| 摘要 |
PURPOSE:To provide a discharge lamp lighting device which does not cause excess loads on an inverter circuit even after one discharge lamp has started lighting. CONSTITUTION:The DC output of a DC power source E is oscillated at an oscillation circuit 12 via switching elements Q1, Q2 and a driving circuit to induce high frequency alternating currents and to light up discharge lamps FL1, FL2. The voltage of a condensor C1 is used to allow a lamp voltage to be detected by a lamp voltage detection circuit 15. When the lamp voltage is low, a control circuit 16 controls the oscillation circuit 12 so that the lamp voltage will be increased. When one fluorescent lamp FL1 lights up to increase the voltage of a resistance R2 in a one side lighting circuit 14, electric currents are supplied to the control circuit 16. The control circuit 16 prevents the oscillation circuit 12 from excessively increasing the output of the inverter circuit 11 so that the inverter circuit 11 will not undergo excess loads. |
