| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lighting device which supplies a current to a semiconductor light-emitting element by using an insulating transformer, and can enhance conversion efficiency in feedback control while reducing the cost, and to provide a lighting fixture using the same. <P>SOLUTION: The lighting device comprises a transformer T1 having a primary winding N1, a secondary winding N2 and a tertiary winding N3 coupled magnetically where a rectifying and smoothing circuit 3 is connected across the primary winding N1 and an LED unit 7 is connected across the secondary winding N2, a switching element Q1 which conducts and interrupts a current supplied to the primary winding N1, and a control unit 5 which controls on/off operation of the switching element Q1 based on the output from the tertiary winding N3 thus controlling the LED current Io supplied to the LED unit from the secondary winding N2. <P>COPYRIGHT: (C)2012,JPO&INPIT |
