pole-changer
... pole极，极点、杆、柱 pole-changer换极器 policeman淀帚橡皮头玻璃搅棒 ...
pole reverser
... pole pitch at the commutator 换向葡的极距 pole reverser 换极器 pole shoe 极靴 ...
relay pole changer
pole changing switch
pole changing starter
点击反馈点击反馈