程控恒流源设计

Design of the Programmable Constant Current Source

介绍以集成电路LM2678电压转换芯片为核心,PIC单片机为控制器的程控恒流源基本电路。此电路结构简单,输出稳定。在0~5 A的范围内连续可调,且开环实验最大非线性误差小于3%。若加以程序校正或闭环控制,整机输出电流控制精度可超过0.1%。

This paper describes the basic programmable constant current source circuit which is based on LM2678 voltage converter chip and controlled by PIC microcontroller. This circuit structure is very simple. The output is stable and adjustable in the range of 0-5 A. The maximum nonlinearity error in open-loop experimentsis less than 3%. If the circuit is corrected by program or closed-loop controlled, the whole output current control accuracy is expected to exceed 0.1%.