make-before-break contact 先闭后开触点 ; 先接后离触点 ; [通信] 先合后断触点

two-way make-before break contact 双向先合后断触点

two-way make-before-break contact 双向先合后断触点

two way make-before break contact 双向先合后断触点

change-over make before break contact 先通后断转换触点

make-before-break changeover switch contact 先闭后断换向开关接点

two way break before-make contact 双向先断后合触点

break-before-make contact 先开后合触点

break before make contact 先断后合触点