| 摘要 |
PURPOSE:To generate alarm set verifying sound having a specified volume and comfortable tone quality by using a capacitor which is charged when an alarm switch is set, and by sounding by the charging characteristics of the capacitor when the alarm is set. CONSTITUTION:The capacitor 5 is charged through a transistor Q1 when the alarm is set by the alarm switch 3. The connecting point between the alarm switch 3 and the capacitor 5 is connected to a reference switch 2. When the alarm switch 3 is turned off, transistors Q3 and Q2 are off, and a sounding means 4 does not operate. Then, the alarm switch 3 is turned on with the reference switch 2 being off, the capacitor 5 is charged through the transistor Q1, the transistor Q2 is turned on for a specified period, the sounding means 4 operates, and the alarm set verifying sound is generated. At this time, since a current flows the sounding means 4 via the transistor Q2, the set verifying sound is going to have a constant volume and tone quality. In this constitution, comfortable verifying sound can be generated. |
