FR2368187A1 - Two wire intercommunication equipment - uses set direct voltages to call specific remote stations using power source at remote station - Google Patents

Two wire intercommunication equipment - uses set direct voltages to call specific remote stations using power source at remote station

Info

Publication number
FR2368187A1
FR2368187A1 FR7730024A FR7730024A FR2368187A1 FR 2368187 A1 FR2368187 A1 FR 2368187A1 FR 7730024 A FR7730024 A FR 7730024A FR 7730024 A FR7730024 A FR 7730024A FR 2368187 A1 FR2368187 A1 FR 2368187A1
Authority
FR
France
Prior art keywords
remote
call
point
power source
remote point
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.)
Withdrawn
Application number
FR7730024A
Other languages
French (fr)
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.)
ACET Srl
Original Assignee
ACET Srl
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 ACET Srl filed Critical ACET Srl
Publication of FR2368187A1 publication Critical patent/FR2368187A1/en
Withdrawn legal-status Critical Current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
    • H04M11/02—Telephonic communication systems specially adapted for combination with other electrical systems with bell or annunciator systems
    • H04M11/025—Door telephones

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Devices For Supply Of Signal Current (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

The intercommunication equipment can transmit between a central point and subsidiary points using only two wires. It may be used for other operations such remote calling, remote switching, private communication, and automatic delay operation of remote units. The equipment uses a calibrated direct current supply to call any particular remote point. The call current excites a call sound at the remote point using a power supply at the remote point. It has a transmission circuit for each remote point which is excited according to the particular voltage for that remote point. The transmission circuit comprises a transistor differential amplifier, ordinary and Zener diodes, a capacitor, resistors and a series of resistors connected to the call push-button.
FR7730024A 1976-10-14 1977-10-06 Two wire intercommunication equipment - uses set direct voltages to call specific remote stations using power source at remote station Withdrawn FR2368187A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT2830076A IT1075034B (en) 1976-10-14 1976-10-14 DOOR PHONE SYSTEM, WORKING WITH TWO COMMON WIRES, BETWEEN A MAIN PLACE AND THE VARIOUS DERIVATIONS

Publications (1)

Publication Number Publication Date
FR2368187A1 true FR2368187A1 (en) 1978-05-12

Family

ID=11223316

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7730024A Withdrawn FR2368187A1 (en) 1976-10-14 1977-10-06 Two wire intercommunication equipment - uses set direct voltages to call specific remote stations using power source at remote station

Country Status (3)

Country Link
ES (1) ES231156Y (en)
FR (1) FR2368187A1 (en)
IT (1) IT1075034B (en)

Also Published As

Publication number Publication date
ES231156U (en) 1977-11-16
ES231156Y (en) 1978-04-01
IT1075034B (en) 1985-04-22

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Legal Events

Date Code Title Description
ST Notification of lapse