一种常见精密恒流源的改进与应用

Improvement and Application of a Common Precision Constant Current Source

常见的TL431与晶体管搭建的恒流源电路有着温度系数小、电流精密等优点。但这种恒流源的电源电压的变化会影响到输出电流大小,且负载的变化对恒流源的影响也比较大。本文巧妙地利用常见的7805和2N7000对TL431恒流源进行改进,分别从仿真与实验的角度验证了改进后恒流源的优越性能,并利用改进后的恒流源电路进行了实际应用。

The common constant current source circuit structured by TL431 and transistor has many advantages such as tiny temperature coefficient,precisie current and so on.But the supply voltage of this constant current source change will affect the size of the output current,and the load change will affect the size of the output current too.This article clever uses 7805 and 2N7000 to improve the TL431-constant current source.The superior performance of the improved current source has been verifed from the perspective of simulation and experiments.The improved constant current source circuit has applied practically.