点焊是一种金属的连接方法。在焊接时,焊件通过焊接电流局部发热,并在焊件的接触加热处施加压力,形成一个焊点。附有xu型控制箱的NA型点焊机已经成为建筑施工中一种必不可少的设备。它的引燃电路采用了二个引燃管正、反并联作为离子开关,与焊接变压器的初级线圈相串联,然后,由时间 Spot welding is a metal connection method. During welding, the weldment is locally heated by the welding current, and pressure is applied at the contact heater of the weldment to form a weld spot. The NA spot welder with the xu control box has become an essential equipment for building construction. Its ignition circuit uses two igniter tubes, the positive and the negative parallel, as the ion switch, which is connected in series with the primary coil of the welding transformer, and then, by the time