| 摘要 |
PURPOSE:To make comparators outside the triangular wave signal generating circuit needless, by applying the sound signal to the inversion terminal of the comparator and by adding the output of this comparator and the integral value of this output and by inputting the addition result to the noninversion terminal of the comparator and by obtaining a pulse width modulation signal from the output terminal. CONSTITUTION:Sound signal (b) amplified by sound amplifier 3 is inputted to the inversion terminal of comparator 7. The output voltage of comparator 7 and the output voltage obtained by integrating this output voltage by the Miller circuit consisting of operational amplifier 8, resistance R5, and capacitor C2 are added and are applied to the noninversion terminal of comparator 7, and a pulse width modulation signal is obtained from the output terminal. |
