Patent ID: 6057649
Filing Date: 2000-05-02
Classification: C04B,H01F,H01J

Abstract:
An illumination unit, comprising:an electrodeless low-pressure discharge lamp; anda supply device,said lamp comprising a discharge vessel enclosing a discharge space in a gastight manner, an ionizable filling within said discharge space, and a coil for inducing a high-frequency magnetic field which maintains a discharge in the discharge space, said coil including a sintered core of polycrystalline ferrite material and a winding connected to the supply device, the ferrite material having a granular structure in which the major portion of the grains has a monodomain structure,the supply device including means for energizing said coil for inducing a high-frequency magnetic field which starts and maintains a discharge in the discharge space, characterized in that the losses in the core, when measured at room temperature in an alternating magnetic field with a frequency of MHz and at a magnetic flux density of 10 mT, are at most 150 mW/cm.sup.3.