公开(公告)号：BR8502791A

公开(公告)日：1986-02-18

申请号：BR8502791

申请日：1985-06-12

Applicant: IBM

Inventor： BONNET YVES AIME ,  JACQUART CHRISTIAN

IPC: H04Q3/72 ,  H04M3/22 ,  H04M3/14

Abstract: The circuit of the present invention detects variations of a current IL flowing in a telephone line LL. A low-value resistor r is connected in series with line LL. A constant voltage generator is connected across this resistor. The current Is applied to resistor r by the contant voltage generator varies as a function of IL. This being so, a measurement of the variations of Is will reflect variations of IL and, therefore, can be used to detect both amplitude and directional variations of IL.

公开(公告)号：AU4368385A

公开(公告)日：1986-01-02

申请号：AU4368385

申请日：1985-06-14

Applicant: IBM

Inventor： BONNET YVES AIME ,  JACQUART CHRISTIAN

IPC: H04Q3/72 ,  H04M3/22 ,  H04M3/14 ,  G01R19/00

Abstract: The circuit of the present invention detects variations of a current IL flowing in a telephone line LL. A low-value resistor r is connected in series with line LL. A constant voltage generator is connected across this resistor. The current Is applied to resistor r by the contant voltage generator varies as a function of IL. This being so, a measurement of the variations of Is will reflect variations of IL and, therefore, can be used to detect both amplitude and directional variations of IL.