| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-emitting diode lighting device capable of further reducing a power loss of an impedance means serially connected with a switching element of a step-down chopper and excellent in temperature characteristics and having little variations in an output current. SOLUTION: The light-emitting diode lighting device is provided with a step-down chopper DC equipped with a first circuit A serially including a switching element Q1, an impedance means Z1 and a first inductor L1, a second circuit B serially including the first inductor and a diode D1, a self-excitation type driving signal generation circuit DSG equipped with a second inductor L2 magnetically coupled with the first inductor and impressing an induced voltage on a controlling terminal of the switching element to maintain the switching element in an On state, and a turn-off circuit TOF provided with a comparing means which, after detecting a voltage of the impedance means, outputs when the detected voltage exceeds a reference value, and a switching element which is turned on by the output of the comparing means and turns off the switching element by short-circuiting an output terminal of the self-excitation driving signal generation circuit. COPYRIGHT: (C)2010,JPO&INPIT |
