Design of constant current power based on FET

This paper introduced the principles and developing process of constant current powers base on MOSFET in order to improve the accuracy and stability of current source.The electric circuit used closed-loop feedback control and its current could be continuously adjusted between 0 mA～5 000 mA.The choice of critical elements such as FET,sample resistance and so on has been explained properly.The various factors which affect the stability of constant current power were analyzed and concrete instruction comments in view of component's welding were given.At the same time,power loss and radiating in the actual design were analyzed deeply.Test results show that stability of this design is better than 0.5%,and it can be used in measuring and testing.