Patents Represented by Attorney R. Frederick Hamann
  • Patent number: 4388500
    Abstract: An improved electronic hybrid for coupling signals between two wire and four wire transmission circuits. The hybrid includes a pair of amplifiers associated with a pair of terminating impedances which are serially connected between the amplifier outputs and the two wire port. The amplifiers driving the two wire port through the terminating impedances are biased to couple a dc potential to the two wire line whereby the terminating impedances serve as battery feed resistors. Each amplifier-impedance arrangement includes a feedback circuit connected from the junction between the impedance and the two wire port and an input of the amplifier for providing positive feedback for the amplifier so that the output impedance of the hybrid is maintained at a desired level using battery feed resistors of smaller value than heretofore required. The result is the ability to drive longer loops through the smaller series impedances while at the same time exhibiting the desired terminating impedance.
    Type: Grant
    Filed: February 27, 1981
    Date of Patent: June 14, 1983
    Assignee: Wescom, Inc.
    Inventor: John F. Regan