| 摘要 |
PROBLEM TO BE SOLVED: To provide a ballast equipped with a control circuit that can be obtained economically and energy-efficiently in an existing ballast. SOLUTION: The ballast has an inverter having an inverter output terminal and in which an inverter output voltage is supplied to the inverter output terminal, a resonance output circuit connected between the inverter output terminal and a lamp and in which an ignition voltage is supplied, and a control circuit connected between the resonance output circuit and the inverter. The control circuit monitors the voltage, and when the monitored voltage reaches a prescribed level, the inverter is controlled to maintain an operating frequency at a present value over a prescribed time so that the resonance output circuit is made to maintain the ignition voltage at an appropriate level over a prescribed time, and when the lamp is ignited within a prescribed time, the control of the inverter is stopped and the operating frequency is prevented from reducing to the prescribed minimum value or lower during a lamp stabilized period, and when the lamp is not ignited within the prescribed time, the inverter operation is shut down. COPYRIGHT: (C)2009,JPO&INPIT |
