With the rapid development of modern urban and rural construction, people began to attach great importance to urban lighting systems. At present, street lamps generally use a high-voltage sodium lamp structure powered by a commercial power supply, which consumes a large amount of electricity and has low efficiency, and the solar street lamps are superior to ordinary lighting systems in power, light efficiency and service life. In addition, the current urban lighting system mainly adopts scattered manual control and time control mode. 23. The time control mode causes the lighting time to be unreasonable in seasonal changes and weather changes. The manual method not only wastes human resources but also wastes a lot of power. In view of this, it is very necessary to design a system to detect the light and dark to control the street light on/off in real time, not only to save the fund project: the national college student innovation and entrepreneurship training program (201310694009).
Manpower, and save a lot of power, has potential practical value and application prospects.
2 system overall design scheme Solar street light automatic control system consists of four parts, including STC12C5A60S24 single-chip minimum system module, battery charging module, mains conversion module, power switching module. The whole system takes the STC12C5A60S2 single-chip module as the core, and the intelligent control circuit switches the street light when the ambient light intensity changes to achieve the lighting purpose. The power switching module selects one of the storage and the mains to supply power to the street lamp and the single chip microcomputer, which makes up for the shortage of the street lamp illumination when the power storage is insufficient. In addition, when the system fails, the mains supply is selected. 3 system hardware design 3.1 mains conversion module At present, the urban lighting system is based on 220V AC power supply, this module realizes the conversion of 220V AC mains to 12V DC to provide power for street lamps, and converts to 5V to provide power for single-chip system (see transformer) T1 converts 220V AC to 15V AC, and uses diode bridge D6 and L7812CV three-terminal regulator integrated chip U4 to convert and output 12V DC VCC12S. VCC12S and battery output 12V DC VCC12X input LM7805 three-terminal regulator integrated chip Pressed to 5V DC to supply power to STC12C5A60S2 single-chip system. The mains and storage together supply power to the single-chip system, which guarantees the power required for the operation of the single-chip system. As long as one of the two can supply power normally, the single-chip system can work normally and solve the problem. Since the solar power generation is susceptible to the weather and the battery is used as a single power source, the power supply of the single chip is insufficient.
The battery charging module adopts the charging integrated circuit CN37225 with the maximum power point tracking function of the solar cell (see N3722 is a one-piece (down to page 116) solar battery-powered PWM buck mode charge management integrated circuit with small package shape and peripheral The advantages of less components and simple use. The output voltage of the battery charging module is 12V, which directly charges the battery BATTARY. After the Schottky diode AD1 and the mains conversion module output, the MCU is powered.
When the solar power generation is affected by the weather and the battery power supply is insufficient, the street lighting will be seriously insufficient. At this time, the mains supply power is required. Therefore, the utility model has designed the mains and storage switching modules. The IRLML6401PM0S tube is used as a switching component in the module. The mains conversion module VCC12S port and the battery charging module VCC12X port jointly output 12V to provide input for the power switching module, and VCC12 provides power for the LED. When the battery is fully charged, the system sends a low-level command (XDDY port) through the P0.2 port of the STC12C5A60S2 microcontroller, and the P0.1 port sends a high-level command (SD-DY port). The battery provides power for the LED lamp, and the battery circuit is insufficient. When the mains power supply supplies power to the LED lights.
3.4STC12C5A60S2 MCU minimum system module The control center of the solar LED street lamp automatic control system is the minimum system of STC12C5A60S2 MCU. STC12C5A60S2 single-chip microcomputer is connected with light intensity detection circuit, street lamp circuit, fault indication circuit, clock circuit, reset circuit (see. Photoresistor LR1 resistance light intensity changes and change. If the light intensity changes, the microcontroller P1.0 port is high Level, the P0.3 port sends a high level command, so that the relay K1 is closed, and the LED light illuminates. The fault indication circuit provides an indication for the system failure. When the system fails, the P1. 0 port sends a high level command. The indicator light D5 is illuminated. The low-voltage detection port P1.1 4 system software design software control design is the core part of the single-chip system. This system uses the STC12C5A60S2 single-chip microcomputer as the core control component, and performs system control through C51 programming. When the system detects the external signal When changing, control the street light switch, street light power switch, and fault alarm indication. See the main program flow chart.
5 Conclusions This paper designs a solar LED street light automatic control system based on STC12C5A60S2 single-chip microcomputer, and designs the minimum system module of STC12C5A60S2 single-chip microcomputer, battery charging module, power switching module and mains conversion module. When there is no fault in the system, the solar energy is charged for the battery during the day, and the power supply and the storage battery are alternately powered at night; when the system is faulty, the fault indicator light is on, and at the same time, the power is switched to the mains supply at night, which is convenient for maintenance and meets the lighting needs.
4 Characteristics of accidental injury cases using off-campus personnel in school sports facilities. In recent years, such injuries have occurred in many schools in China. These cases have the following characteristics: 4.1 The specificity of the subject is for the off-campus personnel, although the school has a fixed The obligation of safety and security should be paid attention to and guided. However, outsiders have their own freedom, autonomy and self-protection ability. They should have certain control and discrimination ability on their own behavior and the consequences of their actions. Therefore, specific issues should be specific in the determination of responsibility. analysis.
4.2 Particularity of space Such cases are accidents that occur in school-administered teaching places, stadiums and other sports facilities and cause personal injury to off-campus personnel. Although the school campus is relatively independent, it is also an open space, and the mobility of off-campus personnel is large, which increases the difficulty of campus safety management.
4.3 The speciality of liability assumes the causes of accidents, such as irregular physical exercise, substandard equipment, activity intensity and difficulty exceeding the ability, the reason of the off-campus personnel themselves, the influence of others on him or sports. Improper management of equipment. Due to too many responsible subjects and too many reasons for mixing, it is necessary to determine how to take responsibility according to the fault of each party in the specific case and the magnitude of each cause. 5. Responsibility analysis and recommendations 5.1 Responsibilities and recommendations of the school Responsibilities are divided into the safety management of stadium facilities and the safety guarantees for off-campus personnel. According to the above two, it is determined whether the school is at fault, and according to the type of sports activities, the degree of fault and the responsibility of the school are determined. To specifically analyze the responsibilities of the school.
Recommendation: The school should strictly manage sports facilities such as sports grounds, equipment, sports venues, etc., such as timely cleaning of the venue, installation of lighting facilities, setting of warning signs, and immediate inspection and maintenance of venues and equipment.
Not only must we provide teachers and students for the school, but also provide a good and safe physical exercise environment for the off-campus personnel. Although the school management expenses have increased, but the accidental accidents have been reduced, the school and the society are more harmonious, and at the same time reduce In the long run, it is conducive to the construction and development of the school.
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