基于单片机控制的直流恒流源设计 电气工程及自动化专业毕业设计 毕业论文.doc

上海电机学院 毕业设计论文 课 题 基于单片机控制的 直流恒流源设计 学 院（系） 电气学院 专 业 电气工程及其自动化 年 级 学 号 姓 名 导 师 定稿日期：2011-5-6 摘 要 恒流源是一种可以提供恒定电流的电源，在现代的仪器和电子设备中通常需要高精度、高稳定性的直流恒流源。此外它也被广泛的用于计量、测量等场合。 恒流源常用的实现方法有晶体管、集成运放、可调集成稳压模块等。通过不同的组合可设计出可输出的电流小到几十毫安大到十几安培的电流源。高新能的恒流源不但可以提高电子器件以及科学仪器的使用效率，同时还可以减少产品的开发时间，具有较高的经济和实用价值。 本文所设计的基于单片机控制的直流恒流源采用AT89S52单片机为控制器，由运算放大器构成恒流源配以12位D/A、A/D转换～采用键盘恒流精度稳定工作。Abstract Constant-current source is a power which can provide constant current. In modern instruments and electronic instruments often requires high precision and high stability dc current source. In addition, it has also been widely used in metrology, measurement occasions. Constant-current source implementation of methods commonly used transistors, amplifier, adjustable integrated voltage regulator and so on. Designed by different combinations, constant-current can output current as small as ten mA and as big as ten A current. High-performance constant-current source and electronic devices will not only improve the efficient use of scientific instruments, but also can reduce product development time, with high economic value and practical value. In this paper the designed DC constant-current based on Microcontroller AT89S52 Single-chip Microcomputer source used for the controller, the operational amplifier LM324 and darlington device TIP122 constant current source constituted the main circuit, and with a 12-bit D / A, 16-bit A / D conversion chip output 20mA ~ 2000mA complete range of step classes less than 10mA constant current. Man-machine interface uses 4 × 4 keyboard input preset value and to achieve step function, through the LED digital display preset current value and measured value. Constant in order to achieve a certain accuracy, stability of the constant current source can be designed. Key words: Single-chip Microc