通信设备的直流供电电压都有一定的电压范围 ,而提供直流电压的蓄电池组维护使用的充电电压 ,往往高出通信设备所要求的电压范围。为兼顾两者的要求 ,一般可采用在设备回路上加串降压二极管的方法 ,使两者在开关电源母线上的电压一致。现介绍一种降压自动控制电路 (图 1 ) ,使 Communication equipment DC power supply voltage has a certain voltage range, while providing DC voltage battery pack maintenance charge voltage used, often higher than the communication equipment required voltage range. In order to take both of them into consideration, a method of adding a series of buck diodes on the equipment loop can be adopted to make the voltages of the two switches in the switch power bus line consistent. Now introduce a step-down automatic control circuit (Figure 1)