Patents by Inventor Ted J. Lewandowski

Ted J. Lewandowski 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).

  • Pulse rejection and duration correction circuit
    Patent number: 4266099
    Abstract: A circuit which is particularly adapted for reconstructing fixed time duration dialing pulses in a telephone communications system while rejecting spurious pulses of less than a selected pulse duration. The circuit utilizes two coupling networks having integrated outputs of opposite polarity which are summed after passing through two separate switching amplifiers. The summed outputs are fed through a third switching amplifier having a hysteresis characteristic so that it switches only when both outputs have switched to the same polarity.
    Type: Grant
    Filed: May 29, 1979
    Date of Patent: May 5, 1981
    Assignee: Northern Telecom Limited
    Inventors: Inanc Kayalioglu, Vincent G. Roman, Ted J. Lewandowski
  • Negative impedance converters
    Patent number: 4151493
    Abstract: An improved negative impedance converter is provided comprising an additional differential operational amplifier to improve signal handling capability.
    Type: Grant
    Filed: October 3, 1977
    Date of Patent: April 24, 1979
    Assignee: Northern Telecom Limited
    Inventor: Ted J. Lewandowski