Patents by Inventor Gerd Schiefer

Gerd Schiefer 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).

  • Electric circuit with transient voltage doubling for improved operation of a discharge lamp
    Patent number: 4766350
    Abstract: The invention relates to an electric arrangement for operating a an electric discharge lamp (13) which is connected in series with a coil (14) and a switch (15) to a pulsatory direct voltage source. The combination of the lamp and the coil is shunted by a rectifier. The lamp is shunted by a capacitor (18) and the switch is periodically rendered conductive at an instant when the instantaneous voltage of the pulsatory direct voltage source is between 0.5 and 0.8 times the then required re-ignition voltage of the lamp. The voltage build up across the capacitor (18) after the switch has become conducting causes the lamp to reignite. The luminous efficacy of the lamp is comparatively high.
    Type: Grant
    Filed: September 10, 1982
    Date of Patent: August 23, 1988
    Assignee: U.S. Philips Corporation
    Inventors: Theo Husgen, Hubert Raets, Gerd Schiefer, Jan Zwier
  • Tunable high frequency input circuit for a television receiver that tunes both VHF and UHF channels and can be readily integrated
    Patent number: 3939429
    Abstract: The IC television tuner has a tunable oscillator and a fixed oscillator, two mixer stages and a filter in between. This tuner operates at two intermediate frequencies the first of which lies in the GHz range. The two oscillators are coupled through hybrid rings.
    Type: Grant
    Filed: July 2, 1974
    Date of Patent: February 17, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Klaus Lohn, Georg Lutteke, Gerd Schiefer, Lammert Bruntink, Paulus Petrus Maria Groenewegen, Hans Viktor Weinerth, Wilhelmus Antonius Joseph Marie Zwijsen, Karel Petrus Van Rooij