JPS54127364A - Electronic watch with battery life alarm - Google Patents

Abstract

PURPOSE:To warn the need for battery exchange to the user before the battery life terminates by detecting the voltage drop of the battery with a detection circuit, changing the frequency of the time signal and advancing the watch within the range of giving no hindrances to daily life. CONSTITUTION:The voltage VDD of a battery 9 is divided with resistances 41, 42 and is beforehand so regulated by regulating the resistances 41, 42 that when the battery voltage is normal the output of an inverter 43 becomes 0 and when it lowers to a certain value, e.g., 1.4V or under the output becomes 1. When the voltage lowers, the output of the inverter 43 becomes 1. At this time, the 1-hour pulse emitted from a sexagesimal counter 5 makes the output of AND 34 1 and sets the Q1 of the FF31 of the first stage of the sexagesimal counter 3 at 1. Hence, the counters 3, 5 count only 3559 where they should count 3600, resulting in the advance of 1 second per hour, i.e., 24 digits of a daily difference. If the set signal is applied to the FF32 of the second of the counter 3, the daily difference becomes 48 seconds as shown by a dotted line. Even in an analog circuit, the output of the AND 34 is similarly applied to a driving circuit 19 and the time is advanced by 1 second per hour.