GB516192A - Improvements in and relating to electric alarm systems - Google Patents

Improvements in and relating to electric alarm systems

Info

Publication number
GB516192A
GB516192A GB2069538A GB2069538A GB516192A GB 516192 A GB516192 A GB 516192A GB 2069538 A GB2069538 A GB 2069538A GB 2069538 A GB2069538 A GB 2069538A GB 516192 A GB516192 A GB 516192A
Authority
GB
United Kingdom
Prior art keywords
alarm
frequency
cycles
receiver
filter
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
GB2069538A
Other languages
English (en)
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.)
Individual
Original Assignee
Individual
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
Priority to BE435409D priority Critical patent/BE435409A/xx
Application filed by Individual filed Critical Individual
Priority to GB2069538A priority patent/GB516192A/en
Priority to FR857679D priority patent/FR857679A/fr
Publication of GB516192A publication Critical patent/GB516192A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B27/00—Alarm systems in which the alarm condition is signalled from a central station to a plurality of substations

Landscapes

  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Alarm Devices (AREA)
GB2069538A 1938-07-12 1938-07-12 Improvements in and relating to electric alarm systems Expired GB516192A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE435409D BE435409A (pm) 1938-07-12
GB2069538A GB516192A (en) 1938-07-12 1938-07-12 Improvements in and relating to electric alarm systems
FR857679D FR857679A (fr) 1938-07-12 1939-07-11 Perfectionnements aux appareils d'alarme électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2069538A GB516192A (en) 1938-07-12 1938-07-12 Improvements in and relating to electric alarm systems

Publications (1)

Publication Number Publication Date
GB516192A true GB516192A (en) 1939-12-27

Family

ID=10150142

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2069538A Expired GB516192A (en) 1938-07-12 1938-07-12 Improvements in and relating to electric alarm systems

Country Status (3)

Country Link
BE (1) BE435409A (pm)
FR (1) FR857679A (pm)
GB (1) GB516192A (pm)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109658671A (zh) * 2018-12-13 2019-04-19 中国电子科技集团公司第四十研究所 一种医用电器设备听觉报警系统及方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109658671A (zh) * 2018-12-13 2019-04-19 中国电子科技集团公司第四十研究所 一种医用电器设备听觉报警系统及方法

Also Published As

Publication number Publication date
FR857679A (fr) 1940-09-24
BE435409A (pm)

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