| 摘要 |
PURPOSE:To enable the thinned-out lighting within the range where a current transformer can control this unit, and also, protect a circuit by stopping the oscillation in case that it gets over the range where the current transformer can control itself, in an object where three or more discharge lamps are connected, being equipped with a self exciting inverter circuit making use of a current transformer. CONSTITUTION:A detection means 14 detects the number of installed discharge lamps 8a-8c, and in case that number of installed discharge lamps is a specified number (two) or over in the range of control by a saturable transformer 4, a control means 10 changes over the level of oscillation of an inverter circuit 1, according to its number so as to maintain the lighting properly. But, in case that the number of installed discharge lamps is less than a specified number (two) beside the range of control by the saturable current transformer 4, a stop means 15 stops the oscillation of the inverter circuit 1. |
