| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the fluctuation of a power supply voltage to a control circuit. <P>SOLUTION: A transformer T1 includes a primary coil L1, a secondary coil L2 and an auxiliary coil L3 provided on the side of the primary coil L1. The potential at one end of a first output capacitor Co1 is fixed. A first diode D1 is provided such that a cathode thereof is on the side of the first output capacitor Co1 between the other end of the first output capacitor Co1 and one end of the secondary coil L2. A switching transistor M1 is provided on a route of the primary coil L1. The potential at one end of a second output capacitor Co2 is fixed. A second diode D2 and a switch SW3 for a mask are provided in series between the other end of the second output capacitor Co2 and one end of the auxiliary coil L3. A control circuit 10 receives a voltage generated in the second output capacitor Co2 at the power supply terminal and controls the ON/OFF of the switching transistor M1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
