Student's name is Cheng (professional title), supervisor of class 05 16 of mechanical and electrical engineering, graduation project (thesis) June 65438+1October 21. The basis of topic selection 1, the purpose of topic selection, and the theoretical and practical significance of this topic; Objective: (1) to exercise their comprehensive application ability of theoretical knowledge and skills. (2) Improve your ability to search for documents and process information. (3) Cultivate your understanding of general scientific knowledge in society. (4) Enhance your knowledge and ideas and design papers. Theoretical significance: Acousto-optic controlled delay switch is used to replace the switch in the corridor of residential quarters. Only after dark, when someone walks through the stairs and makes footsteps or other sounds, the corridor lights will automatically light up to provide illumination. When people enter a house or leave an apartment, the corridor lights will go out automatically after a delay of several minutes. In the daytime, even if there is sound, the corridor lights will not light up, which can achieve the purpose of energy saving. Acousto-optic controlled delay switch is not only suitable for corridors in residential areas, but also for public places such as factories, office buildings and teaching buildings. It has the advantages of small size, beautiful appearance, easy manufacture and reliable work, and is suitable for lighting equipment in various building corridors. Practical significance: reducing energy consumption, saving energy and paying attention to environmental protection are the main trends in the world today, and incandescent lamps with high energy consumption and aggravating greenhouse effect are becoming more and more unpopular. Following the announcement of the timetable of "banning incandescent lamps in the year after the EU", it is a foregone conclusion that incandescent lamps will be abandoned worldwide, and environmentally friendly and energy-saving fluorescent lamps are substitutes for incandescent lamps. There is no doubt that energy-saving fluorescent lamps are better than incandescent lamps, but corridor lighting limits the use of fluorescent lamps. Because corridor lighting is unsustainable, people need light only after passing by, and continuous switching will affect the service life of fluorescent lamps, so acousto-optic incandescent lamps are widely used in corridor lighting field. 2. The research status and production demand of this topic at home and abroad; Research Status: Due to the rapid rise of lighting equipment industry in China in recent years, China has become one of the main exporters of electric light source products. Lighting equipment industry is a general competitive industry, and it is one of the industries that China's light industry opened to the outside world earlier. After China's entry into WTO, some world-renowned brand enterprises have successively entered the domestic production and marketing fields, making domestic competition internationalized. Strengthening the development of energy-saving light sources and lighting appliances with different grades, styles and uses, and accelerating the development, popularization and application of green energy-saving light source products are the key points of structural adjustment of lighting equipment industry in China. The lighting equipment industry in China will face unprecedented opportunities and challenges, and the huge commercial benefits brought by it have also become the focus of some enterprises. Production demand: With the globalization of global economy, the pace of industrial adjustment in developed countries is further accelerated, and the production of general lighting electrical products is transferred to developing countries, and China is a relatively suitable country. First, China has the conditions to produce these products, and second, the labor cost is relatively low, which makes China gradually become a big exporter of lighting electrical products. Looking forward to the future domestic market, the demand will continue to increase year by year. The following strong factors indicate that the lighting market in China still has great potential. Infrastructure construction: With the rapid development of airports, railways, ports and urban rail transit, every project needs lighting. Urban lighting project: the floodlighting of city squares, green spaces, roads and buildings has developed from big cities to small and medium-sized cities. 3. The development trend and main problems of this discipline. Development trend: According to the market demand forecast at home and abroad, the high-speed growth period of China lighting appliance industry will continue. How to predict the future more scientifically is a problem we are facing. Further improving the quality and grade of lighting products is not only the current task before us, but also the long-term goal of the whole industry. As far as the domestic market demand is concerned, people's living standards are gradually improving, and the requirements for the quality of living environment are getting higher and higher, which puts forward higher requirements for lighting electrical products. New building lighting standards have been formulated and will be approved for implementation soon. The new standard is basically in line with international standards, and puts forward requirements for lighting in different occasions. It also requires our production enterprises to adapt to the requirements of the new standards and provide corresponding products for various lighting places. From the analysis of the international market, although our exports have increased substantially year by year, most of our products are still at the middle and low level in the international market. Anyone who has been to Frankfurt knows that there is still a big gap between our products and the international advanced level. In addition, if a large number of inferior and low-priced products are exported, they will also encounter anti-dumping lawsuits, which will affect the export of the whole industry. Therefore, we still have to speak out loudly that quality is the life of an enterprise. At present, China has become a big producer of lighting electrical products in the world, and our goal is to become a strong producer of lighting electrical products. There are obvious gaps between China and developed countries in terms of quality, grade, production technology, equipment, materials and new product development ability. When we see our achievements, we can also clearly recognize our own gaps and make continuous progress. Let's work together in Qi Xin to make greater contributions to the healthy development of the lighting industry. Main problems: (1) The price of voice-controlled incandescent lamp is low, but the failure rate of its control circuit is high, especially in the use environment with large background noise, frequent switching will burn out components, so the service life is generally short. (2) When selecting the acousto-optic switch, we must know the performance of its sensors and their mutual adjustment ability under working conditions.