Patents by Inventor Chuk Seto

Chuk Seto 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).

  • Constant current line circuit with class features
    Patent number: 6865271
    Abstract: A line circuit utilizing a differential amplifier whose output is regulated to zero volts D.C. (when the subscriber's set is off-hook) by a negative feedback circuit, for controlling a voltage controlled power supply which provides a constant current feed to the subscriber's loop. The differential amplifier also transmits audio signals received from the subscriber's loop directly to a PABX via an unbalanced terminal. When the loop range exceeds a predetermined threshold, the circuit reverts to a voltage feed operation thereby allowing operation over long loop lengths and the ability to provide on-hook CLASS services.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: March 8, 2005
    Assignee: Mitel Networks Corporation
    Inventor: Chuk Seto
  • Constant current line circuit with class features
    Publication number: 20010031047
    Abstract: A line circuit utilizing a differential amplifier whose output is regulated to zero volts D.C. (when the subscriber's set is off-hook) by a negative feedback circuit, for controlling a voltage controlled power supply which provides a constant current feed to the subscriber's loop. The differential amplifier also transmits audio signals received from the subscriber's loop directly to a PABX via an unbalanced terminal. When the loop range exceeds a predetermined threshold, the circuit reverts to a voltage feed operation thereby allowing operation over long loop lengths and the ability to provide on-hook CLASS services.
    Type: Application
    Filed: March 30, 2001
    Publication date: October 18, 2001
    Applicant: Mitel Knowledge Corporation
    Inventor: Chuk Seto
  • Constant current line circuit with class features
    Patent number: RE40897
    Abstract: A line circuit utilizing a differential amplifier whose output is regulated to zero volts D.C. (when the subscriber's set is off-hook) by a negative feedback circuit, for controlling a voltage controlled power supply which provides a constant current feed to the subscriber's loop. The differential amplifier also transmits audio signals received from the subscriber's loop directly to a PABX via an unbalanced terminal. When the loop range exceeds a predetermined threshold, the circuit reverts to a voltage feed operation thereby allowing operation over long loop lengths and the ability to provide on-hook CLASS services.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: September 1, 2009
    Assignee: Mitel Networks Corporation
    Inventor: Chuk Seto