Independent amplitude control, available only on some inverters, allows the EN and EP amperage values to be set independently. Independent control of the EN and EP portions of the AC cycle allows the operator to direct more or less energy into the work piece, as well as take heat off the tungsten.
For example, when welding a thick piece of aluminum, the operator can put 250 amps of EN into the work and only 60 amps of EP into the tungsten. This provides faster travel speeds, faster feed of filler rods, deeper penetration, and the potential to eliminate pre-heating. Some companies cut production time by up to two-thirds using this technology.
Independently increasing EN amperage while maintaining or reducing EP amperage also narrows the arc cone, lets the operator use a smaller diameter electrode to make narrower welds and may allow the use of straight argon in place of argon/helium.