Patents by Inventor Andrew O. Johnsen

Andrew O. Johnsen 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).

  • Patent number: 7402956
    Abstract: A ballast (10) for powering at least one gas discharge lamp (20) comprises a switching converter (100) and an inverter (900). Switching converter (100) includes a transistor (130) and a control circuit (200) that provides substantially zero voltage switching of the transistor (130) at a very high frequency. Preferably, control circuit (200) includes a drive circuit (300), a turn-on synchronization circuit (400), a current mirror circuit (500), a rail voltage regulator circuit (600), and a lamp current regulator circuit (700). Drive circuit (300) is preferably realized by a circuit arrangement that includes a standard pulse-width modulation integrated circuit (310).
    Type: Grant
    Filed: October 21, 2005
    Date of Patent: July 22, 2008
    Assignee: Osram Sylvania Inc.
    Inventors: Andrew O. Johnsen, Bernhard Ertl, Gerwin Thiel, John Cross
  • Patent number: 7230349
    Abstract: A high intensity discharge (HID) assembly comprises ballast circuits which includes a micro-controller, and an HID headlamp. In order to deter theft of the HID assembly from a vehicle, the micro-controller communicates with a vehicle computer, checks the VIN of the vehicle, and if the micro-controller does not recognize the VIN, causes the HID headlamp to operate in a flickering power output mode. The ballast circuits include a power control circuit, a lamp current regulator, a 400v regulator, a current sense circuit, a turn-on synchronization circuit, a shut down circuit, and a pulse width modulator.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: June 12, 2007
    Inventors: Andrew O. Johnsen, Vipin Madhani, Guy P. Bouchard
  • Patent number: 7211965
    Abstract: A circuit for operating a high intensity discharge (HID) lamp includes an H-bridge connected between a common terminal and a power line, and a control circuit connected to the H-bridge. The control circuit includes a transformer having a primary winding connected between the common terminal and a power terminal and a secondary winding connected between the common terminal and the power line, and a current sense resistor connected in series between the secondary winding and the common terminal. The HID lamp is connected to the common terminal and to the second winding so as sense a current across the current sense resistor.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: May 1, 2007
    Assignee: Osram Sylvania Inc.
    Inventors: Andrew O. Johnsen, Bernhard Ertl, Guy P. Bouchard, Vipin Madhani
  • Patent number: 7057356
    Abstract: A circuit for operating a high intensity discharge (HID) lamp includes an H-bridge connected between a common terminal and a power line, and a control circuit connected to the H-bridge. A boost circuit is connected in parallel with the H-bridge between the power line and the common terminal, where the boost circuit includes a resistor, a Zener diode and a capacitor connected in series.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: June 6, 2006
    Assignee: Osram Sylvania Inc.
    Inventors: Andrew O. Johnsen, Bernhard Ertl, Guy P. Bouchard, Arnulf Rupp
  • Patent number: 7042165
    Abstract: A first vehicle lamp driver circuit for a light emitting diode (LED) array, the LED array having a first string of four LEDs in series and a second string of four LEDs in series. A first LED driver drives the first LED string and a second LED driver drives the second LED string. In a STOP mode of operation, the current to both LED strings is controlled by the LED driver in series with the LED string. In a TAIL mode of operation, the current is provided to only one LED string via a series connected diode and resistor. When there is reduced input voltage, operation of the LED strings is provided by switching circuits that short-out one LED in each LED string. A second vehicle lamp driver circuit comprises a first LED string and a second LED string in series with a control switch having a feedback circuit for maintaining constant current regulation to control the sum of the current in each LED string and reduce switching noise.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: May 9, 2006
    Assignee: Osram Sylvania Inc.
    Inventors: Vipin Madhani, Andrew O. Johnsen