Inverter circuit for producing synthesized sinusoidal waveforms

An inverter circuit for generating synthesized sinusoidal outputs of a desired frequency comprising:

• means for generating a first, a second and a third fundamental rectangular waveform at a desired frequency wherein each of the first, the second and the third rectangular waveforms is out of phase with the other two by 120.degree.;
• means for generating notched rectangular waveforms for each of the first, the second and the third fundamental waveforms;
• a first means for combining the notched rectangular waveforms for each of the first, the second and the third fundamental waveforms to provide a single rectangular triplex waveform having a frequency equal to three times the frequency of the desired frequency;
• a second means for combining the first fundamental rectangular waveform, the notched rectangular waveform for the first fundamental waveform and the single triplex waveform to provide the synthesized sinusoidal output in phase with the first fundamental waveform;
• a third means for combining the second fundamental rectangular waveform, the notched rectangular waveform for the second fundamental waveform and the single triplex waveform to provide the synthesized sinusoidal output in phase with the second fundamental waveform;
• a fourth means for combining the third fundamental rectangular waveform, the notched rectangular waveform for the third fundamental waveform and the single triplex waveform to provide synthesized sinusoidal output in phase with the third fundamental waveform;
• and
• means for filtering the synthesized sinusoidal outputs coupled to the second, third and fourth combining means to provide filtered sinusoidal outputs wherein each filtered sinusoidal output has an amplitude of K volts.