Patents by Inventor John Charles Glenn

John Charles Glenn 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).

  • AC-powered, microprocessor-based, dimming LED power supply
    Patent number: 7791326
    Abstract: A dimmable, light-emitting diode (LED) power supply adapted to provide a direct current (DC), constant current (“constant current source”) from a conventional, phase-controlled 120 VAC, 60 Hz power source is disclosed. The constant current source of the present invention utilizes two processes to control dimming. In a first process, the phase angle of the input voltage is used to control the duty cycle of a line frequency pulse width modulation (PWM). In a second process, a proportional-current limit adjustment is used to control the average current to the LED during the ON time of the line frequency by PWM. As a result, at relatively low phase angles, peak currents can be lowered, reducing flicker and improving the audible noise levels generated by the circuit.
    Type: Grant
    Filed: December 28, 2007
    Date of Patent: September 7, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Mark Cobb Dahlman, John Charles Glenn
  • AC-powered, microprocessor-based, dimming LED power supply
    Publication number: 20090167203
    Abstract: A dimmable, light-emitting diode (LED) power supply adapted to provide a direct current (DC), constant current (“constant current source”) from a conventional, phase-controlled 120 VAC, 60 Hz power source is disclosed. The constant current source of the present invention utilizes two processes to control dimming. In a first process, the phase angle of the input voltage is used to control the duty cycle of a line frequency pulse width modulation (PWM). In a second process, a proportional-current limit adjustment is used to control the average current to the LED during the ON time of the line frequency by PWM. As a result, at relatively low phase angles, peak currents can be lowered, reducing flicker and improving the audible noise levels generated by the circuit.
    Type: Application
    Filed: December 28, 2007
    Publication date: July 2, 2009
    Inventors: Mark Cobb Dahlman, John Charles Glenn