短語詞組短語Normally y open valve 常開閥normally y open interlock 工子點normally -open gate 常開門normally y open contact 常開接點;常開觸點Normally y open 常開的;正常斷開的NO Normally Open 通常是打開的;常開的;常開normally open circuit 正常斷開電路normally open track circuit 開路式軌道電路 返回 normally open