Based the characteristics of variable polarity TIG welding

a tiny current short arc ignition was designed

which solved the problem of tungsten weariness

especially when the state of DCEP（direct current electrode positive）. There are three stages of tiny current short arc ignition

the three stagers are short stage

maintain stage and current slow rising stage

and the current of the short stage can be only 2 ～3 A. The experiments proved that the arc ignition is stable without any obvious tungsten weariness and arc extinguish

and the arc ignition success rate is quite high.