| 摘要 |
PROBLEM TO BE SOLVED: To achieve a fail-safe slow release relay circuit stable in a slow release time.SOLUTION: The slow release relay circuit includes: a switch circuit 30 which is series-connected to a coil R of a relay 50 and carries out conduction/cut-off switching of a coil feed circuit 55; a storage circuit 20 which is parallel-connected to the coil R and the switch circuit 30 and charged by feeding to the feed circuit 55 from outside, and in which discharge after break of external feeding is carried out via the coil R and the switch circuit 30; and a charge-discharge circuit which is parallel-connected to the coil R and the switch circuit 30 and charged by external feeding, and in which discharge after break of external feeding is carried out by bypassing the coil R and the switch circuit 30. The switch circuit 30 switches conduction/cut-off of the feed circuit 55 corresponding to a level of a charging voltage of the charge-discharge circuit 10. Capacity C2 of the storage circuit 20 is larger than capacity C1 of the charge-discharge circuit 10, and a relay operation retainable time after break of external power feeding is longer than a conductive state maintaining time of the feed circuit 55 after break of external power feeding. |
