| 摘要 |
PURPOSE:To decrease the power consumption in the circuit by forming an incoming trunk connection circuit by a DC voltage supply circuit whose output voltage is reduced when a current increases and an AC current control circuit. CONSTITUTION:The current of a voice signal is controlled so as not to be given to an incoming trunk connection circuit by AC current block means 10, 11. On the other hand, as to the DC current, the output voltage of a DC voltage supply means 13 is set to a value equal but in opposite polarity to the power supply in an incoming trunk of an exchange. Thus, the power supply in the incoming trunk and the output voltage of the DC voltage supply means 13 are cancelled together, and only the output voltage of the DC voltage supply means 12 exists in the incoming trunk connection circuit. Since the output voltage of the DC voltage supply means 12 is decreased as the current increases, the power consumption represented by a product of a potential difference across the AC current blocking means 10, 11 and the flowing current is reduced. |
