| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a small and low-cost power unit which is possible of output continuously for a specified hold time after instantaneous drop (drop of input voltage to a specified value). <P>SOLUTION: The power unit 1 inputs the AC from an AC power source 3 into input terminals 7 and 9. One end of the primary winding L1 of a transformer 11 is connected to the input terminal 7. A switching circuit 13 is connected between the other end of the primary winding L1 and the input terminal 9. The switching circuit 13 has switches S1-S4 and a capacitor C1. The switch S1 and the switch S2, and the switch S3 and the switch S4 perform complementary switching action. During stationary operation, the AC power source 3 supplies the primary winding L1 with power and outputs power via the secondary winding L2 and also charges the capacitor C1. At instantaneous drop, it supplies the primary winding L1 with electric energy accumulated in the capacitor C1, and outputs specified voltage continuously for a specified hold time or more. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
