Static inverter wherein a plurality of square waves are so summed as to produce a sinusoidal output wave

Claim 1

AN ARRANGEMENT FOR INVERTING UNIDIRECTIONAL POTENTIAL INTO THREE PHASES ALTERNATING POTENTIAL OF A PREDETERMINED FREQUENCY COMPRISING FIRST, MENS FOR PRODUCING A FIRST RESULTING VOLTAGE WAVE OF STEPPED CONFIGURATION, SAID FIRST MEANS COMPRISING A FIRST PLURALITY OF VOLTAGE GENERATORS, EACH OF SAID GENERATORS PRODUCING A SQUARE SHAPED OUTPUT VOLTAGE WAVE OF SAID PREDETERMINED FREQUENCY, MEANS COMBINING THE OUTPUT WAVES OF SAID GENERATORS TO PRODUCE SAID FIRST RESULTING VOLTAGE WAVE OF STEPPED CONFIGURATION, MEANS FOR DIFFERENTLY DIMENSIONING THE TIME OCCURRENCE OF EACH OF SAID SQUARE WAVES SO THAT THE DISCONTINUITIES IN SAID FIRST RESULTING WAVE OCCUR AT SELECTED INTEGRAL MULTIPLES OF A GIVEN ELECTRICAL ANGLE, AND MEANS FOR DIMENSIONING THE CHANGE IN AMPLITUDE OF SAID RESULTING WAVE AT TIMES CORRESPONDING TO THE OCCURRENCE OF EACH DISCONTINUITY TO BE PROPORTIONAL TO THE COSINE OF THE ELECTRICAL ANGLE CORRESPONDING TO THE TIME OF OCCURRENCE OF EACH SUCH DISCONTINUITY, SECOND MEANS AND THIRD MEANS FOR PRODUCING RESPECTIVELY SECOND AND THIRD RESULTING VOLTAGE WAVES OF STEPPED CONFIGURATION IDENTICAL TO SAID FIRST RESULTING VOLTAGE WAVE, AND MEANS FOR PROVIDING A PHASE DISPLACEMENT OF 120 ELECTRICAL DEGREES BETWEEN SAID FIRST, SECOND AND THIRD RESULTING WAVES.