| 摘要 |
The invention relates to power supply circuits, and in particular those used for directly supplying, from a telephone line, the bell or other items in a telephone set. In order to avoid unacceptable crosstalk or distortion due to saturation of the power supply circuit when the AC signal on the line drops below the value (Vs) of the regulated output voltage of the power supply, there is provision for detection of this saturation (56) and current shunting (T2, T3) that increases progressively with saturation, such that, seen from the line, the current consumption or impedance of the set remains constant despite the disturbances due to saturation.
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