Miniature electronic device having time informing sound generating function

Claim 1

A miniature electronic device having a time informing sound generating function, comprising: a source of reference frequency signals; a time counting means for counting said reference frequency signals and for producing present time information and a signaling time signal; means for setting an alarm time; alarm signal generating means coupled to said time counting means and to said alarm time setting means for generating an alarm signal at the time of practical coincidence of an alarm time set in said alarm time setting means and the present time information provided by said time counting means; sound generating means including means for receiving at least one of a signalling time signal and an alarm signal, a piezoelectronic buzzer and a driver coupled to said receiving means for push-pull driving of said piezoelectronic buzzer to thereby audibly inform of the signaling time and alarm time in response to said signaling time signal and to said alarm signal, respectively; signal judging means responsive to a signal supplied to said receiving means of said sound generating means for judging whether the signal supplied to said sound generating means is a signaling time signal or an alarm signal; and sound volume control means coupled to said sound generating means and to said signal judging means for changing the voltage provided to said piezoelectric buzzer by said driver in accordance with the output signal from said signal judging means so as to generate different volume sounds responsive to said signaling time signal and alarm time signal, respectively.