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Superheterodyne paper
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1.

Through practice, I have a certain perceptual and rational understanding of the installation and debugging of electronic components and radios, which lays a good foundation for studying electronic technology courses in the future. At the same time, the internship has enabled me to acquire practical knowledge and assembly skills of radios, cultivate my ability to integrate theory with practice, improve my ability to analyze and solve problems, and enhance my ability to work independently. The most important thing is to cultivate team spirit, discuss with other students and make progress together. Details are as follows: 1. Familiar with the use, maintenance and repair of common tools for manual welding. 2. Basically master the welding technology of manual soldering iron, and be able to independently complete the installation and welding of simple electronic products. Familiar with the production process of electronic product installation process. 3. Familiar with the steps and methods of printed circuit board design, familiar with the process of making printed circuit boards by hand, and able to design and make printed circuit boards according to circuit schematic diagrams and components. 4. Be familiar with the categories, models, specifications, performance and application scope of commonly used electronic devices, and be able to consult relevant electronic device books. 5. Be able to correctly identify and select commonly used electronic devices, and skillfully use ordinary multimeter and digital multimeter. 6. Understand the welding, debugging and maintenance methods of electronic products. V. Internship content: weekly task lecture operation 1. Watch the video about the internship, grasp the internship as a whole, and clarify the purpose and significance of the internship; 2. Explain the operation methods and precautions of welding; 3. Distribution and inventory tools. 2 10.5 practice welding in the afternoon 3.0 2 am 1. Explain the design requirements, methods and principles of printed circuits; 2. Explain the production process of printed boards; 3. Explain the reading method of printed circuit diagram. 4. Practice welding; 5. Distribute and inventory components. 2.7 0.60.2 In the afternoon, draw the principle and printed diagram of dimming circuit printed circuit. 3.0 principle of drawing dimming circuit in the morning and printing 3.0 afternoon 1. Explain the working principle and classification of radios; 2. Explain the types, models, application scope and methods of radio components and how to choose the components correctly. 3. Explain how to use tools to test components 3.0 Assemble, weld and debug the radio in the morning. 3.5 pm1. Assemble, weld and debug radios; 2. Hand in products and score. 3.0 Give the welding products to the teacher for grading, clean up the desktop and clean up in the morning. 3.5 pm Q&A 3.0 6. Feelings about welding practice: During the one-week internship, the most challenging training for me is welding. Welding is one of the basic methods of metal processing. Its basic operation "five steps"-pre-welding preparation, weldment heating, solder melting, solder removal and soldering iron removal (also called "three steps") seems simple, but it takes a long time to master. The first solder joint can only be described as "ugly", but the welding assessment forced us to complete the assessment goal in just one day, which can be said to be a qualitative leap. So I'm patient and cautious. Take your time. In the process of constantly challenging myself, the hand holding the soldering iron stopped shaking, the hand sending the solder can basically master the dosage, and the welding technology is becoming more and more mature. When I finally finished a qualified solder joint in the shortest time, the fear of welding had already dissipated and was replaced by confidence in my own hands-on ability. In this process, I deeply feel that seemingly simple things may not be the case. In the process of welding practice, I learned a lot of things I didn't know before. For example, before the internship, I only knew that there were electric soldering irons, but I didn't know that there were many kinds of electric soldering irons, such as single use, dual use, temperature regulation, constant temperature, direct heating, induction, internal heating and external heating. Also, you can't use rosin to wipe the soldering iron before hanging tin, which will accelerate its corrosion and reduce air pollution, and so on. However, there are many things that I don't understand. 1. Why should tin be hung on the weldment to prevent oxidation? As long as I clean the surface of welded components, I don't understand; 2. After the electric soldering iron is completely heated, whether to apply flux or hang tin first, I use the latter, and some people use the former. They are all welded, but I often can't weld them in the process of welding, and doesn't the latter accelerate its corrosion and reduce air pollution? I don't understand. I want practical ability, so the design of printed circuit board diagram is to challenge my ability to accept new knowledge quickly. It is a great challenge for me to spend an afternoon accepting and digesting what the teacher said without touching the printed circuit board before. In this process, I mainly exercised the spirit of teamwork and discussed the progress with other students. Because I am not very clear about circuit knowledge, it can be said that it is vague. But when I don't know anything, I will ask other students for advice. Even if they are busy thinking, they will stop to help me and eliminate my blind spots. When I tell them what I think, they won't accept my suggestion because I am ignorant. In the whole process of this internship, although I was only a supporting role, I deeply felt the sincerity of friendship between my classmates. During my internship, I was familiar with the process flow, design steps and methods of printed circuit boards. However, it's a pity that I can't design the printed circuit board diagram independently. This internship makes me believe that my knowledge is not perfect and my ability of hands-on design needs to be improved. Eight or six superheterodyne radios assembly and debugging experience For me, this is undoubtedly a new knowledge, a challenge, and I have learned a lot of valuable knowledge. This internship is my most interested internship and my most failed internship. I like disassembly since I was a child, and I failed this time. Although I succeeded for the second time, I had more internship time than others. To sum up this internship, I sometimes feel very careless and insecure. I thought the radio was good at first, but it never sounded during the test. I didn't know that the switch was turned on until I asked my classmates. Turn on the switch and prepare for inspection. Before the inspection, I tested it again with great confidence. Great, break the wire connecting the speaker, and then weld the street of the speaker again. The screwdriver accidentally fell from the welding place of the speaker. As the saying goes, it never rains but it pours. Later, the SP 1 connector broke down and the copper foil at the welding place melted. Had to be invalidated. Hey. In this internship, I understand the importance of self-confidence. However, I also understand that my hands-on ability is still very insufficient. Under such circumstances, I am not qualified for the future work. Therefore, in the future study process, I will try my best to combine theory with practice, pay attention to training my hands-on ability, and let myself have some confidence in my future work. Overall, I am full of enthusiasm for this course. First, I have been interested in this kind of small production since I was a child. At that time, I didn't know how to weld, and I liked to take things apart, but in this way, this thing was scrapped. The current electrical and electronic practice class is to learn how to put things back. Every step I take, I am as happy as a child and have a sense of accomplishment. Second, the characteristics of electrical and electronic practice are that students do it themselves, master certain operational skills, and design, make, assemble and debug themselves. It organically combines basic skills training, basic technological knowledge and innovation enlightenment to cultivate our practical ability and innovative spirit. As a college student in the information age and a highly skilled person trained by the country, it is not enough to operate the mouse only. Basic hands-on ability is the foundation and necessary condition of all work and creation. Through a week's study, I feel that I have gained something in the following aspects: First, I have a preliminary and systematic understanding of the theory of electronic technology. We learned the welding skills of common components and circuit components, the design, production and technological process of printed circuit board diagram, the working principle of radio and the functions of components. This knowledge is not only effective in the classroom, but also of great guiding significance to the study of electronic technology courses in the future, and also has practical significance in daily life. Second, it is a great exercise for your practical ability. Experience is the mother of wisdom. Throughout the ages, all inventions have been tested by practice. If the hands-on ability is not enough, you can talk about making achievements in future scientific research, especially experimental research. During the internship, I exercised my hands-on ability and improved my ability to solve problems. For example, when assembling and debugging the radio, several gaskets were welded together with small spacing, but the task was still completed.

2. How to learn electrical technology well?

Electrical operation skills training is a compulsory practical course for electrical and electromechanical majors in secondary vocational schools. Practice teaching is a necessary link to improve students' practical ability and social adaptability, and it also embodies the characteristics of vocational education. Therefore, to train vocational school students well, we should give consideration to knowledge and ability, especially strengthen practical teaching. The author believes that in strengthening practical teaching, we should pay attention to the following aspects:

First, actively guide and help students build confidence

At the beginning of enrollment, vocational high school students know almost nothing about their major. At this time, some students will be curious about their professional knowledge because of their existing life experience, while others will be afraid of being unfamiliar with their majors. In view of the above situation, we might as well start with extra-curricular tutoring: first, set up an electrician production and maintenance interest group and make simple circuits (such as doorbells, voice-activated lights, burglar alarms, double lights and so on). ) Stimulate self-confidence and cultivate students' interest. The production content starts with simplicity and practicality. When making, teachers should analyze circuit faults with students, find out the causes of faults, and improve students' maintenance skills. The finished works can be displayed in the school window, which is inspiring to students. Secondly, we can guide students to read some relevant newspapers and magazines, and also encourage students to collect relevant information online, so as to learn more about the development status and professional development direction of maintenance electrician industry, broaden their knowledge and cultivate their innovative thinking ability. Thirdly, in the practice of maintenance teaching, students can be encouraged to learn some simple maintenance skills from the small electrical appliance maintenance personnel around them. With the accumulation of maintenance experience, students can be encouraged to carry out voluntary maintenance outside school to improve their maintenance skills and social adaptability. Students experience the joy of success in maintenance, which is conducive to improving students' learning enthusiasm. Fourth, teachers should lead by example, take part in some beneficial maintenance activities, improve their professional level, explain their experiences to students, and keep their interest and confidence for a long time.

In the process of electrician practice, some students are afraid of electricity. At this time, as a teacher, we should strengthen guidance, not only educate students about safety knowledge, but also encourage students to do more work, sum up experience in operation, overcome difficulties and enhance confidence.

Second, a clear goal to improve the teaching effect

"Without pressure, there is no motivation", so we should strengthen target education in electrician practice teaching. When students are under pressure, they will have the motivation to change "I want to learn" into "I want to learn". We can divide the whole teaching goal of electrician practice into four stages. In the first stage, focusing on the identification and familiarity of devices, students are mainly required to be familiar with the functions of various parts of devices. On this basis, students can repair and maintain some faulty equipment and become more familiar with the functions of each equipment. In the second stage, the goal is to be familiar with the circuit principle and wiring diagram. Teachers should first review students' relevant theoretical knowledge, and then guide students to draw wiring diagrams in class. The main purpose of this is to let students know how to connect the lines and what to do in practice. In the third stage, the goal is technology. After students master how to connect wires, they emphasize the technical requirements of students. Teachers first explain the wiring process requirements, students assemble according to the process requirements, and gradually improve the wiring quality and process level. The fourth stage focuses on repeated training and improvement. To sum up, knowing the objectives of each stage and the difficulty of practice before practice can not only build students' self-confidence, but also help them master skills effectively, which is conducive to improving the teaching effect of electrician practice.

Third, strict requirements, improve the technical level.

In electrician practice, there are many components on the circuit board, many technological requirements and high standards. In view of this situation, strict requirements should be put forward for every link of internship. Therefore, it is particularly important to establish an appropriate grading standard. The grading standard should be based on the standardization of operation skills, which is conducive to cultivating students' independent analysis and operation ability and rigorous and practical learning attitude. Take "Y-δ step-down start control circuit" as an example. In order to make it easy for students to accept, students can be asked to review its working principle and draw its wiring diagram according to the circuit drawing. Then, they are asked to assemble the control circuit according to the drawings. The main purpose is to enable students to assemble correctly, and the process should be strictly required when assembling, and further standardized through scoring standards. When connecting the control circuit, the line installed by students may not realize the control function. At this time, students can be encouraged to carefully analyze the fault and try to find out the fault point. Resistance method can be used for detection. When an individual can't solve the problem, several students can analyze it together until the fault point is found, so that students can feel the pride of success, which is conducive to students' self-confidence and correct treatment of the next internship. For typical faults, teachers can analyze them with the whole class, find out the reasons and avoid making them again, which is very helpful to understand and master the whole line. Finally, the teacher wants the students to assemble and connect the whole line, and under the guidance of the teacher, the connected line is electrified for trial operation, so that the students can have a sensory understanding of the working process of the whole line.

On the premise that students can correctly complete the route according to the standard, they can appropriately raise the requirements, emphasize the importance of the time spent, and improve their proficiency through repeated training to meet the needs of social practice. For students who have outstanding skills and spend less time in each internship, take the assembly circuit as a model to set an example among students and enhance their learning confidence. At the same time, we should also pay attention to persuading some students to "get quick success unilaterally" and guide them to carry out practical training step by step, so as not to be greedy for quick results, which will lead to the bad result that the skill level will not be improved.

Fourth, pay attention to the cultivation of good habits and abilities and improve social adaptability.

In practice, students must be educated to form meticulous and methodical habits. In electrician practice, there are many equipments, which are easy to be damaged and safety accidents are easy to occur. Each student's equipment and circuits can be numbered, and the responsibilities can be clearly defined. Those who violate the operating rules or intentionally damage the equipment should be compensated to ensure the normal use of components, which is conducive to cultivating students' good habits of caring for public property and adapting to the requirements of safe and civilized production in enterprises.

Faults in assembly line are widely reflected in social practice, which is a good opportunity to cultivate students' analytical ability and independent thinking ability. First of all, teachers should base themselves on theoretical teaching methods, so that students can master the circuit principle skillfully and analyze what kind of faults will occur when a device or a circuit has problems, which is the basis for students to carry out fault analysis. Secondly, teachers should introduce a variety of different troubleshooting methods to students, clarify their advantages and disadvantages, guide students to troubleshoot, cultivate students' multi-faceted and multi-angle inquiry quality, improve their thinking ability, and make them know how to avoid general failures. Sometimes teachers can deliberately set up faults, let students analyze and troubleshoot, provide more practical opportunities, help students learn troubleshooting methods, and let students use what they have learned flexibly. We can also use the opportunity of social practice to encourage students to do more social practice to meet the ability demand of social development.