Patents by Inventor Laimons Freimanis

Laimons Freimanis 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).

  • Telephone subscriber line circuit
    Patent number: 4056689
    Abstract: A communication line interface circuit including a floating current source supplying a constant current substantially independent of loop length is disclosed. The line interface circuit is provided with circuitry for line supervision and the detection of dial pulse signaling.
    Type: Grant
    Filed: January 5, 1977
    Date of Patent: November 1, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: Laimons Freimanis
  • Telephone subscriber line circuit
    Patent number: 4056691
    Abstract: A communication line interface circuit including a floating current source supplying a constant current substantially independent of loop length is disclosed. The line interface circuit is provided with circuitry for line supervision and the detection of dial pulse signaling.
    Type: Grant
    Filed: January 5, 1977
    Date of Patent: November 1, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Laimons Freimanis, Harry Edward Mussman, DeWitt Paul Smith
  • Telephone ringer circuit
    Patent number: 4042786
    Abstract: A telephone ringing circuit responds to both conventional high voltage 20Hz ringing signals and low voltage tone alerting signals. A conventional electromechanical ringer is connected across the telephone line and is responsive to high voltage 20Hz ringing signals. A high capacitance capacitor is charged by the dc voltage present on the telephone line and is discharged across the electromechanical ringer when a tone detector circuit connected across the line detects a tone alerting signal, thereby activating the electromechanical ringer.
    Type: Grant
    Filed: April 26, 1976
    Date of Patent: August 16, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: Laimons Freimanis