测控专业毕业论文《基于单片机的继电器设计》定稿.doc

毕业设计（ 论 文）说明书 论文题目 学 号 学生姓名 专业班级 指导教师 总评成绩 年 月 日 本毕业设计基于单片机AT89S51所设计的，通过AT89S51单片机的P2.0和P2.1引脚输出低（高）电平时，三极管Q1和Q2饱和导通（截止），+5V电源加到继电器线圈两端，继电器吸合（释放），同时状态指示灯发光二极管也点亮（熄灭），继电器的常开触点闭合（释放），相当于开关闭合（断开）。通过插针引出，然后接上正反转的外部电路，从而实现电动机的正反转控制。 关键词：  Abstract Microcontroller penetrated into every field of our lives, almost hard to find which areas no traces of single-chip microcomputer. Missile navigation devices, control plane various kinds of instrument, computer network communications and data transmission, real-time in the process of industrial automation control and data processing. Single-chip microcomputer is widely used in instruments and meters, household appliances, medical equipment, aerospace, special equipment of intelligent management and process control, etc. In recent years, with the rapid development of electronic information industry, as a basic element of relay is widely used in home appliances, communications, automotive, instrumentation, machinery and equipment, aerospace and other automation control field. Recent statistics show that in electronic components products, the relay has become the first big products. Single chip microcomputer control relay circuit can be seen everywhere in our daily life, but an infinite small components. I passed the inspection of a large number of relevant documents and papers, to sum ??up their experience and actively learning to properly complete the graduation project writing to ask instructor through the learning of others. Designed by this experiment based on AT89S51, output by MCU P2.0 and P2.1 pin is low (high) electricity at ordinary times, transistors Q1 and Q2 saturation conduction (as), + 5 v power supply to the relay coil ends, relay (release), absorption and status indicator leds light up (out), the normally open relay contact closure (release), is equal to the switch is closed