京广线汨罗—蒲圻段上的 4 0 0 MHz中继器充电盘 ,自运用后常有故障出现 ,特别是该盘电源变压器 ,常常被烧坏。经查找得知 ,上述故障原因是充电电路 (参见充电盘电路图 )为恒压充电 ,电流随电池电压的下降而增大 ,而电路限流电阻取样值不合理 ,使电源变压器长时间、大电流超负? Beijing Guangluo Miluo - Pu 圻 section on the 400 MHz repeater charging disc, often after the operation failure, especially the power adapter, the disc is often burned. The search shows that the reason for the above fault is that the charging circuit (see the charging circuit diagram) is a constant voltage charging, the current increases with the decrease of the battery voltage, and the sampling value of the circuit current limiting resistance is unreasonable, which causes the power transformer to operate for a long time, Overloaded?