From June, 5438 to April, 2008, China's electronic component industry achieved a main business income of 485.676 billion yuan, a year-on-year increase of 32.56%. The growth rate of electronic components industry exceeded the average growth rate of electronic information industry by 1 1.9 and 14 percentage points respectively. In terms of proportion, the proportion of electronic components industry in the whole industry has also increased from 30% in the same period to 33. 1%. However, with the rising cost of raw materials and labor, the deterioration of demand environment and the acceleration of RMB appreciation, the performance growth of electronic component manufacturers has been continuously suppressed, and the characteristics of listed companies are obvious. In 2008 1 quarter, excluding LCD panels, the operating income of the whole industry was 10 103 million yuan, up by 3 1. 17% year-on-year, but the net profit was 373 million yuan, up by only 6.57% year-on-year. Resistance is represented by "r" plus a number in the circuit, for example, R 1 is represented by the number 1. The main functions of resistors in the circuit are shunt, current limiting, voltage division, bias and so on.
1. Parameter identification: the unit of resistance is ohm (ω), and the amplification unit is kiloohm (kω), megaohm (mω), etc. The conversion method is: 1 megohm = 1000 kiloohm = 1000000 ohm. There are three methods to mark the parameters of resistors, namely, direct marking, color marking and digital marking. A, the number scale method is mainly used for small-volume circuits such as patches, for example, 472 means 47×100Ω (that is, 4.7k); 104 means 100Kb, and the color ring labeling method is most used. Here are some examples: four-color ring resistor Five-color ring resistor (precision resistor).
2. See the following table for the relationship between color code position and resistance multiplying power: allowable deviation of color effective digital multiplying power (%) silver /x0.0 1 10 gold /x0. 1 5 black 0 +0/ brown1x10/kloc-. The yellow 4 x65438 1. capacitance is generally represented by "c" plus a number in the circuit (for example, C 13 is represented by the number 13). Capacitor is an element with two metal films attached to each other and separated by insulating material. The characteristics of capacitors are mainly blocking DC and circulating AC. The size of the capacitor means the amount of electric energy that can be stored. The blocking effect of capacitance on AC signal is called capacitive reactance, which is related to the frequency and capacitance of AC signal. Capacitance XC= 1/2πf c (f stands for the frequency of AC signal, and c stands for capacitance) The commonly used capacitor types in telephones are electrolytic capacitor, ceramic capacitor, patch capacitor, monolithic capacitor, tantalum capacitor and polyester capacitor.
2. Identification method: The identification method of capacitance is basically the same as that of resistance, which is divided into three methods: direct standard method, color standard method and number standard method. The basic unit of capacitance is farad (F), and other units are millifarad (mF), microfarad (uF), nanofarad (nF) and picofarad (pF). Where: 1 method = 10 3 millifarad = 10 6 microfarad = 10 9 nanofarad =10/2 picofarad, and the capacitance value of the capacitor with large capacity is directly indicated on the capacitor. For example, 10 uF/ 16V, and the capacitance value of a small capacitor is expressed by letters or numbers. Letter representation:1m =1000uf1p 2 =1.2pf1n =1000pf digital representation. For example, 102 means10×10 2pf =1000pf224 means 22× 10 4pf = 0.22 uf3, and the allowable error of the capacitance error indicator F G J K L M is 1%. Crystal diodes are usually represented by "D" plus numbers in circuits. For example, D5 is represented by the number 5.
1. Function: The main feature of diode is unidirectional conduction, that is, under the action of DC voltage, the on-resistance is very small; However, under the action of reverse voltage, the on-resistance is extremely large or infinite. Because of the above characteristics, diodes are often used in circuits such as rectification, isolation, voltage stabilization, polarity protection, coding control, frequency modulation and static noise in cordless phones. Crystal diodes used in telephones can be divided into rectifier diodes (such as 1N4004), isolation diodes (such as 1N4 148), Schottky diodes (such as BAT85), light-emitting diodes and zener diodes.
2. Identification method: diode identification is very simple. The N pole (negative pole) of most small power diodes is marked with a colored circle. Some diodes also use diode-specific symbols to indicate the P pole (positive pole) or the N pole (negative pole), while others use symbols such as "P" and "N" to determine diode polarity. The anode and cathode of LED can be identified by the length of the pin, with the long pin being positive and the short pin being negative.
3. Precautions for testing: When testing the diode with a digital multimeter, the red stylus is connected to the anode of the diode, and the black stylus is connected to the cathode of the diode. At this time, the measured resistance is the forward on resistance of the diode, which is just the opposite of the contact pin connection of pointer multimeter.
4. The commonly used 1N4000 series diodes are as follows: model1N4001N40021N40031N40041N40051. In the circuit, Zener diode is usually represented by "ZD" plus a number. For example, ZD5 stands for Zener diode with number 5.
The voltage stabilizing principle of 1. Zener diode: The characteristic of Zener diode is that the voltage at both ends remains basically unchanged after breakdown. In this way, when the voltage regulator is connected to the circuit, if the voltage at each point in the circuit changes due to the fluctuation of power supply voltage or other reasons, the voltage at both ends of the load basically remains unchanged.
2. Fault characteristics: The main faults of Zener diode are open circuit, short circuit and unstable regulated value. Among these three faults, the former shows that the power supply voltage rises; The latter two faults are characterized by the power supply voltage becoming low to zero volts or unstable output. The models and adjustment values of commonly used zener diodes are as follows: model1n47283.3v; 1n 47293.6v； 1n 4730 3.9V； 1n 47324.7v； 1n 47335. 1V； 1n 47345.6v； 1n 4735 6.2V； 1n 4744 15V； 1n 4750 27V； 1n 475 130v； 1N476 175V (the adjustment value is on the right). In a circuit, inductance is usually represented by "L" plus a number. For example, L6 is represented by the number 6. The induction coil is made by winding the insulated wire on the insulated skeleton for a certain number of turns. DC can pass through the coil, DC resistance is the resistance of the wire itself, and the voltage drop is very small; When AC signal passes through the coil, self-induced electromotive force will be generated at both ends of the coil, and the direction of self-induced electromotive force is opposite to the direction of applied voltage, which hinders the passage of AC, so the characteristic of inductance is to resist AC through DC. The higher the frequency, the greater the coil impedance. Inductance and capacitance can form an oscillation circuit in the circuit. Inductance generally has direct calibration method and color calibration method, and color calibration method is similar to resistance. For example, brown, black, gold and gold represent the inductance of 1uH (error 5%).
The basic unit of inductance is Heng (h), and the conversion unit is:1h =103mh =106uh. Transistors are often represented by "q" plus numbers in circuits, such as Q 17 for transistors numbered 17.
1. Features: Transistor (triode for short) is a special device with two PN junctions and amplification capability. There are two types of transistors, NPN and PNP, which can make up for each other in working characteristics. The so-called counter tube in OTL circuit is paired with PNP type and NPN type. PNP transistors commonly used in telephones are: A92, 90 15, etc. NPN transistors include A42,9014,9018,9013,9012, etc.
2. Transistors are mainly used for amplifying circuits, and there are three connection modes for common circuits. For comparison, the following table lists the characteristics of three transistor connection circuits for your reference. Common emitter circuit Common collector circuit (emitter output) Common base circuit has large input impedance (several hundred ohms to several thousand ohms) and small output impedance (several thousand ohms to several tens ohms). The voltage amplification factor is large (less than 650 ohms to tens of ohms). ) small (less than 1 and close to 1) high power amplification factor (about 30 ~ 40 dB) small (about 10 dB) medium (about 15 ~ 20 dB) good frequency difference. The continuation table adopts multistage amplifier intermediate stage, low-frequency amplifier input stage and high-frequency or output stage for impedance matching. 1. field effect transistor has the advantages of high input impedance and low noise, so it is also widely used in various electronic devices. In particular, field effect transistor can be used as the input stage of the whole electronic equipment, and it can obtain the performance that ordinary transistors can not achieve.
2.FET is divided into junction type and insulated gate type, and its control principle is the same. As shown in figure 1- 1- 1 are symbols of two models:
3. Comparison between FET and transistor (1) FET is a voltage control element, while transistor is a current control element. When the signal source only allows a small current, the field effect transistor should be selected; When the signal voltage is low and allows more current to be drawn from the signal source, the transistor should be selected. ⑵ FET is called unipolar device because it uses majority carriers to conduct electricity, while transistors use both majority carriers and minority carriers to conduct electricity. It is called a bipolar device. ⑶ The source and drain of some field effect transistors can be used interchangeably, and the gate voltage can also be positive or negative, which is more flexible than transistors. (4) FET can work under the condition of low current and low voltage, and its manufacturing process can easily integrate many FETs on a silicon chip, so FET has been widely used in large-scale integrated circuits. ; At the same time, the simple repair methods of some parts are introduced, which provides readers with detailed technical data such as technical parameters of common parts and replacement parts of common parts.
On the basis of the 2004 edition, this book supplements many new semiconductor devices, photoelectric devices, digital laser devices, digital display devices and vacuum devices of color kinescope, and adds specific models, technical parameters and application circuits of new components. The new version is more informative, more practical and closer to the practical application of readers.
This book is a popular, novel and practical popular science reading, which is suitable for technicians, maintenance personnel and application personnel of electronic products. It can be used as the basic teaching material of electronic technology in electronic mechanic schools, vocational schools and secondary specialized schools; It can also be used as a reference book for electronic enthusiasts. Chapter 65438 +0 electronic components
1. 1 resistor
1. 1. 1 function of resistor
1. 1.2 Various resistances
Main technical parameters of 1. 1.3 resistor
1. 1.4 semi-adjustable resistor
Quality appraisal and substitution of 1. 1.5 resistor
1. 1.6 Several Special Resistors
1.2 potentiometer
1.2. 1 Structure and function of potentiometer
1.2.2 Various potentiometers
1.2.3 naming method and main technical indexes of potentiometer
1.2.4 Maintenance and replacement of potentiometer
1.3 capacitance
1.3. 1 fixed capacitor
1.3.2 main technical parameters of capacitor
1.3.3 quality inspection, replacement and repair of fixed capacitors
1.3.4 Structure and specifications of variable capacitor
1.3.5 Repair and replacement of variable capacitors
1.3.6 semi-variable capacitor (trimming capacitor)
1.4 inductance element
1.4. 1 Self-inductance and inductance of the coil
1.4.2 Types and parameters of inductors
1.4.3 Common inductance coils in household appliances
Measurement and substitution of 1.4.4 inductor
Working principle and structure of 1.4.5 transformer
1.4.6 main technical parameters of transformer
1.4.7 transformers for various purposes
1.4.8 transformer fault and repair
1.4.9 magnetic element
Exercise 1
Chapter 2 Photoelectric Devices and Laser Heads
2. 1 ordinary LED
2. 1. 1 ordinary LED
2. 1.2 voltage source light emitting diode
2. 1.3 flashing LED
2. 1.4 infrared LED
2. 1.5 infrared emitting semiconductor laser diode
2.2 Photocell and Optocoupler
2.2. 1 photodiode
2.2.2 Silicon photovoltaic cell
phototransistor
photocoupler
2.2.5 Various photoelectric switches
phototransistor
2.3 photoelectric display device
2.3. 1 semiconductor LED digital display
LCD
Fluorescent digital tube
2.3.4 LED
plasma panel display
2.4 Laser head and CD
2.4. 1 laser head
2.4.2 Detection, maintenance and replacement of laser head
2.4.3 CD
Exercise 2
Chapter 3 Semiconductor Discrete Devices
3. 1 crystal diode
3. 1. 1 Basic knowledge of semiconductors
3. Working principle of1.2 crystal diode
3. 1.3 Various crystal diodes
3. 1.4 main technical parameters of crystal diode
3. Quality Identification and Substitution of1.5 Crystal Diodes
3.2 transistor
3.2. Working principle of1transistor
3.2.2 Classification and shape of transistors
3.2.3 Main technical parameters of transistor
3.2.4 Simple test method of transistor
Transistor calibration
3.2.6 Detection Method of High Power Tube
darlington tube
3.2.8 Replacement and substitution of transistors
3.3 field effect transistor
3.3. Working principle of1junction field effect transistor
3.3.2 Working principle of MOS field effect transistor
3.3.3 Main technical parameters of field effect transistor
3.3.4 How to distinguish the quality of FET?
3.3.5 Application and substitution of field effect transistor
3.3.6 High voltage compound field effect transistor
3.4 Thyristors and Single Junction Transistors
3.4. 1 Working principle of common unidirectional thyristor
TRIAC：TRIode AC semiconductor switch
3.4.3 Turn off the thyristor.
3.4.4 Main technical parameters of thyristor
Multi-purpose thyristor
3.4.6 Check the quality of thyristor with multimeter.
unipolar junction transisor
3.5 transistor array device
Exercise 3
Chapter 4 Semiconductor Integrated Circuits
4. 1 Basic knowledge of semiconductor integrated circuits
4. 1. 1 integrated circuit shape
4. 1.2 internal structure of integrated circuit
4. 1.3 Difference between integrated circuit and discrete component circuit
4. 1.4 Various integrated circuits
4.2 Semiconductor Digital Integrated Circuit
4.2. 1 bipolar digital integrated circuit
4.2.2 MOS digital integrated circuit
4.3 Semiconductor Analog Integrated Circuit
Characteristics and types of analog integrated circuits
4.3.2 Audio Amplification Integrated Circuit
4.3.3 Voltage-stabilized integrated circuit
Integrated operational amplifier
4.4 Semiconductor Power Amplifier Module Circuit
4.4. 1 fool175,275 power amplifier circuit
4.4.2 D series fool power amplifier circuit
4.4.3 AMP- 1200 integrated power amplifier circuit
4.5 Semiconductor Music Integrated Circuit
4.5. 1 semiconductor music integrated circuit
4.5.2 Various music integrated circuits
4.5.3 Wonderful use of music integrated circuits
4.6 Voice Integrated Circuit
4.6. 1 speech synthesis integrated circuit
4.6.2 One-time programmable voice integrated circuit
4.6.3 Electronic voice recording and playback module
4.7 TV integrated circuit
Television application specific integrated circuit
4.7.2 ASIC for TV remote control system
4.8 Application and substitution of semiconductor integrated circuits
4.8. 1 nomenclature and technical parameters of integrated circuits
4.8.2 Judging the quality of integrated circuits
4.8.3 Replacement and substitution of integrated circuits
Exercise 4
Chapter V Electric Vacuum Devices
5. 1 black and white picture tube
5. 1. 1 black and white picture tube structure
5. 1.2 working principle of black and white picture tube
5. 1.3 electron gun
5. 1.4 phosphor screen
5. 1.5 glass shell
5. 1.6 Parameters and uses of black-and-white kinescope
5.2 color kinescope
5.2. 1 three guns and three beams color cathode ray tube
5.2.2 Single-gun three-beam color picture tube
5.2.3 White Convergent Color CRT
5.2.4 New color picture tube
5.2.5 Inspection and replacement of kinescope
5.2.6 New direction of color kinescope
Exercise 5
Chapter 6 Plate Components
6. Characteristics and classification of1chip components
6.2 Sheet Passive Components
6.3 Sheet Active Devices
6.4 Surface Assembly Technology and Welding Method
6.5 Dismantling and assembling sheet parts in spare time.
Exercise 6
Appendix a graphic symbols and text symbols of common electrical diagrams
Appendix B Comparison Table of Domestic and Foreign Models of Commonly Used Semiconductor Tubes
Appendix c representative of common integrated circuits for TV sets at home and abroad
Appendix d practice answers