Patents by Inventor Douglas William Brooks

Douglas William Brooks 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).

  • Output protection for arc discharge lamp ballast
    Patent number: 6292339
    Abstract: Output protection for arc discharge lamp ballasts is provided by applying sampled ballast current to a burden capacitor selected to present a low impedance across the winding to a substantially symmetrical waveform of the sample current. Asymmetry between the positive and negative half-cycles of the sample waveform, such as partial rectification caused by abnormal lamp operation, results in charge buildup across the capacitor. Sufficient charge buildup actuates a ballast disabling switch such as a silicon controlled rectifier.
    Type: Grant
    Filed: March 23, 1999
    Date of Patent: September 18, 2001
    Inventor: Douglas William Brooks
  • Floating reference fault protection circuit for arc discharge lamp ballast
    Patent number: 6175189
    Abstract: A fault protection circuit for fluorescent lamp ballasts cuts off ballast power to the lamp in response to fast rise-time changes but not slower changes in either current output or voltage output of the ballast. The fault protection circuit is compatible with different ballast circuit topologies and features a floating reference level which renders the circuit insensitive to the lamp load wattage, making the circuit particularly useful in so-called universal ballasts.
    Type: Grant
    Filed: April 6, 1999
    Date of Patent: January 16, 2001
    Assignee: Bruce Industries, Inc.
    Inventor: Douglas William Brooks