You 'd better check the swith first .

你最好先检查开关。

It is a sensitive swith tiny contact clearnce , instant action , and finny travel . It candrive the contrac rapidly and directly incertain travel with certain action force in order to switch over the circuit .

用一定的动作力通边一定的行程，使触点连动而进行电路转换的灵敏开关。具有微小触点间隙，瞬时动作和微小行程的特点。