车站值班员为了省事 ,在办理闭塞时 ,违反行车制度 ,同时扳动相邻 2站的磁石盘扳键 ,同时与接入的 2个值班员讲话。为了杜绝此类违章发生 ,需将锁闭电路设计成 1个值班员只能接入 1个用户分机 (组呼盘除外 )。分析电路可知 ,当值班员同时扳动 2个用户分盘扳键时 ,则 - 2 4 V电 In order to save trouble, the station attendant violated the traffic regulations while handling the blockage, and simultaneously pulled the magnet disk pull keys of the two adjacent stations and simultaneously spoke with the two attendants on the access. In order to prevent such violations occur, the lock circuit must be designed as a watch attendant access to a user extension (except group call disc). Analysis of the circuit shows that when the attendant at the same time pulling two users sub-plate pull key, then - 24V