近几年来，医院里的各种精密仪器越来越多的采用UPS作为电源，UPS电源按其输出波形可分为方波输出和正弦波输出两大类，而按其操作方式又可分为后备式和在线式的两种。从UPS的设计原理可知，它能提供一连续及可调节的电力输出；它能消除断电、电压不稳、突波、尖波及市电杂讯等 In recent years, various kinds of precision instruments in hospitals have increasingly used UPS as a power source. UPS power supplies can be classified into square wave output and sine wave output according to their output waveforms. According to their operating modes, they can be divided into two major categories. Both fallback and online. From the design principle of the UPS, it can provide a continuous and adjustable power output; it can eliminate power failure, voltage instability, surge, spikes, and mains noise, etc.