The EK-PGC series programmable program-controlled DC power supply system is controlled fully by the microprocessor (MCU), so that a higher resolution and accuracy can be obtained and the data input of the system is completely controlled by the touch screen, which is fast, accurate and convenient. It is easy as well to use the communication interface (RS-485) to communicate with the computer, so as to meet the user demand for automated testing and automatic control. The adjustment of the voltage/current is calibrated by the software, so that there is no man-made error, thus making the instrument more accurate. The over-voltage and the over-current protection are set up entirely by the software and detected by the hardware, thus fulfilling the protection function quickly and accurately.