| 摘要 |
PURPOSE:To obtain a preferred sound volume level by dividing a sound volume control voltage set variable into plural voltages by using plural resistors, selecting the divided voltage and applying it to the sound control amplifier circuit as the sound volume control voltage so as to attain finer sound volume adjustment. CONSTITUTION:An output of an integration circuit 5 is divided by resistors 8- 15, the divided voltage is selected at a changeover circuit 7 by using a signal of a key matrix circuit and a microcomputer 2' of an operating section 1' and applies it to the sound output circuit 6. Further, the operating section 1' is provided with an operation section of [up], [down] of a 6-bit counter 3 and minute voltage division of the sound control volume is attained in common use with the voltage section after said voltage division so as to attain finer adjustment of the sound volume. |
