DE1441404A1 - Alarm system - Google Patents

Description

Alarm system Me find ^ _{alarm system}

in particular to one that demands the occurrence of a badge **, elcnes a warning or an A ₁ Or _n , such as the presence of a burglar or the presence of a fire, remnants and one to one, more or less far Remote alarm * device * is activated if it detects such an event by means of a hearing device.

Alarm systems of this type currently in use work almost exclusively with wire transmission, i.e. the FUhI device is connected to the alarm device by a conductive wire. This requires a considerable description of the application of such systems. You require more or less permanent installations and are expensive and poor. not from existing lines, such as rented aero lines (which is a very expensive proposition). Can be borrowed for use, the distance

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voltage between the filling device and the alarm device very limited. Therefore, if several sensing devices arranged in different places in a house had to be effective should be made to set an alarm device, such as one in a certain part of the house, e.g. in the bedroom, arranged bell to operate, special lines are laid from each sensing device to the alarm device. Any change in the location of one of the sensing devices necessarily necessitated a corresponding change in the Line routing. If an alarm should not only be triggered in the individual building to be protected, but also in a remote central station, such as a fire station, then special telephone lines had to be used.

Proposals have already been made to replace wire transmission with wireless transmission in order to to avoid the aforementioned disadvantages. However, such wireless systems and especially those that are capable of are not expected to notify a remote central station of the presence of a particular hazard because of the possibility of mutual electromagnetic interference between the alarm systems provided point signals and the radio signals transmitted for other purposes (the term used here "Radio" refers to any type of transmission system that works with radiation of relatively high frequency).

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At the different frequency bands used for radio purposes are available because of about them There is a great need to transmit numerous types of messages, and their use is dependent on the appropriate Authorities closely controlled. It is very difficult or impossible practically to specialize one for a given alarm system to receive the intended frequency channel, even if the system is intended for an authority such as the local police and especially if the system is for a private organization, such as a security company, is determined. The sending of alarm signals cannot only affect other transmissions that are used on the special channel are sent, interfering, but there is also the possibility that these other transmissions activate the alarm system and thereby trigger a false alarm.

A main purpose of the invention is to provide an alarm system of the wireless type comprising the aforesaid Overcomes disadvantages and which in particular operates to transmit on a given frequency channel which is not exclusively assigned to it, but also via which other signals (here as "external signals" designated), whereby the alarm signal is sent over this channel without it being itself can be adversely affected by external signals.

The problem in question is caused by the fact

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complicated that, especially when a remote central station serving a plurality of participants in The question comes, must be provided at this central station means that identify the individual participants of whose property goes off a given alarm signal. The signal transmission device located on the participant's property can easily be adapted in such a way that they receive a signal peculiar to them, i.e. one which can be identified by a correspondingly adapted receiving device at the central station But the need for such a code or identification signal complicates it Problem of interference with other transmissions that are sent simultaneously on the frequency channel used, in particular, the identification signal may differ from the external signals not be covered up or mutilated.

According to the invention, these purposes are achieved in that a time delay device on the receiving device is provided, which not only on the receipt of the alarm system in question peculiar signal, but also responds to the period of time during which this signal is received, and in particular to the period of time, during which the signal is continuously received, responds and actuated according to this period of time.

The signal itself is preferably in the form of a carrier frequency which is in the frequency channel which the Alarm system has in common with other broadcast systems, and

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this carrier frequency signal is in a predetermined modulated in a characteristic way. The signal receiving device responds only to the reception of a signal which exhibits this characteristic modulation «and on these catfish are reduced to a minimum by false alarms caused by external signals. The belittling of false ones However, keeping alarms to a minimum is not sufficient; they must be essentially completely eliminated.

It is entirely possible that the other transmissions randomly contained modulation oscillations in the commonly used frequency channel «which are similar to those« which are used to identify the alarm signal in the alarm system concerned. Accordingly, the signal receiving device becomes made sensitive to the length of time during which a predetermined signal is continuously received will. Therefore, if the signal receiving device picks up a series of rapid pulses from extraneous signals, so it is without effect; each time interval between the pulses effectively starts the timing process anew. on in this way only that which occurs continuously for a predetermined period of time, e.g., 3 or 5 seconds Receipt of the predetermined signal put the receiving device in the state in which the alarm device is actuated will.

In the preferred embodiment of the invention, the alarm system can have two signal transmission and reception stages.

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sen, of which one or the other or both with the time sensitive delay device described above be provided. The first stage consists of one or more sensing devices located in a given building and a signal receiving device arranged in the same building, with its alarm device preferably sends a point signal to a central station in addition to generating an audible alarm. The second stage causes this point signal to be sent, received at the central station and an alarm device to be activated the central station. Since the central station is used for a number of individual systems, this should be sent to the central station Signal also contain a special signal that identifies the particular location from which the signal originates, and in the central station there are means for converting this identification signal into a message, which indicates the place of danger.

It is preferable that the signal sent to the central station consists of two sub-signals, of which the one is an actuation signal which is sensed at the central station and which if it is during a predetermined Period of time is continuously sensed, the central station in the state for receiving and converting the subsequently sent second partial signal, which is an identification signal.

To avoid the possibility of mutual interference between

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the alarm signal and other transmissions on the used Reduce common frequency channel, are preferably also means for automatically switching off the Sender and in particular the sender that sends the alarm signal from the subscriber concerned to the central station, provided after the sender has worked for a sufficient amount of time to deliver the desired message to the Central station to send. This period of time is preferably long enough to allow the transmitter to receive the identification signal transmits several times, thereby minimizing the possibility of the identification signal being made indeterminable by prerad signals, the be sent simultaneously on the relevant frequency channel.

The invention is explained in more detail below with reference to the drawing using an exemplary embodiment.

Fig. 1 is a block diagram "of the first stage of the overall system according to the invention, wherein the various structural parts of this first stage are relatively close to one another are located, e.g. in a special building

Fig. 2 is a block diagram of the second stage of the overall plant according to the invention, and this second stage is located in a remote central station. Fig. 3 is a circuit diagram of a current

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circuit which is used to measure the length of time during which a predetermined signal is continuously received to operate an alarm device in accordance with the signal. The first stage of the overall system shown in Fig. 1 has a plurality of sensing devices 2, which are arranged at the appropriate places in a house and respond when a particular event, such as the presence of a fire or the presence of an intruder , entry. Each of these sensing devices 2 can form a self-contained unit which, when it senses the occurrence of the event, becomes effective in order to send out an alarm signal 4.

Each sensing device 2 may include a crystal-controlled radio transmitter, the emitted oscillation is provided with a characteristic sound modulation _a The sensing device 2 can be made of a battery powered be, and its transmitter can be characterized into effect will be that a switch under illustrates control of a, for example, heat-responsive Organ _s that forms part of the Fühlvor'rich «device 2 is closed. The sensing device 2 can be protected, for example by encapsulation, so that it can operate continuously over a longer period of time, for example three minutes

Way works reliably, even when doing it high Temperatures on the order of 530 ° G is exposed.

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In most domestic or industrial systems, it is not necessary that the sensing devices 2 differ from one another, i.e. each can transmit the same tone-modulated high-frequency signal 4 (Pig. I).

Any desired location within the house, such as the bedroom, or within a building, such as * .B * the supervisory office, is one generally designated with 6 Receiving device arranged. This receiving device 6 has a receiver 8 which is based on the carrier frequency of the Signal 4 is tuned and which is connected to a filter amplifier 10, the output 12 of which is only the sound modulation of the Signal 4 contains. The purpose of the filter is to ensure that the remainder of the circuit is the Receiving device 6 responds only to the modulated signal 4 and not to different or other sources originating signals, i.e. external signals which use the same or essentially the same carrier frequency, or is responsive to signals from sensing devices in adjacent Buildings are sent out, and which should be provided with different carrier and / or modulation frequencies.

The output of the filter amplifier Io is via a Line 12 is fed to a time delay switch device 14, which is designed to measure the length of time during which it continuously receives the modulation signal records. The timing arrangement in device 14 operates non-accumulatively and resets itself quickly so that if a plurality of pulses in a predetermined path

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every pulse that has a duration that is less than the total duration required for the work is without any effect. Only if the modulated signal has been continuous for a predetermined period of time is received, the time delay device 14 is made effective.

As soon as the time delay device 14 is activated, an alarm device l6, which is triggered by a bell is indicated, put into operation. The alarm device 16 generates an audible alarm, but one could as well Apparatus providing a visible alarm, such as a lamp, can be used. The output 18 of the time delay switch device 14 also excites a relay 2½, which in turn operates a transmitter 24 via a line 22 sets the point signals 26 at a predetermined carrier frequency (which is the same as the carrier frequency of the signal 4 or different from this). The relay 2ü continues to operate via lines 28 and 3υ a modulator 32, which is the carrier frequency of the signal imposes a predetermined tone modulation. The signal 26 constitutes an alarm form in addition to that from the alarm device 16 audible (and, if desired, visible) alarm provided.

Those connecting the relay 2o to the modulator 52 Lines 28 and 3ü run, as shown, over a delay circuit 34. This delay circuit can occur during the

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initial excitation of the modulator 32 must be ineffective, so that a continuous tone-modulated signal 26 is transmitted from the transmitter 24 for a predetermined period of time on the order of yj seconds. After this point in time, the delay circuit 34 becomes effective in order to separate the lines 28 and 30 and to connect the line 28 to a pulse code generator 36, which is then connected via a line 38 to the modulator 32 in order to control the latter. During the following period of time, the pulse code generator 36 controls the modulator 32 in such a way that the transmitter 24 transmits a series of coded modulation pulses which are specific to the subscriber station in question. For example, a three-digit coded number may be transmitted by generating a burst of pulses at the modulation frequency at a repetition rate of 3 Hz, the number of pulses being numerically equal to the first digit of the coded number. After a pause of one second, during which no modulation is imposed on the transmitter 24, there follows a second similar burst of pulses which correspond to the second digit of the identifying coded number. This is followed by a pause of one second, followed by a further burst of impulses corresponding to the third digit * this can be followed by a further pause of two to three secondary * ' ¹ , after which the coded number is repeated. The coded number can be repeated several times, for example five times

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follow, after which the delay circuit j54 made effective can be to turn off the transmitter 24 completely. The system then remains ineffective until it is reset manually will. It is preferable * that the relay 20 also via a line 4ü the receiver 8 switches off as soon as the device 16 has been put into operation and the Sender 24 has worked.

The initial continuous tone-modulated signal 2.6 is used to actuate the signal receiving device, which is located at the central station and is generally designated 42 in FIG. 2. This signal receiving device 42 has a receiver 44 which is connected to a filter amplifier 46 which, like the filter amplifier Iu (FIG. I) acts to transmit the audio modulation of the signal 26 in an amplified form, see below. The output of the filter amplifier 46 is fed via a line 40 to a time delay switch device 5u which may be similar to the time delay switch device 14 of FIG. 1 and which acts to measure the time during which it continuously receives the tone-modulated signal * Da if it only measures the continuous reception of this signal, it is not influenced by impulses that it picks up from external signals.

Only when the desired signal is in the right way and received continuously for the predetermined period of time, which may be on the order of five seconds

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has been, the time delay switch device becomes 5u effective to an alarm device 5 ^ via a line 52 actuate, shown in Fig. 2 as an audible alarm providing device such as a bell, and the can also be supplemented by a device providing a visible alarm. In this way the supervisory staff will in the central station for the presence of danger made aware in the relevant subscriber station.

When the time delay switch device 5υ through the continuous reception of the predetermined tone modulation is actuated, it becomes effective to a line 56 a normally closed gate 58 to open. The outcome of the Filter amplifier 46 is then via a line 6υ, the open Gate 58 and a line 62 of a decoding device 64 fed. This decoding device 64 is designed so that it is based on the identifying signals that follow sent as part of the signal 26, and in accordance therewith a reading device 66 and a Printing device 68 actuated.

At the central station, the following essentially takes place:

When first the first part of the signal 26 (i.e. the continuous tone modulated or actuating part of this signal) is received, nothing happens but that the Time delay device 5ö starts to work. If the actuating part of the 3 signal for a predetermined time

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-14- 144 HOA

duration of ζ.Β »has been received continuously for five seconds is, the alarm device 54 is actuated and the gate opened, so that the decoding device 64 is made effective. As soon as the transmitter located at the subscriber station 24 stops and starts sending the continuous tone-modulated actuating part of the alarm signal, the identifying one modulated with the coded pulses To send part of the alarm signal, the identifying signal part is decrypted by the decoding device 64, and the numbers corresponding to its pulses are printed by the printing device, thereby enabling the supervisory staff the subscriber station in the central station which is a danger is displayed. As each series of identifying numbers is different from the one at the subscriber station If the sensitive transmitter 24 is preferably sent several times, the printing device 6ö prints several sets of numbers.

The reason why it is desirable to send the signal more than once is to practically eliminate any adverse interference which may originate from external transmissions and which could lead to errors in the printed numbers. While such a disturbance could cause errors in one set of the signals, it is unlikely to cause errors in all of the sets of the signals. If, for example, the coded signal sent out by the subscriber station is the number ^ι 'ΐ21 ^κ and is sent five times and if the printing device 68 -due to a disturbance-

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If, for example, the sequence of numbers "521", "121", "352 ¹¹ J" 121% "121" is printed on premds signals, then it is obvious that the correct identifying number is "121".

The various structural parts of the alarm system shown in block form in FIGS. 1 and 2 can be any of well-known designs, "however, the provision of a non-accumulative working, see quickly resetting Time delay device, responsive to the continuous receipt of a predetermined signal, to certain Problems related to execution. Accordingly, in Pig. a circuit developed for this purpose is shown, which has proven to work particularly advantageously. He can use the time delay device 14 according to Pig. I and / or form the time delay device 5u according to FIG.

The output line 12 and 48 of the filter amplifier Iu or 46 is, as can be seen from Fig. 3, to a Capacitor 7υ connected, in turn via a line 71 is connected to a rectifier 72. Between the line 71 and a grounded line 78 are a resistor 74 and a rectifier lying parallel to this switched. The first-mentioned rectifier 72 is connected via a line 80 to the base 82 of a transistor 84, and a capacitor 86 is connected between line 80 and grounded line 78.

A voltage divider consisting of two resistors 88 and 90 is between a - 12 V DC bias

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Line 92 and the grounded line 78 are connected, the base 82 of the transistor & k being connected to the junction 9 * k lying in the line 80 between the two resistors 88 and 90 * The emitter 96 of the transistor 84 is connected via a line 98 grounded line 78 connected. A capacitor 3.00 is connected in series with two resistors Iü2 and Iü4 between the -12 V line 92 and the grounded line 78. The junction 110 between the resistors 102 and io4 is connected to the collector 106 via a line io8 Transistor 84 is connected, and the junction 112 between the jKondeneatop 100 and the resistor 102 is connected to the base Hk of a further transistor II6. The emitter 118 of this Transistor® J.16 is connected via a resistor 120 to the grounded line TS, and aeia Collector 122 is connected to the «12 V line 92 via a line 12 $ *

Another transistor 126 is provided Base 128 through a resistor 130 to the grounded line 78 * whose emitter 1J2 via an oil rectifier 13% with the ge © rd®ten line 78 and its collector 136 over A profile windings 13S connected to the 12 V soffit 92 is. DIs junction 142 between the emitter I32 of the Transistor 126 and the like * lohten 1J4 is via one Resistor 14o connected to the «12 V» line 92 * between the base 128 of the transistor 126 and the emitter 118 of the

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transistor Il6 is connected to the points l46 and l48 a Zener diode l44. The Relaiswiaklung 138 actuated via a line Ι5υ, shown in a truely manner, the alarm device 16 and, if used, the gate via a line 54 58 (Figures 1 and 2).

The circuit according to FIg * 2 works as follows: The negative peaks from the filter amplifier lu or, 46 The tone modulation obtained is essentially conducted to the broth by the rectifier 76. The modulation signal is rectified by the Olelohriohter 72, and the rectified output is smoothed by the capacitor 86. Of the Transistor 84 is normally biased so that it is conductive "to short-circuit the capacitor or to make it ineffective" as soon as a rectified audio signal goes through resistor 90. will be the one at the base 82 of the transistor 84 is changed to turn off the transistor. This occurs when the received audio signal exceeds a predetermined level, and the The shutdown effect is independent of the level of the received signal, provided that it exceeds the predetermined minimum hardness «

Once transistor 84 is biased to turn off

is »begins the capacitor lüu to move over the resistors Iü2 and Iu4 to be charged, the charging speed being in As is known, the relative values of the Strora circle elements Ιυυ, 1υ2 and lo4 are ventilated. The condenser lüü

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affects the bias at the base il4 of the transistor 116 and therefore controls the one passing through this transistor Emitter current, which in turn determines the voltage across the Connection point 146 of Zener diode 144 controls. The order is such that when the capacitor lüü charges up, the Emitter current of transistor 116 increases, with the speed the increase in the emitter current is determined by the charging speed of the capacitor luu. When the voltage at point 146 is the breakdown voltage the zener diode exceeds 144, the diode becomes conductive, so that in the transistor 126 current flows and thereby the relay winding 15b is excited.

in the foregoing it is assumed that the audio signal is continuous above the predetermined minimum amplitude Lasts as long as the capacitor needs Iuü to turn to charge to the required value. Palis, however, the sound signal interrupted or should drop below the predetermined minimum amplitude, even if briefly, disappears the turn-off bias voltage at the base Ö2 of the transistor b4, so that the transistor becomes conductive and the capacitor low discharges. This discharge takes place via the resistor Ιυ2, but not via the resistor 1ü4, and the resistance Iü2 is given a sufficiently smaller value to enable a very rapid discharge. Indeed Is it only intended to limit the discharge current to a safe value

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As soon as the capacitor discharges, what in a takes place in a very small fraction of a second (preferably in five to fifteen milliseconds), its tenting function (discharge) must start from the beginning so that it causes the relay winding 138 to be energized. Hence the Circuit non-accumulative and rapidly resetting, and he energizes the relay winding 1J58 only when a signal of a predetermined magnitude has been continuously received · Further has, since the transistor 84 is only used as a switch over the Capacitor 100 works, the size of its signal at the beginning does not Influence on the delay time, provided that the size of the signal input has a predetermined minimum value exceeds.

For the constituent parts of the time delay circuit shown in Fig. J5, the following values are taken as an example or types indicated:

Capacitor 70 0.1 microfarads Rectifier 72 silicon diode 1N4835A Resistance 7 * 10 000 Chm Rectifier 76 silicon diode 1N483A Translator 84 2N1305-FNP Capacitor 86 0.1 microfarads Resistance 88 220 οου uhm Resistance 9u 4 7üü 0hm Capacitor ίου 50 microfarads Resistor 102 220 Uhm

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Resistance io4 lüü 000 ohms

Transistor 116 2N1305-PNP

Resistance 120. * 7,000 ohms

Transistor 126 2H1572-PNP

Resistance 130 10,000 ohms

Rectifier 134 silicon diode 1H483A

Resistance l40 10,000 ohms

Zener diode lH 1FT51

From the above, it can be seen that the alarm system according to the invention both with regard to the in Fig. 1 as » the first stage shown and the second stage shown in FIG. 2, each considered one, as well as with regard to the combination of both »levels on the desired frequency channel can send without causing any noticeable disturbance to other Sigsaal © sent on this itaaal and without itself being adversely affected by such other signals. Because it is therefore not necessary that If a special frequency channel is assigned to the alarm system in question, it is obvious that it is much easier is applicable to different places than others previously proposed wireless systems, yet it has all the significant advantages that bsi the wireless signal transmission compared to the wire signal transmission can be maintained

Although in the circuit arrangement according to Flg. 1 the electrical connection

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-Sl-

The wiping of the FUhlTorriohtung 2 and the receiving device 6 is shown as a wireless connection and also the electrical connection "wipe the subscriber station according to FIG. 1 and the central station according to Pig. 2 is shown as a wireless connection, it is obvious that one or the other of these connections can also be a wire connection, without thereby impairing the usefulness and the value of the system according to the invention with regard to that electrical connection which is of the wireless type, be affected.

ORIGINAL

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Claims (1)

Claims 1.) Alarm system, characterized by a sensing device, one-connected to this work-wise and from its actuatable signal transmission device which, when actuated, sends out a signal of a certain character, and a signal receiving device which is in working relationship with the signal transmitting device and upon receiving a predetermined one Signal is effective to operate an alarm device, wherein the signal receiving device is a time delay device which detects the reception of the signal of a certain character and the actuation of the Alarm device only allows after the signal for a predetermined period of time, for example in the Of the order of several seconds, has been effectively received essentially continuously 2 ·) Alarm system according to claim 1, characterized in that the tent delay device is one that does not work accumulatively and quickly resets itself. jj.) Alarm system according to claim 1 or 2, characterized in that that said alarm device has a second signal transmission device and at a remote one Place a second signal receiving device is arranged, which is in receiving relationship with the second signal transmitting device stands and, upon receipt of a predetermined signal, takes effect to actuate a second alarm device. 4.) Alarm system according to claim 3, characterized in that 909807/0236 that the second signal receiving means is a second time delay device which includes the reception of the signal of a particular character at the second signal receiving means detects and enables the activation of the second alarm device only after the signal during has been effectively received essentially continuously for a predetermined period of time " 5.) Alarm system according to one of claims 1 to 4, daduroh characterized in that the first-mentioned signal transmission device transmitted signal is a high-frequency carrier V- having gerwelle printed with a predetermined modulation is, and that the time delay device only responds to the reception of this modulation « 6 ·) Alarm system according to one of claims 1 to 5, characterized in that the one part of the signal receiving device forming time delay provision for changes is insensitive to the amplitude of the signal above a predetermined minimum amplitude and to the Presence of the signal with an amplitude above the predetermined minimum amplitude as well as on the duration anöpricht during which such a signal is continuously received. 7.) Alarm system according to one of claims 1 to 6, characterized in that the signal transmission device during A first predetermined period of time an actuation signal and then an identification signal sends that the 909807/0235 H4U04 Signal receiving device apart from its function * the actuation to enable the alarm device * Performs identification functions that the © inen part of the Signalerapfangaeinriehtung constituting time delay device acts to operate the alarm device and the signal receiving device can only be brought into the state for performing the identification functions after the beta * was received during a second period of time which is no greater than and represents at least a substantial fraction of the first predetermined period of time. 8.) Alarm system according to claim 7 * characterized in that that means are provided which act on the signal transmission device to make it ineffective after it the actuation signal and a predetermined number of the identification signals sent. 9 ') The alarm system according to claim 7 or 8, characterized f in that the actuating signal is composed of a substantially continuous tonmodulierten carrier frequency which is transmitted during the first predetermined period tent, and that the identification signal consists of a series of pulses. 10.) Alarm system according to one of claims 1 to 9, characterized characterized in that the time delay device comprises: one operative with the alarm device connected output circuit, which is a first electronic 909307/02 3 5 Contains valve which has a first control electrode, the bias of which the valve and the output circuit between βineβ an effective and an ineffective state controls, one Time delay circuit operatively connected to the first control electrode of the first electronic valve and acts to build up the bias on this electrode until you see the electronic valve in his is in an effective state, a discharge circuit that is operationally connected to the time delay circuit and a normally substantially blocked second electronic valve having a second control electrode has, and means which apply the signal to the second control electrode so that the second electronic valve is biased into a substantially open state by the presence of the signal. 11 ·) Alarm system according to claim 10, characterized in that the operational connection between the time delay current circuit and the first electronic valve has a third electronic valve which has a third control electrode connected to the time delay circuit and has an output circuit that connects to the first control electrode of the first electronic valve via a Zener * Diode is operationally connected 12.) Alarm system according to one of claims 1 to 9, characterized in that the time delay device comprises the following parts: a signal input circuit, a first 90 9 8 0 7/02361 original ws? Eoted electronic valve having a first Auegangskreie and a first control electrode _Ä with which represent signal input circuit is connected, a Zeitversögerungsatroinkreis, which comprises a capacitor through which the first output Kreiß of the first electronic valve connected in Entladabeziehung to the capacitor ISTJ © in second electronic valve, the © inen second Auegangskreis and Oine second control electrode. that is with ü @ m capacitor · the tent delay circuit in VorsparniungsbeZiehung connect to it, a third electronic valve, which has a third output circuit and a third control electrode is connected operatively with the sin bias circuit , a Zener diode connected between the second output lsr β Is of the second valve and the bias circuit and © in the working element in the third output circuit of the third electronic valve _β 90980-7 / 0-23 $