In modern cities, population and cars are growing day by day, urban traffic is becoming more and more congested, and people's safety is becoming more and more important. Therefore, red and green traffic signal poles have become one of the important things for traffic management departments to manage traffic. With traffic lights, people's safe travel has a great guarantee.
Since the birth of the Traffic Light, its internal circuit control system has been continuously improved, and the planning method has also begun to be diverse, so that the traffic light is more intelligent. Especially in recent years, with the rapid development of electronics and computer skills, electronic circuit analysis and planning methods have been greatly improved, electronic planning automation has become a modern electronic system can not lack of things and means, these for the traffic light control circuit planning provides a certain skill base.
MCU is the core control element, including microprocessor, memory, input and output and other functional components. They are connected via the address bus, the data bus, and the control bus. Connect to external devices and peripheral chips via input/output lines. The hardware circuit is relatively simple, mainly controlled by software, the control method is flexible and diverse, and can be easily completed through the program such as interruption. It is characterized by replacing hardware planning with software planning, which improves the reliability and cost performance of the system. However, in the planning of hardware and software should be planned, anti-interference function is poor, not general, and need to have an interface circuit with it, the price is medium, the production is difficult, repair is difficult.
The relay touch control system is mainly composed of relays, touchers, buttons, stroke switches, etc., and its control method is intermittent, so it is also called intermittent control system. Although this system also has the advantages of simple structure, low price, simple protection, strong anti-interference ability, but the disadvantage of this control system is the use of fixed wiring method, more wiring, poor flexibility, low working frequency, easy to damage by electric shock, high environmental requirements, poor reliability.
Digital logic circuit control system is mainly composed of various logic components, including counters, triggers and various gate 8, hardware planning ideas are very simple, low cost, fewer components, small size, good stability, reliability and cost performance are high. The difficulty lies in the integration of the circuit, and the protection personnel must have certain electrical knowledge.
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