| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric circuit for driving a plurality of gas discharge lamps (6) connected to an AC power source (2). SOLUTION: The electric circuit includes at least one transformer (1) having one primary winding (4) and a plurality of secondary windings (5), each being provided on one of the transformers. The gas discharge lamps are connected in series with the secondary windings to constitute a circuit ring. In the circuit ring, currents of the equal amounts flow through all the lamps. In order to further improve logical equalization in brightness of all the lamps brought about by the above, a closed circuit ring is formed by connecting elements in regular order of a lamp-a secondary winding-a lamp-a secondary winding (an LS type) or a lamp-a lamp-a secondary winding-a lamp-a lamp-a secondary winding (an LLS type). The circuit ring has high-resistance earth connections of connecting an actual zero potential point with an earth potential (9) via a current asymmetry detection circuit (ADC) (8) of the number corresponding to at least a half of the number of lamps which are present at least in the circuit ring. COPYRIGHT: (C)2010,JPO&INPIT |
