Patents Examined by J. A. Popek
  • Telephone set ringing current injection device
    Patent number: 4306118
    Abstract: A telephone set line circuit ringing current injection device having a hybrid circuit in which each feed wire is connected in series with a resistor, and a stage consisting of a diode connected in parallel with the collector-to-emitter circuit of a transistor. The cathode of one diode is connected to the collector of the transistor on the side of one of the feed wires, the anode of the other diode and the emitter of the other transistor are connected to the other wire.
    Type: Grant
    Filed: September 14, 1979
    Date of Patent: December 15, 1981
    Assignee: Le Materiel Telephonique Thomson-CSF
    Inventors: Michel Ciboulet, Jean L. Belly, Antoine Malo-Huerto
  • Power circuit for loudspeaker telephone
    Patent number: 4304969
    Abstract: A power circuit for a loudspeaker telephone station incorporates separate capacitors across the power terminals of the transmitting and receiving amplifiers, with a regulating circuit for charging the capacitor connected across the receiving amplifier only after the other capacitor has been fully charged. A control circuit for the telephone station is connected in parallel with the transmitting amplifier.
    Type: Grant
    Filed: September 7, 1979
    Date of Patent: December 8, 1981
    Assignee: Siemens Aktiengesellschaft
    Inventor: Klaus Walla
  • Subscriber station network
    Patent number: 4303805
    Abstract: A solid state network for subscriber stations which uses a first active element to couple both the transmitter and the receiver to the telephone lines and uses non-inductive component for compensation to minimize costly heavy components and to facilitate transmission and reception of communication signals almost independently of variations in line length.
    Type: Grant
    Filed: May 21, 1979
    Date of Patent: December 1, 1981
    Assignees: United Networks, Inc., Manu-Tronics, Inc.
    Inventors: Jan Synek, Michael Tentler