基于PIC16F73单片机产生SPWM控制波形，驱动全桥逆变电路组成的在线式纯正弦波UPS电源系统，采用电压反馈闭环的程序(The online pure sine wave UPS power system based on the SPWM control waveform generated by PIC16F73 single chip and the full bridge inverter circuit, and the program of voltage feedback cl