Schematic diagram

Schematic diagram is a kind of circuit diagram used to embody the working principle of electronic circuit, also known as? Electrical schematic diagram? . Because it directly reflects the structure and working principle of electronic circuits, it is generally used in the design and analysis of circuits. When analyzing the circuit, we can know the actual working situation of the circuit by identifying the symbols of various circuit elements drawn on the drawings and their connection methods. The diagram below shows the schematic diagram of the radio circuit.

Block diagram (block diagram)

Block diagram is a kind of circuit diagram which uses blocks and lines to represent the working principle and composition of the circuit. Fundamentally speaking, this is also a schematic diagram. However, in this kind of drawing, there are almost no symbols except boxes and connecting lines. The main difference between it and the schematic diagram above is that all the components of the circuit and their connection modes are drawn in detail in the schematic diagram, while the block diagram only divides the circuit installation function into several parts, depicts each part as a box, adds a simple text description to the box, and illustrates the relationship between the boxes with connecting lines (sometimes arrows).

Therefore, the block diagram can only be used to reflect the general working principle of the circuit, while the schematic diagram can not only show the working principle of the circuit in detail, but also be used as the basis for collecting components and making circuits. The following figure shows the block diagram of the above radio circuit.

assembly diagram

It is a kind of drawing used for circuit assembly, and the symbols on the drawing are often the physical outline drawings of circuit elements. As long as we connect some circuit components according to the picture, we can complete the assembly of the circuit. This kind of circuit diagram is generally for beginners.

According to the different assembly templates, the assembly drawings are also different. The printed circuit board to be introduced below is used in most electronic products, so the printed circuit board is the main form of assembly drawing.

Read the circuit diagram

When analyzing the circuit, we can know the actual working situation of the circuit by identifying the symbols of various circuit elements drawn on the drawings and their connection modes. Schematic diagram is a circuit situation used to reflect the working principle of electronic circuits.

PCB diagram is the mapping diagram of circuit board, which describes the wiring of circuit board and the location of components in detail.

Look at the circuit diagram, first look at the power supply part, to understand what power supply the circuit works under, AC or DC, single power supply or multi-power supply and voltage level. I see, and then look at the sub-circuit. First, distinguish between digital circuits and analog circuits. For analog circuits, look at the signal acquisition, find out the source of the signal, including RF, audio, various sensors, meters and other circuits, and analyze whether the signal is AC, DC or pulse, voltage or current. Analyze the function of the subsequent circuit to see whether it is demodulation, amplification, shaping or compensation. Finally, it depends on whether the output circuit is modulated or driven. Digital circuit mainly analyzes the logic function and function of the circuit.

To understand the circuit board, it is best to first understand its electrical schematic diagram (circuit diagram), master the labeling method and working principle of electronic components, master the normal parameters of some commonly used components and their functions in normal circuits, and then analyze the circuit board (called printed circuit board) to understand its working principle and some things that need to be mastered quickly.

Molecular circuit module, then find the core component of the sub-circuit (of course, you should be familiar with this component), find out the relationship between the electrical quantities of each sub-circuit module, and finally get the output and input or function of the whole circuit.

The whole circuit has certain functions and consists of unit circuits, which form signal processing branches with certain functions, and then these branches form the whole circuit. First, find out what the circuit diagram you are looking at is, what kind of circuit it belongs to, whether it is audio, video, digital or mixed circuit, and then interpret these circuits with the corresponding knowledge of unit circuits. At the same time, we should analyze them from AC signal level and DC level. The DC part of the circuit is the basis of the normal operation of the circuit, and the AC signal can only be processed after the DC circuit is normal. Without a good DC state, the circuit can't work normally.

It should also be analyzed from the frequency level and gain level of the amplifier. When the circuit processes signals with different frequencies, due to the nonlinear components in the circuit, there will be different processing results for different frequencies, and the amplifier will have different amplification capabilities for signals with different frequencies. When designing the circuit, the required frequency signal will be purposefully processed to meet the functional requirements of the machine. Then it is necessary to analyze the relationship between unit circuits and the relationship between input and output of unit circuits.

What happened to the AC signal after passing through these circuits, and so on. Only by knowing the working principle of each branch can we analyze the working principle of the whole machine. Sometimes, there is signal cross-connection between branch circuits. For example, a line retrace pulse of a line output circuit of a TV set is used in a color decoding circuit, and the line output circuit and the color decoding circuit are connected with each other. At this time, these branches can be understood as another unit circuit, and then analyzed.

I think there is a sequence problem: for example, high-frequency circuits, we must first master the relationship between the functions of the circuits and the input and output. After we have a general grasp, it is like catching the bull's nose, because although the circuits are different and the devices are different, the frequency spectrum of their input-output relationship will not change. Then, the basic principle and method of realizing this function transformation are analyzed, which are specific to some parts.

The circuit design is based on the analysis of the circuit schematic diagram, but first of all, we need to know the pins and basic functions of the required chip, so as to better understand the working principle of the circuit and apply it to our own circuit, which is conducive to the cutting and expansion of the circuit.

Firstly, we have a general understanding of the circuit schematic diagram, and divide each functional module, such as power module, controller module, storage module, audio module, GPRS module and so on. By analyzing each module one by one, we can finally have a general understanding of the functions to be realized by the circuit. It is best to master the common or common unit circuit principles, such as power module, voltage stabilizing module, storage module, and common chips, such as 7805, 78 12.

I want to divide the circuit I want to design into several modules, so that they can be designed into different schematic diagrams and finally integrated. When there is a signal input in the circuit, what is the voltage and current at each base point? We should have a rough estimate. For the circuit with amplifiers R, L and C, it depends on whether it is an oscillating circuit, an amplifying circuit or a shaping circuit. After self-analysis and self-design, you will know and master the basic principle of the circuit, and accumulate experience in design and debugging in your future design.

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