JPS5643859A - Polarity-inversion-signal detecting circuit - Google Patents

Polarity-inversion-signal detecting circuit

Info

Publication number
JPS5643859A
JPS5643859A JP11874779A JP11874779A JPS5643859A JP S5643859 A JPS5643859 A JP S5643859A JP 11874779 A JP11874779 A JP 11874779A JP 11874779 A JP11874779 A JP 11874779A JP S5643859 A JPS5643859 A JP S5643859A
Authority
JP
Japan
Prior art keywords
main
polarity
circuit
diode bridge
output
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
JP11874779A
Other languages
Japanese (ja)
Other versions
JPS5925418B2 (en
Inventor
Yoshiaki Takeda
Shuji Kunii
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.)
Tamura Electric Works Ltd
Original Assignee
Tamura Electric Works 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
Application filed by Tamura Electric Works Ltd filed Critical Tamura Electric Works Ltd
Priority to JP11874779A priority Critical patent/JPS5925418B2/en
Publication of JPS5643859A publication Critical patent/JPS5643859A/en
Publication of JPS5925418B2 publication Critical patent/JPS5925418B2/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Meter Arrangements (AREA)
  • Prepayment Telephone Systems (AREA)

Abstract

PURPOSE:To eliminate the OFF operation of a polarity-inversion signal detecting circuit by inserting two current detectors in diode bridge sides connected between the 1st and 2nd main wires at the talking circuit input sides of a telephone set and by providing a coincidence circuit for main-wire polarity output. CONSTITUTION:Between main wire terminals L1 and L2, diode bridge circuit DB is connected and in sides forming a DC loop to an office when main wire L1 of diode bridge circuit DB is held positive and L2 is held positive, the 1st and 2nd current detectors PC1 and PC2 are inserted. When hook switch contacts HS1 and HS2 are changed over with the handset off the hook, the 1st flip-flop F1 remembers that by the 1st current detector and when a called subscriber makes an answer after dial origination, the 2nd flip-flop F2 remembers that by the 2nd current detector. Then, AND gate AND1 checks identity between those and sends out an identity output. This output is unchangeable without reference to the connection direction of the main wires.
JP11874779A 1979-09-18 1979-09-18 Public telephone pole reversal signal detection circuit Expired JPS5925418B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11874779A JPS5925418B2 (en) 1979-09-18 1979-09-18 Public telephone pole reversal signal detection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11874779A JPS5925418B2 (en) 1979-09-18 1979-09-18 Public telephone pole reversal signal detection circuit

Publications (2)

Publication Number Publication Date
JPS5643859A true JPS5643859A (en) 1981-04-22
JPS5925418B2 JPS5925418B2 (en) 1984-06-18

Family

ID=14744047

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11874779A Expired JPS5925418B2 (en) 1979-09-18 1979-09-18 Public telephone pole reversal signal detection circuit

Country Status (1)

Country Link
JP (1) JPS5925418B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS583657U (en) * 1981-06-27 1983-01-11 株式会社田村電機製作所 Polarity detection circuit of terminal equipment
JPS58207755A (en) * 1982-02-09 1983-12-03 Iwatsu Electric Co Ltd Detecting circuit of polarity inversion
JPH0312553U (en) * 1990-04-12 1991-02-07

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS583657U (en) * 1981-06-27 1983-01-11 株式会社田村電機製作所 Polarity detection circuit of terminal equipment
JPS641811Y2 (en) * 1981-06-27 1989-01-17
JPS58207755A (en) * 1982-02-09 1983-12-03 Iwatsu Electric Co Ltd Detecting circuit of polarity inversion
JPH0312553U (en) * 1990-04-12 1991-02-07

Also Published As

Publication number Publication date
JPS5925418B2 (en) 1984-06-18

Similar Documents

Publication Publication Date Title
GB1529452A (en) Detection of direct currents or voltages
SE8403631L (en) TRANSFER OF DATA CALLS
JPS5643859A (en) Polarity-inversion-signal detecting circuit
ES488564A1 (en) Call device for an automatic subscriber telephone installation with extensions.
JPS55134568A (en) Data collector
JPS5772452A (en) Telephone set with speaker receiving function
JPS5613866A (en) Communication device
US3748391A (en) Telephone ring-trip circuit
JPS5439510A (en) Detection circuit for outgoing call
JPS57160254A (en) Connection control system
CA1116329A (en) Loop, dial pulse and ring trip detection circuit
US3909550A (en) Key telephone systems
JPS55134567A (en) Incoming transfer system
JPS56168464A (en) Automatic dialing device
JPS5660153A (en) Calling system of branch connection telephone set
ES8500535A1 (en) Telephone call channel appliance. (Machine-translation by Google Translate, not legally binding)
JPS56156056A (en) Discriminating system for incoming call
GB1012053A (en) Improvements in or relating to telephone intercepting trunk circuits
JPS5758452A (en) Button telephone device
JPS56123132A (en) Cordless telephone set
JPS5486206A (en) Call pickup system
JPS5787268A (en) Telephone system
JPS522110A (en) Calling position detecting system
GB1494136A (en) Telephone exchanges
JPS532011A (en) Calling signal and calling tone transmitting at telephone exchange