| 摘要 |
PURPOSE:To prevent the operation of a stand-by power source in the presence of commercial power by providing an initial reset function to the stand-by power source equipment and blocking transmission of erroneous backup command signal. CONSTITUTION:An erroneous backup command signal blocking unit C is connected with an uninterruptible power source equipment A and a load unit B. The command signal blocking unit C comprises an AND gate 13 and a time switch 14. Upon throw-in of a commercial power source 1, a control circuit 7 is initially reset through an initial reset function circuit 8. Upon finish of initial rest, a time switch 14 starts operation and produces and H output after predetermined time later. When a power interruption detecting circuit 12 for a load B detects power interruption, an H output is produced and AND condition 13 is satisfied, thereby a control circuit 9 switches a switch 10 to the side of an inverter 6. By such arrangement, erroneous operation of a stand-by power source is prevented when the commercial power source is not interrupted regardless of the function of the initial reset unit for the load unit. |
