| 摘要 |
PURPOSE:To vary and set the increase/decrease time of sound volume by sending a sound volume control signal out of a remote control transmitter and setting stepwise the amount of stepping or step frequency of sound volume control by the reception part of an acoustic equipment side on the basis of said signal. CONSTITUTION:When changeover switches S1 and S2 are advanced from free contacts 1 and 11, an IC10 generates a control signal which increases or decreases sound volume by 1-4 steps as one stage and a light emitting diode D sends out a remote control signal. The reception part 20 when receives the remote control signal converts it into the sound volume control signal. A decoding circuit 21 supplies an up or down count instruction to an up/down counter 22 according to the sound volume control signal. Then, the counter 22 counts clock pulses to send out a four-bit count output. This output is branches into four, which are supplied to a full adder circuit 26. One of the branch outputs is inputted to the full adder 26 when the sound volume control signal indicates one step as one stage. Then, the full adder 26 supplies a control current to an amplifying circuit 27 through a DA converter 28 corresponding to the sound volume control signal. |
