Brief description:Electronic technologyThe basic course was designed to provide an in-depth and shallow teaching to beginners and to include 40 flash video courses. The course detailed core electronic technical knowledge on applications of diodes and triodes, design and analysis of basic circuit maps. Learners will systematically master the theory and practice of electrons and basic circuits, including the working principles of the diodes, the magnification and switch control functions of the triodes, and the reading and writing skills of the basic circuit maps. This knowledge provides the basis for in-depth learning on analog circuits and other electronic engineering skills。
1. Introduction to basic knowledge on electronic technologies 1. 1 origin and development of electronic technologies
The history of electronic technology dates back to the beginning of the twentieth century and, with the invention of vacuum tubes and the advent of transistors, it has evolved to become the foundation of the modern information society. Over time, electronic technology has continued to integrate disciplines such as computers, communications and so forth, creating a wide range of areas, including embedded systems, microelectronics and circuit design。
1. 2 application of electronic technologies in modern life
In modern life, almost every corner of the world is bound by the application of electronic technology. From simple remote controls to complex aircraft control systems, electronic technologies have improved the ease of life and promoted the development of many industries, such as industrial automation, remote communications and medical equipment。
1. 3 core skills of electronic engineers
The core skills required of electronic engineers include circuit design, signal analysis, system integration and programming. At the same time, they need to have some capacity for project management and teamwork, as well as up-to-date industry knowledge and technological insights。
Through the introduction of this chapter, the reader will have a basic understanding of electronic technologies, which will provide a good basis for further learning from the more advanced content of this series。
2.Bipolar application2. 1 structure and type of diode 2. 1. 1 physical structure of the diode
The core function of the basic element in the diode, electronics, is to allow one-way current flow. Physically, it consists of a p-type semiconductor and a n-type semiconductor, both of which are exposed in an area called the pn knot. At this point of contact, the reorganization of electronics and hollows has created a depletion zone, which has an impact on electronic mobility. When a positive voltage (i. E. A positive p-end, a negative n-end) is applied to the diodes, the depletion layer becomes narrower, the electrons are able to flow through the pn and the diode catheter. When reverse voltage is applied, the depletion layer is widened to prevent current flow and the diode is closed。
Graph lr
a [p-type semiconductor] -- > | > [pn conductor]
b -- > c [n-type semiconductor]
d [n-type semiconductor] -- > | inverse bias | b [pn closing]
c -- b
b-> inverse bias e2. 1. 2 characteristics of different types of diodes
Different diodes apply to different applications because their design and manufacturing processes determine their electrical properties. For example, the ordinary contour diode is applied to the arc-to-dc contours; the shortki diode is coloured in switch speed and low positive-down; the led and laser diodes are used in a wide range of applications in the field of display and communication。
2. 2 operating principles for diodes 2. 2. 1 single-flow guidance
One-way current guidance is one of the core properties of the diode. When the diode ends plus positive voltage, the reduced width of the depleted area, plus the fact that the electric field exceeds the built-in power field, allow electronics and empty holes to be composited across the depleted area, thus enabling currents to flow. This process can normally be expressed as:
I = i 0\cdot (e^ (\frac{v}}-1)Of these, i is the current via the diode, i 0 is the reverse saturated current, v is the voltage added to the diode, n is the ideal factor (usually between 1 and 2) and v t is thermal voltage (approximately 26 mv@room temperature)。
2. 2. 2 inverse penetration properties and protection
When the diode is added to the reverse voltage, the width of the depletion zone increases rapidly and the intensity of the electric field in the depletion layer increases. When the intensity of the field reaches a certain level, electronics may acquire enough energy to collide with other atoms, creating more electro-empty pairs, leading to a sharp increase in currents, a phenomenon known as piercing. The voltage when punched is called piercing. In practical applications, penetration is an important parameter to ensure that the diodes are not damaged in high voltage working environments。
2. 3 application of diodes in circuits 2. 3. 1 fluiding and pressure stabilization
In power design, the diodes are used for the ac to transfer the dc flow chain. The purpose of current circuits is to convert the exchange voltage to direct current voltage. The simplest current circuit is half-wave, which uses only one and a half cycles of power exchange. A more efficient full-wave whole-flow circuit can be achieved using the full cycle of power exchange through the use of a bridge full-flow circuit consisting of four diode tubes。
Steady diodes (zina diodes) are another application that uses diode reverse penetration. The steady-pressure diode tube works in the piercing area, but is capable of providing stable voltage output in case of load changes because the manufacturing process controls the accuracy of the piercing。
2. 3. 2 application of diodes in signal processing
The diodes play an important role in signal handling circuits. For example, they can be used as wave detectors to remove the frequency of the wave in the modem signal and leave the modem message. The diode switch is another application whose working method is that the conductive and cut-off properties of the diode can be used to control the path of the signal。
For example, in am broadcast receivers, diodes can be used to isolate audio signals from the carrier. In circuits, the diodes respond to the amplitude changes of the input signal through their non-linear response, thus enabling the signal to be detected。
The diodes are less used in digital logical circuits, but can be used to protect circuits against the reverse input of voltage into sensitive electronic devices, which is important for improving the reliability of circuits。
In the next section, we will explore the magnification and switch control function of the tripolar tube, which will lead us to a better understanding of the role of electronic components in signal processing and power control。
3. 1 structure and classification of triode 3. 1. 1 basic structure of triode
Triode is a semiconductor device with two pn structures with three end points: collator, c, bCase, short b and launch pole (emitter, short e). In the npn-type triodes, the collector poles and the launch of the ultra-n semiconductor, the base of the extreme p semiconductor, while in the pnap-type triodes, the aggregate poles and the launch of the extreme p semiconductor, the base of the extreme n semiconductor. The work of the triodes relies on the control of current trans-basic-launching condensed currents, which in turn affect the condensed-launching condensed currents。
Graph lr
a [launching polar e] -- > | | | | | | | | | | | | | | | [ [ | | | > > > > > > > > > > > > >
b-> magnification or control of c-[collective pole c]3. 1. 2 distinction between npn and pnp triodes
Npn and pnp triodes differ in the nature of current flows, but they work in essentially the same way. The main difference is current direction and conductivity:
3. 2 amplification of triodes 3. 2. 1 work to magnify circuits points
In amplification circuits, the work point of the tripolar tube (also known as static work point or q point) is a fixed state of operation of the tripolar tube, commonly referring to the specific values of the collectivated electrode current (ic) and the collector polar-launched polar voltage (vce). The location of this point determines the ability of the triode to magnify the signal. The correct setting of work points is key to scaling up circuit stabilization。
3. 2. 2 magnifying multiples and frequencies response
The magnification capacity of the triodes is determined by direct flow magnification times beta (beta) and exchange magnification times hfe (small signal amplification times). Beta values refer to the ratio of the total electron current variability to that of the base electron. The frequency response describes the magnification capacity of the triode under different frequency signals, which is reduced under the high frequency signal due to the capacity effects and limitations of the internal structure of the transistor。
3. 3 switch control for triodes 3. 3. 1 switch speed and drive capacity
When triodes are used as switches, their switch velocity, i. E., the time required to switch from a conduit state to a cut-off state and the time required to switch from a cut-off to a conduit state, is essential for the design of digital circuits. Driver capacity is the maximum load current that the triode can withstand, which determines the maximum load that the triode can drive on a given circuit。
3. 3. 2 examples of applications of triodes in digital circuits
In digital circuits, triodes can be used as switches to control the breakage of electricity. For example, in a simple switch circuit, the base pole of the tripolar tube receives an appropriate signal that can channel between the collector and the transmitter poles, driving the load between the collector and the power source. The following is an example of a typical digital circuit using npn-type triodes:
// example: control led lamps with tripolar tubes
i don't knowSasepin = 3; / /matrix-led foot-link to numerical entry 3
int ledpin = 13; / / launch extreme-led foot connections to the built-in led (leg 13 on most arduino boards)
void setup()
pinmode(b)Asepin, output; / /set the base pole to the output mode
pinmode(ledpin, output); / / set led to output mode
♪ i'm sorry ♪
void loop(){
digitalwrite(b)Epin, high; / /gy-high-altitude wiring all
delay (1000); / / 1 second delay
digitalwrite(b)Asepin, low; / /matrix low-level end
delay (1000); / / 1 second delay
♪ i'm sorry ♪In the above code, the lighting and neutralization of led lamps is controlled by sending high and low level signals to the base pole. Attention is drawn here to the need for appropriate electrical resistance between the poles and the launch poles in order to limit currents across the poles and avoid the maximum currents of the cells above the tripolar tubes. At the same time, suitable load resistance should be selected between ced-launching poles to ensure that currents are within safe limits。
The above sections demonstrate the basic application of the tripolar tube in magnifying signal and switch control and its means of implementation, which are essential for understanding signal handling and control mechanisms in electronic devices。
4. Design and analysis of basic circuit maps 4. 1 basic composition and symbols of circuit charts
The circuit chart is a graphical expression of the electronic circuit, which uses standardized symbols and links to indicate the electrical connection between the elements and between the power source and the ground. Understanding the basic composition and symbols of circuit maps is essential for the design and analysis of circuits。
4. 1. 1 symbolic representation of electronic components
The electronic widget symbol is the smallest unit in the circuit map, and each symbol represents a specific electronic component. For example:
The symbols are designed to be concise and to facilitate the rapid identification of the elements in the circuits and how they are connected。
4. 1. 2 basis for reading and drawing circuit maps
Reading circuit maps requires first familiarization with the elements represented by the symbols, then understanding the connection and direction of the signal flow of the circuit. The drawing of circuit maps is subject to certain rules:
Specialized electronic mapping software, such as altium designer, eagle, etc., is usually used in the drawing of circuit maps to ensure that the graphics are accurate and standardized。
4. 2 circuit design process
The design of the circuit is a systematic, step-by-step process, and detailed pre-design preparations and design steps and methods are described below。
4. 2. 1 pre-design preparations
Adequate preparation is required before the design of the circuit is initiated, including:
These preparations are critical to the success of the circuit design。
4. 2. 2 path design steps and methods
General steps in the design of circuits include:
This process not only guides beginners in the design of circuits, but also serves as a reference for experienced engineers to optimize design。
4. 3 analytical techniques for circuit maps
Circuit chart analysis is an important means of understanding the working principles of circuits and of diagnosing failures. This section presents the analysis of the principles of the circuit and the techniques of fault diagnosis and circuit optimization。
4. 3. 1 analysis of the principles of circuit operation
A rationale analysis of the circuit map requires:
The analysis of the logic of circuits helps to understand the logic and physical behaviour of circuits。
4. 3. 2 fault diagnosis and circuit optimization
Fault diagnosis is an important component of circuit analysis. The following steps are generally used for the diagnosis of failure:
After diagnosis of failure, electrical circuits can be optimized based on problems identified:
The optimization process requires repeated testing and validation to ensure that the changes achieve the desired results and improve circuit performance and stability。
The above is an in-depth introduction to the design and analysis of basic circuit maps, from the symbolic expression of electronic components, the process of circuit design to the analytical techniques of circuit maps, the contents of which are intended to provide readers with knowledge of the design and analysis of circuit maps from the base to the next steps. In the next section, we will further explore the design and operation of analog circuits。
5. Simulation of circuit working principles and design 5. 1 basic concepts of analogue circuits
Simulation circuits are electronic circuits for the processing of analogue signals compared to digital circuits. Simulation signals are continuous in time and in range, in contrast to the fragmentation of digital signals。
5. 1. 1 distinction between analogue signals and digital signals
Simulation signals can be expressed by continuously changing voltage or currents, such as volume or temperature changes. Simulation signals can easily be amplified, filtered and mixed directly through electronic devices, but they are sensitive to noise and susceptible to interference. This sensitivity to simulated signals complicates the design of analogue circuits。
In contrast, digital signals are expressed through discrete levels, such as high and low levels of binary systems. Digital circuits are usually considered easier to design and standardize, especially in large-scale integrated circuits (ic). The introduction of digital signal processing (dsp) technology allows complex functions to be performed with high accuracy and reliability。
5. 1. 2 major applications of analogue circuits
Simulation circuits are widely used in a number of areas, including:
These applications of analogue circuits require precise and reliable design to ensure optimal system performance。
5. 2 important components in simulated circuits
In analogue circuit design, specific components perform critical functions in which compute amplifiers and filters are two essential elements。
5. 2. 1 actuation and application of amplifiers
Op-amp is a high-benefit straight-flow amplifier with two input (reverse and same input) and one output. Operating amplifiers are usually used for various simulations, such as additions, subtractions, points and fractions。
The main method of operation of the amplifier is based on its high-opening ring gain. Ideally, when the differential input is zero, the output of the algorithm amplifier tends to be infinite. In practical applications, however, it stabilizes its output through feedback loops, making the actual magnification multiples determined by the feedback network。
Op-amp applications include:
5. 2. 2 design and application of filters
The filter is a circuit that allows a signal to pass within a given frequency range while preventing other frequency signals from passing. In the design of analog circuits, filters are essential, for example, to separate bass and altimeters from the audio system or to select specific signal channels in wireless communications。
There are four main types of filters: low, high, transit and barrier. They are designed to rely on basic electronic components such as electrical resistance, capacitors, electrons and operating amplifiers。
Key parameters for filter design include:
5. 3 case analysis of analog circuit design
Practical analog circuit design is a multi-step process involving theoretical analysis and experimental validation. The design process needs to take into account the performance requirements of circuits, their cost and the feasibility of manufacture。
5. 3. 1 details of physical circuit design steps
Circuit design begins with the conceptualization phase, which requires clear design objectives and functional requirements. Once the specifications of the circuits are established, the next steps include:
5. 3. 2 common problems in design and solutions
Some of the common problems that may be encountered in modelling circuit design are:
In order to effectively address these issues, designers need to have a deep knowledge and experience and to use circuit simulation software for repeated simulation and validation。
The design and realization of analog circuits is a complex but very creative exercise that requires designers to understand the theory of circuits in depth, have the capacity to solve practical problems and have precision control over the characteristics of electronic components. Through continuous experience and experience, engineers can design both stable and efficient analog circuit systems。
6. E-engineering hands-on skills development
In the area of electronic engineering, theoretical knowledge and hands-on skills are equally important. This chapter will explore in depth the development of practical electronic engineering skills, starting with the identification and use of basic electronic components, to circuit board design and welding techniques, and finally to the basic operation of laboratories and the use of measurement instruments。
6. 1 identification and use of basic electronic components
To become an electronic engineer, it is first necessary to be familiar with the identification and use of basic electronic components. The three most common components of the circuits are resistance, capacitive and sensory, each with different functions and characteristics。
6. 1. 1 awareness of commonly used resistance, capacitivity and perception
Electrical resistance is used to limit current flow in circuits, usually marked by electrical resistance values in om(th). There are a number of methods to mark resistance, most commonly the colour ring system, which usually consists of four rings, with the first two showing values, the third indicating multiples and the fourth indicating error。
The capacitor is used to store the charge, usually consisting of two pieces of metal, separated by the medium and having a capacity in farah (f). Capacitive values may be fixed or variable and usually indicate their rated capacity on the capacitors。
The electron sense is primarily a component of a wire used to generate magnetic fields in circuits and store energy in henry (h). The value of electrons is determined mainly by the number of coils, the area of the coil and the distance between them。
6. 1. 2 component selection and measurement in practical application
In selecting the components, consideration is given not only to whether their specifications and parameters meet the requirements of the circuit design, but also to the temperature, humidity, etc. Of the actual working environment. For example, ambient temperatures can affect resistance and the stability of the electrical capacity, and the perception may affect the electrons by causing thermal expansion or contraction of the coil due to temperature changes。
The measurement of electrical resistance can be done using a one-size-fits-all form, while the measurement of the capacity and sense requires the use of a specific lcr form. The correct measurement methods include the selection of the appropriate range, the correct placement of the element's leg to the test bar, and attention to read stabilization values。
6. 2. Design and welding techniques for circuit boards
Circuit boards (pcb) are an essential part of electronic equipment, and the good or bad design and welding techniques directly affect the performance and reliability of electronic products。
6. 2. 1 basic process for pcb design
The pcb design process includes the following steps:
Develop design specifications, including the size of circuit boards, the number of layers and the required electronic components. Designing the principle map and mapping the circuit connection. Converts to the pcb layout for the placement of components and the drawing of lines. Upon completion of the design and wiring, a drc (design rules check) is performed to ensure that there are no errors. The last is the export of the gerber file, which is a standard document format manufactured by pcb. 6. 2. 2 artisanal and smt welding techniques
Artificial welding is used mainly for the installation or repair of a small number of components, and commonly used tools include welders of sissy, welded saline and hot wind guns. Welding is performed with regard to temperature control and the quality of the welding points。
Smt (surface patching technique) welding is a welding process that uses a piece of paste element to be installed directly on the surface of the circuit board. During the smt welding process, ensure that welding is printed in a uniform manner, that the stickers are accurate and that welding is melted into welding points using a reflow furnace。
6. 3 laboratory basic operating and measurement instrument use
The laboratory is an important site for experiments and measurements by electronic engineers. Accurate operations and correct measurement tools are the basis for obtaining accurate data。
6. 3. 1 methods of use of tens of thousands of meters, oscillators
One of the most commonly used measurement tools for electronic engineers is the universal meter, which can be used to measure electrical voltage, currents, electrical resistance and the breakdown of diodes. Pre-use should ensure that the correct measurement range is selected and that the accuracy of the reading is observed。
The oscilloscope, which is used to observe waveforms and signal changes in circuits, is a powerful instrument for analysing circuit dynamics. When using oscilloscopes, the probe decay ratio and trigger conditions are correctly set to capture the wave shape clearly。
6. 3. 2 experimental data analysis and error processing
Analysis of experimental data is an integral part of the experimental study and is key to determining its success. Once the experiment is completed, the data collected need to be collated, analysed and compared. For data error processing, statistical methods, such as averages, standard deviations, etc., can be used to reduce the impact of system errors and random errors。
Introduction: the e-technology foundation course was designed to provide in-depth learning for beginners and to include 40 flash video courses. The course detailed core electronic technical knowledge on applications of diodes and triodes, design and analysis of basic circuit maps. Learners will systematically master the theory and practice of electrons and basic circuits, including the working principles of the diodes, the magnification and switch control functions of the triodes, and the reading and writing skills of the basic circuit maps. This knowledge provides the basis for in-depth learning on analog circuits and other electronic engineering skills。
