JPS558105A - Return signal detection circuit for multiple transmission device - Google Patents

Return signal detection circuit for multiple transmission device

Info

Publication number
JPS558105A
JPS558105A JP7992278A JP7992278A JPS558105A JP S558105 A JPS558105 A JP S558105A JP 7992278 A JP7992278 A JP 7992278A JP 7992278 A JP7992278 A JP 7992278A JP S558105 A JPS558105 A JP S558105A
Authority
JP
Japan
Prior art keywords
return
signals
reference voltage
signal
level
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
JP7992278A
Other languages
Japanese (ja)
Other versions
JPS5948599B2 (en
Inventor
Keiichi Mizuguchi
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.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita 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 Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP7992278A priority Critical patent/JPS5948599B2/en
Publication of JPS558105A publication Critical patent/JPS558105A/en
Publication of JPS5948599B2 publication Critical patent/JPS5948599B2/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q9/00—Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Selective Calling Equipment (AREA)

Abstract

PURPOSE:To secure an automatic change of the reference voltage and thus to realize the detection of the return signals regardless of the variation of the number of terminals by switching the input resistance of the reference voltage generator in accordance with the change of the voltage level of the return signals to the central control unit from the terminal unit. CONSTITUTION:The current mode signals containing the return signals are converted into the voltage and then supplied to one terminal of comparator A2 via positive polarity current amplifier A1 to be compared with the reference voltage given from reference voltage generation amplifier A3. In case the level of the false return signal other than the return signal is higher than the reference voltage, the false return signal is delivered from transistor Tr2 in the period except for the generation period of gate signal SG. This signal sets counter COUN2, and decoder DEC11 turns on and off Tr3-17 ia the strobe signals generated from AND circuit AND2 with every 3 units of the gate signal to increase gradually the input resistance of amplifier A3. Thus, the reference level is heightened. And if this level becomes higher than the -terminal input voltage to be supplied to comparator A2, Tr2 delivers no false signals but does the return signals.
JP7992278A 1978-06-30 1978-06-30 Return signal detection circuit for multiplex transmission equipment Expired JPS5948599B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7992278A JPS5948599B2 (en) 1978-06-30 1978-06-30 Return signal detection circuit for multiplex transmission equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7992278A JPS5948599B2 (en) 1978-06-30 1978-06-30 Return signal detection circuit for multiplex transmission equipment

Publications (2)

Publication Number Publication Date
JPS558105A true JPS558105A (en) 1980-01-21
JPS5948599B2 JPS5948599B2 (en) 1984-11-27

Family

ID=13703784

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7992278A Expired JPS5948599B2 (en) 1978-06-30 1978-06-30 Return signal detection circuit for multiplex transmission equipment

Country Status (1)

Country Link
JP (1) JPS5948599B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60110766A (en) * 1983-11-19 1985-06-17 Nippon Paint Co Ltd Paint composition

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04133295U (en) * 1991-06-03 1992-12-11 日興電機工業株式会社 sound device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60110766A (en) * 1983-11-19 1985-06-17 Nippon Paint Co Ltd Paint composition
JPH0422188B2 (en) * 1983-11-19 1992-04-15 Nippon Paint Co Ltd

Also Published As

Publication number Publication date
JPS5948599B2 (en) 1984-11-27

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