METHOD AND DEVICE FOR THE SECURITY OF CLOSED ROOMS

For the protection of closed areas the invention a procedure for the protection of closed areas against break-down, unauthorized entering and/or unwanted opening of windows and doors as well as a device for the execution of the procedure concerns procedures and device.

It will ever more important, closed areas against break-down to secure unauthorized entering and such a thing since straight break-down thefts have a strongly rising tendency, how results from the statistics of such crimes and which is constantly documented also by those increase insurance premiums for break-down thefts.

For the protection of areas different systems are well-known, which have however different disadvantages.

One can attach movement alarm units, which are relatively expensive however and can only then for the release by alarm be used, if in the areas nobody is in the areas, condition itself in the areas persons, then the movement alarm units cannot differentiate between unauthorized and authorized use of these areas.

Even if the areas are to be protected if one is in the areas, all openings must be secured such as windows and doors, by which an unauthorized one could penetrate, by opening alarm units. This he demands now with a great many windows and doors a large number of such opening alarm units as well as complicated Verdrah do towards, those with high costs of. M.Laterial =i Al: beitslohn are connected. In addition with subsequent mounting of these protection facilities the building is verunziert by the over all attached, cable.

The task of the invention consists of creating a procedure and a device of the kind initially specified by which on simple and effective way opening doors and windows is announced.

The solution according to invention consists of that inside the area the air pressure measured, made of which determined frequency spectrum by changes of air pressure lowfrequent changes filtered and with detection such change run is produced towards a signal.

The invention been based on the surprising realization " that open of doors and windows by changes of air pressure, i.e. pressure waves of completely characteristic low frequencies is accompanied. These frequencies in the air pressure change spectrum arise only when opening windows and doors, not however with the normal use area also inhabited.

It is surprisingly possible from there with the procedure according to invention and the device to determine by such a air pressure measurement in a place also an inhabited area whether windows or doors are opened. It showed up that appropriate equipment can be set up even in an area, in which many humans is, who enjoy themselves loud maintained or offering. The equipment does not address in this case, only then, if a window or a door is opened, announces it this through Lichtzeichent acoustic indications, Mel dungen to an alarm center or similar notifications of emergency, as it admits from usual alarm systems is, if in completely different area of a house a window or a door is even opened, announces the device according to invention this, condition is only that between the equipment and the window or the door, which are net and/or geöff no hermetically locked door is. Even if an object which can be secured is divided by closed doors into several subspaces, one always comes. still with a relatively small additional number erfin dungsgemäßer devices for the protection of these areas out.

If in the context of this registration of changes of air pressure the speech is, then is not meant fluctuations, which one calls thereby under any circumstances only of usual changes of air pressure, which one measures for example with a barometer, on the contrary is meant also of air pressure changes or - normal wise sound. Sound with very low frequencies is generally called Infraschall.

The invention is characterised by that Infraschall events are measured and evaluated, whereby with a particularly favourable execution form Infra of sound events with a length of time of 100 MSEC become filtered until 1 second, preferably approximately 400 MSEC.

With a favourable execution form changes of the resonance behavior of the area are detected, which did not mention measurement and/or detection of the characteristic events and announcing the alarm can inside half and with the help of relatively small geschlosse nen equipment take place, it is complex Installa tionsleitungen necessarily. The equipment could be operated e.g. with batteries, so that one can bring it easily also to another place in a house. If one wants to turn it off in an area, which one wants to leave afterwards, then well-known mechanisms can actually be planned, by which the equipment with time delay sharply ge scolded become can, so that the equipment can still leave initializing person the area, without an alarm is announced. Appropriate time delays can be intended for the alarm release, so that one keit the Möqlich to switch after entering the area and before releasing the alarm the equipment off.

- When particularly favourably has it proven to filter he eignisse with frequencies of less than approx. 5 cycles per second.

As lower limit for the detected change of air pressure frequencies favourable-proves a frequency of approx. 0,5Hz planned. When particularly suitably for the Dete'r " tion and simultaneous avoidance of false alarms has itself a frequency range with approximately 2.5 cycles per second proven, a device for the execution of the procedure is characterised there through that it exhibits a sound receiver, which are provided with one hermetically by a diaphragm locked excavating area and an electronic evaluation circuit, this sound receiver works in the kind of a barometer, takes up thus also extremely slow air pressure fluctuations, since with an increase of the air pressure the diaphragm is continued to press in the direction of the locked cavity and with a degradation of the outside air pressure by de@n locked cavity away-continues to itself bend, - the deflection of the diaphragm can be detected then, z.3, mechanically, and into an electrical measured variable vmge changes becomes, which sets then auzge for a frequency filtering becomes.

Genauer-und better knows the air pressure fluctuation however ge will measure, if the device exhibits mechanisms to the Mes sung from changes of capacity with movement of the diaphragm. In the case of change of the deflection of the diaphragm the capacity changes e.g. from an electrode attached on the diaphragm to a being certain electrode, which can be fastened e.g. to the cavity. Change of self amplifier lich can be the two electrodes the entire diaphragm, if this consists of metal, as well as the cavity wall, when particularly suitable, details, reliable and costing favorable letting mechanism for changes of capacity has themselves high frequency measuring instrument proven. If the capacity of the measuring instrument is the resonant circuit capacity of a tank circuit, then frequency changes the oscillation, if this is specified by the appropriate resonant circuit. These frequency changes can then detek.

to be tiert in addition, and electronically processed, one could measure changes of impedance of the capacity alone or a Paralleloder of series-tuned circuit circle, which arises because of the changes of capacity.

The invention is described in the following on the basis of favourable execution forms with reference to the attached designs. Show.

Fig. device, and Fig would in accordance with-eat 1 a block diagram of an invention. 2 a cut by a sound receiver, like it with the invention being used can do, in Fig, 1 is represented a sound receiver 1, which is connected with an electronic evaluation circuit 2.

The evaluation circuit 2 is then connected with a Schalteinheit 3, by which einge places characteristics of the alarm and can be changed, like for example the delay between detection of an alarm condition and release of the alarm or different duration of the alarm after occurance of of an event, 40 with the evaluation circuit 2 is also still another attitude mechanism 4 connected, at which the sensitivity of the device can be stopped.

The unit 3, in which time delay, alarm duration and such a thing can be adjusted, is then still with the alarm system 5 is connected, by the alarm given, for example a siren, a signal light and the resembles, which exhibit sound receivers of the Pig, 2 a housing 6, to whose an inner wall an electrode 7 is fastened.

Opposite of the electrode 7 the housing 6 exhibits an opening, which is locked for trischen line 10, the diaphragm 8 with a conduction 11 with a diaphragm 8, so that between electrode 7 and diaphragm 8 a cavity 9 is enclosed, the electrode 7 is connected with one elek.

If the air pressure changes, then also the by bend of the diaphragm 8, whereby the capacity of the Konden is changed sators, % that through electrode 7 changes and diaphragm 8 is formed, yy