| 摘要 |
PURPOSE:To make constant a voice characteristic irrespective of long and short of a subscriber's line, to maintain a small power consumption in a terminal and to make compact a set by providing a voltage detector and a voice- attenuator for attenuating a voice input to a subscriber's terminal in accordance with a detected value of a supplied voltage. CONSTITUTION:A direct current power source 12 for feeding a constant current to a subscriber's telephone set is provided in a subscriber's terminal 1 and a voltage detector 14 and a voice attenuator 13 for attenuating a voice input to the subscriber's terminal 1 in accordance with a detected value of a feeding voltage are disposed. For instance, the direct current power source 12 feeds the constant current to the subscriber's line. A voice signal externally incoming the subscriber's terminal is attenuated by the sound attenuator 13 provided at its input section and fed to the telephone set through the subscriber's line. the quantity of an attenuation of the attenuator 13 is controlled by the voltage detector 14 for detecting the supplied voltage to the subscriber to make constant the sound characteristic.
|
