CA1242012A - Monitoring system - Google Patents
Monitoring systemInfo
- Publication number
- CA1242012A CA1242012A CA000480832A CA480832A CA1242012A CA 1242012 A CA1242012 A CA 1242012A CA 000480832 A CA000480832 A CA 000480832A CA 480832 A CA480832 A CA 480832A CA 1242012 A CA1242012 A CA 1242012A
- Authority
- CA
- Canada
- Prior art keywords
- control assembly
- monitoring system
- switch
- receiver
- alarm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/02—Mechanical actuation
- G08B13/14—Mechanical actuation by lifting or attempted removal of hand-portable articles
- G08B13/1445—Mechanical actuation by lifting or attempted removal of hand-portable articles with detection of interference with a cable tethering an article, e.g. alarm activated by detecting detachment of article, breaking or stretching of cable
- G08B13/1454—Circuit arrangements thereof
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B29/00—Checking or monitoring of signalling or alarm systems; Prevention or correction of operating errors, e.g. preventing unauthorised operation
- G08B29/18—Prevention or correction of operating errors
- G08B29/181—Prevention or correction of operating errors due to failing power supply
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Burglar Alarm Systems (AREA)
Abstract
ABSTRACT
Monitoring System The monitoring system comprises a control device (16) operated by a battery (30). A monitoring circuit (31) is provided for the control of the battery voltage. Upon the connection or disconnection of the enabling switch (20), the detection circuit (24) produces a pulse by which the switch (37) of the monitoring circuit is caused to be conductive. The time of the battery check is restricted to the duration of said pulse.
Thus, a permanent discharge of the battery (30) is excluded by the monitoring circuit.
(Fig. 1).
Monitoring System The monitoring system comprises a control device (16) operated by a battery (30). A monitoring circuit (31) is provided for the control of the battery voltage. Upon the connection or disconnection of the enabling switch (20), the detection circuit (24) produces a pulse by which the switch (37) of the monitoring circuit is caused to be conductive. The time of the battery check is restricted to the duration of said pulse.
Thus, a permanent discharge of the battery (30) is excluded by the monitoring circuit.
(Fig. 1).
Description
Monitoring System The invention relates to a monitoring system comprising at least one sensor and a battery-operated control device to which the sensor is connected and which containsan enabling switch responsible for the functioning of the signals of the sensor, an alarm transmitter activatable by the signals of the sensor and a monitoring circuit for the battery voltage.
It has been known, as a safeguard against burglary, to fit articles such as textiles offered e.g. in retail shops or in big stores, with sensors which become responsive if the article is removed. For inst. clips fixed at textiles are connected through a cable to a control device. For the removal of the article, it is necessary to undo the clip whereby an electric intact within ' it is opened. If, with a control device in operative condition, the clip is opened, an alarm signal is generated to inform the staff of the shop that a clip has been separated from the associated article. The control device includesan ena3lina switch operable by a key of the staff to disconnect the monitoring system if an article is sold. If the monitoring system is disconnected, the clip may be removed from the article without giving alarm. Subsequently, the monitoring system must be activated again. Monitoring systems of this type are mostly used for textile goods offered on stands or rails in shops where a current supply from mains is frequently not available. Therefore, a battery is often used to supply current to the monitoring system. In such a case, the battery should be discharged to the least extent to avoid its frequent replacement. To ensure operability of the system, it is necessary to- control the battery voltage. To this effect, circuits no lly current carrying ,,~
.~
~2~ 2 are required which, on the other hand, additionallY
discharge the battery. In other words, the monitoring circuit for the battery constitutes an important current consumer reducing the life time of the battery.
It is the object of the invention to provide a monitoring system of the type disclosed above in which important functions are controlled with the aid of a current-saving circuit, the failure of said functions being indicated.
The problem is solved according to the invention in that, due to the enabling switch, the monitoring system for the battery voltage is so controlled that it is normally disconnected while it is operative for a limited space of time upon the connection and/or disconnection of the enabling switch.
In the monitoring system of the invention, the battery voltage is not continuously controlled, but a control is only made if the enabling switch is put on or off, for a respective short space of time only. While the logic circuits in the control device which need be operative in service may consist of electronic elements for inst. of semiconductor elements in C-MOS-technique, having an extremely low rest current demand, the monitoring circuit of the battery voltage calls for elements which are traversed by a higher current which is not maintained permanently but which is only connected if the enabling switch is activated. By this means, the battery voltage is controlled only at certain moments so that the control circuit discharges the battery but only temporarily.
As a result, the monitoring system may be operated by batteries of a relatively low capacity ~ampere/hr).
Suitably, there is provided a detection circuit for connecting and/or disconnecting the enabling switch and for controlling an electronic switch of the monitoring system.
In a monitoring system of the type dealt with above in which, prior to taking the article from its sensor, the enabling switch is disconnected, the latter need be frequently switched on and off. It may happen, therefore, that due to an oversight, the enablina switch is not reconnected upon the removal of the article. To avoid a resultant accidental inoperativeness of the monitoring system thus incapable of performing its duty, a preferred embodiment of the invention provides a delay circuit which, upon the disconnection of the enablina switch gives alarm unless, within a defined space of time, it is switched on again. The time lag is rated to be long enough to permit, upon the disconnection of the enabling switch, the separation of the article from its sensor and a subsequent operative reconnection of the monitoring system.
Preferably, the enabling switch of a key switch design comprises a key detector for detecting the presence of a key in a keyhole and for giving alarm, if the key is kept in the keyhole for a time longer than predetermined.Thus, the staff will remember that by negligence, the key is still in the key switch. At the same time, it will be prohibitive for burglars to benefit from the situation that a key has been left in the key switch and to switch the monitoring system into inoperativeness.
For each sensor, a memory storing the sensor signal and controlling a signal lamp inherent to said sensor may be provided.
- 4 - %
The signal lamps of all sensors are mounted at the control device. If alarm is set off by one of the sensors, it is possible to determine immediately from the respective lamp at the control device, the sensor which triggered alarm. In other words, if alarm is given, it will take no time to find out the article for which investigations are to be made.
According to a preferred embodiment of the invention, the memories of all sensors may be reset by a resetting signal generated by the disconnection and/or connection of the enabling switch. The sensor which became responsive to trigger alarm will be reset if the system is put into inoperativeness or with the next operative cycle. Thus, the system will be immediately ready for action without the need of a manual resetting of the respective sensor.
According to a specific feature of the invention which is of independent importance,also without the forgoing features, it is provided that the control device includes a transmitter emitting coded signals characteristic of the control device of the respective activated sensor, and that a receiver receiving the signals of the transmitter is provided for delivering signals to a decoder for identifying the activated control device. Such a monitoring system is operated by a wireless transmission of the alarm signals from the control device to the receiver. Should the monitoring system be used to protect in retail shops, department stores etc. the articles offered for sale and to which the sensors are applied, one sole receiver may be coordinated to a plurality of control devices. If a sensor of a control device becomes responsive, the latter emits a coded signal combination which is received by the receiver which controls an indicator at which the control device having caused the alarm is indicated.
Preferably, the receiver is mounted at the ceiling so that its frequency range covers a large surface of the room, in which a plurality of control devices may be distributed. They are mounted for inst. at clothing stands. If an article of clothing protected by a sensor is taken from the rack without permission, the control device becomes responsive to send out the coded identification signal. By optical and/or acoustic signals, the staff is informed that alarm has been triggered by a control device. By a number indication, the respective control device or the stand where the theft took place, may be identified immediately. It is of particular importance in this system installed in rooms that the emission of the senders of the control devices is directed upwardly and that the receivers are mounted at the ceiling with a frequency range directed downwardly.
The alarm being triggered at once if one of the sensors becomes responsive, burglars will be intimidated because, at that moment, the stolen article is not yet removed from the selling rack. In other words, the burglar is taken in the very act rather than after it It is also advantageous that alarm is triggered at the respective control device, i.e. at the rack but also at the central receiver by optic and/or acoustic means. The burglar is under the impression of being detected from various sides.
Conveniently, the receiver controls a flash. It turned out, indeed, that a strongly deterrent effect on burglars is caused by bright flashlight. Further, if this is coupled with the release system of a camera covering with its pick-up range the control device giving alarm, the respective person having caused the alarm will be photographed accordingly.
During the closing hours or at night, it is not reasonable to flash or to cause acoustic alarm because persons other than burglars will not be present in the business rooms. Therefore, it is advisable to change over at night the receiver for the activation of an alarm system. Such alarm systems are normally mounted in business premises. The monitoring system supplies its alarm signals to such an existing alarm device which is effective to the outside and probably connected to a Police Station. The connection of the monitoring system to the alarm system will be effected by the latter.
One embodiment of the invention will be explained hereunder in more detail with reference to the drawings.
Fig. 1 is a schematic wiring diagram of the monitoring system, Fig. 2 is a perspective view of the monitoring system in a big department store, Fig. 3 is an illustration of one embodiment of the housing of the control device and Fig. 4 is another example of the installation of the receiver and several alarm generators.
Referring now to Fig. 1, the monitoring system illustrated comprises a plurality of sensors 10 which consist of clips having legs 12,13 pivotable around a hinge 11 and the ends of which are pressed against one another by a spring (not shown). The end of one clip leg 13 includes a microswitch 14 which, if operated, opens a current circuit, said microswitch being activated if the fabric of a textile article is clamped between the ends of the clip legs 12,13. If the fabric between the legs is removed by drawing, the clip leg ends are directly adjoined without an actuation of the switch 14.
Each sensor may be fixed at another garment. The illustrated monitoring system may be for inst. used to protect by sensors all of the garments put on the stand and provided with them. Each sensor 10 is connected by cable 15 to the control device 16, the cable 15 being of the multiconductor type. For a better survey, one line is shown only.
Each cable 15 is connected to the control device through a plug connection 17. If the circuit is interrupted by the microswitch 14, a set signal is applied to the set input S of a memory 18, which is a flip-flop in the instant case. Thus, it is stored by memory 18 that the microswitch 14 has been opened even if the microswitch 14 will be closed subsequently. The output Q of the memory is connected to the input of an AND gate 19 whose other input is joined to the service switch 20. If the monitoring system is activated such as shown in the drawing by the position of the enabling switch 20, the switch condition of AND gate 19 is met as soon as memory 18 is set. The output signal of each AND gate 19 serves as a trigger signal for a signal generator generating square pulses with a predetermined pulse duty factor. The signal generator 21 enables an audio- frequency generator 22 connected to a buzzer 23 or loudspeaker. All of the signal generators 21 are connected to one common audio-frequency generator 22, and all signal generators 21 have different pulse duty factors and different pulse lengths so that the signals produced by the individual signal generators 21, generate different sequences of sounds and interruptions. By this means, the sensor which became responsive may be easily identified acoustically. Further, the output Q
of each memory 18 controls a light diode 24 which, as long as the memory 18 is set, is luminous.
All of the memories 18 are reset with the disconnection of the enabling switch 20 or if it is switched on again. At that moment, a short pulse is supplied to the resetting inputs R of all memories via an RC-member 25 connected to the enabling switch 20.
Further, through an inverter 26 and a delay circuit 27 causing a delay D1 for inst of 10 s, the output of the service switch 20 is connected to thecontrol input of another signal generator 28 which controls an audio-frequency generator 29 that may also excite the buzzer 23. Due to circuit 26 to 29, an intermittent acoustic signal is caused, if, upon the disconnection of the service switch 20, the latter is not connected again within a time longer than the operating time of the time-lag member 27. Whenever an article provided with a sensor 10 is being sold, the sales-girl turns off the service switch 20 to separate the respective sensor 10 from its article, the enablina switch 20 being closed again subsequently. Unless this is done, alarm is triggered by circuit 27 to 29.
9 ~2~
Referring now to the drafted circuit, a logic signal "l"-signal designates a positive voltage, a logic "0"-signal a voltage near zero.If the enablinq switch 20 is turned off, i.e.a zero potential is applied, the timer 27 is put onto operation through the inverter 26.
The contacts of a key detector 20' are parallel-connected to the contacts of switch 20, the key detector 20' being a switch adapted to determine in the keyhole the precence of the key required for activation of the system. If the key is in the keyhole, the switch is placed into a position in which positive voltage is applied to the switch lever.
In the absence of a key in the keyhole, the key detector 20' takes its rest position in which its switch lever is earthed., the latter being connected to a timer : 27' the delay time D2 of which is shorter than the delay time of the delay circuit 27 and which is e.g. 3 s. The output of the time 27' is connected to the input of the signal generator 28. In conjunction with the timer 27', the key detector 20' is responsible for making sure that the key is not left longer in the keyhole than for a predetermined time. If the key is not removed by negligence, an alarm signal is given upon the end of the delay time of the timer 2~/'.
While the key switch 20 becomes responsive to the actuation of the key to maintain the respective condi-tion if the key is removed subsequently, the key detector 20' is responsive to the presence of a key in the keyhole, and it automatically returns to its rest position as illustrated in Fig. 1.
All components of the circuit are operated by the battery 30 which normally supplies 6 volt. If the voltage of the battery has decreased to 4,5 volt, alarm must be given to ensure a timely exchange of the battery. The monitoring circuit 31 being present at the battery voltage, contains a series circuit including a resistor 32 as well as a ~ener diode 33 which is an element in which,irrespective of the battery voltage level, a constant voltage drop occurs within certain limits. It is also possible to use in place of the Zener diode 32 other voltaye-stabilizing elements, e.g. a series circuit of a plurality of diodes, a glow lamp or the like. A voltage divider consisting of the resistors 34 and 35 is provided in parallel to the series circuit 32,33. The taps of the series circuit 32,33 and of the voltage divider are connected to the inputs of a comparator 36 supplying a signal at its output if the voltage at the tap of the voltage divider has decreased to below the voltage of the zener diode 33. The voltage at the tap of the voltage divider 34,35 is proportional to the battery voltage while the voltage of the Zener diode 33 can be con-sidered constant. The Zener diode 33 and resistor 35 are connected to a mass potential through a switch 37 in the form of a transistor. the monitoring circuit is only operative if the transistor 37 is conductive.
If the transistor 37 is locked, the monitoring circuit 31 does not supply an output signal. The signal of the monitoring circuit 31 is supplied to a time function element 38 effective for about5 seconds and whose output signal energizes~the audio frequency generator 39. If the battery voltage has dropped below the admissible minimum value, the time function member 38 generates through the audio frequency generator 39 an alarm signal of 5 seconds at the buzzer 23.
Switch 37 is contro~edby the detection circuit 40 in responee to the operation of theenabling iswiteh 20 which, to this effeet,is eonnected through a differentiator comprising a eapacitor 41 and resistor 42, to the mass potential,and through a seeond differentiator comprising capacitor 43 and resistor 44 to the plus pole of battery 30.
As for resistor 42, a diode 45 is eonnected in parallel thereto for short-eircuiting negative voltages towards the mass potential, while a diode 46 is connected in parallel to resistor 44 to short-circuit the positive pulses to the positive pole of battery 30. If the enabling switch 20 is set from the illustrated on-position into the off-position, capacitor 41 is discharged, while capacitor 43 will be eharged. As a result thereof, a positive pulse being formed at line 47 is eonducted through the OR-gate 49 to the eontrol input of switch 37 to trigger it for some time into the conductive state. In said short space of time of some milliseconds, the battery voltage is checked in the monitoring circuit 31.
With the subsequent resetting of the enabling switch 20 into the on-position, the capacitor 43 is discharged, while a negative pulse being formed at line 48 is invertered by in-verter 50 to be transmitted to the OR-gate 49. pence, even with a connection of the service switch 20, the monitoring circuit 31 is caused to be operative for a short time.
If the enabling switch 20 is switched on, it is connected through the resistor 51 to the positive pole of the battery 30.
The tone frequencies of the tone generators 22,29 and 39 being different, events causing alarm may be distinguished acoustically. Sensors 10 may be identified by their different tone sequence frequencies or pulse duty factors.
g The outputs of all AND-gates 19 are connected to the inputs of a coder 51 which emits a pulse sequence through a light emittinq diode 52 if one of the sensors 10 has become responsive, said diode 52 ! emitting electromaqnetic waves in the infrared range. The coder 51 generates pulses in accordance with a specific pulse pattern with the aid of which at the receiver 53 which receives the infrared signals, the control device 16 may be detected - which emitted said pulses. The determination is performed by the decoder 54 connected downstream of the receiver 53 and controlling an indicating means 55 showing in figures the number of the control device which caused the alarm. Further, a flashlight apparatus being activated by the alarm call emits one or more flashes. At the same time, a camera 57 may be operated together with the flashing in order to take a photograph of the region in which the control device is installed.
Fig. 2 shows a perspective view of the monitoring system in a textile shop. Dresses 58 offered for sale are suspended at stands 59 to each of which a monitoring device 16 is secured which is located in a housing having a plurality of plug connections17 adapted to receive cable plugs. Each cable end is provided with a sensor 10 of the prong-type described with the aid of Fig. 1. The top of the housing contains two exit apertures 66 through which may be emitted the beams of a luminous diode 52. Further, the top of the housing includes~an opening 60 of a keyhole adapted to receive a magnetic key to operate the enabling switch 20 (Fig. 1).
The housing of the control device 16 shown with the stand 59 left-hand it Fig. 2 is plate-shaped and mounted coaxially to the stand 59 which is of a round design having a circular rail to suspend the clothes. The stand 59 illustratd right-hand in Fig. 2 has straight suspension bars 62, the control device 16 being arranged in an elongated housing that extends along the upper end of the stand 59 and in horizontal direction.
The receiver 53 together with the decoder 54 is mounted in a housing 63 fixed to hang down from the ceiling of the room. The underside of the housing 63 contains the infrared eye 64 of the receiver.
If any of the control devices 16 supplies infrared alarm pulses, they are received and evaluated by the receiver 53.
The indicator 55 at the housing 63 shows the illuminated number of the stand in which one sensor 10 became responsive.
Along the 1ower edges of the housing 63, flashlight lamps 56 emit flashes in case of alarm.
Suitably, each transmitteremits pulses at regular intervals which are identified by the receiver but which are no pulses. By this means, one may determine whether the radiation connection between sender and receiver is interrupted or whether one of the senders or receivers has been shielded.
If so, a warning signal may be produced.
The arrangement illustrated in Fig. 4 comprises a receiver 53 mounted at the ceiling and connected through a cable 65 to ele-ments 55,56 and 57 fitted at the lateral boundary wall of the room or at a pillar.
It has been known, as a safeguard against burglary, to fit articles such as textiles offered e.g. in retail shops or in big stores, with sensors which become responsive if the article is removed. For inst. clips fixed at textiles are connected through a cable to a control device. For the removal of the article, it is necessary to undo the clip whereby an electric intact within ' it is opened. If, with a control device in operative condition, the clip is opened, an alarm signal is generated to inform the staff of the shop that a clip has been separated from the associated article. The control device includesan ena3lina switch operable by a key of the staff to disconnect the monitoring system if an article is sold. If the monitoring system is disconnected, the clip may be removed from the article without giving alarm. Subsequently, the monitoring system must be activated again. Monitoring systems of this type are mostly used for textile goods offered on stands or rails in shops where a current supply from mains is frequently not available. Therefore, a battery is often used to supply current to the monitoring system. In such a case, the battery should be discharged to the least extent to avoid its frequent replacement. To ensure operability of the system, it is necessary to- control the battery voltage. To this effect, circuits no lly current carrying ,,~
.~
~2~ 2 are required which, on the other hand, additionallY
discharge the battery. In other words, the monitoring circuit for the battery constitutes an important current consumer reducing the life time of the battery.
It is the object of the invention to provide a monitoring system of the type disclosed above in which important functions are controlled with the aid of a current-saving circuit, the failure of said functions being indicated.
The problem is solved according to the invention in that, due to the enabling switch, the monitoring system for the battery voltage is so controlled that it is normally disconnected while it is operative for a limited space of time upon the connection and/or disconnection of the enabling switch.
In the monitoring system of the invention, the battery voltage is not continuously controlled, but a control is only made if the enabling switch is put on or off, for a respective short space of time only. While the logic circuits in the control device which need be operative in service may consist of electronic elements for inst. of semiconductor elements in C-MOS-technique, having an extremely low rest current demand, the monitoring circuit of the battery voltage calls for elements which are traversed by a higher current which is not maintained permanently but which is only connected if the enabling switch is activated. By this means, the battery voltage is controlled only at certain moments so that the control circuit discharges the battery but only temporarily.
As a result, the monitoring system may be operated by batteries of a relatively low capacity ~ampere/hr).
Suitably, there is provided a detection circuit for connecting and/or disconnecting the enabling switch and for controlling an electronic switch of the monitoring system.
In a monitoring system of the type dealt with above in which, prior to taking the article from its sensor, the enabling switch is disconnected, the latter need be frequently switched on and off. It may happen, therefore, that due to an oversight, the enablina switch is not reconnected upon the removal of the article. To avoid a resultant accidental inoperativeness of the monitoring system thus incapable of performing its duty, a preferred embodiment of the invention provides a delay circuit which, upon the disconnection of the enablina switch gives alarm unless, within a defined space of time, it is switched on again. The time lag is rated to be long enough to permit, upon the disconnection of the enabling switch, the separation of the article from its sensor and a subsequent operative reconnection of the monitoring system.
Preferably, the enabling switch of a key switch design comprises a key detector for detecting the presence of a key in a keyhole and for giving alarm, if the key is kept in the keyhole for a time longer than predetermined.Thus, the staff will remember that by negligence, the key is still in the key switch. At the same time, it will be prohibitive for burglars to benefit from the situation that a key has been left in the key switch and to switch the monitoring system into inoperativeness.
For each sensor, a memory storing the sensor signal and controlling a signal lamp inherent to said sensor may be provided.
- 4 - %
The signal lamps of all sensors are mounted at the control device. If alarm is set off by one of the sensors, it is possible to determine immediately from the respective lamp at the control device, the sensor which triggered alarm. In other words, if alarm is given, it will take no time to find out the article for which investigations are to be made.
According to a preferred embodiment of the invention, the memories of all sensors may be reset by a resetting signal generated by the disconnection and/or connection of the enabling switch. The sensor which became responsive to trigger alarm will be reset if the system is put into inoperativeness or with the next operative cycle. Thus, the system will be immediately ready for action without the need of a manual resetting of the respective sensor.
According to a specific feature of the invention which is of independent importance,also without the forgoing features, it is provided that the control device includes a transmitter emitting coded signals characteristic of the control device of the respective activated sensor, and that a receiver receiving the signals of the transmitter is provided for delivering signals to a decoder for identifying the activated control device. Such a monitoring system is operated by a wireless transmission of the alarm signals from the control device to the receiver. Should the monitoring system be used to protect in retail shops, department stores etc. the articles offered for sale and to which the sensors are applied, one sole receiver may be coordinated to a plurality of control devices. If a sensor of a control device becomes responsive, the latter emits a coded signal combination which is received by the receiver which controls an indicator at which the control device having caused the alarm is indicated.
Preferably, the receiver is mounted at the ceiling so that its frequency range covers a large surface of the room, in which a plurality of control devices may be distributed. They are mounted for inst. at clothing stands. If an article of clothing protected by a sensor is taken from the rack without permission, the control device becomes responsive to send out the coded identification signal. By optical and/or acoustic signals, the staff is informed that alarm has been triggered by a control device. By a number indication, the respective control device or the stand where the theft took place, may be identified immediately. It is of particular importance in this system installed in rooms that the emission of the senders of the control devices is directed upwardly and that the receivers are mounted at the ceiling with a frequency range directed downwardly.
The alarm being triggered at once if one of the sensors becomes responsive, burglars will be intimidated because, at that moment, the stolen article is not yet removed from the selling rack. In other words, the burglar is taken in the very act rather than after it It is also advantageous that alarm is triggered at the respective control device, i.e. at the rack but also at the central receiver by optic and/or acoustic means. The burglar is under the impression of being detected from various sides.
Conveniently, the receiver controls a flash. It turned out, indeed, that a strongly deterrent effect on burglars is caused by bright flashlight. Further, if this is coupled with the release system of a camera covering with its pick-up range the control device giving alarm, the respective person having caused the alarm will be photographed accordingly.
During the closing hours or at night, it is not reasonable to flash or to cause acoustic alarm because persons other than burglars will not be present in the business rooms. Therefore, it is advisable to change over at night the receiver for the activation of an alarm system. Such alarm systems are normally mounted in business premises. The monitoring system supplies its alarm signals to such an existing alarm device which is effective to the outside and probably connected to a Police Station. The connection of the monitoring system to the alarm system will be effected by the latter.
One embodiment of the invention will be explained hereunder in more detail with reference to the drawings.
Fig. 1 is a schematic wiring diagram of the monitoring system, Fig. 2 is a perspective view of the monitoring system in a big department store, Fig. 3 is an illustration of one embodiment of the housing of the control device and Fig. 4 is another example of the installation of the receiver and several alarm generators.
Referring now to Fig. 1, the monitoring system illustrated comprises a plurality of sensors 10 which consist of clips having legs 12,13 pivotable around a hinge 11 and the ends of which are pressed against one another by a spring (not shown). The end of one clip leg 13 includes a microswitch 14 which, if operated, opens a current circuit, said microswitch being activated if the fabric of a textile article is clamped between the ends of the clip legs 12,13. If the fabric between the legs is removed by drawing, the clip leg ends are directly adjoined without an actuation of the switch 14.
Each sensor may be fixed at another garment. The illustrated monitoring system may be for inst. used to protect by sensors all of the garments put on the stand and provided with them. Each sensor 10 is connected by cable 15 to the control device 16, the cable 15 being of the multiconductor type. For a better survey, one line is shown only.
Each cable 15 is connected to the control device through a plug connection 17. If the circuit is interrupted by the microswitch 14, a set signal is applied to the set input S of a memory 18, which is a flip-flop in the instant case. Thus, it is stored by memory 18 that the microswitch 14 has been opened even if the microswitch 14 will be closed subsequently. The output Q of the memory is connected to the input of an AND gate 19 whose other input is joined to the service switch 20. If the monitoring system is activated such as shown in the drawing by the position of the enabling switch 20, the switch condition of AND gate 19 is met as soon as memory 18 is set. The output signal of each AND gate 19 serves as a trigger signal for a signal generator generating square pulses with a predetermined pulse duty factor. The signal generator 21 enables an audio- frequency generator 22 connected to a buzzer 23 or loudspeaker. All of the signal generators 21 are connected to one common audio-frequency generator 22, and all signal generators 21 have different pulse duty factors and different pulse lengths so that the signals produced by the individual signal generators 21, generate different sequences of sounds and interruptions. By this means, the sensor which became responsive may be easily identified acoustically. Further, the output Q
of each memory 18 controls a light diode 24 which, as long as the memory 18 is set, is luminous.
All of the memories 18 are reset with the disconnection of the enabling switch 20 or if it is switched on again. At that moment, a short pulse is supplied to the resetting inputs R of all memories via an RC-member 25 connected to the enabling switch 20.
Further, through an inverter 26 and a delay circuit 27 causing a delay D1 for inst of 10 s, the output of the service switch 20 is connected to thecontrol input of another signal generator 28 which controls an audio-frequency generator 29 that may also excite the buzzer 23. Due to circuit 26 to 29, an intermittent acoustic signal is caused, if, upon the disconnection of the service switch 20, the latter is not connected again within a time longer than the operating time of the time-lag member 27. Whenever an article provided with a sensor 10 is being sold, the sales-girl turns off the service switch 20 to separate the respective sensor 10 from its article, the enablina switch 20 being closed again subsequently. Unless this is done, alarm is triggered by circuit 27 to 29.
9 ~2~
Referring now to the drafted circuit, a logic signal "l"-signal designates a positive voltage, a logic "0"-signal a voltage near zero.If the enablinq switch 20 is turned off, i.e.a zero potential is applied, the timer 27 is put onto operation through the inverter 26.
The contacts of a key detector 20' are parallel-connected to the contacts of switch 20, the key detector 20' being a switch adapted to determine in the keyhole the precence of the key required for activation of the system. If the key is in the keyhole, the switch is placed into a position in which positive voltage is applied to the switch lever.
In the absence of a key in the keyhole, the key detector 20' takes its rest position in which its switch lever is earthed., the latter being connected to a timer : 27' the delay time D2 of which is shorter than the delay time of the delay circuit 27 and which is e.g. 3 s. The output of the time 27' is connected to the input of the signal generator 28. In conjunction with the timer 27', the key detector 20' is responsible for making sure that the key is not left longer in the keyhole than for a predetermined time. If the key is not removed by negligence, an alarm signal is given upon the end of the delay time of the timer 2~/'.
While the key switch 20 becomes responsive to the actuation of the key to maintain the respective condi-tion if the key is removed subsequently, the key detector 20' is responsive to the presence of a key in the keyhole, and it automatically returns to its rest position as illustrated in Fig. 1.
All components of the circuit are operated by the battery 30 which normally supplies 6 volt. If the voltage of the battery has decreased to 4,5 volt, alarm must be given to ensure a timely exchange of the battery. The monitoring circuit 31 being present at the battery voltage, contains a series circuit including a resistor 32 as well as a ~ener diode 33 which is an element in which,irrespective of the battery voltage level, a constant voltage drop occurs within certain limits. It is also possible to use in place of the Zener diode 32 other voltaye-stabilizing elements, e.g. a series circuit of a plurality of diodes, a glow lamp or the like. A voltage divider consisting of the resistors 34 and 35 is provided in parallel to the series circuit 32,33. The taps of the series circuit 32,33 and of the voltage divider are connected to the inputs of a comparator 36 supplying a signal at its output if the voltage at the tap of the voltage divider has decreased to below the voltage of the zener diode 33. The voltage at the tap of the voltage divider 34,35 is proportional to the battery voltage while the voltage of the Zener diode 33 can be con-sidered constant. The Zener diode 33 and resistor 35 are connected to a mass potential through a switch 37 in the form of a transistor. the monitoring circuit is only operative if the transistor 37 is conductive.
If the transistor 37 is locked, the monitoring circuit 31 does not supply an output signal. The signal of the monitoring circuit 31 is supplied to a time function element 38 effective for about5 seconds and whose output signal energizes~the audio frequency generator 39. If the battery voltage has dropped below the admissible minimum value, the time function member 38 generates through the audio frequency generator 39 an alarm signal of 5 seconds at the buzzer 23.
Switch 37 is contro~edby the detection circuit 40 in responee to the operation of theenabling iswiteh 20 which, to this effeet,is eonnected through a differentiator comprising a eapacitor 41 and resistor 42, to the mass potential,and through a seeond differentiator comprising capacitor 43 and resistor 44 to the plus pole of battery 30.
As for resistor 42, a diode 45 is eonnected in parallel thereto for short-eircuiting negative voltages towards the mass potential, while a diode 46 is connected in parallel to resistor 44 to short-circuit the positive pulses to the positive pole of battery 30. If the enabling switch 20 is set from the illustrated on-position into the off-position, capacitor 41 is discharged, while capacitor 43 will be eharged. As a result thereof, a positive pulse being formed at line 47 is eonducted through the OR-gate 49 to the eontrol input of switch 37 to trigger it for some time into the conductive state. In said short space of time of some milliseconds, the battery voltage is checked in the monitoring circuit 31.
With the subsequent resetting of the enabling switch 20 into the on-position, the capacitor 43 is discharged, while a negative pulse being formed at line 48 is invertered by in-verter 50 to be transmitted to the OR-gate 49. pence, even with a connection of the service switch 20, the monitoring circuit 31 is caused to be operative for a short time.
If the enabling switch 20 is switched on, it is connected through the resistor 51 to the positive pole of the battery 30.
The tone frequencies of the tone generators 22,29 and 39 being different, events causing alarm may be distinguished acoustically. Sensors 10 may be identified by their different tone sequence frequencies or pulse duty factors.
g The outputs of all AND-gates 19 are connected to the inputs of a coder 51 which emits a pulse sequence through a light emittinq diode 52 if one of the sensors 10 has become responsive, said diode 52 ! emitting electromaqnetic waves in the infrared range. The coder 51 generates pulses in accordance with a specific pulse pattern with the aid of which at the receiver 53 which receives the infrared signals, the control device 16 may be detected - which emitted said pulses. The determination is performed by the decoder 54 connected downstream of the receiver 53 and controlling an indicating means 55 showing in figures the number of the control device which caused the alarm. Further, a flashlight apparatus being activated by the alarm call emits one or more flashes. At the same time, a camera 57 may be operated together with the flashing in order to take a photograph of the region in which the control device is installed.
Fig. 2 shows a perspective view of the monitoring system in a textile shop. Dresses 58 offered for sale are suspended at stands 59 to each of which a monitoring device 16 is secured which is located in a housing having a plurality of plug connections17 adapted to receive cable plugs. Each cable end is provided with a sensor 10 of the prong-type described with the aid of Fig. 1. The top of the housing contains two exit apertures 66 through which may be emitted the beams of a luminous diode 52. Further, the top of the housing includes~an opening 60 of a keyhole adapted to receive a magnetic key to operate the enabling switch 20 (Fig. 1).
The housing of the control device 16 shown with the stand 59 left-hand it Fig. 2 is plate-shaped and mounted coaxially to the stand 59 which is of a round design having a circular rail to suspend the clothes. The stand 59 illustratd right-hand in Fig. 2 has straight suspension bars 62, the control device 16 being arranged in an elongated housing that extends along the upper end of the stand 59 and in horizontal direction.
The receiver 53 together with the decoder 54 is mounted in a housing 63 fixed to hang down from the ceiling of the room. The underside of the housing 63 contains the infrared eye 64 of the receiver.
If any of the control devices 16 supplies infrared alarm pulses, they are received and evaluated by the receiver 53.
The indicator 55 at the housing 63 shows the illuminated number of the stand in which one sensor 10 became responsive.
Along the 1ower edges of the housing 63, flashlight lamps 56 emit flashes in case of alarm.
Suitably, each transmitteremits pulses at regular intervals which are identified by the receiver but which are no pulses. By this means, one may determine whether the radiation connection between sender and receiver is interrupted or whether one of the senders or receivers has been shielded.
If so, a warning signal may be produced.
The arrangement illustrated in Fig. 4 comprises a receiver 53 mounted at the ceiling and connected through a cable 65 to ele-ments 55,56 and 57 fitted at the lateral boundary wall of the room or at a pillar.
Claims (16)
1. A monitoring system comprising:
a) battery-operated control assembly and at least one sensor removably attachable to an object and electrically connected to said battery-operated control assembly, b) said control assembly including an enabling switch, an alarm generator, and a normally inoperative monitoring circuit electrically coupled to determine the voltage of a battery for supplying electrical power to said control assembly, c) said enabling switch being electrically coupled to the monitoring circuit and being effective to cause the functioning of signals of the sensor to control the monitoring circuit, d) the alarm generator being activatable by the signals of the sensor when an attached object is removed without authorization, e) said control assembly including means for operating the monitoring circuit for a limited amount of time upon the electrical connection and/or disconnection of the enabling switch.
a) battery-operated control assembly and at least one sensor removably attachable to an object and electrically connected to said battery-operated control assembly, b) said control assembly including an enabling switch, an alarm generator, and a normally inoperative monitoring circuit electrically coupled to determine the voltage of a battery for supplying electrical power to said control assembly, c) said enabling switch being electrically coupled to the monitoring circuit and being effective to cause the functioning of signals of the sensor to control the monitoring circuit, d) the alarm generator being activatable by the signals of the sensor when an attached object is removed without authorization, e) said control assembly including means for operating the monitoring circuit for a limited amount of time upon the electrical connection and/or disconnection of the enabling switch.
2. A monitoring system as defined in Claim 1 wherein the monitoring circuit includes an electronic switch, and the control assembly includes a detection circuit which is effective to detect activation and/or deactivation of the enabling switch and includes said means for operating the monitoring circuit which controls said electronic switch.
3. A monitoring system as defined in claim 1 wherein the control assembly includes a delay circuit effective to set off an alarm upon the deactivation of the enabling switch unless a reactivation of the enabling switch takes place within a defined period of time.
4. A monitoring system as defined in claim 1 wherein the control assembly includes a key detector at a keyhole at which the enabling switch of thy key switch type is arranged to detect the presence of a key and to give alarm if the key is kept in the hole for an amount of time longer than a predetermined amount of time.
5. A monitoring system as defined in claim 1 wherein the control assembly includes a memory electrically connected to each sensor for storing a sensor signal which controls a signal lamp electrically connected to each said sensor.
6. A monitoring system as defined in claim 5 wherein the memories of all sensors may be reset by a resetting signal produced with the activation and/or deactivation of the enabling switch.
7. A monitoring system as defined in claim 1 wherein the control assembly includes a transmitter and a receiver, the transmitter emits coded signals characteristic of the controlled asembly of the respective activated sensor, and the receiver received the coded signals of the transmitter for delivering generated signals to a decoder to identify the control assembly.
8. A monitoring system as defined in claiam 7 wherein the receiver controls a flashing means.
9. A monitoring system as defined in claim 7 wherein the receiver is adapted to changed over for activating an external alarm device.
10. A monitoring system as defined in claim 7 wherein the transmitter is effective to emit maintenance signals at predetermined time intervals and the receiver is effective to detect the absence of such maintenance signals for a determined period of time to subsequently generate an alarm signal.
11. A monitoring system as defined in claim 1 wherein the control assembly includes a transmitter and a receiver, the transmitter emits coded signals characteristic of the controlled assembly of the respective activated sensor, and the receiver controls a flashing means, the receiver is adapted to be changed over for activating an external alarm device.
12. A monitoring system as defined in claim 11 wherein the transmitter is effective to emit maintenance signals at predetermined time intervals and the receiver is effective to detect the absence of such maintenance signals for a determined period of time to subsequently generate an alarm signal.
13. A monitoring system as defined in claim 1 wherein the monitoring circuit includes an electronic switch, and the control assembly includes a detection circuit which is effective to detect activation and/or deactivation of the enabling switch and includes said means for operating the monitoring circuit which controls said electronic switch, the control assembly includes a delay circuit effective to set off an alarm upon the deactivation of the enabling switch unless a reactivation of the enabling switch take place within a defined period of time.
14. A monitoring system as defined in claim 1 wherein the monitoring circuit includes an electronic switch, and the control assembly includes a detection circuit which is effective to detect activation and/or deactivation of the enabling switch and includes said means for operating the monitoring circuit which controls said electronic switch, the control assembly includes a delay circuit effective to set off an alarm upon the deactivaiton of the enabling switch unless a reactivation of the enabling switch takes place within a defined period of time, the control assembly includes a key detector at a keyhole at which the enabling switch of the key switch type is arranged to detect the presence of a key and to give alarm if the key is kept in the hole for an amount of time longer than a predetermined amount of time.
15. A monitoring system as defined in claim 1 wherein the control assembly includes a memory electrically connected to each sensor for storing a sensor signal which controls a signal lamp electrically connected to each said sensor, the control assembly includes a transmitter and a receiver, the transmitter emits coded signals characteristic of the controlled assembly of the respective activated sensor, and the receiver received the coded signals of the transmitter for delivering generated signals to a decoder to identify the control assembly.
16. A monitoring system as defined in claim 15 wherein the transmitter is effective to emit maintenance signals at predetermined time intervals and the receiver is effective to detect the absence of such maintenance signals for a determined period of time to subsequently generate an alarm signal.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19843422225 DE3422225A1 (en) | 1984-06-15 | 1984-06-15 | MONITORING SYSTEM |
| DEP3422225.1 | 1984-06-15 | ||
| EP84112390.4 | 1984-10-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1242012A true CA1242012A (en) | 1988-09-13 |
Family
ID=6238411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000480832A Expired CA1242012A (en) | 1984-06-15 | 1985-05-06 | Monitoring system |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0171459A1 (en) |
| JP (1) | JPS6134692A (en) |
| CA (1) | CA1242012A (en) |
| DE (1) | DE3422225A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6329894U (en) * | 1986-08-11 | 1988-02-26 | ||
| FR2658639B1 (en) * | 1990-02-20 | 1992-05-07 | Etie Sa | ELECTRONIC PROTECTION SYSTEM AGAINST THEFT OF OBJECTS. |
| JP2630876B2 (en) * | 1991-08-30 | 1997-07-16 | 三洋電機株式会社 | Warning sound generator |
| FR2685524A1 (en) * | 1991-12-18 | 1993-06-25 | Koune Bernard | Device for anti-theft protection of objects on display in businesses and on industrial premises, or premises open to the public |
| US5910768A (en) * | 1995-04-04 | 1999-06-08 | Ott; Reinhold | Anti-theft device |
| DE19512567C1 (en) * | 1995-04-04 | 1996-07-11 | Reinhold Ott | Theft protection device, esp. for radio-, TV-, video- and telephone equipment |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU6649874A (en) * | 1973-03-14 | 1975-09-11 | Steven Grant Marshall | Alarm system |
| DE2854434C2 (en) * | 1978-12-16 | 1983-11-24 | Burkhard 4052 Korschenbroich Zülow | Anti-theft device, in particular for sales items |
| DE3046895C2 (en) * | 1980-12-12 | 1982-09-23 | Gerald 8021 Taufkirchen Kampel | Avalanche search device, especially for use in searching for avalanche victims |
| DE3109577A1 (en) * | 1981-03-13 | 1982-10-28 | Robert Bosch Gmbh, 7000 Stuttgart | Method and device for checking the operation and battery of electronic safety devices |
| DE3302459A1 (en) * | 1982-05-07 | 1983-11-10 | Reinhold 7000 Stuttgart Ott | Theft protection for displayed goods |
| DE3300560A1 (en) * | 1983-01-10 | 1984-07-19 | Burkhard 4052 Korschenbroich Zülow | Theft protection device |
-
1984
- 1984-06-15 DE DE19843422225 patent/DE3422225A1/en not_active Ceased
- 1984-10-13 EP EP84112390A patent/EP0171459A1/en not_active Withdrawn
-
1985
- 1985-05-01 JP JP9241085A patent/JPS6134692A/en active Pending
- 1985-05-06 CA CA000480832A patent/CA1242012A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3422225A1 (en) | 1985-12-19 |
| JPS6134692A (en) | 1986-02-18 |
| EP0171459A1 (en) | 1986-02-19 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |