Abstract: A rotary transformer having a rotor assembly mounted on a shaft and a plurality of associated cooperative stators rotatably mounted about the rotor assembly. The stators are angularly adjustable, relative to each other, about the axis of the shaft. Electrical power is delivered to one of the stators (the primary stator), which functions as a primary of the transformer. The remaining stators (secondary stators) function as a secondary of the transformer. The relative angular orientation between the secondary stators determines the magnitude of the output voltage from the secondary stators.

Abstract: An adjustable speed drive system is provided which employs a unique induction machine which includes a rotor assembly mounted on a shaft, and associated cooperative first and second stators. The two stators are angularly adjustable, relative to each other, about the axis of the shaft. The net excitation of the rotor and thus the operating point of the machine on the torque-speed curve of a load on the shaft of the machine is a function of the relative angular displacement of the two stators. A third stator may be employed to enhance the efficiency of the machine by feeding excess rotor power back into the power line.

Abstract: An inductance machine having a rotor assembly electromagnetically coupled to first and second synchronous magnetic fields. The first and second synchronous magnetic fields have a relative angular displacement about the rotor axis which may be adjusted.

Abstract: A power supply for a load such as a computer, which is sensitive to power interruptions. A switching regulator is coupled to both the AC power line and a rechargeable battery, and makes automatic transitions between AC operation and battery operation, utilizing a transistor switch and an energy storage transformer coupled to both power sources and to the load. The transistor switch is driven by a variable duty cycle control signal provided by a programmed current feedback circuit responsive to both output voltage and instantaneous switch current. The feedback circuit cuts off the switch each time the peak current through the switch reaches a value corresponding to the desired output voltage--thus improving control loop stability and maintaining a constant peak current through the switch to substantially eliminate ripple. The circuit enables one terminal of the battery to be connected to one terminal of the switching transistor, to minimize noise.

Abstract: A base drive circuit for a power switching transistor in a power inverter circuit utilizes a center tapped current transformer winding to regeneratively couple the collector current of the power switching transistor to its base drive electrode. A first segment of the center tapped transformer winding is coupled via a control transistor to provide proportional base drive to the power transistors when it is biased into conduction.This forward drive mode continues until the control transistor is biased nonconducting, at which point, the second segment of the center tapped transformer winding is connected to the base drive electrode to provide a reverse drive current to the power transistor base to provide rapid turn-off and reset the transformer.

Abstract: An uninterruptible power supply utilizes a switching circuit which under normal operation modulates at a high frequency a signal provided by a commercial AC line to control the energy flow through a transformer between an input accepting the AC line source and a rectified DC output. The switching circuit which performs the modulation is optimally arranged to be coupled to a reserve energy source such as a charge storage capacitor or battery. It operates upon failure of the AC signal input to provide energy from the reserve source to the load by operating as a switching regulator.

Abstract: Primary and secondary currents of a converter transformer in a double-ended converter are continuously monitored to detect the onset of saturation in the magnetic core of the transformer. When the onset condition is detected, the conductive roles of the oppositely phased switching transistors in the converter are reversed to limit and counteract the onset of saturation in the magnetic core of the transformer.