| 摘要 |
PROBLEM TO BE SOLVED: To make possible generating a buzzer sound with much information amounts, soft tone quality and easy for adjusting the volume by supplying a voltage of a capacitor to a buzzer in the state connecting a power source to the capacitor and disconnecting the power source from the capacitor. SOLUTION: The buzzer 2 is driven in two modes. Its first mode repeats between operation and non-operation of a transistor 15 at a short period in the state operating the transistor 13. The second mode repeats between the operation and the non-operation of the transistor 15 at a short period in the state operating no transistor 13. Then, though the drive power of the buzzer 2 is supplied from source lines 11, 12 in the first mode, and is supplied from the capacitor 17 in the second mode, since the potential Va of the terminal 2a of the buzzer 2 is equal to charging potential, a drive voltage according to the voltage of the capacitor is supplied to the buzzer 2. |
