| 摘要 |
PURPOSE:To compensate the fluctuation of input voltage with a small size structure by controlling the output of an inverter energizing a discharge lamp to keep constant using a means varying the output of the inverter stepwise. CONSTITUTION:When a controller 30 is controlled with outer control signals, turned on state of an FET 27 in a impedance device 20 is changed to control the turned on duration of a transistor(TR) 5, the output of an inverter device 1 energizing a discharge lamp 2 is varied stepwise. The integrated output of a DC source 6 is detected by a TR 32 in the controller 30 to turn on the TR 32, and the detected output of the TR 32 is compared with a reference voltage of a reference voltage generating means 31 to control the turning on of a TR 33. And depending upon the continuity of the FET 27 the resultant capacity including capacitors 23, 24 of the device 20 is varied, and depending upon the corresponding impedance variation the turned on detection of the TR 5 is controlled, thus the fluctuation of the output voltage of a source 6 can be compensated with a small size structure using a means varying the output of the inverter stepwise. |
