Abstract: A high frequency switching regulator drives plural loads by way of an output transformer. The transformer includes plural secondary windings connected to plural loads. One of the secondary windings is connected to a main output channel including a circuit for maintaining the current in the main channel above a predetermined minimum required for proper voltage regulation of the other channels. The circuit includes a current transformer in a line of the main channel. The current transformer contains a saturating core that saturates in response to a main channel current slightly above the predetermined minimum main channel current. An impedance responsive to current in the current transformer loads the main channel so that the main channel current is never less than the predetermined value regardless of the impedance between load terminals of the main channel. This assures proper inverter operation to maintain full voltage regulation of the other output channels.

Abstract: A plurality of conventional, parallel a.c. to d.c. to a.c. to d.c. converters are driven by a common a.c. source supply current to a common load. Each of the converters includes a controller for a pulse width modulated chopper; the controller determines the amplitude of d.c. current at the output terminals of the particular converter. Input terminals of each controller are responsive to the output voltage of the particular converter with which the controller is associated. A common controller for the controllers of the individual converters is responsive to the load voltage. The common controller varies the impedance of a single variable impedance connected in parallel to remote sense input terminals of the controller of each of the converters.

Abstract: A full wave bridge inverter includes four switch arms, each including N bipolar, parallel transistor switching elements. During a first interval, emitter-collector paths of all transistors in the first and second arms are forward biased so current flows in a first direction from a DC source through a bridge diagonal. During a second interval, emitter-collector paths of all transistors of the third and fourth arms are forward biased so current flows from the source through the diagonal in a second direction. The transistors have a tendency to be activated into the conducting and cut-off conditions at different times, and different transistors have a tendency to conduct differing amounts of current while forward biased. To overcome these tendencies, there are 2N.sup.2 transformers, each including first and second windings having like numbers of turns.

Abstract: A full bridge inverter includes four bipolar transistors of like conductivity type, connected in a bridge circuit including an apex to which a load is connected. During a first time interval, emitter collector paths of a first pair of transistors are connected betwen a DC source and the apex so that current flows in a first direction through the apex while the transistors are forward biased. The emitter collector paths of a second pair of transistors are connected with the source and the apex so that current flows in a second direction through the apex during a second interval while the transistors of the second pair are forward biased. A first transformer has first and second windings respectively connected in series with the emitters of the transistors of the first pair, such that voltages at the emitters of the transistors of the first pair have a tendency to vary in the same direction.