help you learn how to read electrical circuits.

Full line circuits are used in three-phase circuits. They display the electrical equipment connected to all three phases. Single-line diagrams show equipment located on only one middle phase. This difference must be indicated on the diagram.

Schematic diagrams do not indicate secondary elements that do not perform primary functions. Due to this, the image becomes simpler, allowing a better understanding of the principle of operation of all equipment. Wiring diagrams, on the contrary, are carried out in more detail, since they are used for the practical installation of all elements of the electrical network. These include single-line diagrams displayed directly on the building plan of the facility, as well as cable route diagrams along with transformer substations and distribution points plotted on a simplified master plan.

In the process of installation and commissioning, detailed schemes with secondary circuits became widespread. They are allocated additional functional subgroups of circuits associated with turning on and off, individual protection of a section, and others.

Designations in electrical diagrams

In every electrical circuit there are devices, elements and parts that together form a path for electric current. They are distinguished by the presence of electromagnetic processes associated with electromotive force, current and voltage, and described in physical laws.

In electrical circuits, all components can be divided into several groups:

1. The first group includes devices that generate electricity or power sources.
2. The second group of elements converts electricity into other types of energy. They perform the function of receivers or consumers.
3. The components of the third group provide the transfer of electricity from one element to another, that is, from a power source to electrical receivers. This also includes transformers, stabilizers and other devices that provide required quality and voltage level.

Each device, element or part corresponds to a symbol used in graphic representations of electrical circuits, called electrical circuits. In addition to the main symbols, they display power lines connecting all these elements. Sections of the circuit along which the same currents flow are called branches. The places of their connections are nodes, indicated on electrical diagrams in the form of dots. There are closed paths for the movement of current, covering several branches at once and called circuits of electrical circuits. The simplest electrical circuit diagram is single-circuit, and complex circuits consist of several circuits.

Most circuits consist of various electrical devices that differ in different modes of operation, depending on the value of current and voltage. In idle mode, there is no current in the circuit at all. Sometimes such situations arise when connections are broken. In the nominal mode, all elements operate with the current, voltage and power that are indicated in the device passport.

All components and conventions electrical circuit elements are displayed graphically. The figures show that each element or device has its own symbol. For example, electrical machines may be depicted in a simplified or expanded manner. Depending on this, conditional graphic schemes are also built. Single-line and multi-line images are used to show winding leads. The number of lines depends on the number of pins, which will be different for various types machines. In some cases, for the convenience of reading the diagrams, mixed images can be used, when the stator winding is shown in expanded form, and the rotor winding is shown in simplified form. Others are done in the same way.

They are also carried out in a simplified and expanded, single-line and multi-line methods. This determines the way the devices themselves are displayed, their outputs, winding connections and other constituent elements. For example, in current transformers, a thick line marked with dots is used to depict the primary winding. For the secondary winding, a circle can be used with a simplified method or two semicircles with an expanded image method.

Graphic images of other elements:

• Contacts. They are used in switching devices and contact connections, mainly in switches, contactors and relays. They are divided into closing, opening and switching, each of which has its own graphic pattern. If necessary, the image of contacts in a mirror-inverted form is allowed. The base of the moving part is marked with a special unshaded dot.
• . They can be single pole or multi pole. The base of the moving contact is marked with a dot. For circuit breakers, the type of release is indicated in the image. Switches differ in the type of action, they can be push-button or track, with break and make contacts.
• Fuses, resistors, capacitors. Each of them corresponds to certain icons. Fuses are depicted as a rectangle with taps. For fixed resistors, the icon can be with or without taps. The moving contact of a variable resistor is indicated by an arrow. Capacitor drawings show fixed and variable capacitance. There are separate images for polar and non-polar electrolytic capacitors.
• Semiconductor devices. The simplest of these are diodes with a p-n junction and one-sided conduction. Therefore, they are depicted as a triangle and an electrical connection line crossing it. The triangle is the anode and the dash is the cathode. For other types of semiconductors, there are their own designations defined by the standard. The knowledge of these graphic drawings greatly facilitates the reading of electrical circuits for dummies.
• Sources of light. Available on almost all electrical circuits. Depending on the purpose, they are displayed as lighting and signaling lamps with the help of the corresponding icons. When displaying signal lamps, it is possible to shade a certain sector corresponding to low power and low luminous flux. In alarm systems, along with light bulbs, acoustic devices are used - electric sirens, electric bells, electric horns and other similar devices.

How to read electrical diagrams correctly

The circuit diagram is a graphic representation of all elements, parts and components between which an electronic connection is made using current-carrying conductors. It is the basis for the development of any electronic devices and electrical circuits. Therefore, every novice electrician must first master the ability to read a variety of circuit diagrams.

It is the correct reading of electrical circuits for beginners that allows you to understand well how to connect all the parts in order to get the expected end result. That is, the device or circuit must fully perform its assigned functions. For the correct reading of the circuit diagram, it is necessary, first of all, to familiarize yourself with the symbols of all its components. Each detail is marked with its own conventional graphic designation - UGO. Typically, such conventional signs display the general design, characteristics and purpose of a particular element. The most striking examples are capacitors, resistors, speakers and other simple parts.

It is much more difficult to work with components represented by transistors, triacs, microcircuits, etc. The complex design of such elements also implies a more complex display of them on electrical circuits.

For example, each bipolar transistor has at least three terminals - base, collector and emitter. Therefore, their conventional representation requires special graphic symbols. This helps to distinguish between parts with individual basic properties and characteristics. Each symbol carries certain encrypted information. For example, bipolar transistors can have a completely different structure - p-p-p or p-p-p, so the images on the diagrams will also be noticeably different. It is recommended that before reading the circuit diagrams, carefully read all the elements.

Conditional images are very often supplemented with clarifying information. On closer examination, you can see Latin alphabetic characters next to each icon. Thus, this or that detail is indicated. This is important to know, especially when we are just learning to read electrical circuits. There are also numbers next to the letters. They indicate the corresponding numbering or specifications elements.

Any radio engineering or electrical device consists of a certain number of different electrical and radio elements (radio components). Take, for example, the most ordinary iron: it has a temperature control, a light bulb, a heating element, a fuse, wires and a plug.

The iron is an electrical device assembled from a special set of radio elements with certain electrical properties, where the operation of the iron is based on the interaction of these elements with each other.

To carry out the interaction, the radio elements (radio components) are electrically connected to each other, and in some cases they are placed at a small distance from each other and the interaction occurs through an inductive or capacitive coupling formed between them.

The easiest way to understand an iron is to take an accurate photograph or drawing of it. And to make the presentation exhaustive, you can take a few photos. appearance close-up from different angles, and several photos of the internal device.

However, as you noticed, this way of representing the device of the iron does not give us anything at all, since only a general picture of the details of the iron is visible in the photographs. And what radio elements it consists of, what their purpose is, what they represent, what function they perform in the operation of the iron, and how they are electrically interconnected, we do not understand.

That is why, in order to have an idea of ​​what kind of radio elements such electrical devices consist of, they developed conventional graphic symbols radio components. And in order to understand what parts the device is made of, how these parts interact with each other and what processes take place in this case, special electrical circuits were developed.

Wiring diagram is a drawing containing in the form of conventional images or symbols the components (radio elements) of an electrical device and the connections (connections) between them. That is, the electrical circuit shows how the radio elements are connected to each other.

Radio elements of electrical devices can be resistors, lamps, capacitors, microcircuits, transistors, diodes, switches, buttons, starters, etc., and the connections and connections between them can be made by mounting wire, cable, plug-in connection, printed circuit board tracks, etc. .d.

Electrical circuits should be understandable to everyone who has to work with them, and therefore they are performed in standard symbols and used according to a specific system established by state standards: GOST 2.701-2008; GOST 2.710-81; GOST 2.721-74; GOST 2.728-74; GOST 2.730-73.

There are three main types of schemes: structural, principal electrical, wiring diagrams (mounting).

Structural scheme(functional) is developed at the first stages of design and is intended for general familiarization with the principle of operation of the device. In the diagram, rectangles, triangles or symbols depict the main nodes or blocks of the device, which are interconnected by lines with arrows indicating the direction and sequence of connections to each other.

Circuit diagram determines which radio elements (radio components) an electrical or radio engineering device consists of, how these radio components are electrically interconnected, and how they interact with each other. In the diagram, the details of the device and the order of their connection are depicted by conventional signs symbolizing these details. And although the circuit diagram does not give an idea of ​​the dimensions of the device and the placement of its parts on circuit boards, shields, panels, etc., it does, however, allow you to understand in detail its principle of operation.

Wiring diagram or is it also called wiring diagram, is a simplified structural drawing depicting an electrical device in one or more projections, which shows the electrical connections of parts to each other. The diagram shows all the radio elements that make up the device, their exact location, connection methods (wires, cables, bundles), connection points, as well as input and output circuits (connectors, clamps, boards, connectors, etc.). Images of parts on the diagrams are given in the form of rectangles, conventional graphic symbols, or in the form of simplified drawings of real parts.

The difference between the structural, circuit and wiring diagram will be shown further on concrete examples, but we will focus on circuit diagrams.

If you carefully consider the circuit diagram of any electrical device, you will notice that the symbols of some radio components are often repeated. Just as a word, phrase or sentence consists of alternating in a certain order letters assembled into words, so an electrical circuit consists of separate conventional graphic symbols of radio elements and their groups alternating in a certain order.

Conditional graphic designations of radio elements are formed from the simplest geometric shapes: squares, rectangles, triangles, circles, as well as from solid and dashed lines and points. Their combination according to the system provided by the ESKD standard (unified system for design documentation) makes it possible to easily depict radio components, devices, electrical machines, electrical communication lines, types of connections, type of current, methods for measuring parameters, etc.

As a graphic designation of radio elements, their extremely simplified image is taken, in which either their most common and characteristic features are preserved, or their basic principle of operation is emphasized.

For example. A conventional resistor is a ceramic tube, on the surface of which is applied conductive layer with a certain electrical resistance. Therefore, in electrical circuits, the resistor is denoted in the form rectangle symbolizing the shape of the tube.

Thanks to this principle of construction, memorizing conventional graphic symbols is not difficult, and the drawn up diagram is easy to read. And in order to learn how to read electrical circuits, first of all, you need to study the symbols, so to speak, the “alphabet” of electrical circuits.

This is where we will end. We will analyze three main types of electrical circuits that you will often encounter when developing or repeating electronic or electrical equipment.
Good luck!

You can make the simplest electronic circuits for everyday use with your own hands, even without deep knowledge in electronics. In fact, at the household level, radio is very simple. Knowledge of the elementary laws of electrical engineering (Ohm, Kirchhoff), general principles the work of semiconductor devices, the skills of reading circuits, the ability to work with an electric soldering iron is enough to assemble the simplest circuit.

Ham radio workshop

No matter how complex the scheme would have to be, you must have a minimum set of materials and tools in your home workshop:

• Side cutters;
• Tweezers;
• Solder;
• Flux;
• Circuit boards;
• Tester or multimeter;
• Materials and tools for the manufacture of the body of the device.

You should not purchase expensive professional tools and devices to begin with. An expensive soldering station or digital oscilloscope is of little help to a beginner radio amateur. At the beginning of the creative path, the simplest instruments are quite enough, on which you need to hone your experience and skills.

Where to start

Do-it-yourself radio circuits for the home should not exceed the level of complexity that you own, otherwise it will only mean wasted time and materials. With a lack of experience, it is better to limit yourself to the simplest schemes, and as you accumulate skills, improve them, replacing them with more complex ones.

Usually, most of the literature from the field of electronics for beginner radio amateurs gives a classic example of making simple receivers. This is especially true of classical old literature, in which there are not so many fundamental errors in comparison with contemporary literature.

Note! These schemes were designed for the huge power of transmitting radio stations in the past. Today, transmitting centers use less power to transmit and try to get into the shorter wavelength range. Do not waste time trying to make a working radio using the simplest circuit.

Radio circuits for beginners should include a maximum of a couple of active elements - transistors. So it will be easier to understand the operation of the circuit and increase the level of knowledge.

What can be done

What can be done so that it is not difficult and can be used in practice at home? There can be many options:

• apartment call;
• Christmas tree garlands switch;
• Backlight for modding the computer system unit.

Important! Appliances to be powered by household AC power should not be designed unless there is sufficient experience. It is dangerous for life and for others.

Pretty simple circuits have amplifiers for computer speakers, made on specialized integrated circuits. Devices assembled on their basis contain a minimum number of elements and practically do not require adjustment.

You can often find circuits that need elementary alterations, improvements that make it easier to manufacture and configure. But this should be done by an experienced master in order to make the final version more accessible to a beginner.

On what to build

Most of the literature recommends designing simple circuits on circuit boards. At present, this is quite easy. There is a wide variety of circuit boards with different hole patterns and printed tracks.

The principle of installation is that the parts are installed on the board in free places, and then the necessary conclusions are connected to each other by jumpers, as indicated in the circuit diagram.

With due care, such a board can serve as the basis for many circuits. The power of the soldering iron for soldering should not exceed 25 W, then the risk of overheating the radio elements and printed conductors will be minimized.

The solder should be fusible, such as POS-60, and it is best to use pure pine rosin or its solution in ethyl alcohol as a flux.

Highly qualified radio amateurs can design a printed circuit board pattern themselves and execute it on foil material, on which radio elements are then soldered. The design developed in this way will have optimal dimensions.

Design of the finished structure

Looking at the creations of beginners and experienced craftsmen, one can come to the conclusion that the assembly and adjustment of the device is not always the most difficult part of the design process. Sometimes a properly working device remains a set of parts with soldered wires, not closed by any case. At present, you can no longer be puzzled by the manufacture of the case, because on sale you can find all kinds of sets of cases of any configuration and dimensions.

Before you start manufacturing the design you like, you should fully think through all the stages of the work: from the availability of tools and all radio elements to the version of the case. It will be completely uninteresting if in the process of work it turns out that one of the resistors is missing, and there are no replacement options. The work is best done under the guidance of an experienced radio amateur, and, in extreme cases, periodically monitor the manufacturing process at each stage.

Video

Isothread technique, diagrams for beginners.
Works in the technique of isothread- an exciting activity not only for adults, but also for children. At first glance, it seems that this technique is very complicated, in fact, you just need to learn the pattern and everything will turn out great.
You need to master the technique of filling the corner, circle, cobweb. After that, you will be able to complete rather complex paintings using the isothread technique.
teach this art to a child, it is not only interesting, but also useful. This hobby develops perseverance in a child, an eye, fantasy and abstract thinking, coordination of hand movements and fine motor skills, cultivates accuracy and attention.
Filling the corner using the isothread technique:

1. Draw an angle on the cardboard.
2. Divide each side of the angle into the same number of equal segments.
3. Number the point (on one side of the corner - start from the top, on the other - vice versa)
4. Make punctures with a needle or awl at all points except the top.
5. Thread the needle, make a knot.
6. Fill in the corner according to the diagram above.

Filling a circle using isothread technique:

1. Draw a circle.
2. Divide the circle into equal parts.
3. Make punctures in all received points.
4. Fill in the circle according to the scheme.

Schemes of work in the isothread technique:

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