Circuit board factories need circuit diagrams under the premise of producing circuit boards. Circuit diagrams refer to diagrams that use circuit component symbols to represent circuit connections. The circuit diagram is a principle layout diagram drawn with physical and electrical standardized symbols to represent the composition and relationship of various components for the needs of research and engineering planning. From the circuit diagram, we can know the working principle of the components, and provide planning solutions for analyzing performance and installing electronic and electrical products. In designing the circuit, the engineer A calmly proceeded on paper or on the computer, and then proceeded to the actual installation after confirming that it was complete. Improve through debugging, fix bugs, and succeed. The use of circuit simulation software for circuit aided design and virtual circuit experiments can improve the work efficiency of engineers, save learning time and make the physical diagram more .
Circuit board factory: teach you three steps to understand the circuit diagram
1. Read various circuit diagrams according to the order from big to small and from thick to thin
The general circuit diagram mainly includes the whole machine or system block diagram, board or system circuit schematic diagram, printed circuit board diagram and board connection diagram and other types. These circuit diagrams each have their own uses and characteristics, but they are intrinsically linked. When reading these circuit diagrams, you can read them in order from large to small and from thick to thin. This order is in line with the general law of people's understanding of things. Practice has proved that it is an effective method, which can save beginners from taking many detours.
2. According to the basic circuit program, the circuit block diagram (system, board or whole machine) can be read
There are several types of circuit diagrams of the whole machine, and the block diagram is the basis of other types of circuit diagrams, and also the basis of reading circuit diagrams. The block diagram has the simplified block diagram of the whole machine, the detailed block diagram of the whole machine, the block diagram of the plate composition, and the system block diagram. Sometimes, readers do not have complete information at hand, and may not have the above-mentioned block diagrams, or the types of block diagrams are incomplete. In order to read the diagrams correctly and in-depth, readers should draw a reference composition block diagram.
According to the basic circuit program, the circuit block diagram can be drawn. The block diagram of the whole machine can be drawn according to the circuit program of the circuit diagram of the whole machine, the block diagram of the block system can be drawn according to the circuit program of the block circuit diagram, and the block diagram of the system can be drawn according to the circuit program of the system circuit diagram. The circuit composition block diagram does not reflect the specific structure of the circuit, but mainly reflects the function of the circuit, reflects the transformation process of the signal, reflects the connection between circuits at all levels or systems, and reflects the ins and outs of various signals. In fact, one of the important tasks of looking at the circuit diagram is to study and analyze the content, type, waveform and their transformation laws of the transmission signal. The process of drawing block diagrams is a practical process of understanding circuits, and a practical stage of analyzing and researching circuits, which can lay the ideological and material foundation for in-depth reading of practical circuit diagrams. The drawn box diagram can reflect the reader's reading results and level.
3. Analyze the practical circuit schematic diagram (system, board and whole machine) according to the signal conversion principle of the whole machine
On the basis of reading the block diagram, it is necessary to further read the specific practical circuit schematic diagram. In order to truly understand the circuit schematic diagram, it is necessary to read it in combination with the basic principle of the whole machine; that is, to analyze what specific circuit is used to complete the signal processing process, and why this circuit is used to complete this function instead of using other circuits .
According to the thickness and size of circuit functions, practical circuit diagrams can be divided into unit circuit diagrams, system circuit diagrams, block circuit diagrams, and complete machine circuit diagrams. Due to the increasing level of integration, a large number of unit circuits have entered the integrated chip, so the current analysis of practical circuit diagrams is mainly to analyze system circuit diagrams and block circuit diagrams. In fact, the reading system circuit and the board circuit are mainly used to read the integrated circuit, that is, to read the type function of the integrated block, the signal processing process and the function of the lead pin, and also to read the connection between the collector circuits and the integrated circuit. Contact with peripheral circuits or components, etc.
1. Determine the direction of the signal processing flow
According to the overall function of the circuit diagram, the total input terminal and the total output terminal of the entire circuit circle can be found out, and the signal processing flow direction of the circuit diagram can be judged. The function of the wireless microphone is to modulate the voice signal to a high-frequency signal and transmit it out. In the circuit diagram of Figure 1, the phone BM is the main input end, and the antenna W is the main output end. From the total input terminal to the total output terminal is the direction of the signal processing flow, and Figure 1 shows the direction from left to right.
2. Divide the unit circuit
Generally speaking, transistors, integrated circuits, etc. are the core components of each unit circuit. Therefore, we can decompose the circuit diagram into several unit circuits according to the signal processing flow direction with the main components such as transistors or integrated circuits as symbols, and draw the circuit principle block diagram accordingly. Block diagrams help us grasp and analyze circuit diagrams.
3. Analyze the DC power supply circuit
In the circuit diagram, the power supply is usually arranged on the right side. The DC power supply circuit is arranged from right to left. In Figure 1, the DC working power supply of the whole machine circuit is a 6-volt battery, and R4, C6 and Zener diode VD form a voltage stabilizing circuit to improve the stability of the circuit. S is the power switch.
