Patent ID: 7053334

Claim:
An electric arc welder for creating a succession of AC waveforms between an electrode and workpiece by a power source comprising a high frequency switching device for creating individual waveforms in said succession of waveforms, each of said individual waveforms having a profile determined by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz by a pulse width modulator with the magnitude of said current pulses controlled by a wave shaper and the polarity of any portion of said individual waveforms determined by the data of a polarity signal, a profile control network including a frequency setting circuit, a duty cycle setting circuit, an up-ramp rate setting circuit, and a down-ramp rate setting circuit, the profile control network configured to establish a general profile of an individual waveform by setting at least one profile parameter of an individual waveform, said parameters selected from a class consisting of frequency, duty cycle, up ramp rate and down ramp rate, the parameters being set by selective use of the frequency setting circuit, the duty cycle setting circuit, the up-ramp rate setting circuit, and 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, and a magnitude circuit for adjusting the individual waveform to set total current, voltage and/or power without substantially affecting the general fixed profile.