| 摘要 |
PURPOSE:To perform starting easily and securely by generating starting pulses when an output voltage of a DC power supply is a specified value or more, stopping the pulses when jit is decreased to the specified value, and applying the pulses continuously during a lamp starting process. CONSTITUTION:When a power is supplied to a DC power supply circuit 1, a driver 16 is actuated through a lighting control circuit 5, and a power supply control circuit 17. A capacity 15 is charged through an FET 13, a transformer 12, and a diode 14. When a voltage is increased to Va, it is outputted from the control circuit 5 to a start pulse generating circuit 5. An FET 44 is actuated to give pulses to a lamp 3. A start energy is given from the capacity 15 through a diode 43 to a capacity 42. A difference is set between start voltage generating and stopping voltages Va, Vb, and starting pulses are generated continuously after generation of the start pulses till the voltage is decreased to Vb. In a starting process, therefore, the starting pulses can be applied to the lamp 3 continuously, thereby startability of the lamp becomes good and secure. |
