Learning to read electrical circuits. Part 1

  • Dec 14, 2020

Everyone who has decided to master the basics of modern electronics will first of all have to learn to understand electrical circuits. It will not be difficult for a thoughtful user to do this if he carefully reads the materials presented here. After studying them, he can easily "read" even such a relatively complex diagram as this one:

It can be seen from the above photo that for each individual electronic component its own graphic icon and its own unique designation are introduced. For most elements, their nominal value (the value of the electrical parameter they represent) is also indicated in the schematic representation.

Order of designation of power supplies

Any electrical circuit, regardless of its purpose and complexity, is incapable of working without a constant power supply to it.

Note: Within the framework of this article, AC circuits are not considered, since they mainly concern only the field of electrical engineering.

Here are DC sources, namely:

  • Batteries of various classes and voltages.
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  • Typical batteries with a wide range of electrical parameters.
  • Network power supplies and other stationary power sources.

Despite the existing variety of these elements on the diagrams, they are always indicated the same way (with slight deviations).

Battery (galvanic cell)

Regardless of the type of element under consideration, (AA, AAA, etc.), as a rule, it is indicated by two dashes of different lengths (lengths). The longer line corresponds to the plus of the power supply, and the shorter one indicates the minus.

In the schematic space, a typical battery is identified by the letter designation "G" ("E"). If there is a separate power source in it, the latter is represented as a special icon (in the first figure "Vss" 5 Volts).

Representation and labeling of wires and connections

Electrical conductors in diagrams perform an important function, which consists in combining elements into a single functional chain. When transferred to the diagram, they are represented by parallel or intersecting line segments (photo below).

When designating connections, the names of typical installation wires are most often taken, which differ in their cross section, as well as in the material of manufacture, type of insulation and other parameters.

Elements of circuit solutions and their combinations

To learn how to understand electrical circuits, you will need to familiarize yourself with the main components that make up almost all working circuits. It:

  • Resistors (fixed and variable).
  • Transistors of various types.
  • Semiconductor diodes and LEDs.
  • Capacitors (simple and electrolytic).
  • Inductors of all kinds.
  • Diode bridges, etc.

A graphical representation of some of them can be found in the figure below.

When drawing up diagrams, the necessary elements in the necessary combinations, along with the conductors connecting them, are simply transferred to a blank sheet of paper.