The area of the circuit board is limited. In order to better realize the function and facilitate maintenance, electronic components usually appear in the form of letter codes + numbers. In order to standardize electronic circuits and facilitate use, generally speaking: the meaning of letter codes and the ordering of numbers have certain rules.

A simple example to illustrate:

R1, where R stands for resistor, resistors 1-1.

R11, where R-resistor, 11-11 resistors.

In R111, where R-resistor, 1-functional module, 11 represents the serial number of similar components on this functional module.

Generally speaking, the principle and sequence of reading electronic circuit components.

Example: R118 ~ the 18th resistor on the motherboard circuit.

1. The first English letter or combination indicates the name of the component, which is the code of the component.

2. The first number represents the different modules on the board.

Generally speaking: 1-mainboard circuit, 2-power circuit, 3-feedback circuit, etc., these can be decided by the designer.

3. The following numbers represent the serial numbers of similar components on this functional module. ie: 18th resistor and so on.

Second, the general common electronic circuit component code.

R—Resistor.

VR - Adjustable Resistor.

C—Capacitor.

D—Diode.

ZD - Zener diode.

Q - triode or field effect transistor. e-emitter, b-base, c-collector.

LED—Light Emitting Diode.

T—Transformer.

SW—Switch.

L—Inductance.

K—Relay.

GND—Common ground terminal.

LS—Buzzer.

FS—fuse.

RTH—Thermistor.

The connection between electronic circuit and macro power control circuit

1. The electronic circuit is composed of miniature electronic components, which are connected by circuit boards.

Under normal circumstances, the electronic circuit as a whole will be divided into several parts: power supply part, rectifier bridge part, filter part, voltage regulator part, amplification part, vector output part, etc., and these parts are generally in a roughly fixed mode. The general components, the general principles, can be generalized to a certain extent.

2. Macro power control circuit.

Generally, it is composed of contactors, PLCs, switches, electrical equipment, etc. connected by wires. In the circuit control process, it is generally divided into measurement circuit, power circuit, protection circuit, control circuit, output circuit and so on.

To a certain extent, electronic circuits and macroscopic power control circuits can be transformed into each other to achieve the same purpose. Mastering the abbreviated codes of electronic circuits and how to read them correctly is the basis for learning and repairing electronic circuits.

Of course, these are the default rules of the industry in general. It is best to measure with the help of a multimeter and other equipment, and the measurement results shall prevail.