Patents by Inventor Stefan T. Hadjivassilev

Stefan T. Hadjivassilev 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: 5262932
    Abstract: In one embodiment, a solid state DC power supply includes an inverter (30) having two half-bridges (32, 34) in which are provided pairs of MOSFETS (Q5-Q12) used as switching elements. An output transformer (60) and a rectifier (85) are connected to output terminals (T60). A feedback path includes switching control means (40) separate primary and secondary drive means (10, 20) supplying drive pulses to the switching means (Q5-Q12) in the inverter (30). The secondary drive means (12, 13) amplifies the pulse output of the primary drive means (11) in order to improve the switching speed of the inverter (30). Current detection is provided by a transformer (70) connected to switching (40). The primary and secondary drive means receive pulses from a pulse width modulator (IC5) the output of which is isolated by transformers (TX1, TX2). In a modification, a power converter in the form of a DC power supply includes parallel MOSFET (M) and IGBT (I) switch pairs in each arm of a full wave bridge configuration.
    Type: Grant
    Filed: March 3, 1992
    Date of Patent: November 16, 1993
    Inventors: David L. Stanley, Michael J. Leisten, Adrian K. Lefedjiev, Roumen D. Petkov, Stefan T. Hadjivassilev