spring-actuated stepping relay英 [sprɪŋ ˈæktʃueɪtɪd ˈstepɪŋ ˈriːleɪ]美 [sprɪŋ ˈæktʃueɪtɪd ˈstepɪŋ ˈriːleɪ]【电】弹簧致动步推继电器电力