毕业论文--基于avr单片机的开关电源的设计与实现.docVIP

唐 山 学 院 毕 业 设 计 设计题目：基于AVR单片机的开关电源的设计与实现 基于电源是电子设备的功能模块，其性能的优劣直接影响电子设备的技术性能可靠性。本设计是以At单片机为主控器，本论文主要 The Design and Implementation of Switching Power Supply Based on MCU Abstract To electronic equipments, power is a indispensable function module. It is the energy source of all sort of electric equipment . And the performance of the power influences the technical characteristics and reliability of the electronic equipment. Therefore, it is the basic of the electronic equipments’ efficient and reliable operation that if we can design the good power or not. This design makes a power whose output voltage can be adjusted based on Atmega8 MCU as a main controller,. The system can not only preset the output voltage but also adjust the output voltage, and it has functions such as the flow protection, short circuit protection and digital pipe display. This thesis is about that PWM waves generated by MCU can control the hige power tube. It can test the output voltage through MCU integrated AD converter, and get error signals by comparison of preset voltage, and stabilize voltage by calling adjustment function. MCU can change the size of the output voltage through the keyboard modifying the PWM waves’ buty cycle. Switch power’s output voltage and output current can be show through the digital tube, and it can be show by the digital when the line short-circuited or overload happened. The switch power has a good effect to stabilize the voltage, high efficiency, and its output voltage can be adjusted, and its response speed is high. Key words: Switching power ;PWM ;Voltage adjustable ;Voltage display 目 录 1 引言 1 2 开关电源方案设计 3 2.1开关电源工作原理 3 2.2开关电源方案选择与论证 3 2.3总体结构设计 4 3 系统核心器件选择 6 3.1单片机简介 6 3.1.1引脚说明 6 3.1.2 Atmega8I/O口概述 8 3.2 Atmega8的AD功能 9 3.2.1 ADC功能简介 9 3.2.2 ADC相关寄存器 10 3.3 Atemga8的PWM功能 14 3.3.1 PWM波形发生器选择 14 3.3.2时钟源选择 16 4硬件电路设计 17 4.1电源电路设计 17 4.1.1整流滤波电路设计 17 4.1.2开关变换电路设计 17 4.2控制电路设计 18 4.2.1时钟电路设计 18 4.2.2单片机复位电路设计