Fuzzy PID Theory Based Digital Switch Power Supply

In this paper, a new digital switch power supply is introduced, which is based on TL494 PWM, half-bridge converter circuit and PIC16F72. This system employs fuzzy PID algorithm, which not only take the advantage of fuzzy controller, like good robustness, instant response, small overshoots, but also play the characteristics, such as high precision and dynamic tracing, to the full. After measurement repeatedly, the voltage regulation is 0.17%, load regulation is -0.47%, peak-to-peak value of ripple voltage is within 0.1V, and full load efficiency can reach 88.15%.