开关稳压电源设计毕业设计.docVIP

摘要 开关电源是一种比较新型的电源。它具有效率高，重量轻，可升、降压，输出功率大等优点。但是由于电路工作在开关状态，所以噪声比较大。 本系统以89C52为核心，电压可预置，步进电压为1V，输出电压范围为20V到30V可调，输出电流为0—0.5A，可显示预置电压，显示输出电压，输出电流。该系统主要由最小单片机系统，开关电源DC-DC模块电路，A/D信号采集以及D/A控制输出和过流保护部分、显示部分等组成。系统通过键盘预置电压值送给D/A控制电路形成闭环反馈回路，采样电压间接推算出电流并显示当电路的输出电流过大时控制电路会自动切断输出电压、蜂鸣器进行报警从而形成保护，当电流恢复正常时电路自动回复功能。本系统具有调整速度快，精度高，电压调整率低，负载调整率低，效率高，无需另加辅助电源板，输出纹波小及过流保护等优点。 关键词：STC89C52、LM2576、LM2587、DC/DC变换、 ABSTRACT Switching power supply is a comparative new type of power supply. It has high efficiency, light weight, can rise, the blood pressure, output power etc. But because the circuit work in the switch state, so the noise is bigger. This system with 80 c52 as the core, voltage can be preset, stepping voltage for 1 v, output voltage range of 20 v to 30 v adjustable, output current is 0-0.5 A, it can display preset voltage, shows that the output voltage and the output current. The system is mainly composed of single chip microcomputer system minimum, switching power supply DC - DC module circuit and A/D signal acquisition and D/A control output and over-current protection part, display section, etc. System through the keyboard preset voltage value to D/A control circuit form closed-loop feedback circuit, sampling voltage indirectly calculated current and display when circuit output current too big when control circuit will automatically cut off the output voltage, buzzer to alarm and formation protection, when current are back to normal that the circuit auto reply function. This system has the adjusting speed, accuracy, high voltage adjustment rate is low, negative ? KEY WORDS：“STC89C52”、“LM2576”、“LM2587”、“DC/DC conversion”、 目 录 第一章 稳压电源设计阐述 1 1.1 技术指标 1 1.2 开关稳压电源简介 1 1.3 问题总结 2 第二章 方案论证 3 1.1 单片机控制模块 3 1.2 电源控制核心模块 3 1.3 显示模块 6 1.4 键盘输入模块 6 1.5 系统各模块的最终方案 6 第三章 总体设计及模块简介 7 1.1 STC89C52的介绍 7 1.2 LM2576简介 9 1.3 LM2587简介 10 1.4 LCD12864的简介 11 1.5 TLV5638的简介 13 第四章 硬件电路设计 14 1.1 单片机最小系统 14 1.2 主控电路设计 15 1.3 升压电路设计 16 1.4 降压电路设计 16 1.5 过流保护电路设计 17 1.6 按键电路显示电路