Standardized data for dimming of fluorescent lamps

In another paper by the authors (see ibid., vol.1, p.665-72, 2002), a description is given of standardized data concerning the static properties of electrodes of fluorescent lamps and also of the preheating data for the electrodes. In this publication we explain the physical and engineering principles that are the basis of the new approach to standardized information for dimming of fluorescent lamps. Descriptions with the additional 'heating current' and 'total current' or I/sub LH/ are discussed. Next to these descriptions the latest approach with the sum of squared lead-in wire currents to an electrode is explained: the so-called "SoS lines". This information was generated in a Panel of ELMAPS TC4. It is shown that taking the energy balance around the hotspot of the electrodes as the starting point, relatively simple expressions can be derived for the additional heating that is required if fluorescent lamps are dimmed. As a next step in the standardization process, the data for the "SoS lines" of single capped fluorescent lamps will be included in the IEC 60901 standards.