Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B13/00—Burglar, theft or intruder alarms
  • G08B13/02—Mechanical actuation
  • G08B13/14—Mechanical actuation by lifting or attempted removal of hand-portable articles
  • G08B13/1409—Mechanical actuation by lifting or attempted removal of hand-portable articles for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector
  • G08B13/1418—Removal detected by failure in electrical connection between the appliance and a control centre, home control panel or a power supply

Definitions

• the present invention relates to a controlling and/or registering system of the kind that includes at least one system monitoring host computer and a number of monitorable devices or objects belonging to the system.
• the invention is also based on the premise that the monitoring host computer can communicate either directly or indirectly with each of the monitorable and monitored devices or groups of devices, while each of said monitored devices or groups of devices can communicate with the host computer either directly or indirectly through the medium of information-carrying signals that are so adapted with respect to carrier frequency or the like as to enable the signals to be transmitted and perceived through the medium of transmission via conductors that belong to mains voltage networks.
• An aim of the present invention is to provide a controlling and/or registering system that can be readily supplemented to provide a relevant inventory register over all the monitorable and/or monitored devices.
• the inventive system also includes a facility whereby the presence of monitored devices can be supervised continuously by virtue of a physical connection with said monitored devices.
• the inventive system includes a facility by means of which a device, an object or the like whose function does not require the use of an available mains voltage system to be monitored, and therewith create conditions for forming an alarm activating system which will issue an alarm when a monitored device is stolen or unintentionally removed, this facility being additional to the aforesaid facility or being the sole facility.
• the present invention also relates to a detector that can be connected in a controlling and/or registering system, said detector being adapted to enable the system to detect the removal of or an attempt to remove one of several connected detectors from a device or object, or to detect disconnection of the detector electrically from the system.
• the present invention is based on a controlling and/or registering system according to Internation- al Patent Application No. PCT/SE95/01037.
• Controlling and/or registering systems that are comprised of a monitoring unit or a host computer and a number of devices that can be monitored and/or are monitored by the host computers are known to the art in several different forms.
• a fire-control system that utilizes central equipment or a host computer to sense a number of measuring points and to activate alarm equipment immediately one of the measuring points is switched from a non-fire indicating state to a fire indicating state.
• the inventory list in question, stored in the computer unit, can be read-out and/or printed-out, by activating circuits adapted herefor.
• This publication discloses a security system in which diverse security units are used to monitor electronic devices that may be connected to a common voltage supply network.
• One type of security device (10) used in the system can be connected to equipment to be monitored.
• This security unit includes an identity code that is unique to said security unit and therewith to the equipment to which it is connected.
• a further security unit (20) used in the system is mounted in the wall outlet or electric socket (14) to which the monitored equipment is connected to its voltage supply. This security unit (20) also has an individual identity code.
• a central computer (30) is connected to the same supply voltage and polls the monitored devices via the voltage network.
• the security unit 10 answers to the security unit 20 which, in turn, answers to the central computer.
• the central computer is not only able to see that a given device is connected but also to which wall socket.
• the common supply voltage network is used for the transmission of communications.
• This publication describes a security system for monitoring a number of personal computers, working stations or other computers that are supplied with voltage from a common voltage supply network.
• the security units provided in respective computers are comprised of a modem which functions to transmit and receive information over the supply voltage network.
• the functions lie in the computer software in which the internal processors and memories are used.
• Communication between respective computers is effected in a manner similar to that used generally in local area networks (LAN), but with the difference that transmission takes place over the standard voltage supply network instead of over a dedicated communications network.
• LAN local area networks
• This publication describes a monitoring system in which monitored devices (4) are connected to the general voltage network through the medium of a special cable (1) and an alarm unit (3).
• the alarm unit (3) is in contact with a control station (11) via communication over the general voltage network.
• the special cable (1) is designed to enable the alarm unit to detect removal of the cable from a device (4) or severing of the cable. In such cases, the alarm unit alarms the control station via the voltage network.
• This publication describes a multi-signal system in which a number of remote units are in contact with a main unit via a voltage supply network installed in a building.
• the system is unlike any of the earlier described systems or the present invention, since this known system is intended to transmit signals from a number of remote units of different types.
• These units may be units for sound transmission, units for the transmission of alarm signals for different types of alarms, such as fire alarms, smoke detection, water level alarms or a call for medical assistance.
• the units may also be intended for the transmission of control signals for different control systems, such as heating or air-conditioning control systems.
• Each remote unit communicates with the main unit on a unique frequency band, which is the modulation frequency used in the communication.
• a total of up to ninety-nine separate frequency bands are used.
• the system can be configured so that a remote unit will send a signal continuously, wherein interruption of the signal is noticed by the main unit which then activates some kind of alarm. Conversely, instead of transmitting continuously, a remote unit may not begin to transmit until it wishes to draw attention to an alarm situation.
• Each remote unit is identified by a unique transmission frequency and a unique identity number.
• a remote unit may be a portable unit that is carried by a cleaner who is required to connect the unit to the mains when cleaning of a room is complet- ed, and to key-in the number of the room concerned on a number selector or keypad on the remote unit and therewith send to the main unit a signal that indicates that the room has been cleaned.
• a remote unit can be used with several different identity numbers (room numbers), wherein the main unit detects which remote unit is transmitting, by virtue of the transmission frequency, and from which room the signal is transmitted, by virtue of the room number.
• each remote unit must be allocated a specific transmission frequency before communication can be established between the remote unit and the main unit in this particular case. It will also be obvious that the various units are allocat- ed a transmission frequency and an identity number through the medium of hardware selectors, such as dipswitches or rotary switches, manually on each individual remote unit.
• the "alarm units" disclosed in the aforesaid publications are mainly electronic arrangements that are intended to be connected mechanically and/or electrically to the devices concerned, in one way or another.
• the system may be intended to protect an object or an area from unauthorized use or tres ⁇ pass, or to establish an inventory system.
• the system may also be intended to monitor a sequence of events, for instance in an industrial process.
• alarm units that are applied to a device or an object and that cause an alarm to be activated upon their removal from a guarded or supervised area, or that are adapted to activate an alarm when the object is removed from a guarded area, or that are destroyed when removed illegally from the object to which they are fitted, or that are adapted to destroy the object to which they are fitted or to render said object unusable in any other way when an illegal attempt is made to remove said unit.
• alarm units e.g. antitheft devices
• alarm units are often manufactured in large numbers and can be offered at low prices. They are normally used in stores who wish to protect their goods through the medium of an alarm system. Alarm units of this kind may therefore often be easily removed legally from the object to which the units are applied when an object is purchased.
• This publication describes a system that uses sensors which are connected to the system via an electric conductor.
• the publica ⁇ tion describes different embodiments of the construction of a sensor with the aid of two, three or more electric conductors in the cable, wherein an interruption in or a short-circuiting of a circuit can be detected.
• the publication also describes how a communications circuit can comprise a part of the system and how a sensor can be connected to the system through the medium of a specific communications circuit.
• This publication describes a self-adhesive contact device which is intended to be fastened to theft-attractive articles and to be connected to an alarm system.
• the contact device includes a contact spring which is intended to break an electric circuit when an attempt is made to remove the contact device from an article.
• This publication describes a device which is intended to identify an alarm-emitting detector.
• a predetermined number of detectors are connected to the device mutually in parallel in a loop connected to a line-unit.
• the line-unit transmits a first signal and detectors that have an alarm status are adapted to cause a specific voltage drop across the loop in response to the first signal.
• This voltage drop generates an alarm signal from the line-unit to the device.
• the voltage drop also generates a second signal in the loop from the line-unit and the alarm detector is adapted to deliver to the line-unit a pre-programmed identification signal in response to the second signal, thereby enabling the alarm-emitting detector to be identified.
• This publication describes an alarm system in which fire detec ⁇ tors send a specific signal to a control panel in the event of a fire.
• This signal includes an identifying address and the change in the output signal of the alarm-emitting detector in addition to the fire signals that are normally emitted by conventional fire detectors.
• the control panel thus indicates fire zones, alarm detectors and the changes in their output signals.
• This publication describes an electronic remote monitoring system that includes a plurality of series connected emitters, each of which actuates the next emitter, and so on, subsequent to emitting a zero-signal or an alarm signal.
• a zero-signal or an alarm signal When the last emitter has emitted its signal, there is a brief interruption in the line voltage and a new sensing cycle then commences.
• Each emitter emits its own specific signal, which is generated by a bit pattern generator belonging to a respective emitter.
• Another technical problem is one of realizing how a controlling and/or registering system can be readily supplemented with different types of detectors that are adapted to immediately detect damage to the detector and/or disengagement of the detector from the system, and that will enable the detector that initiated the alarm to be clearly identified.
• Another technical problem is one of realizing how one such detector can be constructed and manufactured in a cost-effective manner and with a relatively small number of components. It will also be seen that a technical problem resides in realiz ⁇ ing how such a detector can be made to function without being connected electrically to the device to which it is attached.
• Another technical problem is one of realizing the advantages and possibilities that are afforded by a detector that can be connected to a system capable of providing a highly advanced alarm function and that can be identified unambiguously in the system.
• a further technical problem is one of realizing the necessity of providing an identification circuit that includes a detector and that forms part of an unbroken electrically conductive loop, whereas a further technical problem is one of realizing how such a loop can be constructed from the detector components and in combination with the identification circuit and the connection cable belonging to the alarm element.
• Another technical problem is one of realizing the advantages that are gained when the identification circuit is comprised of an integrated circuit that is given an unchangeable, unique identity in manufacture.
• Another technical problem is one of realizing the advantages that are afforded when a loop connected to the alarm system includes a number of slave detectors in the absence of an identification circuit.
• Yet another technical problem is one of realizing the possibili ⁇ ties that are afforded by a system construction in which a detector forms a system-connected loop in coaction w th a plurality of slave detectors, and to realize the possibilities that are afforded by such a system that includes a plurality of such loops connected to one and the same system.
• the present invention takes as its starting point a controlling and/or registering system that is comprised of at least one system-monitoring host computer and a plurality of devices or objects that can be monitored and/or that are monitored by the host computer, wherein the host computer and said devices or objects may be supplied with voltage from one and the same mains voltage system, wherem the monitoring host computer can communicate with each of the monitorable devices or objects through the medium of information-carrying signals, and each of the monitorable devices or objects are able to communi ⁇ cate with the host computer through the medium of information- carrying signals, said information-carrying signals being transmitted on electrical conductors within the mains voltage system.
• Such a system is also based on a master unit belonging to the host computer being connectable and connected between the host computer and an electrical socket or outlet belonging to the mains voltage system, and that a satellite unit belonging to monitored devices or objects is connectable to and connected to an electrical socket device or outlet belonging to the mains voltage system, wherein the master unit is adapted to control the actuation of each monitored device or object by transmitting and receiving information-carrying signals to and from said monitored devices or objects, and wherein said master unit is adapted to register and/or adapted to register in said host computer at least all monitored devices or objects.
• Such a system is also based on respective monitored equipment or objects communicating with a master unit via a satellite unit and by communication between satellite unit and a master unit respectively taking place via the mains voltage system.
• a device or object monitoring satellite unit and/or the monitored device or object is allotted an identification code by the master unit when the satellite unit is actuated.
• the present invention relates to a detector which is connectable to a satellite unit and adapted so that the satellite unit is able to detect the removal of the detector from a supportive surface or an attempt to remove said detector from said surface or when the detector is disconnected from the satellite unit.
• a proposed detector includes an alarm element having on one side thereof an adhesive material operative in fixing the detector to a supportive surface, and a connecting cable which is connected to the alarm element and extends therefrom to the satellite unit.
• the supportive surface is preferably a surface on the device or object to be monitored.
• a plurality of detectors can be connected to one and the same satellite unit, where said detectors are included in a common electrically conductive loop.
• the alarm element of at least one of the detectors forming said conductive loop is a so-called first type of alarm detector and includes an identification circuit that has a unique identity, wherein the loop commences from the satellite unit and passes through a first conductor in the connecting cable, connects with the identifying circuit via means provided herefor in said alarm element, continues from the identification circuit to a second conductor in the connection cable and then returns to the satellite unit via said second conductor.
• the identity of the satellite unit can be read or established via the loop, and said means is adapted to short-circuit the loop "upstream" of the identification circuit and/or to break the loop upon removal of the alarm detector from the supportive surface or when an attempt is made to remove said detector, wherein the satellite unit is no longer able to read or establish the identity of the detector.
• the identification circuit may be comprised of an integrated circuit that has been allocated a unique and unchangeable identity in manufacture.
• Such circuits are commercially available at a relatively low cost; which enables an inventive detector to be sold at a low price.
• the inventive system may include a second type of alarm detector having a first and a second connection cable, wherein the first connection cable may connect the alarm detector to the satellite unit or to one or more further detectors and the second connection cable may extend the loop to at least one further detector, said loop still constituting a closed loop through the medium of the second detector or second detectors.
• certain detectors may be comprised of a first type of slave detector that is adapted to provide the same function as an alarm detector with respect to the ability to break or short-circuit the loop, although without including an identification circuit.
• the loop within the slave alarm element constitutes the same loop as that within an alarm element belonging to an alarm detector with the exception that no identification circuit is included.
• the slave means within a first type of slave detector may also include a first component having an impedance value that corresponds to the impedance value of the identification circuit.
• this first component may be comprised of a first resistor that has a resistive value which corresponds to the resistive value of the identification circuit.
• This first type of slave detector is intended to form the last unit on a loop which also includes a second type of alarm detector.
• the inventive system may also include slave detectors of a second type, these second-type detectors having the same properties as the earlier described first-type slave detectors but with the difference that the slave alarm element of this type of slave detector is allocated a first and a second slave connection cable, wherein the first slave connection cable connects the slave detector to the satellite unit, either directly or via a further detector, and wherein a second slave connection cable extends the loop to a further detector.
• the slave means in the second-type slave detectors may also be supplemented with a component that is allocated an impedance value that corresponds to the impedance value of the identification circuit, such as a second resistor whose resistive value corresponds to the resis ⁇ tive value of the identification circuit.
• the loop will preferably be terminated with an alarm detector, so as to prevent slave detectors that are connected in the loop downstream of an alarm detector to be short-circuited and then disconnected. Such disconnection would not be detected in such a combination, because the loop would still be intact through the short-circuit and the identification circuit could still be contacted by the satellite unit.
• An inventive system may also include a plurality of different satellite units to which a plurality of different electrical loops are connected, said satellite units including different constellations of solely one alarm detector or one alarm detector in coaction with one or more slave detectors.
• the advantages that are primarily characteristic of a controlling and/or registering system in coaction with one or more detectors in accordance with the invention reside in the ability to connect to a satellite unit detectors which can be applied to an object to be monitored, where removal of a detector, or an attempt to remove a detector, or disconnection of a detector from the satellite unit will immediately indicate to the satellite unit that something is amiss and will also cause the object concerned to be identified.
• each loop with an associated constellation of detectors can be adapted to a specific object or to a group of several objects, thereby enabling several objects to be monitored or supervised by one and the same satellite unit.
• the present invention thus provides a system that enables a plurality of different devices or objects to be monitored and readily controlled from a central host computer.
• the detectors can be offered for sale at a relatively low price because of their very simple construction and because of the low- cost of the components of said detectors.
• Figure 1 illustrates schematically an inventive controlling and/or registering system
• Figure 2 is a side view, partly in section, of one embodiment of a first type of alarm detector;
• Figure 3 is a simplified electrical schema of an alarm detector according to Figure 2;
• Figure 4 illustrates from above and partly in section an embodiment of a second type of alarm detector
• FIG. 5 is a simplified electrical schema of an alarm detector according to Figure 4.
• FIG. 6 illustrates one possible compilation of connecting conductors
• Figure 7 illustrates another possible compilation of a connect ⁇ ing conductor
• Figure 8 is a side view, partly in section, of one embodiment of a first type of slave detector
• Figure 9 is a simplified electrical schema of a slave detector according to Figure 8.
• Figure 10 is a side view, partly in section, of one embodiment of a first type of slave detector according to Figure 8 that includes a supplementary component;
• Figure 11 is a simplified electrical schema of a slave detector according to Figure 10;
• Figure 12 illustrates an embodiment of a second type of slave detector from above and partly in section
• Figure 13 is a simplified electrical schema of a slave detector according to Figure 12;
• Figure 14 illustrates an embodiment of a second type of slave detector according to Figure 12 that includes a supplementary component, said detector being shown from above and partly in section;
• Figure 15 is a simplified electrical schema of a slave detector according to Figure 14;
• Figures 16-21 illustrate schematically the various possibili ⁇ ties of constructing a system to which different configurations of alarm detectors and slave detectors can be connected to a satellite unit;
• Figure 22 illustrates schematically a system in which the loop is comprised of cordless communication between a satellite unit and a plurality of detectors.
• Inventive detectors are adapted to a particular controlling and/or registering system of the kind described in the Interna ⁇ tional Patent Application PCT/SE95/01037. The reader is referred to this Application for a more thorough understanding of a system according to the present invention.
• Figure 1 is a schematic illustration of such a system which comprises a host computer 1 that monitors the system either directly or indirectly, and a plurality of devices or objects or the like ul, u2, ..., un monitored by the host computer.
• the monitoring host computer 1 can communicate with each of the monitored devices, or groups of said devices, either directly or indirectly, and each of the monitored devices, or groups of said monitored devices, can communicate with the host computer through the medium of information-carrying signals, either directly or indirectly.
• These information-carrying signals are adapted partly for transmission via a mains voltage system 11 and a master unit 12 belonging to the host computer 1 is connected between the host computer 1 and an electrical contact device Ilk or outlet belonging to the mains voltage system 11.
• a satellite unit A belonging to a monitored device or the like is connected to an outlet Ilk of the mains voltage system 11, and the master unit 12 is adapted to control actuation of each satellite unit, by sending information-carrying signals to and receiving information-carrying signals from the satellite unit A via the mains voltage system 11.
• the master unit 12 is adapted to register and/or monitor devices ul, u2, ..., un and/or is adapted to register said devices in the host computer 1.
• Respective satellite units A are thus adapted to interlink one or more devices ul, u2, ..., un with the master unit 12 via the mains voltage system 11.
• the present invention is concerned with the manner in which this interlinking can be achieved with devices or objects that need not necessarily be themselves connected to the mains voltage system, such as non-electrically connected devices or objects in a store, or valuable objects in an exhibition room or show room, or in the home.
• the master unit allocates an identification code to the satellite unit on the first occasion of actuating a satellite unit belonging to a monitored device or devices.
• the inventive detectors enable a device or an object to be connected to the system anywhere where a connection point is found, a satellite unit A, which is in contact with the host computer 1 via the mains voltage system 11.
• FIG. 2 Shown in Figure 2 is a specific type of detector, a first type of alarm detector XA, which can be connected to a satellite unit A and which includes an alarm element 2 whose one side has a flat or generally flat surface 2 ' on which there is provided an adhesive material 21 by means of which the detector can be affixed to a supportive surface, and a connection cable 3 which is connected to the alarm element and extends from said element to the satellite unit A and connected thereto.
• a first type of alarm detector XA which can be connected to a satellite unit A and which includes an alarm element 2 whose one side has a flat or generally flat surface 2 ' on which there is provided an adhesive material 21 by means of which the detector can be affixed to a supportive surface
• a connection cable 3 which is connected to the alarm element and extends from said element to the satellite unit A and connected thereto.
• the alarm element 2 includes an identification circuit 4 which has a unique identity.
• the identification circuit 4 is in electrical contact with the satellite unit A through the medium of a loop 3 ' intended for the transmission of information- carrying signals, the illustrated loop being an electrically conductive loop that passes through the detector XA.
• the loop 3' passes from the satellite unit A via a first conduc ⁇ tor 31 in the connection cable 3.
• the first conductor 31 is connected to the identification circuit 4 and the loop 3 ' continues from the identification circuit 4 to a second conductor 32 in the connection cable 3 through the medium of means 5 in the alarm element, whereafter the loop returns to the satellite unit A via the second conductor 32.
• the unique identity of the identification circuit 4 can be read or established by the satellite unit A through the medium of the loop 3 ' .
• the means 5 is adapted to short-circuit the loop 3' "upstream" of the identification circuit 4 and/or break the loop 3 ' upon removal of the alarm detector XA from the supportive surface or when an attempt is made to remove said detector from said surface, therewith resulting in an interruption in the ability of the satellite unit A to read said identity, in accordance with the equivalent electrical schema of an alarm detector of a first type shown in Figure 3.
• breaking and/or short-circuiting means are known to the art, and these are illustrated in the Figures by different electrically conductive parts that have been pressed together and that fall apart when an attempt is made to remove the detector. Another possibility is to use commercially available microswitches. Since the manner in which the means 5 is implemented plays no significant part in the present inven ⁇ tion, it will not be described in more detail in this document.
• the satellite unit A is adapted to inquire after the presence of each alarm detector connected to the satellite unit A, by polling said each detector, i.e. checking said detector at regular intervals. If a detector fails to respond, this indicates that the loop to which the detector is connected is either broken, short-circuited or disconnected.
• the identification circuit 4 is comprised of an integrated circuit that is given in manufacture a unique identity that cannot be changed subsequent to manufacture.
• identification circuits are commercially available at relatively low prices, owing to the fact that they are mass produced and because their circuit structure is uncomplicated.
• An example of one such circuit is an integrated circuit designa ⁇ ted DS2401 and available from Dallas Semiconductor Corporation in the U.S.A.
• Figure 3 shows the first type of alarm detector 1 at the final end of the loop 3 ' .
• One of the aims of the present invention is to enable a detector to be combined with different slave detec ⁇ tors, wherein a slave detector will have the same ability to break or short-circuit the loop as a detector, although without containing an identification circuit, and that an unauthorized person will be unable to determine which connected detectors are alarm detectors or slave detectors respectively.
• connection cable it is necessary for the connection cable to have branches that can accommodate a detector which receives the loop and sends the loop further. This means that the alarm detector can be seated in the centre of a loop while terminating the loop with a slave detector.
• Figure 4 illustrates an alarm detector of a second type XB, wherein the detector is allocated a first and a second connection cable 31, 32.
• the first connection cable 31 connects the detector to the satellite unit A or to one or more further detectors via the loop 31 '
• the second connection cable 32 extends the loop 32' to at least one additional detector, said loop 3' (3i 32' ) still forming a closed loop via the additional detectors.
• a detector need not be connected directly to the satellite unit and that the loop may have passed via one or more additional detectors before reaching the first-mentioned detector.
• connection cable used may be a cable that has at least two electrically conductive layers.
• connection cable may be comprised of a flexible multi-layer circuit board to which two detectors 2, 2' are connected, wherein the circuit board has a first electrically conductive layer el that is positioned beneath a second electrically conductive layer e2 with an electrically insulating layer il located therebetween.
• Figure 11 shows that this circuit board can be bent around a corner on the supportive surface on which the detectors are applied.
• FIG. 8 illustrates a first type Z of slave detector IS that includes a slave alarm element 2S and a slave connection cable 3S which extends from the slave alarm element to the alarm system A.
• the slave alarm element 2S and the slave connection cable 3S may be given an external appearance that is identical to the appear ⁇ ance of an alarm detector, so that an unauthorized person will be unable to distinguish between an alarm detector and a slave detector.
• the electrically conductive loop 3 ' passing through the slave detector IS departs from a first conductor in the loop and continues through a first slave conductor 3aS in the slave connection cable 3S and connects with a second slave conductor 3bS in the slave connection cable 3S via slave means 5S in the slave alarm element 2S, whereafter the loop 3' returns to the second conductor in the loop 3 ' via the second slave conductor 3bS.
• a slave detector does not include an identification circuit.
• Figure 9 is an equivalent electric schema of a slave detector IS of a first type Z. It will be seen that it forms a very simple circuit that has a breaking function. There is no need for a short-circuiting function in this case, since such a function has no practical significance.
• the slave means active within the slave alarm element 2S may be given a first component 41 which has an impedance value that corresponds to the impedance value of an identification circuit, as shown in Figure 10.
• FIG. 11 shows an equivalent electrical schema for a first-type slave detector Z in accordance with this embodiment. It will be seen that a short-circuiting function can be achieved through the medium of a second circuit breaker B2, although such a function has no practical application in the illustrated case.
• the first type of slave detector Z is intended to terminate a loop when a second type of alarm detector XB is placed somewhere in the loop between the terminating detector and the satellite unit.
• a second type of slave detector Y is intended to be positioned somewhere between the satellite unit and the loop termination. Since the second type of slave detector can be placed "upstream" of, or before, the alarm detector, it is appropriate to incorpo ⁇ rate in this type of detector both a breaking and a short- circuiting function.
• a second-type slave detector includes a slave alarm element 2S and a first and a second slave connection cable 3IS, 32S extending from the slave alarm element 2S.
• the first slave connection cable 31S connects the slave detector to the satellite unit either directly or indirectly through the medium of additional detectors, whereas the second slave connec ⁇ tion cable extends the loop 3' to at least one further detector.
• the slave alarm element 2S and the slave connection cables 31S, 32S may be given an external appearance that is identical to the external appearance of an alarm element and connection cables belonging thereto, so that an unauthorized person will be unable to distinguish between an alarm detector and a slave detector.
• the electrically conductive loop 3' (31'S, 32'S) passing through the slave detector IS is formed by coupling the first slave connection cable 31S with the second slave connection cable 32S through the medium of slave means 5S in the slave alarm element.
• Figure 13 is a simplified equivalent electronic schema of a slave detector of a second type Y.
• This type of slave detector includes both a breaking Bl and a short-circuiting B2 function.
• the slave means 5S active within the slave alarm element 2S may include a second component 42 that has an impedance value which corresponds to the impedance value of an identification circuit, as shown in Figure 14.
• the electric characteristic may be adapted readily, by allowing the second component 42 to have the form of a second resistor whose resistive value corresponds to the resistive value of an identification circuit.
• Figure J.5 illustrates an equivalent electric schema for a second type of slave detector Y according to this embodiment. It will be seen that this type of slave detector affords both a breaking Bl and a short-circuiting B2 function.
• slave detectors shall be used with or without components (41, 42) will depend somewhat on the number of slave detectors used in a loop and on the physical length of the loop.
• the circuit DS2401 acts through the loop at a very low amperage ( in the order of ⁇ A) , and the system will thus be sensitive to current losses and consequently it may be desirable to exclude any additional components from the slave detectors, such as a resistor.
• one of these detectors shall comprise an alar ⁇ detector of the first or the second type, and remaining detectors will comprise slave detectors of the first or the second type.
• Figure 16 shows a system that includes a satellite unit A to which a fir ⁇ t-type alarm detector XA is connected.
• Figure 17 illustrates a system that includes a satellite unit A to which a first-type alarm detector XA and one or more second- type slave detectors Yl, Y2, ..., Yn are connected.
• Figure IB shows a system that includes a satellite unit A to which a second-type alarm detector XB and a first-type slave detector Z are connected.
• Figure 19 shows a system that includes a satellite unit A to which a second-type alarm detector XB, a fir ⁇ t-type slave detector Z and one or more second-type slave detectors Yl, Y2, ... , Yn are connected.
• two or more detectors in a loop can be comprised of alarm detectors.
• Such a constellation requires special handling of the polling procedure, since the iden t ification circuits in respective alarm detectors such a loop lie sequentially in series as shown in Figure 20 , where two slave detectors Yl and Y2 lie in a common loop with two alarm detectors XI and X2.
• Figure 21 shows a system that includes a satellite unit A having connected thereto a plurality of electric loops SI, S2, ..., Sn which include different constellations of an alarm detector ; • ; and no slave detector for one or more slave detectors cf the first type Z cr tne second type Y connected thereto .
• a plurality of loops can be connected to a common satellite unit and that a plurality of satellite units can coact in a common system, thereby enabling a plurality of objects to be monitored and guarded.
• a single loop is not limited to the task of guarding or protecting a single object and that a single loop may extend over a plurality of objects and thereby guard and protect the same.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Alarm Systems (AREA)
• Burglar Alarm Systems (AREA)

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Publications (1)

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Family Applications (1)

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Cited By (4)

Citations (7)

• 1995
  • 1995-11-28 SE SE9504260A patent/SE9504260D0/xx unknown
• 1996
  • 1996-11-28 WO PCT/SE1996/001559 patent/WO1997020295A1/en not_active Application Discontinuation
  • 1996-11-28 CA CA 2238716 patent/CA2238716A1/en not_active Abandoned
  • 1996-11-28 EP EP96941271A patent/EP0883868A1/de not_active Withdrawn
  • 1996-11-28 AU AU10462/97A patent/AU1046297A/en not_active Abandoned

Patent Citations (7)

Non-Patent Citations (1)

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