A Numerical Controlled Constant Current Source Based on Power MOSFET

Supercapacitor is widely used in high power energy storage device, and its charge and discharge properties decide the energy storage devices of important performance indicators. In this paper, in order to research the charging performance of supercapacitors, a constant current test system which is based on microcontroller was designed. The system use a program-controlled constant current source which focuses on high-power MOSFET in accordance with the current data gotten from the sampling circuit, adjust the output current by PID algorithm, and thereby enhance the controlling precision of the output of the constant current. Under the combined control between upper machine and lower machine, the test system can map out potential function curve following time-varying, so that the supercapacitor’s charge process implement visualization. The result which tests the supercapacitor shows that the circuit has a simple structure and the current is very stable, which can be applied to all kinds of energy storage device which requires high current for charge and property test.