GB1006362A - An improved ultra-sonic detector - Google Patents
An improved ultra-sonic detectorInfo
- Publication number
- GB1006362A GB1006362A GB2698261A GB2698261A GB1006362A GB 1006362 A GB1006362 A GB 1006362A GB 2698261 A GB2698261 A GB 2698261A GB 2698261 A GB2698261 A GB 2698261A GB 1006362 A GB1006362 A GB 1006362A
- Authority
- GB
- United Kingdom
- Prior art keywords
- transistor
- output
- fire
- sound
- signals
- 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
- G08B13/16—Actuation by interference with mechanical vibrations in air or other fluid
- G08B13/1609—Actuation by interference with mechanical vibrations in air or other fluid using active vibration detection systems
- G08B13/1618—Actuation by interference with mechanical vibrations in air or other fluid using active vibration detection systems using ultrasonic detection means
- G08B13/1627—Actuation by interference with mechanical vibrations in air or other fluid using active vibration detection systems using ultrasonic detection means using Doppler shift detection circuits
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Burglar Alarm Systems (AREA)
Abstract
1,006,362. Fire and burglar alarms. R. R. CLARK. July 26, 1962 [July 26, 1961], No. 26982/61. Heading G4N. [Also in Division H3] A fire or burglar alarm system comprises an emitter of ultrasonic waves including a local transistor oscillator 10 connected to an ultrasonic output transducer 20, and a receiver comprising transistor amplifiers 50, 80 and a switching transistor 101 having a normally energized relay 110 in its collector circuit. Any disturbance of the standing wave sound field, due to a fire or an intruder, causes transistor 101 to switch off and de-energize relay 110 to operate an alarm. Band pass amplifier 50 which has a centre frequency tuned to that of the transmitter output is characterized in that it has automatic gain control (see Division H3) provided by the transistor 53 output via diode 55 and resistor capacity circuit 59 which is connected via a clamping diode 56 to the transistor 52 input. Operation.-If the standing sound wave field is not disturbed, a sound signal of constant amplitude and of the local oscillator frequency only will be received, resulting in a D.C. potential only across the capacitor 71 of filter 70 (i.e. the output of the first detector 61). Disturbance of the standing wave field, however, results in the reception of varying amplitude and fequency sound waves, which produce low frequency A.C. signals at the first detector output. These signals are amplified at 80, and rectified at 91, 92, the resulting D.C. voltage being appliedto the base of transistor 101, to overcome the forward bias via resistor 102, and cut off the transistor. Alarm relay 110 includes " latching " contacts 116 which form a " reset " control. Capacitative coupling for transistor 101 is provided by capacitor 103 to discriminate against stray signals. A test signal may be applied at 123.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2698261A GB1006362A (en) | 1961-07-26 | 1961-07-26 | An improved ultra-sonic detector |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2698261A GB1006362A (en) | 1961-07-26 | 1961-07-26 | An improved ultra-sonic detector |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1006362A true GB1006362A (en) | 1965-09-29 |
Family
ID=10252268
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2698261A Expired GB1006362A (en) | 1961-07-26 | 1961-07-26 | An improved ultra-sonic detector |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1006362A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1985003590A1 (en) * | 1984-02-13 | 1985-08-15 | Cerberus Ag | Method and circuit arrangement for the operation control of ultrasound alarm installations |
WO1985003591A1 (en) * | 1984-02-13 | 1985-08-15 | Cerberus Ag | Method and circuit arrangement for the function control of ultra-sound alarm installation |
GB2299668A (en) * | 1995-04-01 | 1996-10-09 | David Appleby | Fire sensor using ultrasonic sound |
-
1961
- 1961-07-26 GB GB2698261A patent/GB1006362A/en not_active Expired
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1985003590A1 (en) * | 1984-02-13 | 1985-08-15 | Cerberus Ag | Method and circuit arrangement for the operation control of ultrasound alarm installations |
WO1985003591A1 (en) * | 1984-02-13 | 1985-08-15 | Cerberus Ag | Method and circuit arrangement for the function control of ultra-sound alarm installation |
EP0158023A1 (en) * | 1984-02-13 | 1985-10-16 | Cerberus Ag | Method and circuit arrangement for monitoring the operation of ultrasonic alarm systems |
EP0158022A1 (en) * | 1984-02-13 | 1985-10-16 | Cerberus Ag | Method and circuit arrangement for monitoring the operation of ultrasonic alarm systems |
US4727522A (en) * | 1984-02-13 | 1988-02-23 | Cerberus Ag | Method of, and circuit arrangement for, function control of ultrasonic alarm installations |
US4729120A (en) * | 1984-02-13 | 1988-03-01 | Cerberus Ag | Method of, and circuit arrangement for, function control of ultrasonic alarm installations |
GB2299668A (en) * | 1995-04-01 | 1996-10-09 | David Appleby | Fire sensor using ultrasonic sound |
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