交流电弧焊机一般都是间断工作,有40％以上时间处于空载状态。该焊机空载降压装置(简称空载开关)既能保证焊机正常焊接,又能减少焊机的空载损耗。一般空载降压装置是利用耦合电容器与焊机的初级线圈相串联。由于不同型号和容量的焊机,初级线圈电感量不同,还要选用不同容量的耦合电容器,使用不方便。为解决这个问题,我们设计了一种性能较好、使用方便的空载开关,省去了耦合电容器,可同时适用于不同型号,不同容量的交流电弧 AC arc welding machines are generally intermittent work, more than 40% of the time in a state of no-load. The welder no-load step-down device (referred to as no-load switch) can not only ensure the normal welding welder, but also reduce the no-load loss welder. General load-free step-down device is the use of coupling capacitors and the primary coil of the welder in series. Due to different models and capacity of the welder, the primary coil inductance is different, but also the use of different capacity coupling capacitors, inconvenient to use. To solve this problem, we designed a no-load switch with good performance and easy-to-use, eliminating the need for a coupling capacitor, which can be applied to AC arcs of different models and capacities