| 摘要 |
PURPOSE:To provide soft starting without influence of the characteristic of an element with a simple circuit configuration by furnishing a reference signal generating means, which produces a reference signal in a size controlled so that the output voltage of an inverter means becomes below a certain value for a certain period after turning-on of the power supply. CONSTITUTION:For a certain period after turning-on of a power supply, for ex. reference signal generating means 17, 27 produce a reference signal with a level below a certain value, and the reference signal is compared with the signal corresponding to the output voltage of inverter means 1, 3, 5, 7 to obtain the error voltage, and thereupon control means 25, 31 control the output voltage of the inverter means 1, 3, 5, 7. Accordingly the output voltage of inverter means 1, 3, 5, 7 becomes below a predecided value for a certain period after turning-on of the power supply. After passage of the specified period of time, the level of the reference signal will rise also to raise in turn the output voltage of the inverter means 1, 3, 5, 7, which preheats a discharge lamp 11 for a certain period, and thereafter the output voltage of the inverter means 1, 3, 5, 7 to perform lighting of the discharge lamp 11. This enables soft starting without influence of the element characteristic using a simple circuit configuration. |
