WO1991015004A1 - Arrangement for detecting variations in atmospheric pressure - Google Patents
Arrangement for detecting variations in atmospheric pressure Download PDFInfo
- Publication number
- WO1991015004A1 WO1991015004A1 PCT/EP1991/000559 EP9100559W WO9115004A1 WO 1991015004 A1 WO1991015004 A1 WO 1991015004A1 EP 9100559 W EP9100559 W EP 9100559W WO 9115004 A1 WO9115004 A1 WO 9115004A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- arrangement according
- detector arrangement
- signal
- diaphragm
- housing
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/20—Actuation by change of fluid pressure
-
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0001—Transmitting or indicating the displacement of elastically deformable gauges by electric, electro-mechanical, magnetic or electro-magnetic means
- G01L9/0008—Transmitting or indicating the displacement of elastically deformable gauges by electric, electro-mechanical, magnetic or electro-magnetic means using vibrations
- G01L9/0022—Transmitting or indicating the displacement of elastically deformable gauges by electric, electro-mechanical, magnetic or electro-magnetic means using vibrations of a piezoelectric element
-
- 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
- G08B13/1654—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems
- G08B13/1681—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems using infrasonic detecting means, e.g. a microphone operating below the audible frequency range
Definitions
- the detector arrangement can be used wherever detectors are used to detect influences and to generate electrical signals.
- the invention is based on a detector arrangement for detecting small changes in air pressure by means of a pyroelectric element which supplies electrical signals to output lines and which is arranged in a housing having an inlet opening behind a (first) impermeable to infrared radiation, preferably Aperture is arranged, there being a connection from the space between the element and the aperture to the outside air space.
- German utility model G 84 18 132.9 and from European patent B1 0 187 180.
- Such a detector arrangement is based on the fact that the air warms up adiabatically in a closed room when the available volume is compressed somewhat, e.g. by moving a window sash or a door.
- Proelectric elements provide a signal when heated by striking low radiation, such as those comes from a human, a dog or a cat.
- a change in air pressure of the type mentioned also provides such heating;
- an access to the space above the pyroelectric element is provided for the ambient air, which is usually mounted in a small housing.
- the invention has for its object to provide an improved detector of the type mentioned, in which small fluctuations in air pressure can quickly enter the housing with the pyroelectric element, so that a significant improvement in sensitivity to an alarm can be achieved.
- the diameter of the holes in the diaphragm can be on the order of a tenth of the diameter of the surface of the pyore li's element.
- the plurality of holes nevertheless provides a sufficient cross-section for the air access, as is desired for a rapid pressure increase.
- the holes are, seen from the outside, appropriate in front of the Areas adjacent to the active surface of the electrical element are attached in such a way that radiation from the outside does not fall on the active surface, the pyroelectric element can heat up and a signal can thus be triggered.
- the height of the space between the proportional element and the diaphragm corresponds approximately to the diameter of the pyroelectric element. This favors that the air entering when the pressure increases leads to a uniform pressure change over the pyroelectric element and thus to a good utilization of its temperature sensitivity.
- thermo radiation infrared radiation
- a simple heat radiation could already simulate a change in air pressure.
- a second aperture of approximately the same type can be arranged behind the (first) aperture at a certain distance, the holes of which lie opposite a region between the holes of the first aperture in such a way that incident radiation is not successively through holes in the first and second apertures can step through.
- a, preferably radiation-impermeable, third screen is arranged at a short distance from the first screen, the diameter of which is slightly larger than the first screen, so that an open gap is formed at its edge for air access to the first screen becomes.
- a second screen is behind the first screen, ie between
- the third panel can simultaneously provide mechanical protection for the window and the first panel.
- the third screen can also be used as a carrier for other elements that are to be used, for example, to camouflage the sensor.
- the electrical signals are expediently led from the pyroelectric element via a signal former to the alarm transmitter.
- At least one amplifier can be used on the pyroelectric element and / or on the signal shaper, by means of which the internal resistance of the transmitted signal is reduced to such an extent that, e.g. capacitive or inductive, interference from outside will not take effect.
- an arrangement for differentiating or a high-pass filter can be switched on in the signal former, with the aid of which rapid changes, preferably, lead to a signal being given, while gradual changes, such as can occur during the course of the day, remain ineffective.
- the signal former can be constructively connected to the housing surrounding the pyroelectric element or form part of this housing.
- the signal former can be arranged behind the housing so that both can be inserted together into one opening.
- the signal former can also be attached next to the housing so that a widened area for the attachment, e.g. on a wall or on a cupboard.
- the signal former can be attached separately from the housing in the course of the output line to the alarm device.
- the detector with its housing which in many cases is in the field of view of an intruder can be particularly small, while the signal shaper, possibly for the signal processing of several detectors, is attached to a hidden location.
- the signal former can be part of the alarm transmitter, so that only simple electrical connecting lines need to be laid from the detector to the alarm transmitter.
- the signals from different detectors can be coded differently in the signal former and jointly transmitted on a line.
- the signals of several, possibly different, adjacent detectors can be combined and transmitted to the alarm device via a single line.
- a pyroelectric detector expediently contains at least one amplifier stage which requires a certain supply energy. According to an expedient embodiment, this can be supplied by a photo element which is connected to an accumulator. Electrical energy is then generated by daylight and stored in the accumulator and can also be available at night. According to a preferred embodiment, the photo element can be structurally combined with the third aperture, that is to say it can be attached in front of or on the third aperture.
- the signal former can be connected to a telephone system which establishes the connection to the alarm device. This saves additional wiring.
- a telephone system which establishes the connection to the alarm device.
- a plurality of extensions can be provided with signal transmission elements, by means of which at least one sensor signal can be transmitted to the telephone system in various extensions; the alarm device can then be connected to the telephone center and respond as soon as a sensor signal is supplied to an extension. In this way, even in the case of a very extensive office and / or factory building, a central alarm can be ensured without additional wiring.
- a detector used in the invention consists of a cylindrical housing 100 which is flanged inwards at its upper end at the edge 13 and has a window 12.
- a filter disk 14, which forms a first diaphragm and which preferably does not transmit any radiation, is attached inside the edge 13 behind the window 12.
- the filter 14 can be have a corresponding, spectrally selected radiation permeability.
- the lower part of the housing 1 is covered with a material 15, e.g. a plastic, filled, on the surface of which the platelet-shaped, pyroelectric element 16 is attached.
- the element 16 is, except for the front, preferably with a heat-impermeable material, e.g. also surrounded by a thin layer of air in order to avoid undesired heat dissipation into the material 15, which would reduce the sensitivity if necessary.
- the housing 100 is closed on its lower side with a preferably insulating base plate 17. Through this base plate 17 protrude connecting wires or connecting pins 18 with which the electrical connections to a circuit for signal evaluation connected in a known manner are made.
- the signal emitted in the form of a change in resistance is either supplied directly to the pins 18 via connecting lines 19 or is supplied via an amplifier unit 20 mounted in the material 15.
- the parts 12 to 20 form a pyroelectric detector.
- the filter disk 14 is provided with small holes 21 through which the air penetrates from outside into the space between the filter 14 and the pyroelectric element 16 in the event of pressure changes and causes a temperature change there can, which is then detected by the pyroelectric element 16 and passed on as a signal at the terminals 18 to the outside. If only the air pressure changes are to be detected, no radiation, in particular infrared radiation, may fall onto the pyroelectric element 16 from the outside. This can be achieved in that the holes 21 are arranged only in the edge zone outside the effective surface of the pyroelectric element 16.
- the edge zone is very narrow, or to improve air access through a larger number of holes, it may also be necessary to make 16 holes 22 directly above the pyroelectric element.
- the access of radiation to the pyroelectric element 16 can then be prevented by arranging a second screen 23 behind the filter disk 14, which acts as a screen, on which the holes are offset from the holes in the screen 14, preferably below the gaps the holes of the aperture 14 are arranged. This prevents direct access of radiation to the pyroelectric element, and yet the air can flow in through a multitude of holes into the interior above the pyroelectric element.
- an amplifier arrangement 31 which may also be used as a signal shaper, is indicated, which can optionally receive the signal shaper which emits a signal when a signal from the pyroelectric element 16 with a stepper Flank is given that corresponds to a current air pressure change.
- the signals from the amplifier arrangement 31 or else the output signals from the connecting wires 18 are fed via a possibly multi-core connecting line 32 to a signal processing circuit 33, in which a conversion is required, for example for the transmission to the alarm transmitter 34 of the signals men will.
- the signal processing circuit 33 can, if necessary, be supplied with further detectors i gna Le via other lines indicated at 35 and 36.
- the signals are fed via a connection 37 to a telephone extension 38 which is connected to a telephone exchange 40 via a line 39.
- a telephone extension 38 which is connected to a telephone exchange 40 via a line 39.
- further extensions can be connected to this central telephone system 40.
- the alarm transmitter 34 is connected to the telephone center 40 via a connection 42.
- a change in air pressure to be evaluated is registered by the pyroelectric element 16
- a corresponding signal is sent to a telephone extension 38 and from there to the telephone exchange 40 via the lines 19, 18 and 32 and the signal processing stage 33, which then activates the alarm device 34.
- the signal former 33 can, as indicated by lines 43, be structurally combined with the private branch exchange 38, in particular in its housing, so that after the line 32 only the usual, albeit adapted, parts of a private branch exchange can be used .
- a signal suitably formed in the signal former 33 can also be sent to the postal network and be forwarded there to any other telephone connection via the new Temex service.
- Fig. Shows a detector in top view, which along the Line AA in Figure 1 is shown in section.
- FIG 3 shows a detector which corresponds to that in FIGS. 1 and 2, but with a ne (third) diaphragm 45 arranged on supports 46 above the housing 100.
- the diaphragm 45 is slightly larger in diameter than the housing 100, and as a result of the supports 46 there is a gap 47 in the edge region, which in practice is e.g. Can be 1 mm wide.
- the aperture 45 is opaque to radiation and thus protects the pyroelectric element accommodated in the housing 100 from incident infrared radiation. At the same time, it can represent cover and protection against mechanical influences.
- the first screen 16 mounted in the housing 100, as in FIG. 2, is provided with holes; the air and the pressure fluctuations contained in it can freely enter via the annular gap 47.
- FIG. 4 shows a plan view of a sensor according to FIG. 3, of which essentially only the plate 45 can be seen
- the housing 100 is concealed beneath it. Likewise, supports 46 are arranged in opposite angles to one another.
- the aperture 45 can also serve as a carrier for a further, optionally attached element 48, which is designed in the form of a disk.
- the element 48 can be a cover plate which serves to camouflage the sensor arrangement.
- the element 48 can preferably be provided with photoelectric cells and deliver electrical energy when the light is incident. This can be stored in a rechargeable battery in a manner known per se and can thus be used throughout the day, even in the dark, to operate the pyroelectric element, possibly further associated preamplifiers.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Burglar Alarm Systems (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEG9003405.8 | 1990-03-23 | ||
DE9003405U DE9003405U1 (en) | 1990-03-23 | 1990-03-23 | Detector arrangement for air pressure changes |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1991015004A1 true WO1991015004A1 (en) | 1991-10-03 |
Family
ID=6852272
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1991/000559 WO1991015004A1 (en) | 1990-03-23 | 1991-03-22 | Arrangement for detecting variations in atmospheric pressure |
Country Status (4)
Country | Link |
---|---|
KR (1) | KR0155546B1 (en) |
AU (1) | AU7681591A (en) |
DE (1) | DE9003405U1 (en) |
WO (1) | WO1991015004A1 (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3419802A1 (en) * | 1984-05-26 | 1985-11-28 | Al Nour, Vaduz | Break-in alarm device for closed rooms |
EP0187180B1 (en) * | 1985-01-10 | 1989-08-02 | teletronic Hartmuth Jensen | Sensor for monitoring systems |
DE8915081U1 (en) * | 1989-12-22 | 1990-02-08 | Kwon, Ohtai, 2000 Hamburg | Air pressure change detector |
-
1990
- 1990-03-23 DE DE9003405U patent/DE9003405U1/en not_active Expired - Lifetime
- 1990-07-18 KR KR1019900010852A patent/KR0155546B1/en not_active IP Right Cessation
-
1991
- 1991-03-22 AU AU76815/91A patent/AU7681591A/en not_active Abandoned
- 1991-03-22 WO PCT/EP1991/000559 patent/WO1991015004A1/en not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3419802A1 (en) * | 1984-05-26 | 1985-11-28 | Al Nour, Vaduz | Break-in alarm device for closed rooms |
EP0187180B1 (en) * | 1985-01-10 | 1989-08-02 | teletronic Hartmuth Jensen | Sensor for monitoring systems |
DE8915081U1 (en) * | 1989-12-22 | 1990-02-08 | Kwon, Ohtai, 2000 Hamburg | Air pressure change detector |
Also Published As
Publication number | Publication date |
---|---|
DE9003405U1 (en) | 1990-07-26 |
KR910017177A (en) | 1991-11-05 |
KR0155546B1 (en) | 1998-12-15 |
AU7681591A (en) | 1991-10-21 |
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