Easy drawings for beginners. Practical diagrams of different devices

Content:

Each electrical circuit consists of many elements, which, in turn, also include various parts in their design. Most a shining example household appliances are used. Even an ordinary iron consists of heating element, temperature controller, pilot light, fuse, wire and plug. Other electrical appliances have an even more complex design, complemented by various relays, circuit breakers, electric motors, transformers and many other parts. An electrical connection is created between them, ensuring full interaction of all elements and each device fulfilling its purpose.

In this regard, the question very often arises of how to learn to read. electrical circuits, where all components are displayed as conditional graphic symbols. This problem has great importance for those who regularly deal with electrical installations. Correct reading of 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 in advance with the basic concepts and definitions affecting this area.

Any diagram is made in the form of a graphic image or drawing, on which, together with the equipment, all the connecting links of the electrical circuit are displayed. Exist different kinds electrical circuits that differ in their intended purpose. Their list includes primary and secondary circuits, alarm systems, protection, control and others. In addition, there are and are widely used principled and fully linear and expanded. Each of them has its own specific features.

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

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

Full-linear circuits are used in three-phase circuits. They display 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.

On circuit diagrams ah, minor elements that do not perform primary functions are not indicated. Due to this, the image becomes simpler, allowing you to better understand the principle of operation of all equipment. Installation diagrams, on the contrary, are carried out in more detail, since they are used for the practical installation of all elements electrical network. These include single-line diagrams displayed directly on the construction plan of the facility, as well as diagrams of cable routes along with transformer substations and distribution points plotted on a simplified general plan.

During the installation and commissioning process, extensive circuits with secondary circuits have become widespread. They highlight additional functional subgroups of circuits related to switching on and off, individual protection of any section, and others.

Symbols in electrical diagrams

Each electrical circuit contains 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 ensure the transfer of electricity from one element to another, that is, from the power source to electrical receivers. This also includes transformers, stabilizers and other devices that provide the required quality and voltage level.

Each device, element or part corresponds to a symbol used in graphic representations of electrical circuits, called electrical diagrams. In addition to the main symbols, they display the power lines connecting all these elements. The 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 current paths that cover several branches at once and are called electrical circuit circuits. The simplest electrical circuit diagram is single-circuit, while complex circuits consist of several circuits.

Most circuits consist of various electrical devices that differ various modes work, 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 nominal mode, all elements operate with the current, voltage and power specified in the device passport.

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

They are also carried out in simplified and expanded, single-line and multi-line methods. The way of displaying the devices themselves, their pins, winding connections and others depends on this. constituent elements. For example, in current transformers, a thick line, highlighted with dots, is used to depict the primary winding. For the secondary winding, a circle can be used in the simplified method or two semicircles in the expanded image method.

Graphic representations of other elements:

• Contacts. They are used in switching devices and contact connections, mainly in switches, contactors and relays. They are divided into closing, breaking and switching, each of which has its own graphic design. If necessary, it is allowed to depict the contacts in a mirror-inverted form. 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. U circuit breakers The image indicates the type of release. Switches differ in the type of action; they can be push-button or track, with normally open and closed contacts.
• Fuses, resistors, capacitors. Each of them corresponds to certain icons. Fuses are depicted as a rectangle with taps. For permanent resistors, the icon may have taps or no taps. The moving contact of a variable resistor is indicated by an arrow. The pictures of capacitors show constant and variable capacitance. There are separate images for polar and non-polar electrolytic capacitors.
• Semiconductor devices. The simplest of them are pn junction diodes with one-way conduction. Therefore, they are depicted in the form of 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. Knowing these graphical drawings makes reading electrical circuits for dummies much easier.
• Sources of light. Available on almost all electrical circuits. Depending on their purpose, they are displayed as lighting and warning lamps with corresponding icons. When depicting signal lamps, it is possible to shade a certain sector, corresponding to low power and low luminous flux. In alarm systems, they are used together with light bulbs. acoustic devices- electric sirens, electric bells, electric horns and other similar devices.

How to read electrical diagrams correctly

A schematic diagram is a graphical representation of all the elements, parts and components between which an electronic connection is made using live 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 diagrams for beginners that allows you to understand well how to connect all the parts to get the expected end result. That is, the device or circuit must fully perform its intended functions. For correct reading circuit diagram, it is necessary, first of all, to familiarize yourself with the symbols of all its components. Each part is marked with its own graphic designation - UGO. Typically, such symbols reflect the general design, characteristics and the purpose of this or that 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 distinguish between parts with individual basic properties and characteristics. Each symbol carries certain encrypted information. For example, bipolar transistors may have completely different structures - p-p-p or p-p-p, so the images on the circuits will also be noticeably different. It is recommended that you carefully read all the elements before reading the electrical circuit diagrams.

Conditional images are often supplemented with clarifying information. Upon closer examination, you can see Latin alphabetic symbols next to each icon. This way, this or that detail is designated. This is important to know, especially when we are just learning to read electrical diagrams. Near letter designations There are also numbers. They indicate the corresponding numbering or specifications elements.

Learning to read electrical circuit diagrams

I already talked about how to read circuit diagrams in the first part. Now I would like to reveal this topic more completely, so that even a beginner in electronics does not have questions. So, let's go. Let's start with the electrical connections.

It is no secret that in a circuit any radio component, for example a microcircuit, can be connected by a huge number of conductors to other elements of the circuit. In order to free up space on the circuit diagram and remove “repetitive connecting lines”, they are combined into a kind of “virtual” harness - they designate a group communication line. On the diagrams group line denoted as follows.

Here's an example.

As you can see, such a group line is thicker than other conductors in the circuit.

In order not to get confused where which conductors go, they are numbered.

In the figure I marked the connecting wire under the number 8 . It connects pin 30 of the DD2 chip and 8 XP5 connector pin. In addition, pay attention to where the 4th wire goes. For the XP5 connector, it is connected not to pin 2 of the connector, but to pin 1, which is why it is indicated on the right side of the connecting conductor. The 5th conductor is connected to the 2nd pin of the XP5 connector, which comes from the 33rd pin of the DD2 chip. I note that the connecting conductors with different numbers are not electrically connected to each other, and on a real printed circuit board they can be spaced apart different parts fees.

The electronic content of many devices consists of blocks. And, therefore, detachable connections are used to connect them. This is how detachable connections are indicated on the diagrams.

XP1 - this is a fork (aka "Dad"), XS1 - this is a socket (aka “Mom”). All together this is “Papa-Mama” or connector X1 (X2 ).

Electronic devices may also contain mechanically coupled elements. Let me explain what we are talking about.

For example, there are variable resistors that have a built-in switch. I talked about one of these in the article about variable resistors. This is how they are indicated on the circuit diagram. Where SA1 - a switch, and R1 - variable resistor. The dotted line indicates the mechanical connection of these elements.

Previously, such variable resistors were very often used in portable radios. When we turned the volume control knob (our variable resistor), the contacts of the built-in switch first closed. Thus, we turned on the receiver and immediately adjusted the volume with the same knob. I note that the variable resistor and switch do not have electrical contact. They are only connected mechanically.

The same situation is with electromagnetic relays. The relay winding itself and its contacts do not have electrical connection, but mechanically they are connected. We apply current to the relay winding - the contacts close or open.

Since the control part (relay winding) and the executive part (relay contacts) can be separated on the circuit diagram, their connection is indicated by a dotted line. Sometimes the dotted line don't draw at all, and the contacts simply indicate their belonging to the relay ( K1.1) and contact group number (K1. 1 ) and (K1. 2 ).

Still quite clear example- This is the volume control of a stereo amplifier. To adjust the volume, two variable resistors are required. But adjusting the volume in each channel separately is impractical. Therefore, dual variable resistors are used, where two variable resistors have one control shaft. Here is an example from a real circuit.

In the figure, I highlighted two parallel lines in red - they indicate the mechanical connection of these resistors, namely that they have one common control shaft. You may have already noticed that these resistors have a special position designation R4. 1 and R4. 2 . Where R4 - this is the resistor and its serial number in the circuit, and 1 And 2 indicate sections of this dual resistor.

Also, the mechanical connection of two or more variable resistors can be indicated by a dotted line rather than two solid ones.

I note that electrically these variable resistors have no contact between themselves. Their terminals can only be connected in a circuit.

It is no secret that many radio equipment components are sensitive to the effects of external or “neighboring” electromagnetic fields. This is especially true in transceiver equipment. To protect such units from unwanted electromagnetic influences, they are placed in a screen and shielded. As a rule, the screen is connected to the common wire of the circuit. This is shown in the diagrams like this.

The contour is screened here 1T1 , and the screen itself is depicted by a dash-dotted line, which is connected to a common wire. The shielding material can be aluminum, metal casing, foil, copper plate, etc.

This is how shielded communication lines are designated. The figure in the lower right corner shows a group of three shielded conductors.

Coaxial cable is also designated in a similar way. Here's a look at its designation.

In reality, a shielded wire (coaxial) is an insulated conductor that is externally covered or wrapped with a shield of conductive material. This may be copper braiding or foil covering. The screen, as a rule, is connected to a common wire and thereby removes electromagnetic interference and interference.

Repeating elements.

There are often cases when absolutely identical elements are used in an electronic device and it is inappropriate to clutter the circuit diagram with them. Here, take a look at this example.

Here we see that the circuit contains resistors R8 - R15 of the same rating and power. Only 8 pieces. Each of them connects the corresponding pin of the microcircuit and a four-digit seven-segment indicator. In order not to indicate these repeating resistors on the diagram, they were simply replaced with bold dots.

One more example. Crossover (filter) circuit for speaker. Pay attention to how instead of three identical capacitors C1 - C3, only one capacitor is indicated on the diagram, and the number of these capacitors is marked next to it. As can be seen from the diagram, these capacitors must be connected in parallel to obtain a total capacitance of 3 μF.

Likewise with capacitors C6 - C15 (10 µF) and C16 - C18 (11.7 µF). They must be connected in parallel and installed in place of the indicated capacitors.

It should be noted that the rules for designating radio components and elements on diagrams in foreign documentation are somewhat different. But, it will be much easier for a person who has received at least basic knowledge on this topic to understand them.

Below are simple light and sound circuits, mainly assembled on the basis of multivibrators, for beginner radio amateurs. All circuits use the simplest element base, no complex setup is required, and it is possible to replace elements with similar ones within a wide range.

Electronic duck

A toy duck can be equipped with a simple “quack” simulator circuit using two transistors. The circuit is a classic multivibrator with two transistors, one arm of which includes an acoustic capsule, and the load of the other is two LEDs that can be inserted into the eyes of the toy. Both of these loads work alternately - either a sound is heard, or the LEDs flash - the eyes of a duck. A reed sensor can be used as a power switch SA1 (can be taken from sensors SMK-1, SMK-3, etc., used in systems burglar alarm like door sensors). When a magnet is brought to the reed switch, its contacts close and the circuit begins to work. This can happen when the toy is tilted towards a hidden magnet or a kind of “magic wand” with a magnet is presented.

Transistors in the circuit can be any p-n-p type, low or medium power, for example MP39 - MP42 (old type), KT 209, KT502, KT814, with a gain of more than 50. Transistors can also be used n-p-n structures, for example KT315, KT 342, KT503, but then you need to change the polarity of the power supply, turn on the LEDs and the polar capacitor C1. As an acoustic emitter BF1, you can use a TM-2 type capsule or a small-sized speaker. Setting up the circuit comes down to selecting resistor R1 to obtain the characteristic quack sound.

The sound of a metal ball bouncing

The circuit quite accurately imitates such a sound; as capacitor C1 discharges, the volume of the “beats” decreases, and the pauses between them decrease. At the end, a characteristic metallic rattle will be heard, after which the sound will stop.

Transistors can be replaced with similar ones as in the previous circuit.
The total duration of the sound depends on capacity C1, and C2 determines the duration of pauses between “beats”. Sometimes, for a more believable sound, it is useful to select transistor VT1, since the operation of the simulator depends on its initial collector current and gain (h21e).

Engine sound simulator

They can, for example, voice a radio-controlled or other model of a mobile device.

Options for replacing transistors and speakers - as in previous schemes. Transformer T1 is the output from any small-sized radio receiver (a speaker is also connected through it in the receivers).

There are many schemes for simulating the sounds of birdsong, animal voices, steam locomotive whistles, etc. The circuit proposed below is assembled on just one digital chip K176LA7 (K561 LA7, 564LA7) and allows you to simulate many different sounds depending on the value of the resistance connected to the input contacts X1.

It should be noted that the microcircuit here operates “without power,” that is, no voltage is supplied to its positive terminal (pin 14). Although in fact the microcircuit is still powered, this happens only when a resistance sensor is connected to the X1 contacts. Each of the eight inputs of the microcircuit is connected to the internal power bus through diodes that protect against static electricity or incorrect connection. The microcircuit is powered through these internal diodes due to the presence of positive power feedback through the input resistor-sensor.

The circuit consists of two multivibrators. The first one (on elements DD1.1, DD1.2) immediately begins to produce square pulses with a frequency of 1 ... 3 Hz, and the second (DD1.3, DD1.4) is switched on when the logical level “1” arrives at pin 8 from the first multivibrator. It produces tone pulses with a frequency of 200 ... 2000 Hz. From the output of the second multivibrator, pulses are supplied to the power amplifier (transistor VT1) and a modulated sound is heard from the dynamic head.

If you now connect a variable resistor with a resistance of up to 100 kOhm to the input jacks X1, then power feedback occurs and this transforms the monotonous intermittent sound. By moving the slider of this resistor and changing the resistance, you can achieve a sound reminiscent of the trill of a nightingale, the chirping of a sparrow, the quack of a duck, the croaking of a frog, etc.

Details
The transistor can be replaced with KT3107L, KT361G, but in this case you need to install R4 with a resistance of 3.3 kOhm, otherwise the sound volume will decrease. Capacitors and resistors - any type with ratings close to those indicated in the diagram. It must be borne in mind that the K176 series microcircuits of early releases do not have the above protective diodes and such copies will not work in this circuit! It’s easy to check the presence of internal diodes - just measure the resistance with a tester between pin 14 of the microcircuit (“+” power supply) and its input pins (or at least one of the inputs). As with diode testing, the resistance should be low in one direction and high in the other.

There is no need to use a power switch in this circuit, since in idle mode the device consumes a current of less than 1 µA, which is significantly less than even the self-discharge current of any battery!

Setup
A correctly assembled simulator does not require any adjustment. To change the tone of the sound, you can select capacitor C2 from 300 to 3000 pF and resistors R2, R3 from 50 to 470 kOhm.

Flashing light

The flashing frequency of the lamp can be adjusted by selecting elements R1, R2, C1. The lamp can be from a flashlight or a car 12 V. Depending on this, you need to select the supply voltage of the circuit (from 6 to 12 V) and the power of the switching transistor VT3.

Transistors VT1, VT2 - any low-power corresponding structure (KT312, KT315, KT342, KT 503 (n-p-n) and KT361, KT645, KT502 (p-n-p), and VT3 - medium or high power(KT814, KT816, KT818).

A simple device for listening to the sound of TV broadcasts on headphones. Does not require any power and allows you to move freely within the room.

Coil L1 is a “loop” of 5...6 turns of PEV (PEL)-0.3...0.5 mm wire, laid around the perimeter of the room. It is connected in parallel to the TV speaker via switch SA1 as shown in the figure. For normal operation of the device, the output power of the TV audio channel must be within 2...4 W, and the loop resistance must be 4...8 Ohms. The wire can be laid under the baseboard or in the cable channel, and it should be located, if possible, no closer than 50 cm from the wires of the 220 V network to reduce alternating voltage interference.

The L2 coil is wound onto a frame made of thick cardboard or plastic in the form of a ring with a diameter of 15...18 cm, which serves as a headband. It contains 500...800 turns of PEV (PEL) wire 0.1...0.15 mm secured with glue or electrical tape. A miniature volume control R and an earphone (high-impedance, for example TON-2) are connected in series to the coil terminals.

Automatic light switch

This one differs from many circuits of similar machines in its extreme simplicity and reliability and does not need a detailed description. It allows you to turn on the lighting or some electrical appliance for a specified short time, and then automatically turns it off.

To turn on the load, just briefly press switch SA1 without latching. In this case, the capacitor manages to charge and opens the transistor, which controls the relay switching on. The turn-on time is determined by the capacitance of capacitor C and with the nominal value indicated in the diagram (4700 mF) it is about 4 minutes. An increase in the on-state time is achieved by connecting additional capacitors in parallel with C.

The transistor can be any n-p-n type of medium power or even low-power, such as KT315. This depends on the operating current of the relay used, which can also be any other with an operating voltage of 6-12 V and capable of switching the load of the power you need. Can also be used pnp transistors type, but you will need to change the polarity of the supply voltage and turn on capacitor C. Resistor R also affects the response time to a small extent and can be rated 15 ... 47 kOhm depending on the type of transistor.

List of radioelements

Designation	Type	Denomination	Quantity	Note	Shop	My notepad
	Electronic duck
VT1, VT2	Bipolar transistor	KT361B	2	MP39-MP42, KT209, KT502, KT814		To notepad
HL1, HL2	Light-emitting diode	AL307B	2			To notepad
C1		100uF 10V	1			To notepad
C2	Capacitor	0.1 µF	1			To notepad
R1, R2	Resistor	100 kOhm	2			To notepad
R3	Resistor	620 Ohm	1			To notepad
BF1	Acoustic emitter	TM2	1			To notepad
SA1	Reed switch		1			To notepad
GB1	Battery	4.5-9V	1			To notepad
	Simulator of the sound of a bouncing metal ball
	Bipolar transistor	KT361B	1			To notepad
	Bipolar transistor	KT315B	1			To notepad
C1	Electrolytic capacitor	100uF 12V	1			To notepad
C2	Capacitor	0.22 µF	1			To notepad
	Dynamic head	GD 0.5...1W 8 Ohm	1			To notepad
GB1	Battery	9 Volt	1			To notepad
	Engine sound simulator
	Bipolar transistor	KT315B	1			To notepad
	Bipolar transistor	KT361B	1			To notepad
C1	Electrolytic capacitor	15uF 6V	1			To notepad
R1	Variable resistor	470 kOhm	1			To notepad
R2	Resistor	24 kOhm	1			To notepad
T1	Transformer		1	From any small radio receiver		To notepad
	Universal sound simulator
DD1	Chip	K176LA7	1	K561LA7, 564LA7		To notepad
	Bipolar transistor	KT3107K	1	KT3107L, KT361G		To notepad
C1	Capacitor	1 µF	1			To notepad
C2	Capacitor	1000 pF	1			To notepad
R1-R3	Resistor	330 kOhm	1			To notepad
R4	Resistor	10 kOhm	1			To notepad
	Dynamic head	GD 0.1...0.5Watt 8 Ohm	1			To notepad
GB1	Battery	4.5-9V	1			To notepad
	Flashing light
VT1, VT2	Bipolar transistor

Since you have decided to become a self-taught electrician, then probably after a short period of time you will want to make some useful electrical appliance for your home, car or cottage with your own hands. At the same time, homemade products can be useful not only in everyday life, but also made for sale, for example. Actually the build process simple devices at home is not difficult. You just need to be able to read diagrams and use the ham radio tool.

Regarding the first point, before starting production electronic homemade products with your own hands, you need to learn how to read electrical diagrams. In this case, ours will be a good helper.

Among the tools for novice electricians, you will need a soldering iron, a set of screwdrivers, pliers and a multimeter. To assemble some popular electrical appliances you may even need welding machine, but this is a rare case. By the way, in this section of the site we even described the same welding machine.

Special attention should be paid to available materials, from which every novice electrician can make basic electronic homemade products with their own hands. Most often, old domestic parts are used in the manufacture of simple and useful electrical appliances: transformers, amplifiers, wires, etc. In most cases, novice radio amateurs and electricians just need to look for all the necessary tools in a garage or shed in the country.

When everything is ready - the tools have been collected, spare parts have been found and minimal knowledge has been obtained, you can proceed to assembling amateur electronic homemade products at home. This is where our small guide will help you. Each instruction provided includes not only detailed description each stage of creating electrical appliances, but is also accompanied by photo examples, diagrams, as well as video lessons that clearly show the entire manufacturing process. If you do not understand some point, you can clarify it under the entry in the comments. Our specialists will try to advise you in a timely manner!

Recently, having learned that I am a radio amateur, on the forum of our city, in the Radio thread, two people turned to me for help. Both for different reasons, and both of different ages, already adults, as it turned out when we met, one was 45 years old, the other 27. Which proves that you can start studying electronics at any age. They had one thing in common: both were somehow familiar with technology, and would like to independently master the radio business, but did not know where to start. We continued our conversation in In contact with, to my answer that there is a sea of ​​information on this topic on the Internet, study it - I don’t want to, I heard about the same thing from both - that both do not know where to start. One of the first questions was: what is included in the required minimum knowledge of a radio amateur. Listing the necessary skills for them took quite a lot of time, and I decided to write a review on this topic. I think it will be useful to beginners like my friends, to everyone who cannot decide where to start their training.

I’ll say right away that when learning, you need to evenly combine theory with practice. No matter how much you would like to quickly start soldering and assembling specific devices, you need to remember that without the necessary theoretical basis in your head, at best, you will be able to accurately copy other people’s devices. Whereas if you know the theory, at least to a minimum extent, you will be able to change the scheme and adapt it to your needs. There is a phrase that I think is known to every radio amateur: “There is nothing more practical than a good theory.”

First of all, you need to learn how to read circuit diagrams. Without the ability to read diagrams it is impossible to assemble even the simplest electronic device. Also, subsequently, it will not be superfluous to master and self-composition circuit diagrams, in special.

Soldering parts

It is necessary to be able to recognize appearance, any radio component, and know how it is indicated on the diagram. Of course, in order to assemble and solder any circuit, you need to have a soldering iron, preferably with a power no higher than 25 watts, and be able to use it well. All semiconductor parts do not like overheating, if you are soldering, for example, a transistor onto a board, and you were unable to solder the output in 5 - 7 seconds, pause for 10 seconds, or solder another part at this time, otherwise there is a high probability of burning the radio component from overheating.

It is also important to solder carefully, especially the terminals of radio components located closely, and not create “snot” or accidental short circuits. Always, if in doubt, ring the suspicious location with a multimeter in sound testing mode.

It is equally important to remove flux residues from the board, especially if you are soldering digital circuit, or flux containing active additives. You need to wash it off with a special liquid or 97% ethyl alcohol.

Beginners often assemble circuits by surface mounting, directly on the terminals of the parts. I agree, if the leads are securely twisted together and then soldered, such a device will last a long time. But in this way it is no longer worth assembling devices containing more than 5 - 8 parts. In this case, you need to assemble the device on a printed circuit board. The device assembled on the board is different increased reliability, the connection diagram can be easily traced along the tracks, and if necessary, call all connections with a multimeter.

The disadvantage of printed wiring is the difficulty of changing the circuit of the finished device. Therefore, before laying out and etching a printed circuit board, you always first need to assemble the device on a breadboard. You can make devices on printed circuit boards in different ways, but the main thing here is to follow one thing: important rule: copper foil tracks on PCB should not have contact with other tracks, where this is not provided for in the circuit.

Actually there is different ways make a printed circuit board, for example, by separating sections of foil - tracks, with a groove cut through a cutter in the foil made of hacksaw blade. Or by applying a protective pattern to protect the foil underneath (future tracks) from etching using a permanent marker.

Or using LUT technology (laser ironing technology), where the tracks are protected from bleeding by baked-on toner. In any case, no matter how we make a printed circuit board, we first need to lay it out in the tracer program. I recommend it for beginners; it is a manual tracer with great capabilities.

Also, when laying out printed circuit boards yourself, or if you have printed a finished board, you need the ability to work with the documentation for the radio component, with the so-called Datasheets ( Datasheet), pages in PDF format. There are datasheets on the Internet for almost all imported radio components, with the exception of some Chinese ones.

On domestic radio components, you can find information in scanned reference books, specialized sites that post pages with the characteristics of radio components, and information pages of various online stores such as Chip & Dip. The ability to determine the pinout of a radio component is required; the name pinout is also used, because many, even two-terminal parts, have polarity. Practical skills in using a multimeter are also required.

A multimeter is a universal device, with the help of just one, you can carry out diagnostics, determine the pins of a part, their performance, the presence or absence of a short circuit on the board. I think it would not be amiss to remind, especially young beginner radio amateurs, about observing electrical safety measures when debugging the operation of the device.

After assembling the device, you need to arrange it in a beautiful case so that you won’t be ashamed to show it to your friends, which means you need metalworking skills if the case is made of metal or plastic, or carpentry skills if the case is made of wood. Sooner or later, any radio amateur comes to the point that he has to do minor repairs to equipment, first his own, and then, as he gains experience, from friends. This means that it is necessary to be able to diagnose a malfunction, determine the cause of the breakdown, and its subsequent elimination.

Often, even experienced radio amateurs, without tools, find it difficult to unsolder multi-pin parts from the board. It’s good if the parts need to be replaced, then we bite off the leads from the body itself and solder the legs one at a time. It is worse and more difficult when this part is needed to assemble some other device, or repairs are being made, and the part may need to be soldered back later, for example, when searching for a short circuit on the board. In this case, you need tools for dismantling, and the ability to use them is a braid and a desoldering pump.

Usage soldering gun I don’t mention it because beginners often lack access to it.

Conclusion

All of the above is only part of the required minimum that a novice radio amateur should know when designing devices, but having these skills, you can already assemble, with a little experience, almost any device. Especially for the site - AKV.

Discuss the article WHERE TO START FOR A RADIO AMATEUR