JPS6429157A - Hook detection circuit - Google Patents

Hook detection circuit

Info

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
Application number
JP18516987A
Other languages
Japanese (ja)
Other versions
JPH0771168B2 (en
Inventor
Shoji Makino
Hiroshi Oikawa
Nobuo Koizumi
Naohide Kushige
Takashi Saeki
Shigenobu Minami
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Nippon Telegraph and Telephone Corp
Original Assignee
Toshiba Corp
Nippon Telegraph and Telephone Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Nippon Telegraph and Telephone Corp filed Critical Toshiba Corp
Priority to JP18516987A priority Critical patent/JPH0771168B2/en
Publication of JPS6429157A publication Critical patent/JPS6429157A/en
Publication of JPH0771168B2 publication Critical patent/JPH0771168B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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.
JP18516987A 1987-07-24 1987-07-24 Hook detection circuit Expired - Fee Related JPH0771168B2 (en)

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)

* Cited by examiner, † Cited by third party
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

Cited By (2)

* Cited by examiner, † Cited by third party
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