an·nun·ci·a·tor
noun/əˈnʌnsieɪtə(r)/
/əˈnʌnsieɪtər/
(physics)- a bell, light or other device that shows which of several electrical circuits is in use
信号器:铃,灯或其他设备,显示正在使用的几个电路中的哪个词 Word Originmid 18th cent.: from late Latin annunciator, from the verb annunciare, variant spelling of annuntiare.