在日常生活中,为了行动方便和节约用电,往往需要分别在两个地点各安装一个双掷开关(单刀型)。如楼梯间装设的电灯,上楼前要在一层楼将二层、三层……楼梯间的电灯开亮,到了楼上后,又要将电灯熄灭,做到随手关灯、节约用电。这就必须在楼上、楼下各安装一个双掷开关。再如,在卧室门口和床头 In daily life, it is often necessary to install a double-throw switch (single-pole type) at each of two locations for convenience of operation and power saving. For example, if the stairs are equipped with electric lights, they should be on the second floor and the third floor in the first floor before going upstairs. The lights in the stairwell should be turned on. After reaching the upper floors, the lights should be extinguished, so that lights can be turned off and saved. Electricity. This means that a double-throw switch must be installed upstairs and downstairs. Again, in the bedroom door and headboard