signalling system a.c.

插入反转控制器_馆档网 ... "signalling key" 发码电键,信号电键" "signalling system A.C." 交流信号制" ...

... 发码速率;亯号速率 signalling speed 交流亯号制 signalling system A.C. 幅度变化亯号 signalling， amplitude change ...