Patents Assigned to F. Knobel Elektro-Apparatebau AG
  • Patent number: 3975660
    Abstract: A starterless circuit arrangement for the ignition and the operation of one or a number of series connected, low voltage fluorescent lamps which are connected with a stray field transformer coupled with a voltage source. The stray field transformer produces the no-load voltage needed for firing the lamps and possesses heating coils which are connected with the electrodes of the lamps. A cold conductor having markedly positive resistance characteristic is connected in parallel with at least part of the secondary winding of the stray field transformer in order to maintain the voltage applied to the lamp(s) at a value beneath the firing or ignition voltage for such length of time until the electrodes of the lamps are pre-heated.
    Type: Grant
    Filed: March 27, 1975
    Date of Patent: August 17, 1976
    Assignee: F. Knobel Elektro-Apparatebau AG
    Inventors: Fritz Knobel, Ernst Meili