Abrégé

A lighting device (101), comprising: an electrical connector (104) for fitting in a lamp socket; a fluorescent tube (102); an electrode (105) for ionising air; and a ballast circuit (301) configured to supply suitable electrical currents and voltages to the fluorescent tube (102) during starting and subsequent operation. The lighting device (101) also has an ion generator circuit (302) configured to receive a relatively low AC voltage from the connector (104) and supply a relatively high DC voltage to the electrode (105). The ion generator circuit (302) itself comprises: a transformer (L41) having a primary winding and a secondary winding; and a semiconductor device (S41) connected in series with the primary winding. The semiconductor device (S41) is configured such that for voltages up to a threshold voltage the semiconductor device (S41) provides a very high resistance and for voltages above the threshold voltage the semiconductor device (S41) provides a low resistance. Consequently, in use, a current is generated in the primary winding when voltages across the semiconductor device rises (S41) to the threshold voltage.

Classes IPC  ?

• F21V 33/00 - Combinaisons structurales de dispositifs d'éclairage avec d'autres objets, non prévues ailleurs
• H05B 41/26 - Circuits dans lesquels la lampe est alimentée par une puissance obtenue à partir de courant continu au moyen d'un convertisseur, p. ex. par courant continu à haute tension