Patents Represented by Attorney Earl F. Milde, Jr.
  • Patent number: 4485277
    Abstract: A transformerless hybrid circuit arrangement for a subscriber line interface circuit of a telecommunications exchange is disclosed. A preferred embodiment of the hybrid arrangement comprises a first and a second operational amplifier plus a differential amplifier connected together in the following manner: The non-inverting input of the first operational amplifier is connected to a first reference voltage and the output of this amplifier is connected (1) via a first resistor to one wire of the two-wire subscriber line, and (2) via a third resistor to the inverting input of the amplifier. The non-inverting input of the second operational amplifier is connected to a second reference voltage and to the receiving branch of the four-wire line of the telecommunications exchange.
    Type: Grant
    Filed: February 18, 1982
    Date of Patent: November 27, 1984
    Assignee: Siemens Corporation
    Inventors: Morris L. Minch, Theodore W. Wagner