Battery-operated alarm clock - uses alarm buzzer to signal when battery voltage falls below given level

摘要

The alarm clock has a timepiece stage (1) an electromechanical or electronic display stage (4) and an alarm stage with an electroacoustic alarm source. If the voltage of the supply battery (9) for the alarm clock falls below a given value a warning device is actuated. Pref. this warning device comprises a threshold switch (10) coupled to the electroacoustic alarm source, e.g. a piezoelectric buzzer (8), to allow this, to additionally provide a battery voltage warning signal. The threshold switch (10) is pref. coupled to the output of the timepiece stage (1), which comprises a quartz oscillator (2) coupled to a frequency divider (3).