Radio components are the symbols on the diagram. How to read the designations of radio components in the circuit?

In the article you will learn about what kind of radio components exist. Designations on the scheme in accordance with GOST will be considered. You need to start with the most common - resistors and capacitors.

In order to assemble any design, it is necessary to know what the radio components look like in reality, and also how they are indicated on electrical circuits. There are a lot of radio components - transistors, capacitors, resistors, diodes, etc.

Capacitors

Condensers are parts that occur in any construction without exception. Usually the simplest capacitors are two plates of metal. And as the dielectric component acts air. Immediately remember the lessons of physics at school, when the topic of capacitors was being discussed. As a model, there were two huge flat round glands. They were brought closer to each other, then they moved away. And in each position, measurements were taken. It should be noted that mica can be used instead of air, as well as any material that does not conduct electric current. The designation of radio components on imported concepts differs from GOSTs adopted in our country.

Please note that normal current does not flow through conventional capacitors. On the other hand, an alternating current passes through it without much difficulty. Given this property, the capacitor is installed only where it is necessary to separate the variable component in direct current. Consequently, we can make a replacement scheme (by the Kirchhoff theorem):

1. When working on alternating current, the capacitor is replaced by a conductor segment with zero resistance.
2. When working in a DC circuit, the capacitor is replaced (no, not capacitance!) By resistance.

The main characteristic of the capacitor is the electrical capacitance. The unit of capacity is Farad. It is very large. In practice, as a rule, capacitors are used , whose capacitance is measured in microfarads, nanofarads, microfarads. On the circuits, the capacitor is designated as two parallel dashes, from which the bends go.

Variable capacitors

There is also such kind of devices at which capacity changes (in this case due to the fact that there are movable plates). The capacity depends on the size of the plate (in the formula S is its area), and also on the distance between the electrodes. In a variable capacitor with an air dielectric, for example, thanks to the presence of a moving part, it is possible to quickly change the area. Consequently, capacity will also change. But the designation of radio components on foreign schemes is somewhat different. The resistor, for example, is depicted in them as a broken curve.

One of the varieties of variable capacitors is trim. They are actively used in schemes in which there is a strong dependence on parasitic capacitances. And if you install a capacitor with a constant value, the whole structure will not work properly. Therefore, you need to install a universal element, which after the final installation can be adjusted and locked in the optimal position. The diagrams are indicated in the same way as the constants, but only the parallel plates are crossed out by an arrow.

Constant capacitors

These elements have differences in the design, as well as in the materials from which they are made. One can single out the most popular types of dielectrics:

1. Air.
2. Mica.
3. Ceramics.

But this applies exclusively to nonpolar elements. There are still electrolytic capacitors (polar). These elements have very large capacities, ranging from tenths of microfarads to several thousand. In addition to the capacitance of such elements, there is another parameter - the maximum value of the voltage at which its use is allowed. These parameters are prescribed on the circuits and on the capacitor housings.

Designations of capacitors in circuits

It should be noted that in the case of using tuning or variable capacitors, two values are indicated: minimum and maximum capacitance. In fact, on the body, you can always find a range in which the capacitance will change if you rotate the instrument axis from one extreme position to another.

Suppose there is a variable capacitor with a capacity of 9-240 (the default measurement in picofarads). This means that with a minimum overlapping of the plates, the capacity is 9 pF. And at the maximum - 240 pF. It is worthwhile to consider in more detail the designation of radio components on the scheme and their name in order to be able to correctly read technical documentation.

Coupling of capacitors

At once it is possible to allocate three types (all exists so much) connections of elements:

1. Sequential - the total capacity of the entire chain is easy to calculate. It will in this case be equal to the product of all the capacities of the elements, divided by their sum.
2. Parallel - in this case to calculate the total capacity is even easier. It is necessary to fold the capacitors of all the capacitors that enter the chain.
3. Mixed - in this case the scheme is divided into several parts. We can say that it is simplified - one part contains only parallel elements, the second - only sequentially.

And this is only general information about capacitors, in fact, a lot about them can be told, give an example of entertaining experiments.

Resistors: general information

These elements can also be found in any design - even in the radio receiver, even in the control circuit on the microcontroller. This is a porcelain tube on which a thin film of metal (carbon - in particular, soot) was sprayed from the outside. However, you can even apply graphite - the effect will be similar. If the resistors have very low resistance and high power, then a nichrome wire is used as a conductive layer .

The main characteristic of a resistor is resistance. Used in electrical circuits to set the required current in certain circuits. At physics lessons, a comparison was made with a barrel filled with water: if the pipe diameter was changed, the speed of the jet could be controlled. It is worth noting that the thickness of the current-carrying layer depends on the resistance. The thinner this layer, the higher the resistance. In this case, the symbols of the radio components on the circuits do not depend on the dimensions of the element.

Constant resistors

As for such elements, we can distinguish the most common types:

1. Metallized varnished heat-resistant - abbreviated MLT.
2. Moisture Resistant - Sun.
3. Carbon lacquered small - ULM.

Resistors have two main parameters - power and resistance. The last parameter is measured in ohms. But this unit of measurement is extremely small, so in practice, more often you will find elements in which the resistance is measured in megaohms and kilohms. Power is measured exclusively in Watts. And the dimensions of the element depend on the power. The larger it is, the larger the element. And now about what is the designation of radio components. On the schemes of imported and domestic devices, all elements can be labeled differently.

In domestic circuits, the resistor is a small rectangle with a 1: 3 aspect ratio, its parameters are prescribed either from the side (if the element is positioned vertically) or from above (in the case of a horizontal arrangement). First, the Latin letter R is indicated, then the serial number of the resistor in the circuit.

Variable resistor (potentiometer)

Constant resistance has only two conclusions. But the variables are three. On the electrical circuits and on the body of the element, the resistance between the two end contacts is indicated. But between the middle and any of the extreme resistance will vary depending on the position in which the axis of the resistor. In this case, if you connect two ohmmeters, you can see how the reading of one will change in the smaller direction, and the second - in the larger one. It is necessary to understand how to read circuits of electronic devices. The designations of the radio components will not be superfluous either.

The total resistance (between the outermost terminals) will remain unchanged. Variable resistors are used to control the gain (with their help you change the volume in radio receivers, TVs). In addition, variable resistors are actively used in cars. These are fuel level sensors, speed controllers for electric motors, brightness of lighting.

Connecting Resistors

In this case, the picture is completely the same as that of the capacitors:

1. Sequential connection - the resistance of all elements in the chain is added up.
2. Parallel connection - the product of resistances is divided by the sum.
3. Mixed - the whole scheme is broken into smaller chains and calculated step by step.

This can close the review of resistors and begin to describe the most interesting elements - semiconductor (radio components on circuits, GOST for UGO, are discussed below).

Semiconductors

This is the largest part of all radio elements, since not only zener diodes, transistors, diodes, but also varicaps, variconds, thyristors, triacs, microcircuits, etc. are included in the number of semiconductors. Yes, microcircuits are one crystal on which there can be A great number of radioelements - and capacitors, and resistances, and pn junctions.

As you know, there are conductors (metals, for example), dielectrics (wood, plastic, cloth). There can be various designations of radio components on the scheme (a triangle is, most likely, a diode or a zener diode). But it is worth noting that the triangle without additional elements denotes a logical ground in microprocessor technology.

These materials either conduct current, or not, regardless of the state of their aggregation. But there are also semiconductors whose properties vary depending on specific conditions. These are materials such as silicon, germanium. By the way, glass can also be attributed to semiconductors in part - in normal state it does not conduct current, but when the heating is complete, the picture is reversed.

Diodes and zener diodes

The semiconductor diode has only two electrodes: a cathode (negative) and an anode (positive). But what are the features of this radio component? The notation on the diagram can be seen above. So, you connect the power supply with a plus to the anode and a minus to the cathode. In this case, the electric current will flow from one electrode to the next. It is worth noting that the element in this case has very little resistance. Now you can conduct an experiment and connect the battery in reverse, then the resistance to the current increases several times, and it stops moving. And if you direct an alternating current through the diode, you will get a constant output at the output (albeit with small pulsations). When using a bridge circuit, two half-waves (positive) are obtained.

Zener diodes, like diodes, have two electrodes - a cathode and an anode. In the direct connection, this element works exactly the same as the above diode. But if you start up the current in the opposite direction, you can see a very interesting picture. Initially the zener diode does not pass current through itself. But when the voltage reaches a certain value, a breakdown occurs, and the element conducts a current. This is the stabilization voltage. A very good property, through which it turns out to achieve a stable voltage in the circuits, completely get rid of fluctuations, even the smallest ones. The designation of radio components on the circuits is in the form of a triangle, and at its top there is a line perpendicular to the height.

Transistors

If the diodes and zener diodes can sometimes not even be found in the designs, then transistors you will find in any (except the detector receiver). Transistors have three electrodes:

1. Base (abbreviated as "B" is denoted).
2. Collector (K).
3. Emitter (E).

Transistors can work in several modes, but most often they are used in amplifying and key (like a switch). You can make a comparison with the horn - in the base shouted, from the collector flew a strengthened voice. And for the emitter hold your hand - this is the case. The main characteristic of transistors is the gain factor (the ratio of collector current and base). It is this parameter, along with many others, that is fundamental for this radio component. The symbols on the circuit of the transistor are a vertical line and two lines that approach it at an angle. Several common types of transistors can be distinguished:

1. The polar.
2. Bipolar.
3. Field.

There are also transistor assemblies, consisting of several amplifying elements. Here are the most common there are radio components. The notation on the diagram was considered in the article.