| 摘要 |
A lamp driving circuit (110) for driving a gas discharge lamp (11) is described, comprising current generating means (M1, M2, D1, D2, L, C, C1, C2) for generating a lamp current in discontinuous mode or critical discontinuous mode, and a controller (12) for controlling the operation of the current generating means. In an embodiment, the current generating means have HBCF topology. A zero-crossings detector (120) detects zero-crossings of the lamp current, and generates a detection pulse for each detected zero-crossing. A signal processor (130) monitors the detection pulses from the zero-crossings detector (120), and generates a lamp current inhibit signal if the detection pulses are absent during at least a predetermined time interval. The controller, in response to the lamp current inhibit signal, switches off the lamp current generating means.
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