The first part: the report of college students' electrical and electronic practice. Practice content and purpose: the installation, welding and debugging of radio make students understand the assembly process of electronic products; Master the identification and quality inspection of electronic components; Learn the assembly process of the whole machine; Cultivate hands-on ability and rigorous work style.
Identification and measurement: ① Learn how to read the resistance with color ring, then use multimeter to verify whether the reading is consistent with the actual situation, and then nail the resistance on paper and mark the data to improve the welding speed in the next step; ② Learned how to measure diodes and how to identify them? +? ,? Extremely, ③ I learned how to measure the magnification of triode with multimeter and how to identify triode. b？ ,? e？ ,? c？ Three pins of the; (4) Learned to recognize and read capacitance. ╫? Represents chip capacitance, regardless? +? 、? Extreme; ? ┥┣+? Stands for electrolytic capacitor (Note: What are the long legs of electrolytic capacitor? +? What is a short foot? )。
Welding experience: When welding radios, learning to weld should be my greatest gain. Here is a brief introduction to welding experience. The most important thing to pay attention to in welding is welding temperature and time. When welding, the temperature of electric soldering iron should be higher than that of solder, but not too high. It is good that the rosin of the soldering iron joint just smokes, and the welding time should not be too short, because the temperature of the solder joint is too low, the solder joint is not completely melted, and the solder joint is rough, which is prone to virtual welding, while the welding time is long and the solder is easy to flow.
Welding sequence: ① Welding the middle weeks, in order to keep the balance of the printed circuit board, we need to weld the middle weeks of two diagonal corners first. Before welding, we must identify the mid-week color to avoid welding errors. Don't weld all four midpoints on it at once, so it will be difficult to install small parts in the future? (2) Welding resistance. We have nailed the resistor on the paper, so we should weld it in the order of R 1R 13 to avoid missing the resistor. After welding the resistance, we need to use a multimeter to check whether the resistance is the same as the previous value (check whether there is virtual welding). (3) Welding the capacitor, first weld the component capacitor, and pay attention to the reading above (you should know the resistance of 223 components &; 103 type element resistance difference, element capacitance reading method, the first two digits represent the capacitance value, and the last two digits represent the number of zeros), followed by welding electrolytic capacitance, with special attention to long legs. +? Extremely short feet? Extreme? (4) When welding diodes, what is the red end? +? The black end is ⑤ welded triode, must you recognize it? e？ ,? b？ ,? c？ Three pins (note: [V 1, V2, V3, V4] and [V5, V6, V7] are welded in enlarged order)? ⑥ Can the rest of the middle circumference, transformer and switch be welded? The most important thing is to weld the antenna coil, and the four wires must be welded accurately according to the circuit diagram? To solder the discontinuous parts on the printed circuit board, we need to connect them with solder? Pet-name ruby welding horn and battery holder.
Debugging and testing: debugging is a very difficult and patient job, but its purpose and significance are very significant. Through the detection and debugging of radio, we should understand the production and debugging process of general electronic products, initially learn the methods of debugging electronic products, and cultivate the detection ability and meticulous scientific style. First of all, we need to check whether the printed circuit board is damaged at the welding place, whether the resistance is the same as the drawing, whether the diode and triode are wrongly welded in polarity and position, whether the circuit of the circuit board is broken or short-circuited, whether there is a short circuit caused by welding during welding, and whether the positive and negative poles of the power lead-out wires are correct. Second, do you want to power on the test? Carefully adjust the middle of the week after power-on, and be sure to write down each adjustment process. If the adjustment fails, please readjust the belt to its original position. If it really doesn't work, please ask the teacher for help! But we must be patient in the whole process.
Significance and experience of this internship: After two weeks of electrical and electronic internship, we have learned the basic welding technology, radio detection and debugging, electronic product assembly technology, electronic component identification and quality inspection, and assembly technology of the whole machine, which have cultivated our hands-on ability and rigorous work style and laid a good foundation for our future work. The most basic point: when I study analog electronic technology, I always feel that what the teacher says is too abstract. Through this study, I learned a lot. Moreover, this should also be very useful in our future professional courses. As far as our own major is concerned, we still need to systematically learn the knowledge of power electronics technology, automatic detection technology and signals and systems, and this time we used it in the process of radio installation and debugging. In short, in practice, we should always keep a clear head. If there are mistakes, we must carefully and calmly check and analyze them! Finally, I heard my radio successfully play the voice of the dispatched person. I am really happy, and finally feel that my efforts have not been in vain!
Chapter II: Summary of College Students' Electrician Practice During these two months, I learned a lot and realized the importance of practice more deeply. It is very important to master solid theoretical knowledge and apply what you have learned in practice. Through these two months of study, I feel that I have gained something in the following aspects:
First of all, through this internship, I am familiar with the use of several basic electrical tools, such as multimeter, electric soldering iron and other methods and precautions. Have a deep understanding of the models, specifications and application scope of some commonly used electronic devices, such as relays, contactors and transformers. Can understand the schematic diagram and wiring diagram of the circuit and master the basic wiring method of the circuit, have a certain perceptual and rational understanding of the installation and debugging of the circuit, and have a further understanding of the design and principle of the electrical circuit.
Second, their practical ability has been greatly improved. In the past, we paid more attention to the study of theoretical knowledge in school, and our hands-on ability was weak, and our ability to integrate theory with practice was also weak. It's different when you come here. Many things are done by myself. Some things look simple and you know the theoretical knowledge, but when you do it yourself, sometimes there are many loopholes, which is wrong and wrong. At first, it was quite simple to look at the main wiring or welding wire. When I connect or weld wires by myself, I either forget the set number, or the terminals are wrong, or there are virtual solder joints or the welding is not firm, which makes me understand that there is a big difference between theory and practice. Later, after a period of exercise and my own efforts, this situation is very rare. I can quickly and correctly connect the whole circuit, further improve my hands-on ability and gain a lot of practical experience.
Third, the work should be serious, responsible and patient. Many things at work seem simple or make you feel nothing. In fact, there are many places to pay attention to in actual operation. For example, if you accidentally connect the wrong wire, the nature of the whole circuit will change. When you install the machine, it may burn the whole circuit board and even endanger your own safety. Even every wire is responsible for the machine, the work and the people. This requires us to be serious and responsible in our work. Our work needs positive work enthusiasm and practical work style. It often takes a lot of time to install the machine or check the circuit fault, especially when checking the fault, sometimes it takes a lot of time but the problem is still unresolved, which requires us to be patient and persist in solving the problem.
During this period of work, I also encountered many difficulties, and I tried my best to solve them. Think, give, and you will get something. During this time, you got exercise and added a lot of fresh energy to yourself!