JPS6429157A - Hook detection circuit - Google Patents
Hook detection circuitInfo
- Publication number
- JPS6429157A JPS6429157A JP18516987A JP18516987A JPS6429157A JP S6429157 A JPS6429157 A JP S6429157A JP 18516987 A JP18516987 A JP 18516987A JP 18516987 A JP18516987 A JP 18516987A JP S6429157 A JPS6429157 A JP S6429157A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- period
- output
- hook
- flop
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
PURPOSE:To detect accurately on-hook and off-hook state by measuring a period of a signal coming from a telephone line and discriminating to be an incoming signal or a dial signal when the period is a prescribed value or below so as to prevent the output signal of a hook detection circuit from being changed. CONSTITUTION:A timer 19 measuring the period of currents of both polarities coming from the telephone line and a flip-flop 20 whose output is inverted by a signal outputted from the timer 19 when the measured period is longer than the period of the ringer incoming signal are provided and the output signal of the flip-flop 20 is outputted as an on-hook detection signal and an off-hook detection signal. That is, when the period is longer than the pulse period such as a ringer incoming signal, the timer 19 outputs an output signal at a point of time reaching its setting time. The output of the flip-flop 20 is inverted by the output signal. Thus, the on-hook state and the off-hook state are recognized by the output of the flip-flop 20.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18516987A JPH0771168B2 (en) | 1987-07-24 | 1987-07-24 | Hook detection circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18516987A JPH0771168B2 (en) | 1987-07-24 | 1987-07-24 | Hook detection circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6429157A true JPS6429157A (en) | 1989-01-31 |
JPH0771168B2 JPH0771168B2 (en) | 1995-07-31 |
Family
ID=16166040
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18516987A Expired - Fee Related JPH0771168B2 (en) | 1987-07-24 | 1987-07-24 | Hook detection circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0771168B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5111502A (en) * | 1990-04-25 | 1992-05-05 | Command Communications, Inc. | Telephone line bridging sensor |
JPH1051518A (en) * | 1996-04-25 | 1998-02-20 | Samsung Electron Co Ltd | Automatic speech path recovery device for telephone terminal equipment |
-
1987
- 1987-07-24 JP JP18516987A patent/JPH0771168B2/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5111502A (en) * | 1990-04-25 | 1992-05-05 | Command Communications, Inc. | Telephone line bridging sensor |
JPH1051518A (en) * | 1996-04-25 | 1998-02-20 | Samsung Electron Co Ltd | Automatic speech path recovery device for telephone terminal equipment |
Also Published As
Publication number | Publication date |
---|---|
JPH0771168B2 (en) | 1995-07-31 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
LAPS | Cancellation because of no payment of annual fees | ||
R154 | Certificate of patent or utility model (reissue) |
Free format text: JAPANESE INTERMEDIATE CODE: R154 |