中文摘要：

目前很多由分立元件构成的恒流源电流有限,稳定度较差,容易受到元器件参数变化和环境变化的干扰,并难以调节。在此采用闭环控制原理,利用单片机控制ADC和DAC转换模块,达到恒流的目的,并可以根据需要,通过代码改写实现电流的预置。克服了以往分立元件构成的恒流源不稳定的缺点,在实际应用中,达到了良好的供电效果,在多次实地测量中圆满完成任务。

英文摘要：

Many available constant-current sources composed of discrete components have defects which cause the current limitation,poor stability,is vulnerable to the change of environment and component parameters,and difficult to adjust.The closed-loop control principle is adopted in this design.The purpose of constant-flow is achieved with ADC and DAC conversion modules controlled by SCM.If needed,the current preset can be realized by rewriting the code.This design has overcome the shortcomings of the previous constant-current sources which is consisted of discrete components and is unstable.In practice,the power supply of this constant-current source has achieved good results in the numerous field measurements.