| 摘要 |
PURPOSE:To make the operator informed of the sound operation of an electronic volume by allowing the electronic volume to generate an audible tone following resistance change. CONSTITUTION:A resistor array 9 for coarse step and a resistor array 10 for fine step are provided to an input and an output side of an amplifier 1 and its resistance value of the resistor array 9, 10 is changed by the switching of electronic switches 11, 12. Since a sound (e.g., beep tone) from an audible tone generator 8 is transmitted to an output terminal by controlling the switching of a switch 13 in matching with the switching of the said step changeover electronic switches 11, 12, the operator can know that the electronic volume is operated surely. Captions 6, 7 in Fig. are an electronic variable resistor and a control logic. |
