PCBA Tech - How to identify electronic components on a circuit board?

Electronic components refer to the assemblies of electronic products and small machines and instruments,which are often composed of several parts and can be used in similar products. Common pcb components include resistors,capacitors,diodes,transistors,inductors,and other devices.But how to identify electronic components on a circuit board?

Common electronic components and their identification

1.Resistance

The resistance is represented by "R" and a number in the circuit,for example,"R7" represents the resistance numbered.

The main functions of the resistance in the circuit are shunt, current limiting,voltage sharing,bias,filtering (combined with capacitors),and impedance matching.

There are two main methods for identifying resistors:

Number labeling method:mainly used for small volume circuits such as chip mounting

Color coding method:usually used for color ring resistors

2.Capacitance

Capacitance is generally represented by "C" and numbers in the circuit.Capacitance is assemblies composed of two metal films close together and separated by insulating materials in the middle.The main characteristic of a capacitor is its direct current isolation.

There are also two methods for identifying capacitors, namely color coding and number coding.

3.Diode

Diodes are commonly represented by "D" and numbers in circuits, such as D9 for diodes numbered 9.The main characteristic of diodes is unidirectional conductivity,which means that under the action of forward voltage,the conduction resistance is very smallUnder the action of reverse voltage,the conduction resistance is extremely large or infinite.

The identification of diodes is relatively easy,and the polarity of the diode can be determined directly through the symbol symbols "P" and "N".The positive and negative poles of a light-emitting diode can be identified by the length of the pins,with the long pin being positive and the short pin being negative.

4.Transistor

A transistor is commonly represented by "Q" and a number in a circuit,for example,Q3 represents a transistor numbered.

 A transistor is a special device that contains two PN junctions internally and has amplification capability.

The arrangement of the pins of the transistor has a certain pattern,with the plane facing towards itself. From left to right,there are three pins,e, b, and c, which are easy to recognize.

5.Inductance

Inductance is commonly represented by "L" and a number in a circuit.For example,L10 represents an inductance numbered 10,and an inductance coil is made by winding an insulated wire on an insulated skeleton for a certain number of turns.

Theidentification of inductance generally includes direct labeling and color labeling, which are similar to resistors.

Each component has a specific label,either on the main body or on the packaging.Specific markings or codes will include the manufacturer's unique part number,values and tolerances, polarity,and a color-coded strip representing the resistance.

A reference identifier is a set of alphanumeric codes used to identify specific assemblies on a PCB board.The circuit board is usually marked with+and - symbols to identify the positive and negative leads of the polarizing element.Similarly,in the case of unidirectional components such as diodes,mark+and - or A and K respectively to identify the anode or cathode.This is a method of identifying polarized component terminals.

How to identify electronic components on a circuit board?

Shape identification: Identifying electronic components based on their shape and package style. For example, a component in a TO-220 package might include a triode, SCR, FET or dual diode, while a component in a TO-3 package might include a transistor, an integrated circuit, and so on.

Circuit Symbol Identification: Component identification can benefit from parsing the information in circuit symbols. The number of pins, polarity, and other information shown in the circuit symbols can assist in determining the type of component and its function.

Pin Identification and Polarity Recognition: Components are identified by the order in which the pins are arranged and by their polarity characteristics. For example, the diode pin has a positive and negative points, can be identified through the multimeter to detect the direction of its conduction.

Component marking identification: many electronic components have markings printed on the shell, the use of these markings can query the precise model and performance parameters of the component.

Multimeter application: multimeter can measure the voltage, current, resistance and other parameters of electronic components, and then make judgement on the type of components.

Microscope observation: with the help of a microscope to magnify the component pins, markings and other subtleties, in order to more accurately confirm the type of components.

Electronic component automatic identification tool use: electronic component automatic identification tool can be measured through the parameters and characteristics of the component, to achieve automatic identification of component type.

In electronic circuits,there are different electronic components,including resistors,capacitors,inductors,diodes,transistors,integrated circuits,connectors,etc.Each of these assemblies is executed in a specific way to achieve the expected output of the circuit board.