Patents by Inventor Stefan E. Roijers

Stefan E. Roijers 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).

  • Circuit arrangement and signalling light provided with the circuit arrangement
    Patent number: 6147458
    Abstract: A circuit arrangement for operating a semiconductor light source includes connection terminals for connecting a control unit, an input filter, a converter comprising a control circuit, output terminals for connecting the semiconductor light source, an apparatus CM for removing a leakage current occurring in the control unit in the non-conducting state, and a self-regulating circuit for deactivating the apparatus CM. The circuit arrangement is also provided with a detection circuit for detecting an incorrect functioning of the converter or the semiconductor light source. For this purpose, preferably a minimum voltage and a maximum voltage are detected at the output terminals.
    Type: Grant
    Filed: June 29, 1999
    Date of Patent: November 14, 2000
    Assignees: U.S. Philips Corporation, Lumileds Lighting B.V.
    Inventors: Marcel J. M. Bucks, Engbert B. G. Nijhof, Johannes E. Algra, John E. K. G. De Clercq, Pieter W. Habing, Stefan E. Roijers
  • Discharge lamp igniting and operating curcuit having interference signal suppression from 9 KHz to 100 MHz
    Patent number: 5834902
    Abstract: A circuit arrangement for igniting and operating a discharge lamp is provided withinput terminals for connecting a supply source, and a ground terminal, differential-mode and common-mode filters in which inductance and capacitance are incorporated,output terminals for connecting the discharge lamp, anda switch mode power supply connected to the input terminals and the output terminals by respective voltage conduction branches.The circuit arrangement is characterized in that the input terminals and output terminals are connected both to one another and to the ground terminal by respective capacitive filters, in that a bead is included in one of the voltage conduction branches, and in that further common-mode capacitance is present between the inductance and the switch mode power supply. The requirements formulated in both EN55022 and EN55015 can be complied with in this manner.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: November 10, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Oscar J. Deurloo, Stefan E. Roijers