Generally, a whole machine is composed of how many printed circuit boards, printed circuit boards can be large or SMAll. The circuits contained on each printed board are often drawn on a circuit diagram. As a result, the circuit diagram of a whole machine is usually composed of how many modules circuit diagram, each module circuit diagram, you can understand the whole machine circuit diagram, each module circuit diagram covers one or several circuit systems, the complexity of large module circuit diagram is almost the same as that of ordinary small and medium-sized screen TV circuit diagram. Although the circuit is more complex, a variety of module circuit to complete different functions, but they have rules to follow, can be in accordance with a certain way to step together to read.
In order to read the circuit diagram less detours, should use accurate reading methods and steps. Generally take a perimeter, from the outside in the method. By adopting the method of connecting inside and outside, combining before and after, breaking step by step, we can read all circuit diagrams without encountering diffICulties. The specific way to look at the map steps, can be summed up in three sentences, three steps: peripheral start, choose a good entrance; Open gap son, combined before and after; Not easy to solve the place of analysis, in the end.
1, intuitive start, choose the entrance
That is to say, first look at the most intuitive, easy-to-read components and circuits at the edge of the circuit, as the entrance to read the diagram. A number of circuits or blocks can be found from these peripheral recognizables moving inward along the signal line (possibly in the opposite direction of the signal flow).
2, open the gap, combined before and after
No matter what kind of circuit diagram there is a little bit of vulnerability. The complexity and difficulty of each local circuit are always a little different, or the graphics and symbols of some meta-components are not the same as those of ordinary meta-components. These places are the vulnerable links in the inner part of the reading diagram, and are easy to read links. They can be used as the inner break of the reading diagram. These places can be selected as the reading of the breaking mouth, open the gap, can quickly forward, after, left, right combination, and the first step is appropriate, you can read a lot of circuits.
As long as the reader in mind, in the circuit diagram there will always be a lot of readers already know the clear link, capture it can quickly open to see the gap, to the depth of progress. The most intuitive and easy to read inner link is the integrated circuit, especially some large scale integrated circuit, their extraction feet are more than 40, more than 100, very eye-catching in the diagram, the plotter often put them in the core or surface position of the circuit diagram. Then, with these integrated circuits as the core to expand outward, the heart to find a lot of circuits. There is a prerequisite for the integrated circuit as the inner breaking port demand. Be sure to know the specific cell number of these integrated circuits, know the main invitation function of the model integrated circuit, know the name and use of the main extraction foot clearly, otherwise it will bring a lot of inconvenience to the reading of the diagram. Sometimes the reader already knows clearly most integrated circuits, some individual integrated circuits are unfamiliar, according to the composition of the block diagram and before and after combination, can also expect the function of the unknown integrated circuit.
There is also a point in the circuit diagram easy to read, easy to remember the internal material meaning, can also be used as a circuit inside the break. For example, as shown in the figure, the Chinese character deed, the letter of the letter or the abbreviation of the word, a point of close and easy to read the graphic symbol of the component, some adjustable resistance or potentiometer, etc. In order to be able to use these breaks easily and without difficulties, the reader should know clearly the physical meaning of various kinds of letters and words, have a certain foreign language foundation (usually English), the reader should know clearly the reading and listening facilities often used a few professional terms and words; The reader should know clearly the functions, parameters and indicators of these components. The reader's wide range of knowLEDge helps to read the picture, and the reader should have the knowledge to memorize a bit of useful common sense.
3, not easy to solve the analysis of the place, in the end
Through the above two steps to read the process, the circuit diagram of most of the internal essence can be understood. However, there are still parts of the circuit that you don't understand or don't understand very well. The third step can be dedicated to besieging areas that are not easy to solve. This is not an easy part of the picture to solve, but also the final step of the picture. The reader can break the circuit in various ways or by hand and eye which is not easy to solve.
In the practical circuit diagram, it is not easy to understand the place often table now two places, one is the signal flow disposal process in some integrated circuits, because the internal significance of these do not understand, so there is no way to understand the external lead foot function; The other is some peripheral discrete component circuit, can not solve the purpose of setting the circuit, do not know the signal processing process. For these is not easy to solve the local circuit, according to the machine block diagram, according to the function of each local circuit and combine with each other, after thinking law analysis, try to explore the function and signal process analysis method, always can understand these is not easy to solve the local circuit.
In fact, the circuit diagram for reading and use of too much information, the appropriate reader's synthesis, analysis, discussion, will be able to understand the whole picture. Each person's actual situation is different, the way to look at the picture and judge may be slightly different, the process of looking at the picture is not the same. Electronic technology advances rapidly, manufacturers often develop new circuits or circuits with new functions, and even the circuit program is more unusual. On the basis of the above basic thinking clues, we can flexibly complete the drawing office.