| 摘要 |
<p><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. <P>SOLUTION: The power unit 1 rectifies the AC from an AC power source 3 by means of a rectifying circuit 5 and inputs DC into input terminals 7 and 9. A switch S3 is connected between the input terminals 7 and 9, and also a transformer 11 and a switch S1 are connected in series, and further an auxiliary power circuit 13 equipped with a switch S2 and a capacitor C1 is connected in parallel with the switch S1. A control circuit 10 opens the switch S3 during stationary operation, and switches the switches S1 and S2 complementarily, and when it detects the instantaneous drop, it closes the switch S3 in condition that the switches S1 and S2 are complementarily switched. Hereby, it supplies primary winding L1 with electric energy accumulated in a capacitor C1, and outputs specified voltage continuously for a specified hold time. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
