Abstract: A low self-capacitance inductor is described for use as an output inductor in high frequency inverter power supplies. A pair of channel-shaped ferrite core members are assembled with a gap of material approximating the permeability of air. The core members are arranged to provide an axial aperture therebetween. A plurality of conductor segments are disposed in the aperture and are electrically interconnected to plated through holes in a supporting printed circuit board assembly. The conductor turns for the inductor are selected by the pattern of printed circuit interconnections between selected ones of the plated through holes, whereby the same current densities in the inductor are achieved for different conductor turns arrangements.

Abstract: A power supply system that utilizes a plurality of inverter power supplies connect in common to drive a common load with control circuitry for forcing the power supplies to share the load equally is described. Control circuitry associated with each inverter power supply senses the current level provided to the load and compares to the average current provided by all other power supplies in the system. The control circuitry includes circuitry for controlling the pulse width modulator circuitry in response to the sensed condition that the power supply is supplying more than its equal share of the load and causes it to adjust the duty cycle of power switches in the power supply downward to reduce the output current level.

Abstract: A high frequency inverter power supply having isolation between the drive circuitry and the Power Switching device and utilizing a Field Effect Transistor as the Power Switching device is described. Circuitry for rapidly charging the gate capacitance of the Field Effect Transistor for enhancing the rate of its switching to the conductive state and for rapidly discharging the gate capacitance for enhancing the rate of its switching to the non-conductive state is shown.

Abstract: A non-dissipative battery charging circuit utilizing pulse width modulated constant current charging signals and having unregulated charging voltage stepped down by the use of a switching transistor and series inductor is described. Charging current is sensed and fed back to cause control of the charging cycle. Battery voltage is sensed and compared to a reference level for terminating charging when the battery is determined to be fully charged. A clocking and control system responsive to the feedback signals and the sensed voltage levels is described for controlling the activation and duration of application of charging current signals.

Abstract: An AC to DC power supply having a multi-channel, flyback inverter output section regulated via a fixed frequency, pulse width modulation controller. The controller indirectly regulates each channel by regulating an auxiliary channel, whereby the duty cycle of a switching transistor in the flyback inverter section is varied to maintain a constant DC voltage on the auxiliary channel and correspondingly on each output channel.

Abstract: Inverter power supply control circuitry that protects power supply components from relatively quick-changing over-current conditions and that provides regulation of the power supply's output current upon relatively slow-changing load conditions.

Abstract: An inverter power supply circuit that compensates for variations in the power supply's output voltage, which variations are due to variations in output loading, is disclosed. The input side of the circuit's DC-DC Converter-Inverter-Converter coupling transformer incorporates a compensation network having an impedance that is equivalent to the power supply's output impedance. Variations in the output loading cause corresponding proportional changes in the currents passing through the load and the compensating network. The changing current in the compensating network on the input side of the coupling transformer generates a corresponding changing voltage that is coupled, as a positive feedback, to the chopping transistor of the power supply to provide compensation for the variation in loading on the output side of the coupling transformer.

Abstract: A voltage regulation loop for the rejection of line frequency ripple of 0-180 Hz in an inverter power supply is disclosed. The loop includes an error amplifier (E), a pulse-width modulator (P), an inverter (I), a second summing node (N.sub.2), an output filter (F), and a feedback loop back to a first summing node N.sub.1 at the error amplifier. The novel pulse-width modulator is non-linearly operated to provide an improved rejection of the power supply's line frequency ripple and an improved stability.