| 摘要 |
PURPOSE:To obtain the miniaturized system having a minute change of sound field to any sound level and frequency, by arranging plural sound converters concentrically and arranging the converters at the more outside circumference proportionally corresponding to host bits. CONSTITUTION:Sound converters Si are arranged in concentric square form. Input signals are of SM (SIGNAL MAGNITUDE) form. Each bit of the input signal is applied to each operational amplifier OPi of a polarity inversion circuit 1 except the MSB and the MSB is applied to a non-inverting input transistor (TR) TRi of each operational amplifier. When the input signal is positive, since the MSB is 0, the TRi turns off, and ''1'' is outputted when each operational amplifier has input ''1''. Inversely, when the input signal is negative, the operational amplifier outputs -1 with input of ''1''. With input of ''0'', ''0'' is outputted. The signal (-1/0/1) is inputted to a drive amplifier 2-i outputting identically (-1/0/1) in terms of the voltage value to drive each unit Si of an acoustic converter. Each unit is arranged in corresponding to the weight at more outside circumference in propotioning to host bits. |
