Patent ID: 7358459

Claim:
An electric arc welder for creating a succession of AC waveforms between an electrode and workpiece, the electric arc welder comprising: a profile control network including at least one of a frequency setting circuit, a duty cycle setting circuit, an up-ramp rate setting circuit, or a down-ramp rate setting circuit, the profile control network configured to establish a general profile of individual waveforms in the succession of AC waveforms, by setting more than one profile parameter for each of the individual waveforms, said parameters selected from a class consisting of at least one of frequency, duty cycle, up-ramp rate and down-ramp rate, the parameters being set by selective use of the at least one of the frequency setting circuit, the duty cycle setting circuit, the up-ramp rate setting circuit or the down-ramp rate setting circuit, wherein each of the profile parameters are individually settable with respect to each of the other ones of the profile parameters; a magnitude control circuit configured to set total current, voltage and/or power of each of the individual waveforms without substantially affecting the general fixed profile; a wave shaper configured to selectively receive inputs from the profile control network and the magnitude control network to generate an exact profile for each of the individual waveforms; a polarity signal generator configured to receive an input from the wave shaper and to generate a polarity signal which determines a polarity of any portion of each of the individual waveforms; and a high frequency switching circuit configured to receive an input from the wave shaper and to generate each of the individual waveforms at a frequency of at least 18 kHz.