Patents by Inventor Joseph H. Mulkern

Joseph H. Mulkern has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5132888
    Abstract: A DC to DC power converter is implemented which includes an input switching circuit, an input capacitor, a transformer and an output rectifying switching circuit coupled to the transformer. The input switching circuit consists of a minimum of four transistors which are operated in a timed relationship such that bi-directional currents are developed in both primary windings. The output rectifying switching circuit is operated with switching transistors that provide zero-voltage resonant transition (ZVRT) switching. Timing relationships between the input signals control the ZVRT with switching of the transistors. Bidirectional currents in the primary windings of the single transformer element permit a reduction in volume of the magnetic element and the coils of the transformer for a given level of output power.
    Type: Grant
    Filed: January 7, 1991
    Date of Patent: July 21, 1992
    Assignee: Unisys Corporation
    Inventors: David S. Lo, Joseph H. Mulkern
  • Patent number: 4930063
    Abstract: A voltage regulator particularly adapted to A.C. distributed power systems requiring independent voltage regulation at a plurality of frequency responsive power supply modules energized by a power source at a common alternating frequency is provided by resonant tuning of the regulator circuit. An LC resonant circuit determines the operating frequency of the regulator, and may be operated above or below the excitation frequency. The output voltage is applied to a current amplifier which energizes a linearly variable inductor in accordance with the sensed D.C. output voltage. Changes in the output voltage result in changes in the tuned frequency of the LC circuit and the corresponding corrective change in the output voltage. Circuits providing both voltage and current regulation are described.
    Type: Grant
    Filed: April 17, 1989
    Date of Patent: May 29, 1990
    Assignee: Unisys Corporation
    Inventors: Christopher P. Henze, Joseph H. Mulkern