GB1351748A - Electric alarm systems - Google Patents
Electric alarm systemsInfo
- Publication number
- GB1351748A GB1351748A GB3454570A GB1351748DA GB1351748A GB 1351748 A GB1351748 A GB 1351748A GB 3454570 A GB3454570 A GB 3454570A GB 1351748D A GB1351748D A GB 1351748DA GB 1351748 A GB1351748 A GB 1351748A
- Authority
- GB
- United Kingdom
- Prior art keywords
- contacts
- local
- impedance
- opening
- glass
- 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
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B17/00—Fire alarms; Alarms responsive to explosion
-
- 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
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Burglar Alarm Systems (AREA)
Abstract
1351748 Alarm systems BARDIC SYSTEMS Ltd 15 July 1971 [16 July 1970] 34545/70 Heading G4N An alarm system responsive to the opening of contacts 21, located at spaced positions, comprises at each of the spaced positions an impedance 20 in series with contacts 21 and means such as transistor 39 and relay 31 responsive to the collapse of voltage across impedance 21 to energize a local warning device 14. As described, each unit 10 may be located in a separate manually operated break-glass fire call unit in which contacts 21 are held closed by a spring plunger so as to open when the glass is broken. The contacts 21 of the respective units 10 are all connected in series with local batteries 17 and impedances 20 in a ring circuit 11. The voltage across each impedance 20 maintains its associated transistor 39 non-conductive. Opening of any of contacts 21 will cause the voltage across each impedance 20 to collapse, allowing all transistors 39 to be turned on, energizing all the relays 31 and operating all local bells 14. Local illuminating or indicating lamps 32, 33 will also be extinguished. The warning may be cancelled by opening the glass frame which closes contacts 26, short-circuiting the break-glass contacts 21. Alternatively, a further pair of cancelling contacts 26/2 may be included so that the illumination of lamps 32, 33 indicates that the unit has been reset. The system is powered by a local mains-operated rectifier 27 arranged to charge local nickel cadmium batteries 17, diode 30 being included so that lamps 32, 33 indicate mains failure. Modifications.-Contacts 21 may alternatively be in the form of thermal switches or flameresponsive photo-electric switches or may be operated by opening a door or window in a burglar alarm system.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3454570 | 1970-07-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1351748A true GB1351748A (en) | 1974-05-01 |
Family
ID=10366948
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3454570A Expired GB1351748A (en) | 1970-07-16 | 1970-07-16 | Electric alarm systems |
Country Status (3)
Country | Link |
---|---|
AU (1) | AU469354B2 (en) |
GB (1) | GB1351748A (en) |
ZA (1) | ZA714690B (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2819349A1 (en) * | 1977-05-04 | 1978-11-16 | Klaxon Sa | SIGNAL SYSTEM WITH SEVERAL SELF-SUPPLIED SIGNAL ELEMENTS |
FR2405510A1 (en) * | 1977-10-06 | 1979-05-04 | Honeywell Inc | ABNORMAL STATUS WARNING SYSTEM |
FR2410317A1 (en) * | 1977-11-28 | 1979-06-22 | Holzer Walter | WARNING AND ALARM INSTALLATIONS |
US4176346A (en) * | 1977-11-21 | 1979-11-27 | John O. Stapleton | Smoke alarm network |
US4194192A (en) * | 1978-12-11 | 1980-03-18 | General Electric Company | Alarm devices for interconnected multi-device systems |
FR2458296A1 (en) * | 1979-06-13 | 1981-01-02 | Bofors Ab | METHOD AND APPARATUS FOR AUTOMATICALLY COMMISSIONING OTHER SPINNING HEADS OF A FIRE PROTECTION FACILITY AFTER RELEASE OF AT LEAST ONE OF THESE HEADS |
EP0551183A1 (en) * | 1992-01-06 | 1993-07-14 | Tieng-Fu Lin | Detecting and alarm system for detecting short-circuited or broken circuit |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115171325B (en) * | 2022-06-30 | 2024-05-14 | 帝森克罗德集团有限公司 | Automatic alarm electric fire extinguishing controller |
-
1970
- 1970-07-16 GB GB3454570A patent/GB1351748A/en not_active Expired
-
1971
- 1971-07-15 ZA ZA714690A patent/ZA714690B/en unknown
- 1971-07-15 AU AU31235/71A patent/AU469354B2/en not_active Expired
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2819349A1 (en) * | 1977-05-04 | 1978-11-16 | Klaxon Sa | SIGNAL SYSTEM WITH SEVERAL SELF-SUPPLIED SIGNAL ELEMENTS |
FR2405510A1 (en) * | 1977-10-06 | 1979-05-04 | Honeywell Inc | ABNORMAL STATUS WARNING SYSTEM |
US4176346A (en) * | 1977-11-21 | 1979-11-27 | John O. Stapleton | Smoke alarm network |
FR2410317A1 (en) * | 1977-11-28 | 1979-06-22 | Holzer Walter | WARNING AND ALARM INSTALLATIONS |
US4194192A (en) * | 1978-12-11 | 1980-03-18 | General Electric Company | Alarm devices for interconnected multi-device systems |
FR2458296A1 (en) * | 1979-06-13 | 1981-01-02 | Bofors Ab | METHOD AND APPARATUS FOR AUTOMATICALLY COMMISSIONING OTHER SPINNING HEADS OF A FIRE PROTECTION FACILITY AFTER RELEASE OF AT LEAST ONE OF THESE HEADS |
EP0551183A1 (en) * | 1992-01-06 | 1993-07-14 | Tieng-Fu Lin | Detecting and alarm system for detecting short-circuited or broken circuit |
Also Published As
Publication number | Publication date |
---|---|
AU469354B2 (en) | 1976-02-12 |
ZA714690B (en) | 1973-02-28 |
AU3123571A (en) | 1973-01-18 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |