GB866168A - Improvements in or relating to electrical alarm and indicator circuit systems - Google Patents

Improvements in or relating to electrical alarm and indicator circuit systems

Info

Publication number
GB866168A
GB866168A GB2020958A GB2020958A GB866168A GB 866168 A GB866168 A GB 866168A GB 2020958 A GB2020958 A GB 2020958A GB 2020958 A GB2020958 A GB 2020958A GB 866168 A GB866168 A GB 866168A
Authority
GB
United Kingdom
Prior art keywords
switches
relay
contacts
circuits
polarity
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.)
Expired
Application number
GB2020958A
Inventor
Vincent Edward Connor
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.)
ASTRAL SWITCHGEAR Ltd
Original Assignee
ASTRAL SWITCHGEAR 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 ASTRAL SWITCHGEAR Ltd filed Critical ASTRAL SWITCHGEAR Ltd
Priority to GB2020958A priority Critical patent/GB866168A/en
Publication of GB866168A publication Critical patent/GB866168A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
    • G08B29/12—Checking intermittently signalling or alarm systems
    • G08B29/126—Checking intermittently signalling or alarm systems of annunciator circuits

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

866,168. Protective arrangements. ASTRAL SWITCHGEAR Ltd. June 16, 1959 [June 24, 1958], No. 20209/58. Class 38 (5). In an alarm or indicator system having a number of separate alarm circuits fed from a common D.C. supply, a unidirectional device is located in each circuit such that reversal of polarity of the D.C. supply simulates the operation of control switches in all the circuits for test purposes. In each circuit the operation of a control switch S1, which may respond to a fault condition in associated apparatus, causes the energizing of a relay A/3 which momentarily closes contacts A-a to energize a common bell relay B/2. The bell relay closes contacts B-a, which with the now closed contacts A-b of the relay A/3, complete the circuit for a common alarm bell B. The closing of contacts A-b also cause the operation of a " flashing " relay C/2 so that the lamps l1 are flashed over contacts A-c. To test the circuits, the operation of a changeover switch S3 reverses the polarity of the supply from a D.C. source P. A rectifier R associated with each switch S1 is now able to conduct so simultating the operation of the switches and causing the operation of all the relays. Should the circuits be arranged for control by normally closed switches, the rectifiers are connected in series with the switches so that when the polarity is reversed, the rectifiers cease to conduct and simulate the opening of the switches.
GB2020958A 1958-06-24 1958-06-24 Improvements in or relating to electrical alarm and indicator circuit systems Expired GB866168A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2020958A GB866168A (en) 1958-06-24 1958-06-24 Improvements in or relating to electrical alarm and indicator circuit systems

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2020958A GB866168A (en) 1958-06-24 1958-06-24 Improvements in or relating to electrical alarm and indicator circuit systems

Publications (1)

Publication Number Publication Date
GB866168A true GB866168A (en) 1961-04-26

Family

ID=10142229

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2020958A Expired GB866168A (en) 1958-06-24 1958-06-24 Improvements in or relating to electrical alarm and indicator circuit systems

Country Status (1)

Country Link
GB (1) GB866168A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3309685A (en) * 1964-06-16 1967-03-14 Standard Electric Time Co Supervisory circuit
US3345565A (en) * 1965-08-27 1967-10-03 Richard W Cotter Continuity field test bridge circuit with diode-controlled visual indicator means

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3309685A (en) * 1964-06-16 1967-03-14 Standard Electric Time Co Supervisory circuit
US3345565A (en) * 1965-08-27 1967-10-03 Richard W Cotter Continuity field test bridge circuit with diode-controlled visual indicator means

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