该电话照明灯能在夜间电话振铃时点亮床头灯,直至通话完毕,挂机后该灯再持续点亮一分钟便自动熄灭。工作原理开关AN附加在叉簧上。在夜间电话铃响时,电流通过光耦元件T给C1 The phone light can turn on the bedside light when the phone is ringing at night until the call is finished. After the phone hangs up, the light turns off for a minute and automatically turns off. Working principle switch AN attached to the hook on the spring. At night when the phone rang, the current through the optocoupler T to C1