Design of Programmable Switching Power Supply

Abstract

This system designs a high efficient, low ripple switching power supply. It uses single-ended DC-DC forward converter, and the output range is controlled by regulating the pulse width of the PWM controller UC3844. The control part is called double closed-loop control circuit, composed by voltage feedback loop and current feedback loop. It can stable the output voltage, reduce voltage regulation and load regulation. AVR single chip Mega128L is the core processor of the display part which part has the role of collecting the output voltage, using I2C bus interface keyboard, display the measurement of the voltage and the current, and it also designed to protect overcurrent which is used to enhance the reliability of the system.