| 摘要 |
PROBLEM TO BE SOLVED: To enable automatic confirmation of false failure occurrence and reduce recovery time from failure fault. SOLUTION: A double signal power source for telephone constituted of a working/stand-by unit is equipped with a failure automatic reset circuit 110 or 210 which consists of a first counter for counting a time until a failure is automatically reset, a first latch circuit for preventing re-rest for re-failure within a specified term, and an oscillating circuit for generating clocks for the counter, and a working/stand-by automatic switching circuit 111 or 211 which consists of a second counter for counting the time from when a failure is recovered until when automatic switching is performed, a multivibrator for outputting a switching signal after an automatic reset signal is outputted, and a second latch circuit for setting a stand-by state when re-failure is not generated for a previously determined period. |
