GB968170A - An alarm control - Google Patents

An alarm control

Info

Publication number
GB968170A
GB968170A GB1153663A GB1153663A GB968170A GB 968170 A GB968170 A GB 968170A GB 1153663 A GB1153663 A GB 1153663A GB 1153663 A GB1153663 A GB 1153663A GB 968170 A GB968170 A GB 968170A
Authority
GB
United Kingdom
Prior art keywords
transistor
alarm
transistors
march
wires
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
GB1153663A
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.)
Charbonnages de France CDF
Original Assignee
Charbonnages de France CDF
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 Charbonnages de France CDF filed Critical Charbonnages de France CDF
Publication of GB968170A publication Critical patent/GB968170A/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
    • G08B29/18—Prevention or correction of operating errors
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B23/00—Alarms responsive to unspecified undesired or abnormal conditions

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

968,170. Operating single indication receivers. CHARBONNAGES DE FRANCE. March 22, 1963 [March 24, 1962],No. 11536/63. Heading G4F. A control system for an alarm device 1 comprises a first transistor 3, normally biased to be cut-off, a second transistor 5 connected to the first, and a switch 13 normally connecting the bases of the two transistors, the arrangement being such that breaking the circuit between the two bases causes both transistors to conduct and actuate the alarm. In order to prevent tampering with the device, the unit containing the actuating switch 13 is connected to the transistor unit by a three wire circuit 8, 9, 10. If the wires are cut, the transistors become forward biased and the alarm operates. If the wires are shorted together transistor 3 is forward biased and the alarm will again operate.
GB1153663A 1962-03-24 1963-03-22 An alarm control Expired GB968170A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR892147A FR1325869A (en) 1962-03-24 1962-03-24 High security alarm control

Publications (1)

Publication Number Publication Date
GB968170A true GB968170A (en) 1964-08-26

Family

ID=8775276

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1153663A Expired GB968170A (en) 1962-03-24 1963-03-22 An alarm control

Country Status (2)

Country Link
FR (1) FR1325869A (en)
GB (1) GB968170A (en)

Also Published As

Publication number Publication date
FR1325869A (en) 1963-05-03

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