Patents by Inventor Jan W. Denneman

Jan W. Denneman 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).

  • Low pressure mercury discharge lamp circuit arrangement
    Patent number: 5182503
    Abstract: A circuit arrangement suitable for operating a low pressure mercury discharge lamp by means of a high-frequency pulsatory current comprising circuitry for generating a high-frequency pulsatory current from a supply voltage with a modulator for modulating the high-frequency pulsatory current into a substantially square-wave shape voltage with a current amplitude A, with a modulation frequency f and a duty cycle DC together with circuitry for adjusting the duty cycle DC and circuitry for adjusting the amplitude A.
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: January 26, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Jan W. Denneman, Leonardus U. E. Konings
  • Low pressure mercury discharge lamp circuit arrangement
    Patent number: 5166580
    Abstract: A circuit arrangement suitable for operating a low pressure mercury discharge lamp by means of a high-frequency pulsatory current comprising circuitry for generating a high-frequency pulsatory current from a supply voltage with a modulator for modulating the high-frequency pulsatory current into a substantially square-wave shaped voltage with an amplitude A, a modulation frequency f and a duty cycle DC together with circuitry for adjusting the modulation frequency f and circuitry for adjusting the duty cycle DC.
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: November 24, 1992
    Assignee: U.S. Philips Corporation
    Inventors: Jan W. Denneman, Leonardus U. E. Konings
  • Low pressure mercury discharge lamp circuit arrangement
    Patent number: 5164638
    Abstract: A circuit arrangement suitable for operating a low pressure mercury discharge lamp by means of a high-frequency pulsatory current comprising circuitry for generating a high-frequency pulsatory current from a supply voltage with a modulator for modulating the high-frequency pulsatory current into a substantially square-wave shape voltage with a current amplitude A, a modulation frequency f and a duty cycle DC together with circuitry for adjusting the modulation frequency f and circuitry for adjusting the amplitude A and circuitry for adjusting the duty cycle DC.
    Type: Grant
    Filed: January 9, 1991
    Date of Patent: November 17, 1992
    Assignee: U.S. Philips Corporation
    Inventors: Jan W. Denneman, Leonardus U. E. Konings
  • Method of operating a high-pressure discharge lamp
    Patent number: 4868463
    Abstract: A method of and a device for the operation of a high-pressure discharger lamp provided with a discharge vessel (3) which accommodates an ionizable filling and two electrodes (4, 5), between which electrodes in the operating condition the discharge takes place. The lamp is operated from a supply source which supplies a power of periodically alternating value. According to the invention, for each power frequency .nu..sub.i (i=1,2, . . .) the relation .nu..sub.i .gtoreq.60 .nu..sub.1 is satisfied, where .nu..sub.1 is the lowest frequency at which in the operating condition of the lamp standing pressure waves can occur in the discharge vessel (3). Thus, it is possible to operate the lamp so as to be free from arc instabilities due to standing pressure waves.
    Type: Grant
    Filed: December 4, 1984
    Date of Patent: September 19, 1989
    Assignee: U.S. Philips Corp.
    Inventors: Jan W. F. Dorleijn, Rudolf L. A. van der Heijden, Jan W. Denneman
  • Discharge lamp with interference shielding
    Patent number: 4568859
    Abstract: A discharge lamp having a sealed glass vessel filled with gas and a metal vapor, operated with a supply at a frequency of at least 20 kHz. An interference-suppressing conductive layer is arranged on a wall surface surrounding the discharge, and connected to an electric supply lead-in wire. Preferably, a plurality of insulated metal rings, on the outside of the wall, also surround the discharge.
    Type: Grant
    Filed: December 20, 1983
    Date of Patent: February 4, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Henk Houkes, Jan W. Denneman, Pieter Postma
  • Electrodeless gas discharge lamp
    Patent number: 4422017
    Abstract: An electrodeless gas discharge lamp having a closed loop core of a magnetic material the part of which core extends through the lamp vessel, a high frequency field being induceable in this core by means of an h.f. generator in the lamp base, said core is assembled of at least two operable core portions at least a major part of one portion lying within the lamp vessel, and the other of the two portions being located in the lamp base, the lamp base being detachably secured to the lamp vessel.
    Type: Grant
    Filed: August 11, 1982
    Date of Patent: December 20, 1983