Stabilized sine wave inverter

Claim 1

A stabilized inverter apparatus, capable of transforming direct current into alternating current, and particularly sinelike alternating current, by means of trigger controlled current valves in conjunction with a tuned electrical LC circuit, by feeding direct current from a source thereof through a tuning inductor and current valves, applying chopped direct current with alternating polarities across the terminals of the primary winding of the transformer which primary winding has a capacitor connected in parallel therewith, whereby energy may be drawn from said transformer by connecting a load to a winding thereof, and stabilizing means stabilizing the output level by controlled energy feedback to the direct current input from said transformer through rectifiers, said inverter apparatus comprising, in combination, an input connection between one terminal of said DC source and the center tap of a winding of the inverter transformer; energy flow means connected between taps on said winding on opposite sides of said center tap and said connection; said energy flow means comprising respective phase controlled current valves and feeding controlled rectified DC current to said connection; a second capacitor in said connection effecting separation of AC and DC components in said input connection; and a phase angle control connected to said phase controlled current valves and operable to effect application of a variable magnitude charge, of a selected polarity, to said second capacitor in accordance with the setting of said control; said charge being either added to or subtracted from the DC input potential in accordance with the status of the latter.