| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sounding body driving system which uses an output port for indication to light an indicator like an LED without providing an output port only for a sounding body like a buzzer and uses the output port for display to produce a confirmation sound of the sounding body. <P>SOLUTION: A buzzer is connected between output ports 21 and 22 of a control IC 1 which drives two light emitting diodes LED1 and LED2 for displaying charged states of two batteries; and when batteries are attached to a charger and charging is started, the start of charging is reported by outputting a pulse frequency approximating a resonance frequency of the buzzer from output ports S1 (S2) corresponding to the batteries for a prescribed period to sound the buzzer, and light emitting diodes LED1 (LED2) are lit to inform that charging is being performed. When the control IC 1 is a package, the number of pins can be reduced. <P>COPYRIGHT: (C)2004,JPO |
