Title:
【発明の名称】電話機インタフェース装置
Document Type and Number:
Japanese Patent JP2891891
Kind Code:
B2
Abstract:
PURPOSE: To economize a power supply section to a terminal equipment and to prevent malfunction of a terminal equipment when it is started for making a call. CONSTITUTION: A 48V power supply circuit 2 supplies power of DC48V to a terminal equipment 6 when it is hooked on, and when an analog interface circuit 1 detects that the terminal equipment 6 is hooked off, the power supply of DC 48V from the 48V power supply circuit 2 is stopped and the analog interface circuit 1 supplies power of DC24V. As a result, even when terminal equipment other than the terminal equipment 6 is branch-connected to a telephone line L, the terminal equipment 6 discriminates clearly whether the other terminal equipment is busy or in standby based on the feeding voltage and then malfunction is prevented when a terminal equipment is started for making a call.
Inventors:
YAMAGUCHI TAKASHI
Application Number:
JP2504395A
Publication Date:
May 17, 1999
Filing Date:
February 14, 1995
Export Citation:
Assignee:
SHIZUOKA NIPPON DENKI KK
International Classes:
H04M1/00; H04M1/738; H04M19/00; H04Q3/42; (IPC1-7): H04M1/00; H04M19/00
Domestic Patent References:
| JP7177204A | ||||
| JP2202197A | ||||
| JP7307816A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)