| 摘要 |
PURPOSE:To obtain a steady lighting by controlling the average of the supply voltage to have a substantially constant value during a period from the time when a semiconductive switching element which controls the flow of electric current to the discharge lamp is powered to the time when the supply voltage becomes zero. CONSTITUTION:The discharge lamp lighting apparatus comprises a current-limiting impedance element 2 connected to an AC source 1, a discharge lamp 3, a semiconductive switching element 4 for controlling the flow of current to the discharge lamp 3, a pulse generating circuit 11 for generating high voltage pulses, and a control circuit 5 for controlling the power supply to the semiconductive switching element 4. According to this constitution, the voltage of the light apparatus is partly charged by the semiconductive switching element 4 and the voltage thus charged partly is changed by the control circuit 5 in response to the discharge lamp lighting conditions, thereby achieving a steady lighting of the discharge lamp 3. |
