Patent ID: 9041293
Filing Date: 2015-05-26
Classification: H01J,H05B

Abstract:
1. A lamp control system, comprising: a lamp control unit, for controlling a fluorescent lamp, the lamp control unit comprising: a power conversion circuit, for converting a DC signal to an AC signal, comprising a DC signal input terminal and an AC signal output terminal; and a preheat and lighting circuit, coupled to the AC signal output terminal and two terminals of the fluorescent lamp, for preheating and activating the fluorescent lamp and outputting a feedback signal indicating a current flowing through the fluorescent lamp; wherein the preheat and lighting circuit comprises: a resonance circuit, coupled to one of the two terminals of the fluorescent lamp; a diode bridge, having two terminals respectively coupled to the two terminals of the fluorescent lamp, and one of the terminals being coupled to the fluorescent lamp via the resonance circuit; a switching device, the diode bridge having two other terminals, the switching device being coupled to the two other terminals of the diode bridge; and a current detection device, for detecting the current of the fluorescent lamp to output the feedback signal; and a system control unit, for controlling the preheat and lighting circuit in response to the feedback signal; wherein when the feedback signal is smaller than or equal to a threshold, the system control unit enables the switching device, and the resonance circuit performs preheating at the two terminals of the fluorescent lamp via a path provided by the diode bridge; and in response to the feedback signal being greater than the threshold indicating the fluorescent lamp is lighted, the system control unit disables the switching device so as to stop preheating.