基于单片机的简易恒流源系统的设计

计了基于微处理的数字控制恒流源系统，实现了电流从0到2000mA可调的直流恒流源。系统电源部分采用自制供电电源，提供稳定的3.3V和5V供电电压。恒流源部分采用运算放大器外接扩流管构成恒流源电路，既能利用运算放大器保证输出稳定电流，又能结合扩流管实现输出大电流。恒流源控制部分采用高精度单片机C8051F020控制，控制数字量可随意设置，输出电流大小完全可知且大小可任意设定,而且控制精度高。系统显示部分采用 液晶显示，为 点阵 液晶显示，可视面积大，画面效果好，抗干扰能力强，而且使用方便简单。整个数控恒流源具有控制界面直观、简洁的特点,具有良好的人机交互性能。

The Design of Simple Constant-current Source System Based on SCM

The paper designs the digital control constant-current source based on microprocessor, and realizes that the current is adjustable from 0A to 2000mA. The power part adopts self-making supply power, and provides the stable voltages of 3.3V and 5V. The constant-current part uses the operational amplifier with external extension tube to make up the main circuit of constant-current system, and the main circuit not only can use the amplifier ensure the stable output current, but also can combine with the extension tube to achieve large output current. The control part uses the high precision MCU of C8051F020, and realizes the digital quantity that can be arbitrarily set. The magnitude of output current is completely knowable, the size can be arbitrarily set, and the control precision is high. The display part uses liquid crystal of to display, and the display part is liquid crystal of dot matrix. So the visual area is very large, and the picture effect is good. The display part also has a strong anti-interference ability, and is easy to use. The whole constant-current source of digital control has the feature of intuition and simplicity, and has good performance of human-computer interaction.