Because his motor required two alternating currents and four wires , it could not be merely dropped into existing single - phase ac systems ; one would need to install additional wires to the network 因为他的马达需要两道交流电与四条导线，所以没法直接用在现有的单相ac系统；电力网上还得再加装导线。
A circuit arrangement for deriving a phantom circuit . in four wire circuits , the two wires associated with the " go " channel form one " side circuit " , and those associated with the " return " channel form another 用来派生一个幻象电路的电路结构。在四线电路中，与“去程”通道相关联的两线就形成了一个“半边电路” ，而与“回程”通道相关联的两线构成了另一个“半边电路” 。
