在铝及铝合金焊接生产中广泛使用NSA-500-1型交流钨极氩弧焊机。该焊机结构简单、装配紧凑、体积小巧,便于使用和维修。但由于该焊机使用一段时间后,常常发生电弧不稳和中断现象,致使焊接无法进行,从而影响生产。我单位的两台焊机也都有同样的问题,虽然经过几次维修,仍不能根本解决问题。严重时,电弧在80～100A也不能稳定燃 NSA-500-1 AC TIG welder is widely used in aluminum and aluminum alloy welding production. The welder has the advantages of simple structure, compact assembly, compact size, easy use and maintenance. However, due to the use of the welder after a period of time, arc instability and interruption often occur, resulting in welding can not be carried out, thus affecting the production. Both units of my welding machine also have the same problem, although after several repairs, still can not fundamentally solve the problem. Seriously, the arc can not be stable at 80 ~ 100A