Patent ID: 7301784
Filing Date: 2007-11-27
Classification: H05B

Abstract:
1. A lighting control unit for a vehicle lighting fixture, comprising: a switching regulator which converts an input voltage from a power supply to electromagnetic energy and emits the electromagnetic energy to a secondary side of a transformer, in accordance with an ON/OFF operation of a switching element connected to a primary side of the transformer; an energy propagation section which propagates electromagnetic energy emitted from the switching regulator as light emission energy to a semiconductor light source; a primary current detection section which detects a current on the primary side of the transformer; a secondary current detection section which detects a current supplied from the secondary side of the transformer to the semiconductor light source; a voltage detection section which detects a voltage applied to the semiconductor light source; and a control section which generates a switching signal based on the current detected by the secondary current detection section, and controls the ON/OFF operation of the switching element in accordance with the generated switching signal as well as limits an ON operation of the switching element when the current detected by the primary current detection section reaches a limit current value, wherein the control section lowers the limit current value when the voltage detected by the voltage detection section exceeds a first set voltage.