| 摘要 |
<p>PURPOSE:To compensate the output of a sound signal by interposing the compensating circuit, composed of a nonlinear resistance such as a varistor and a resistance connected in series, between the connection point of a rectifying circuit and amplifier and the earth. CONSTITUTION:The output of solid-state transmitter M is amplified by amplifier A. Then, polarity-identity diode connection rectifier REC for supplying amplifier A with driving electric power of constant polarity regardless of characteristics of DC electric power supplied to connection terminals T1 and T2 is provided. Between the earth and the coupling point between output point DI and the connection point of diodes D1 and D2 of this rectifier REC, the compensating circuit composed of a nonlinear resistance such as a varistor and a resistance connected in series is interposed. Consequently, when the subscriber's line connected to terminals T1 and T2 is long and a voltage applied between amplifier terminals DI and DO is low, this compensating circuit can compensate the output level of a sound signal.</p> |
