| 摘要 |
In an electronic instrument subject to power line interruptions and having a standby power supply, an external timer is used to time a predetermined brief period (e.g. 15 seconds to 1 minute). If the timer has not yet expired when standby power is once again developed, then a controller will cause a real time clock to start timing, using the currently held time of day. If the timer has expired when standby power is once again developed, the controller will cause the time of day clock to indicate that its time is no longer accurate. Moreover, if the timer has expired, then the controller will not cause the receiver to be turned on. If the timer has not expired, then the controller will determine if the receiver was turned on when the AC power line failure occurred, and if so, the controller will cause the receiver to turn on. If the receiver was turned off when the AC power line failure occurred, then the controller will cause the receiver to remain in standby mode. If, however, a reset was caused by an extremely fast phenomenon, such as a kine arc, then the receiver would not have had time to store status bytes. Upon waking up, the receiver would note that it was inoperative for only a short time, and that certain functions, such as degaussing need not be performed.
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