GB1278925A - Ionization smoke detector - Google Patents
Ionization smoke detectorInfo
- Publication number
- GB1278925A GB1278925A GB4791370A GB4791370A GB1278925A GB 1278925 A GB1278925 A GB 1278925A GB 4791370 A GB4791370 A GB 4791370A GB 4791370 A GB4791370 A GB 4791370A GB 1278925 A GB1278925 A GB 1278925A
- Authority
- GB
- United Kingdom
- Prior art keywords
- ionization
- current
- smoke detector
- oct
- source
- 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
- G08B17/00—Fire alarms; Alarms responsive to explosion
- G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
- G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fire-Detection Mechanisms (AREA)
Abstract
1278925 Ionization gas detectors NITTAN CO Ltd 8 Oct 1970 [9 Oct 1969] 47913/70 Heading G1N In an ionization smoke detector of the type having a closed ionization chamber 10 connected in series with an open ionization chamber 20, and a F.E.T. 30 having its gate G3 connected to the junction 3 of the ionization chambers, the sourcedrain current of F.E.T. 30 is limited to a maximum value by inverting a second F.E.T. 40 in the source-drain path of the F.E.T. 30. Thus, when no smoke exists and if the gate leakage current of F.E.T. 30 increases (thereby increasing its source-drain current), operation of the alarm device (not shown) is prevented by this current limiting arrangement.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8033769 | 1969-10-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1278925A true GB1278925A (en) | 1972-06-21 |
Family
ID=13715432
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4791370A Expired GB1278925A (en) | 1969-10-09 | 1970-10-08 | Ionization smoke detector |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA928872A (en) |
| DE (1) | DE2049717C3 (en) |
| FR (1) | FR2065109A5 (en) |
| GB (1) | GB1278925A (en) |
| SE (1) | SE356624B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH586941A5 (en) * | 1975-07-25 | 1977-04-15 | Cerberus Ag |
-
1970
- 1970-10-07 FR FR7036157A patent/FR2065109A5/fr not_active Expired
- 1970-10-08 CA CA095192A patent/CA928872A/en not_active Expired
- 1970-10-08 SE SE1367370A patent/SE356624B/xx unknown
- 1970-10-08 GB GB4791370A patent/GB1278925A/en not_active Expired
- 1970-10-09 DE DE19702049717 patent/DE2049717C3/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2049717A1 (en) | 1971-04-29 |
| DE2049717B2 (en) | 1975-05-15 |
| CA928872A (en) | 1973-06-19 |
| DE2049717C3 (en) | 1975-12-18 |
| SE356624B (en) | 1973-05-28 |
| FR2065109A5 (en) | 1971-07-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |