| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an insulation-type power supply device that can lower an output voltage below an effective input voltage, and can reduce an input current distortion, and to provide an illumination device having the same. <P>SOLUTION: A power supply device has: a parallel circuit consisting of a series circuit of input capacitors C1 and C2 connected between DC output ends of a diode bridge 21 that rectifies an AC power, and a series circuit of two switching elements Q1 and Q2; and a transformer T1 having a primary coil connected between a connection point between the input capacitors C1 and C2 and connection point between the switching elements Q1 and Q2, and a secondary coil having a tap. One end of an output capacitor C3 whose both ends work as output ends is connected to the tap of the secondary coil of the transformer T1, and the other end of the output capacitor C3 is connected to both ends of the secondary coil of the transformer T1 via output diodes D3 and D4 respectively. A control circuit 3 on-off drives the two switching elements Q1 and Q2 alternately. <P>COPYRIGHT: (C)2012,JPO&INPIT |
