MCU控制的可编程稳压电源设计.doc

MCU控制的可编程稳压电源设计 摘 要 直流稳压电源是电子设计中常用的设备之一，广泛应用于电子电路的各个领域。传统的直流稳压电源功能简单，难于控制，可靠性低，干扰大，精度低，体积大且复杂度高。而基于单片机控制的直流稳压电源则能较好地解决以上传统稳压电源的不足。 本设计控制芯片选用51系列单片机，基本原理为通过单片机串口在线调整X9313系列数字电位器的阻值，从而实现对三端稳压器LM317输出电压的调整。通过51系列单片机编程可以非常方便地调整X9313数字电位器的阻值。稳压芯片采用三端稳压器LM317，LM317非常易于使用，只需要两个外部电阻即可设置其输出电压。本次设计中使用Keil软件进行单片机的编程，Keil软件功能强大，C语言编程，借助其调试功能，可以直观的了解到软件运行的结果，使繁琐的工作变得简单Proteus软件，可以方便地对单片机及其外围电路进行仿真。 设计中着重研究了X9313系列数字电位器的原理和应用，以及如何通过单片机串口在线调整数字电位器的阻值。数字电位器本身能够承受的电流和电压有限，在实际应用中需要进行扩展，本设计介绍了对其端点电压进行扩展的方法。本设计能够实现计算机在线调整三端稳压器LM317的输出电压，输出电压值和数字电位器的阻值能够在1602液晶上实时显示出来。 关键词：直流稳压电源，单片机，X9313系列数字电位器，三端稳压器LM317， 串口，1602液晶 A DESIGN OF PROGRAMMABLE DC REGULATED POWER SUPPLY BASED ON MCU ABSTRACT The DC regulated power supply is a common device that widely used in the electronic system.Traditional DC Regulated Power Supply has many disadvantages，for example，function is simple, low reliability，big jam,low accuracy，volume is big and system is complicated. The programmable DC regulated power supply based on MCU can solve this problems. This design chooses MCS-51 serieses MCU as a controller, the radical principle of design is changing a X9313 dallastats resistance by MCUs serial port on line.It is very convenient to change a X9313 dallastats resistance by MCUs programming.The design chooses the LM317 as regulation chip,only needs two external resistances to change its output voltage.This design uses Keil software to program MCUs function.The hardware emulation of MCU and peripheral equipment use Proteus software. This design emphasizes the priniple and application of the X9313 dallastat, and how to change a X9313 dallastats resistance by MCUs serial port on line.The X9313 dallastats capability of supply voltage and current is restricted,in practical application need to expand its port voltage and current.This design introduced a method of expand X9313 dallastats port voltage.This design can use computer to change the output voltage of LM317,and the same time display the