JPH0546723B

• Main Author: FUKUSHIMA YOJIRO
• Format: Patent
• Language: English
• Published: 14.07.1993
• Edition: 5
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

PURPOSE:To improve the degree of strains at a micro-input signal level for an acoustic power amplifier by securing such constitution where the 1st and 2nd switches have a fixed width of conduction period when no signal exists. CONSTITUTION:The 1st bias application circuit 58 applies the positive bias voltage to the output signal of the 1st rectifier circuit shown by a figure (q). While the 2nd bias application circuit 59 applies the negative bias voltage to the output signal of the 2nd rectifier circuit shown by a figure (r). A triangular wave having the same amplitude at both positive and negative sides is produced at the output terminal of an operational amplifier centering on the earth potential. The output signal of the circuit 58 is compared with the output triangular wave of the 1st triangular wave generating circuit by the 1st comparator 60. The output of the comparator 60 is shown in a figure (w). While the output of the circuit 59 is compared with the output triangular wave of the 2nd triangular wave generating circuit by the 2nd comparator 61. The output of the comparator 61 is shown in a figure (x). Here the positive and negative pole output switches 64 and 65 have the width of conduction period proportional to the positive and negative pole signal levels of an input signal respectively and also keep a fixed width of conduction period even when no signal exists.