JP3172380B2 - Theft monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a theft monitoring device for detecting theft of articles such as goods and exhibits.

[0002]

2. Description of the Related Art A conventional example of this type of theft monitoring device will be described below with reference to FIGS.

[0003] In the circuit diagram of FIG.
Is a push switch, and the control means 2 includes a sensor 1
The alarm means 3 is sounded when is turned off. The plurality of sensors 1 are connected in series via a control unit 2 and a power supply 4, and the control unit 2 is connected to an alarm unit 3. Further, as shown in FIG. 7A, each sensor 1 is fixed by an adhesive tape 6 for each article 5 to be monitored for theft in the ON state.

[0004] Then, as shown in FIG.
Is peeled off from the article 5, the sensor 1 changes from the on state to the off state, the control means 2 sounds the alarm means 3 to notify that the article 5 has been stolen, and that the article 5 is taken away. It was to prevent it before it happened.

[0005]

However, in the conventional theft monitoring device, it is possible to detect the occurrence of an abnormality in any of the plurality of sensors 1, but it is not possible to individually recognize the sensor 1 in which the abnormality has occurred. Because it was a structure,
In order to find a stolen article, all articles must be checked, and the check operation is extremely complicated.

Therefore, the present invention solves such a problem,
An object of the present invention is to provide a theft monitoring device that can immediately recognize a stolen article even if the number of sensors is large.

[0007]

As a first means for solving the above-mentioned problems, the present invention provides a series of a plurality of sensors for outputting a detection signal when detached from an article, a circuit element and a switch means. A plurality of repeaters each having a connected connection pair, and a main body having a power supply and a detection unit, wherein the electrical constants of the circuit elements are different for each of the repeaters, and the connection pair of the plurality of repeaters is connected to the main body. Connected in parallel to the power supply, and outputs the detection signals of the plurality of sensors to the switch means so as to open and close the switch means. The detection means detects an electric signal introduced into the main body. The configuration was adopted.

[0008] As a second means for solving the above-mentioned problems, the present invention provides a plurality of repeaters each having a connection pair in which the circuit element and the switch means are connected in parallel. Are connected in series to the power source of the main body.

According to a first aspect of the present invention, there is provided the present invention, wherein the circuit element is an electric resistor;
The switch means is a field effect transistor, and is configured to apply a constant voltage to the connection pair.

Further, according to a second means for solving the above-mentioned problems, the present invention provides the above-mentioned, wherein the circuit element is an electric resistor;
The switch means is a field effect transistor, and a constant current is supplied to the connection pair by a constant current circuit.

Further, a first and a second means for solving the above-mentioned problems.
(2) An LED corresponding to a plurality of the sensors according to (2).
Is provided in the repeater, and is turned on in response to the output of the detection signals of the plurality of sensors.

Still further, in the first and second means for solving the above-mentioned problems, the detecting means converts the electric signal to be repeatedly detected into a digital code signal, and the detected initial electric signal is a digital code signal. A first memory that is converted and recorded by the means, and a digital code signal obtained by converting the detected electric signal by the means is the first memory.
The second memory for recording the digital code signal when the recording is different from the recording in the memory, and the presence / absence of a difference between the recording in the first and second memories by converting the electrical signal to be repeatedly detected by the means by the means. A comparing and judging circuit for judging whether there is a difference between the recording of the first memory and the digital code signal obtained by converting the detected electric signal by the means, and Is recorded in the second memory, and when it is determined that there is no difference between the plurality of code signals obtained by converting the plurality of detected electric signals by the means and the recording of the second memory, the second It is configured to output the record of the memory.

As a third means for solving the above-mentioned problem, a constant current circuit of the plurality of repeaters set to different current values is used instead of the circuit element in the first means. May be.

Similarly, as a fourth means for solving the above-mentioned problem, in place of the circuit element and the switch means in the first means, conduction / interruption is controlled by the detection signal, and a plurality of relays are provided. It is also possible to use constant current circuits set to different current values in the device.

[0015]

According to the first and second means,
When the sensor separates from the article, the electric signal introduced into the main body changes, and the change is detected by the detecting means.
The repeater having the switch means opened and closed can be specified.

In the first and second means, the present invention provides a circuit element comprising an electric resistor, a switch means comprising a field effect transistor, applying a constant voltage to a connected pair, or using a constant current circuit. By passing a constant current,
A repeater having the field-effect transistor turned on and off can be specified.

In the first and second means, an LED corresponding to a plurality of the sensors is provided on the repeater, and is turned on in response to the output of a detection signal from the plurality of sensors, so that the object of the theft monitoring is monitored. The sensor from which the article has been detached can be specified.

Further, in the first and second means, the detecting means converts the electric signal to be repeatedly detected into a digital code signal, and the detected initial electric signal is converted and recorded by the means. A first memory for storing a digital code signal when the digital code signal obtained by converting the detected electrical signal by the means is different from the recording of the first memory;
A comparing and judging circuit for converting the electric signal to be repeatedly detected by the means and comparing and judging whether or not there is a difference from the recording in the first and second memories; It is determined whether the recorded and detected electric signal has a difference from the digital code signal converted by the means, and the digital code signal is recorded in the second memory. When it is determined that there is no difference between the plurality of code signals converted by the means and the record in the second memory, the record in the second memory is output, so that the signal can be reliably opened and closed without being affected by noise. The repeater having the switch means can be specified.

According to the third and fourth means, since a constant current circuit is used for each repeater, a predetermined signal is not output to the main body due to a voltage drop due to a wiring resistance to the repeater, for example. , The fear of disappearing.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a theft monitoring apparatus according to a first embodiment of the present invention. The first embodiment will be described. The main body 7 includes a power source 8, a switch 9, and an electric device built in a repeater. The voltage applied to the resistor is kept constant (5 V), and the negative voltage type CMOS three-terminal regulator 10 which hardly consumes its own power, the reference electric resistance 11 of 10 KΩ, the buzzer 1
2. An A / D converter 14 that reads a voltage value applied to the display device 13 and the reference electric resistance 11, converts the value to a binary digital value, and outputs the voltage value output from the A / D converter 14. Control circuit 1 for controlling the operation of buzzer 12 and display device 13 in accordance with the voltage value
5, a connector 16 and a ground 17 are provided. Also,
The control circuit 15 includes first and second memories 18 and 19 for recording the voltage value input from the A / D converter 14,
A comparison / determination circuit 20 is provided for comparing a voltage value input from the converter 14 with a value recorded in the first or second memory 18 or 19 and determining the difference.

One terminal 16a of the connector 16 is
The positive electrode of the power supply 8 is output via the switch 9. One terminal 16 b of the connector 16 is connected to the negative electrode of the external power supply 8 via the CMOS three-terminal regulator 10 and the reference electric resistance 11. One terminal 16 c of the connector 16 is connected to the ground 17. further,
The A / D converter 14 is connected to both ends of the reference electric resistance 11, and measures a voltage value applied to the reference electric resistance 11. Further, the A / D converter 14 includes the control circuit 1
5, and the control circuit 15 is connected to the buzzer 12 and the display device 13.

Each of the sensors 21 to 29 has a phototransistor, and each of the products 30a to 32a, 34a to 36a, 38a to
Cardboard boxes 30-32, 34-3 containing 40a
The phototransistor portion is pierced into 6, 38 to 40, and is installed so as to correspond to each product. When an external light is detected by being pulled out, a signal is output.

Each of the repeaters 42, 43, and 44 has 10
KΩ electric resistance 45, 20KΩ electric resistance 46, 40K
Ω electric resistance 47, a field effect transistor (hereinafter FE)
(Abbreviated as T) 48, 49, 50, a detection circuit 51 that receives output signals from the sensors 21, 22, 23 and turns off the FET 48, and receives an output signal from the sensors 24, 25, and 26 and turns off the FET 49. Detection circuit 52, sensor 2
A detection circuit 53 is provided for receiving the output signals from 7, 28 and 29 and turning off the FET 50.

The repeater 42 includes connectors 54, 5
5, comprising lead wires 56, 57, 58;
The terminals 54a, 54 of the connector 54 are
b, 54c and the terminals 55a, 55b, 5 of the connector 55.
5c are connected. And again, repeater 4
3 and 44 are also connectors 59 and 60 and connector 6 respectively.
4, 65, and leads 61, 62, 63, and leads 66, 67, 68. Like the repeater 42, each terminal 59a, 59b, 59c of the connector 59 and each terminal 60a, 60b of the connector 60. , 60c, and the terminals 64a, 64b, 64c of the connector 64 and the terminals 65a, 65b, 65c of the connector 65, respectively.
1, 62, 63 and lead wires 66, 67, 68, and further, terminals 65a, 65 of the connector 65.
“b” connects the lead wires 66 and 67.

In the repeater 42, the electric resistance 45
One end 45a and the other end 45b are respectively connected to the lead wire 56 at one end 45a and the source 48a of the FET 48 at the other end 45b.
And the drain 48 b of the FET 48 is connected to the lead wire 57. The detection circuit 51 of the repeater 42 includes lead wires 56 and 58, and a gate 48 of the FET 48.
c.

In the repeaters 43 and 44, similarly to the repeater 42, one end 46a and the other end 46b of the electric resistance 46 and one end 47a and the other end 47b of the electric resistance 47 are connected to the lead wire 61 and the FET 49, respectively. Source 49a,
The lead 66 is connected to the source 50a of the FET 50, and the drains 49b, 50b of the FETs 49, 50 are connected to the leads 62, 67, respectively. The detection circuits 52 and 53 of the repeaters 43 and 44 are connected to the lead wires 61 and 63, the lead wires 66 and 68, and the FET 49, respectively.
Of the FET 50 and the gate 50c of the FET 50.

Further, in the repeater 42, the sensors 21, 22, 23 are connected to the detection circuit 51, and the terminals 54a, 54b, 54c of the connector 54 are connected to the terminals 16a of the connector 16 of the main body 7, respectively. , 16
b, 16c.

In the repeaters 43 and 44, the sensors 24 and 2 are connected to the detection circuits 52 and 53, respectively.
5, 26, sensors 27, 28, 29 are connected, and terminals 59a, 59b, 59c of connector 59,
The terminals 64a, 64b, 64c of the connector 64 are connected to the terminals 55a, 55, 55 of the connector 55 of the repeater 42, respectively.
b, 55c, each terminal 60 of the connector 60 of the repeater 43
a, 60b, and 60c.

When the switch 9 is turned on, the power supply 8
From the gates 48c, 49c, of the FETs 48, 49, 50 via detection circuits 51, 52, 53, respectively.
It takes 50c to turn on the FETs 48, 49 and 50. Further, an electric resistance 45-FET48,
Electric resistance 46-FET49, electric resistance 47-FET50
Are connected in parallel, the electric resistance 4
The total current flowing through 5, 46, 47
It enters the MOS three-terminal regulator 10 (a current flows from the output side because this regulator is a negative voltage type). However, since the CMOS type hardly consumes current,
The current flows through the reference electric resistance 11 almost as it is.

Next, the operation of the theft monitoring device according to the first embodiment of the present invention will be described with reference to FIG. 2 (the numbers in parentheses are numbers in FIG. 2). First, when the switch 9 is turned on, the A / D converter 14 reads the initial value of the voltage applied to the reference electric resistance 11 of the main body 7,
It is converted into a digital code signal (step 101).
The A / D converter 14 outputs the digital code signal to the control circuit 15. The control circuit 15 records the digital code signal output from the A / D converter 14 in the first memory 18 built in the control circuit 15 (Step 102). Further, the A / D converter 14 reads a voltage value applied between the reference electric resistances 11 every 25 μsec and converts the voltage value into a digital code signal (step 10).
3) The digital code signal is output to the control circuit 15. The comparison and determination circuit 20 compares the output digital code signal with the digital code signal recorded in the first memory 18 to determine the presence or absence of a difference (step 104), and determines that there is no difference. In case, A one after another
The digital code signal output from the / D converter 14 is compared with the digital code signal recorded in the first memory 18 to repeatedly determine whether there is a difference (step 104). If it is determined that there is a difference, the comparison / determination circuit 20 records the digital code signal output from the A / D converter 14 having the difference in the second memory 19 (step 105). Although not shown, it is recorded that there is one difference in the counter built in the comparison and judgment circuit 20 (step 106).
The comparison / determination circuit 20 further converts the A / D converter 14 into a digital code signal one after another (step 10).
7) The output voltage value is compared with a digital code signal recorded in the second memory 19 to determine whether there is a difference (step 108). If the comparison / determination circuit 20 determines that there is a difference, the process immediately returns to the original process (step 103) of reading the voltage value and converting it into a digital code signal. When the comparison / judgment circuit 20 judges that there is no difference, the counter incorporated in the comparison / judgment circuit 20 counts the number of times that there is no difference (step 110), and the A / D converter 14 successively outputs digital signals. Is compared with the digital code signal recorded in the second memory 19 to determine whether there is a difference (step 108). When it is determined that there is no difference 16 times in a row (step 109), the buzzer 12 is sounded immediately (step 111). Therefore, it is possible to prevent a malfunction of the main body 7 when the voltage value applied to the reference electric resistance 11 changes instantaneously due to noise or the like.

Any one of the sensors 21 to 29 can be removed from the cardboard boxes 30 to 32, 34 to 36, 38 to 40, or the cardboard boxes 30 to 32, 34 to 36, 3
When 8 to 40 are broken, at least one of the sensors 21 to 29 detects the abnormality and outputs a signal to the detection circuits 51, 52, 53 corresponding to each sensor.

The detection circuits 51, 52, and 53 that have received the signals output from the sensors are FETs corresponding to the detection circuits.
The application of voltage to the gates 48c, 49c, 50c of 48, 49, 50 is stopped. Thus, the FETs 48, 49, and 50 corresponding to the detection circuit are turned off. And each F
When the current stops flowing through the electric resistances 45, 46 and 47 corresponding to ET, the value of the current flowing through the electric resistance 11 of the main body 7 changes, and the voltage value applied to the reference electric resistance 11 changes. Although not shown, the repeaters 42, 43,
The LED 44 is provided with an LED corresponding to each sensor, and is turned on when the sensor detects an abnormality.

The A / D converter 14 reads the change in the voltage value applied to the reference electric resistance 11 and the control circuit 15
The navel value is converted into a digital code signal and output.
That is, the A / D converter 14 includes the electric resistances 45, 4
When current flows through all 6, 47, a voltage of 8.75 V is applied to reference electric resistance 11, and a code signal (111) corresponding to this voltage value is output. When the current stops flowing to any one of the electric resistances 45, 46, and 47, the voltages applied to the reference electric resistance 11 are 3.75 V, 6.25 V, and 7.5 V, respectively, and correspond to the respective voltage values. Code signals (011), (101),
(110) is output. Further, the electric resistances 45 and 46, the electric resistances 46 and 47, and the electric resistances 45 and 4
7, when the current stops flowing, the voltages applied to the reference electric resistance 11 are 1.25 V, 5 V, and 2.5 V, respectively, and the code signals (0
01), (100), and (010), and the electric resistance 4
When the current stops flowing to all 5, 46, 47,
The voltage applied to the reference electric resistance 11 is 0 V, and a code signal (000) is output. Control circuit 1
5 is a buzzer 1 which performs the above-described processing based on the digital code signal output from the A / D converter 14.
Sound 4 and identify the repeater that detected the abnormality,
It is displayed on the display device 15. That is, the electric resistance 4
5, 46 and 47 have different electric resistance values, so that the change in the voltage value applied to the reference electric resistance 11 corresponds to the electric resistance at which the current stops flowing, and specifies the repeater to which the sensor that has detected the abnormality is connected. be able to. Further, the relay is provided with an LED that is turned on when the sensor detects an abnormality, so that a stolen article can be specified.

Here, each voltage value applied to the reference electric resistance 11 is generated by a voltage drop based on the current supplied by the electric resistances 45 to 47 in each repeater. Therefore, as shown in FIG.
Instead of 5 to 47, a constant current circuit 70 set to a different current value in each repeater is prepared, and the same is obtained even when the current is directly supplied. The same result is obtained by using a constant current circuit set to a current value of 0.5 mA for the repeater 42x, 0.25 mA for the repeater 43x, and 0.125 mA for the repeater 44x. Further, the CMOS three-terminal regulator 10 of the main body 7 is unnecessary. According to the above configuration, the main body 7 and the repeater 42
Even if the distance between x and 44x is large and the resistance of the connection line cannot be ignored, a predetermined current is supplied.
It has an excellent effect of being hardly affected. Therefore, it is possible to improve the reliability of repeatedly stepping on the wiring,
The restriction on the distance to the repeater can be relaxed, and as a result, the theft monitoring device according to the present invention can be applied to a larger store.

Furthermore, if a constant current circuit is used, as shown in FIG. 4, a constant current circuit 80 capable of controlling conduction / interruption is used in the repeaters 42y to 44y, and a detection signal is directly sent to the constant current circuit 80. What is necessary is just to apply. The constant current circuit 80 has a control terminal 81. When the control terminal 81 is high, the circuit operates, and a set current flows from the power supply 8 (FIG. 1) to the CMOS three-terminal regulator 10 ( Conduction),
If it is low, no current flows (interruption). This constant current circuit 80
According to this, the detection circuits 51 to 53 may be the same as those in the embodiment using the electric resistance, and do not need to be modified (turned off when the sensor is operated, that is, turned off). In this case, (of FIG. 1)
Needless to say, it is not necessary to separately provide switching means such as the FETs 48 to 50. Note that the constant current circuit 70,
The configuration of 80 can use an OP amplifier, discrete components, a three-terminal regulator, a dedicated IC, or the like.

Next, a second embodiment of the present invention is shown in FIG.
In this theft monitoring device, a constant current circuit 69 for keeping the current flowing through the repeaters 42z to 44z constant is provided in the main body 7, and the electric resistances 45, FET48, and the electric resistances provided in the repeaters 42z to 44z, respectively. 46, FET4
9, each connection pair of the electric resistance 47 and the FET 50 is connected to the lead wire 57a, 57b and the lead wire 62, respectively.
a, 62b and the lead wire 67 are connected in parallel via 67a, 67b, so that when the FET corresponding to the sensor that has detected the abnormality is turned off, all the current flows through the electric resistance connected in parallel with the FET. As a result, the current value flowing through the reference electric resistance 11 of the main body 7 changes, and the voltage value applied to the reference electric resistance 11 changes, so that it is possible to identify the repeater to which the sensor that has detected the abnormality is connected.

When the connection between the repeaters is cut off, in the first embodiment, it is found that the repeater has become abnormal in the main body 7, but in the second embodiment, all the main bodies 7 The first embodiment is more preferable than the second embodiment in order to promptly return to the normal state and monitor theft because the repeater informs that the relay is abnormal.

In the first and second embodiments, three sensors are provided for one repeater, and three repeaters are provided.
Although two or four or more sensors are provided for one repeater, and two or four or more repeaters are provided for one repeater.

In the first and second embodiments, the repeater has been described using a connection pair of an electric resistor and an FET. However, the present invention is not limited to this. For example, a circuit element such as a capacitor or a coil may be used instead of the electric resistor. In addition, switch means such as a relay may be used instead of the FET. At that time, it is necessary to make the electric constant of the circuit element different for each repeater.

In the first and second embodiments, when the sensor detects an abnormality, the FET is turned off (open) as the switch means. However, it is also possible to turn on (close) the FET.

Further, in the first and second embodiments, only the battery circuit is built in the main body 7. However, when operating with an external power source, the supply of the external power source is cut off. In this case, the buzzer 12 may be operated by providing another internal battery circuit.

The active repeater may be displayed blinking on the display device 13 provided on the main body 7. In this case, it is possible to give the thief an impression that the theft monitoring device is operating. Yes, it is effective for theft surveillance.

Also, by enabling a switch provided on the main body 7 to be turned on / off by a remote controller,
Operability can be improved.

Further, by making the main body 7 record the date and time when the sensor detects an abnormality, it is possible to use the countermeasure against theft.

[0046]

As described above, according to the present invention, the switch means provided in the repeater corresponding to the sensor is opened and closed by the detection signal output when the sensor is detached from the article, and the switch is provided for each of the repeaters. The electric signal introduced into the main body is changed by making the electric constants different from each other, and preventing or allowing the current to flow through the circuit elements constituting the connection pair by connecting the switch means in series or parallel. Since the change is detected by the detection means provided in the main body, the repeater having the switch means opened and closed when the sensor separates from the article can be specified.

Further, the circuit element is an electric resistor, the switch means is a field effect transistor, and a constant voltage is applied to the connection pair in which these are connected in series.
A constant current circuit is used to supply a constant current to the connection pair in which these are connected in parallel, and the electric field is opened and closed by detecting a change in the voltage applied thereto as the electric signal and detecting the change by the detection means. A repeater having an effect transistor can be specified.

Alternatively, by using a constant current circuit instead of the circuit element, it is possible to prevent the influence of the wiring resistance to the repeater. Therefore, it is possible to improve the reliability of repeatedly stepping on the wiring and to reduce the restriction on the distance to the repeater. As a result, the theft monitoring device according to the present invention can be applied to a larger store. Furthermore, conduction /
If a constant current circuit whose cutoff can be controlled is used, it is not necessary to separately provide the switch means such as a field effect transistor.

Also, LEDs corresponding to the plurality of sensors
Is provided in the repeater, and the LED is turned on in response to the output of the detection signals of the plurality of sensors, whereby the sensor from which the article has been detached can be specified.

Further, the detecting means converts the electric signal to be repeatedly detected into a digital code signal,
A first memory in which the detected initial electric signal is converted and recorded by the means; and a digital memory in which the detected electric signal is converted by the means when the digital code signal is different from the recording in the first memory. A second memory for recording a digital code signal; and a comparison / determination circuit for converting an electrical signal to be repeatedly detected by the means and comparing and judging whether or not there is a difference from the recording in the first and second memories. The comparing and judging circuit judges whether there is a difference between the recording in the first memory and the detected electric signal from the digital code signal converted by the means, and converts the digital code signal into a second code signal. When it is determined in the memory that there is no difference between the plurality of code signals obtained by converting the plurality of detected electrical signals by the means and the recording of the second memory, By outputting the record, it is possible to identify the repeater having a year switching means which is securely opened and closed without being affected by noise.

As a result, it is possible to provide a theft monitoring device capable of immediately recognizing a stolen article even if the number of sensors is large.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of a theft monitoring device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation flow of the first and second embodiments of the present invention.

FIG. 3 is a main part circuit diagram according to a first modification of the first embodiment of the present invention.

FIG. 4 is a main part circuit diagram according to a second modification of the first embodiment of the present invention.

FIG. 5 is a schematic circuit diagram of a theft monitoring device according to a second embodiment of the present invention.

FIG. 6 is a schematic circuit diagram of a theft monitoring device according to a conventional example.

7A and 7B are schematic enlarged views of a sensor of a theft monitoring device according to a conventional example, in which FIG. 7A is disposed together with an article, and FIG. 7B is a view separated from the article.

[Explanation of symbols]

 7 Body 11 Reference resistance 12 Buzzer 13 Display device 14 A / D converter 15 Control circuit 18 First memory 19 Second memory 20 Comparison judgment circuit 21-29 Sensors 30-32, 34-36, 38-40 Cardboard box 42 -44 repeater 45-47 electric resistance 48-50 field-effect transistor 51-53 detection circuit 69 constant current circuit of the second embodiment

Continuation of front page (56) References JP-A-4-2422893 (JP, A) JP-A-5-31428 (JP, U) JP-A-63-122892 (JP, U) JP-A-4-55695 (JP) , U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G08B 13/00-15/02

Claims (8)

(57) [Claims] 1. A sensor comprising: a plurality of sensors for outputting a detection signal when detached from an article; a plurality of repeaters having a connection pair in which circuit elements and switch means are connected in series; and a main body having a power supply and a detection means. The electrical constants of the circuit elements are different for each of the repeaters, the connecting pairs of the plurality of repeaters are connected in parallel to the power supply of the main body, and the outputs of the detection signals of the plurality of sensors are connected to the switch. A burglar alarm device, wherein the switch device is opened and closed, and the detecting device detects an electric signal from a repeater introduced into the main body. 2. A sensor comprising: a plurality of sensors for outputting a detection signal when detached from an article; a plurality of repeaters having a connection pair in which circuit elements and switch means are connected in parallel; and a main body having a power supply and a detection means. The electrical constants of the circuit elements are different for each of the repeaters, the connection pairs of the plurality of repeaters are connected in series to the power supply of the main body, and the outputs of the detection signals of the plurality of sensors are connected to the switch. A burglar alarm device, wherein the switch device is opened and closed, and the detecting device detects an electric signal from a repeater introduced into the main body. 3. The theft according to claim 2, wherein said circuit element is an electric resistor, said switch means is a field effect transistor, and a constant current is applied to said connection pair by a constant current circuit. Monitoring device. 4. The theft monitoring device according to claim 1, wherein said circuit element is an electric resistor, said switch means is a field effect transistor, and a constant voltage is applied to said connection pair. 5. The relay according to claim 1, wherein LEDs corresponding to the plurality of sensors are provided on the repeater, and are turned on in response to detection signals output from the plurality of sensors.
5. The theft monitoring device according to 2, 3, or 4. 6. The detecting means includes means for converting an electrical signal to be repeatedly detected into a digital code signal, a first memory in which the detected initial electrical signal is converted and recorded by the means, and A second memory for recording the digital code signal when the digital code signal whose electric signal is converted by the means is different from the recording in the first memory; and an electric signal which is repeatedly detected by the means. A comparison / determination circuit for comparing the presence / absence of the difference between the recording of the first memory and the recording of the first memory. Determining whether there is a difference from the detected digital code signal, and recording the digital code signal in a second memory; 4. The method according to claim 1, wherein when it is determined that there is no difference between the plurality of code signals converted according to the above and the recording in the second memory, the recording in the second memory is output. 6. The theft monitoring device according to 4 or 5. 7. A plurality of sensors for outputting a detection signal when detached from an article, a plurality of repeaters having a connection pair in which a constant current circuit and switch means are connected in series, and a main body having a power supply and a detection means. The setting current value of the constant current circuit is different for each of the repeaters, the connection pair of the plurality of repeaters is connected in parallel to the power supply of the main body, and output of detection signals of the plurality of sensors is performed. Wherein the switch means is opened and closed to open and close the switch means, and the detection means detects an electric signal from a repeater introduced into the main body. 8. A system comprising: a plurality of sensors for outputting a detection signal when detached from an article; a plurality of repeaters having a constant current circuit capable of controlling conduction / interruption; and a main body having a power supply and a detection means, The set current value of the constant current circuit is different for each of the repeaters, the constant current circuits of the plurality of repeaters are connected in parallel to the power supply of the main body, and the outputs of the detection signals of the plurality of sensors are output. A theft monitoring device characterized in that the constant current circuit is led to a constant current circuit so as to conduct / cut off the constant current circuit, and the detection means detects an electric signal from a repeater introduced into the main body. .