| 摘要 |
PURPOSE:To exactly wake up a person without uncomfortable feeling for user by counting alarm sound interval determining signals by a counter, gradually raising the alarm sound volume according to the output of the counter to control to reset it to lower alarm sound volume after predetermined time. CONSTITUTION:When a standard switch 5 is closed, a single pulse is generated by an alarm sound generator 11 to thereby reset a counter 9. When the reset of the counter 9 is released, the counter 9 counts intermittent alarm sound notifying signals B to control the signal synthesized by a synthesizer 8 from the signals A, B from frequency dividers 2 at resistros R1-R5 to thereby increase the output alarm sound volume by one level. When the output phi6 of the counter 9 become ''H'' level, the output from the gate synthesizer 8 is applied directly to an alarm device 7, and the counter 9 does not receive its input. Thus, the signal from the gate synthesizer 8 is fed directly to the alarm device 7 to thereby cause the alarm device 7 to maintain its volume at constant level. |
