| 摘要 |
PURPOSE:To start a discharge lamp easily by turning on the power source to operate a timer circuit at the starting, increasing the VCE forcibly only in the preheating period, and controlling the VCE constant after the starting. CONSTITUTION:A circuit 2 to detect the collector-emitter voltage VCE of the switching transistor Q1 of an inverter 1, a timer circuit 4 to output an output signal to a VCE constant control circuit 3 at the starting after a specific time passes, and the VCE constant control circuit 3 are provided. The VCE constant control circuit 3 controls the switching transistor Q1 responding to the detected voltage of the VCE detecting circuit 2 to make the VCE constant, and raises the VCE to a specific control level for a specific time until the output signal is received after the starting of the timer circuit 4. That is, the level of the VCE constant control is raised at the starting and the starting is carried out while the output voltage of the inverter 1 is raised. Consequently, a discharge lamp lighting device with a high starting voltage can be obtained. |
