JPS6352553A - Ring trip circuit - Google Patents

Ring trip circuit

Info

Publication number
JPS6352553A
JPS6352553A JP19561786A JP19561786A JPS6352553A JP S6352553 A JPS6352553 A JP S6352553A JP 19561786 A JP19561786 A JP 19561786A JP 19561786 A JP19561786 A JP 19561786A JP S6352553 A JPS6352553 A JP S6352553A
Authority
JP
Grant status
Application
Patent type
Prior art keywords
trip
comparator
circuit
current
hook
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.)
Pending
Application number
JP19561786A
Inventor
Seiji Miyoshi
Takashi Sato
Kenji Takato
Original Assignee
Fujitsu Ltd
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

Links

Abstract

PURPOSE: To surely detect a ring trip while avoiding from being the ineffective load of a ringer signal source even if no call signal is sent by using an integration circuit so as to integrate a voltage generated by a trip current.
CONSTITUTION: The output voltage of a photocoupler 112 based on a call current detected by a trip current detection circuit 11 is integrated by the integration circuit 5 at on-hook period and does not reach a threshold voltage set by a comparator 6, then a trip detection signal keeps the state 'L'. When the receiver of a telephone set 1 is hooked off, a hook switch 11 is closed to cause off-hook state and the impedance ZT of a bell circuit comprising a bell 12 and a capacitor 13 is short-circuited by the hook switch 11. The call current is the superimposition of the AC and DC compnents, the integration output rises and exceeds the threshold voltage of the comparator 6, then the output of the comparator 6 is inverted and the trip detection signal goes to 'H'.
COPYRIGHT: (C)1988,JPO&Japio
JP19561786A 1986-08-22 1986-08-22 Ring trip circuit Pending JPS6352553A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP19561786A JPS6352553A (en) 1986-08-22 1986-08-22 Ring trip circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP19561786A JPS6352553A (en) 1986-08-22 1986-08-22 Ring trip circuit

Publications (1)

Publication Number Publication Date
JPS6352553A true true JPS6352553A (en) 1988-03-05

Family

ID=16344145

Family Applications (1)

Application Number Title Priority Date Filing Date
JP19561786A Pending JPS6352553A (en) 1986-08-22 1986-08-22 Ring trip circuit

Country Status (1)

Country Link
JP (1) JPS6352553A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6185296B1 (en) 1996-11-26 2001-02-06 Nec Corporation Ring trip circuit for stopping call signal at different timing from zero-crossing point of call signal

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6185296B1 (en) 1996-11-26 2001-02-06 Nec Corporation Ring trip circuit for stopping call signal at different timing from zero-crossing point of call signal

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