JP3114686U - Security device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably detect and report various illegal intrusion activities such as a bypass act and an unreasonable removal act as well as an act of cutting a cord-like member (barbed wire etc.) for preventing intrusion, To provide a crime prevention device with enhanced threat, repulse, and deterrent effects against illegal intrusion.
SOLUTION: Conductive barbed wire 3 for preventing intrusion, barbed wire 3 and covered electric wires 5, 6
, 8 is connected to a DC stabilized power supply circuit 12 for applying a predetermined voltage to an electric circuit formed, a resistance detecting device 13 for detecting a change in resistance value of the electric circuit, and an intrusion action is reported. The alarm device 18 and the illumination device 23 for detecting the change of the resistance value by the resistance detection device 13 and the detection holding relay 17 for driving the alarm device 18 and the illumination device 23 are provided.
[Selection] Figure 1

Description

The present invention relates to a crime prevention device, and more particularly, to a crime prevention device using a cord-like member such as a barbed wire provided for preventing intrusion.

Conventionally, fences with barbed wires are used as a crime prevention means for preventing illegal intrusion into private land or facilities. A fence with a barbed wire stretched gives a visually robust impression, but can be cut relatively easily with a tool such as pliers. On the other hand, no defensive measures were taken and it could not be said that the crime prevention effect was high.

In order to solve such a problem, in Patent Document 1 below, when a current is passed through a core wire of a barbed wire, the core wire of the barbed wire is cut when the barbed wire is cut. A barbed fence configured to detect that the flowing current is interrupted and to drive an alarm is disclosed.

However, in the barbed wire fence described in Patent Document 1, an intruder prepares another electric wire for bypass so that current flows even if the barbed wire is cut, and bypasses the barbed wire with the electric wire. When the barbed wire beyond the bypass point is disconnected from the power source, the current flowing through the core wire of the barbed wire is not interrupted by the bypassed wire, so it is impossible to detect that the barbed wire has been disconnected. There was a problem of being able to escape the detection of intrusion.

Further, in the barbed wire fence described in Patent Document 1, even if an intruder tries to remove the barbed wire and forcibly pulls it, the alarm device is not driven unless the barbed wire is cut. There was a problem that it was not possible to detect illegal intrusion other than the above.
JP-A-5-287940

Means for solving the problems and their effects

The present invention has been made in view of the above problems, and various illegal intrusions such as a bypass act using another electric wire or an unreasonable removal act as well as an act of cutting a cord-like member provided for preventing intrusion. It is an object of the present invention to provide a crime prevention device capable of detecting and reporting an action reliably and enhancing the effect of preventing illegal intrusion.

In order to achieve the above object, a crime prevention device (1) according to the present invention includes a cable member having conductivity for preventing intrusion and an electric circuit formed by connecting the cable member and an electric wire to a predetermined circuit. A change in resistance value is detected by a power source for applying a voltage, a resistance value detecting means for detecting a change in resistance value of the electric circuit, an alarm means for informing an intrusion action, and the resistance value detecting means. And an alarm driving means for driving the alarm means.

According to the security device (1), the cord-like member is configured as a part of an electric circuit, and a change in the resistance value of the electric circuit is detected by the resistance value detecting means. Therefore, an action in which the resistance value of the electric circuit changes, that is, a bypass action using not only the cutting action of the cord-like member and the electric wire but also another electric wire for evading the detection of the cutting action Can also be detected. Further, the alarm means is driven based on the detection to threaten and repel intruders, and it is possible to provide a crime prevention device that is highly effective in suppressing illegal intrusions with a simple configuration.

Moreover, the security device (2) according to the present invention can be detected in the security device (1) even when the resistance value detecting means is in a state where application of voltage from the power source to the electrical circuit is interrupted,
The alarm driving unit is configured to drive the alarm unit when the resistance value detecting unit detects a state in which application of voltage from the power source to the electric circuit is cut off.

According to the crime prevention device (2), even when the application of voltage from the power source to the electric circuit is interrupted due to an accident such as a lightning strike or an illegal act of an intruder, the alarm means is driven. Therefore, it is possible to enhance the effect of suppressing illegal intrusion at the time of a power failure.

Moreover, the crime prevention device (3) according to the present invention is the above-described crime prevention device (1) or (2), wherein the cord-like member and / or the electric wire is provided with contact opening / closing means, and the contact opening / closing means is It is characterized by being arranged so that the connection state of the electric circuit changes when a tension of a predetermined value or more is applied to the cord-like member or the electric wire.

According to the security device (3), for example, the contact opening / closing means changes the connection state of the electric circuit when a tension of a predetermined value or more is applied to the cord-like member or the electric wire. Since the electric circuit is opened or arranged so as to be switched to a closed circuit not through the cord-like member, when a tension of a predetermined value or more is applied to the cord-like member or the electric wire, Changes in the resistance value of the electric circuit occur (for example, when the electric circuit is opened, the resistance value becomes infinite, or when the circuit is switched to a closed circuit without the cord-like member, the resistance value (Because the value becomes smaller), it is possible to detect the act of forcibly moving or carelessly moving the cord-like member and the electric wire, detecting various intrusion actions, To raise further Can. It should be noted that the location and number of the contact opening / closing means can be arbitrarily set, and various intrusion acts can be detected by devising the arrangement location.

Moreover, the security device (4) according to the present invention is based on the detection output of the resistance value change output from the resistance value detection means by the alarm driving means in any one of the security devices (1) to (3). The driving and holding means for holding the state for driving the alarm means until the resetting is performed.

According to the crime prevention device (4), the drive holding means holds the state of driving the alarm means until reset based on the detection output of the resistance value change output from the resistance value detection means. Therefore, the alarm means can be driven until it is reset by an administrator or the like (that is, until the operation for canceling the drive state of the alarm means is performed), and the threat to the intruder and the repelling effect can be enhanced.

Moreover, the security device (5) according to the present invention includes an auxiliary power source capable of storing electricity in any one of the security devices (1) to (4), so that driving power is supplied from the auxiliary power source to the alarm means. It is characterized by being configured.

According to the security device (5), since the driving power is supplied from the auxiliary power source to the alarm means, even when the power supplied from the outside such as a commercial power source is cut off after the intrusion The alarm means can be continuously driven by the electric power supplied from the auxiliary power source.

Moreover, the security device (6) according to the present invention is configured such that, in the security device (5), the imaging means can be connected, and driving power is supplied from the auxiliary power source to the imaging means. It is characterized by.

According to the crime prevention device (6), since the driving power is supplied from the auxiliary power source to the imaging means, the power supplied from the outside such as a commercial power source may cause an accident such as a lightning strike or intrusion. Even if it is cut off by an illegal act of the person, the image pickup means can be driven by the electric power supplied from the auxiliary power source, and it is possible to record the entire invasion act as a video or an image.

Moreover, the crime prevention device (7) according to the present invention is configured such that, in any one of the crime prevention devices (1) to (6), the cord-like member has a different resistance value for each unit length. It is characterized by that.

According to the crime prevention device (7), since the cord-like member is configured to have a different resistance value for each unit length, an intruder can resist resistance per unit length of the cord-like member. Measure the value,
Even when trying to perform a bypass action with an electric wire prepared on the basis of the resistance value, the resistance value for each unit length of the cord-like member is different. The illegal intrusion due to the action can be almost completely prevented, and the effect of preventing the illegal intrusion can be further enhanced.

Moreover, the security device (8) according to the present invention is characterized in that, in any of the security devices (1) to (7), the cord-like member is a barbed wire.
According to the crime prevention device (8), since the cord-like member is a barbed wire, a visually robust impression can be given, and the effect of deterring entry can be enhanced psychologically.

Embodiments of a security device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a security device according to the embodiment.
In the figure, reference numeral 1 denotes a fence provided in a boundary area (security area) such as private land or facilities. A support column 2 is erected on the upper surface of the fence 1 at a predetermined interval. A barbed wire 3 wound in a coil shape is stretched. The barbed wire 3 is attached in a state of being supported by the support 2 via an insulating device 4 provided on the support 2. Further, in another embodiment, the barbed wire 3 may be wound around and attached to a support made of non-conductive synthetic resin or the like without using the insulating device 4. The barbed wire 3 is attached so as to be insulated from the fence 1 and the column 2.

The barbed wire 3 may be a general wire formed using iron wire (main wire and barbed wire) plated with lead, zinc, aluminum or the like. It is preferable to use one formed so that the resistance value for each length is different. Examples of the material for forming the barbed wire 3 include alloys made by adding various elements having different resistance values so as to have non-uniform concentrations. A uniform material that has been processed so as to have a non-uniform cross-sectional area may be used.

Moreover, the one end side 3a of the barbed wire 3 is connected to the covered electric wire 5 covered with a non-conductive synthetic resin or the like, and the covered electric wire 5 is connected to the connection terminal 11a of the control box 10 installed in the site. Has been. Further, the other end side 3b of the barbed wire 3 is connected to one end of the covered electric wire 6, and the covered electric wire 6
The other end of the switch is connected to the COM terminal of the switch element 7 attached to the column 2. In FIG. 1, the covered electric wire 6 is arranged in a state of being laid over the fence 1. However, in another embodiment, the covered electric wire 6 is passed through the hollow portion of the barbed wire 3 or the barbed wire is used. 3 may be disposed in a state of being wound around.

The switch element 7 has a lever 7a, a plunger 7b, a movable piece 7c, a COM terminal, an NC terminal, and a NO terminal, that is, a minute contact interval and a snap action mechanism, and is defined as a prescribed movement. A micro switch with a contact mechanism that opens and closes in a case is housed in the case. When the tension | tensile_strength more than predetermined value is applied to the covered electric wire 9 stretched between the support | pillar 2 through the hollow part of the barbed wire 3, the switch element 7 has the spring member 9a connected with the covered electric wire 9. The thread member 9b connected to the covered wire 9 and the lever 7a is pulled, the lever 7a is actuated, the plunger 7b is pushed into the inside, and the movable piece 7c is N
It is arranged so that the contact is opened by switching from the C terminal to the NO terminal. In addition, in FIG. 1, although the end of the covered electric wire 9 is attached to the support | pillar 2, in another embodiment,
One end of the covered electric wire 9 can be attached to the barbed wire 3 or the covered electric wire 6. According to such a configuration, when the barbed wire 3 or the covered electric wire 6 is pulled by an intruder or the like, The contact can be opened.

In addition, a covered electric wire 8 is connected to the NC terminal of the switch element 7, and the covered electric wire 8 is connected to the connection terminal 11 b of the control box 10. A series circuit is formed including these covered wire 5, barbed wire 3, covered wire 6, switch element 7, and covered wire 8.

In the control box 10, a resistance detection device 13 for detecting a change in the resistance value of the series circuit including the barbed wire 3 is connected between the connection terminals 11a and 11b. The resistance detection device 13 includes an AC power source ( A DC stabilized power supply circuit 12 for converting AC100V) 20 into a stable DC power supply (DC12V) is connected.

Further, in the control box 10, a charger 14 configured to rectify an AC power source (AC100) 20 to a required DC voltage and obtain a required charging current is connected to a 12V battery 15. The battery 15 includes an alarm device 18 that emits an alarm sound via the reset switch 16 and the detection holding relay 17, and an illumination light that illuminates an intruder or the like via the covered electric wire 22 connected to the external output terminal 21a. Is connected to a lighting device 23 including a rotating lamp for informing the surroundings.

Further, the battery 15 is also connected to an imaging device 25 having an image recording function via a covered electric wire 24 connected to the external output terminal 21b, and from the battery 15 to the alarm device 18, the illumination device 23, and the imaging device. 25 is configured to be supplied with driving power.

The resistance detection device 13 detects the resistance value of the series circuit including the barbed wire 3 and compares the preset reference resistance value with the detected resistance value of the series circuit, thereby detecting the detected series circuit. When the resistance value is outside the range of the reference resistance value (that is, the resistance value of the series circuit is changed), a detection output for turning on the detection holding relay 17 is performed.

That is, the electromagnetic coil (not shown) constituting the detection holding relay 17 and the battery 15 +
A detection output SW (not shown) interposed between the two terminals is turned on to pass a current through the electromagnetic coil, and two circuits and two contacts connected via the positive terminal of the battery 15 and the reset switch 16 Alarm switch 1 connected to the relay switch (not shown) is turned ON
8. Driving power is supplied to the lighting device 23. The reference resistance value in the resistance detection device 13 can be adjusted in consideration of factors that affect the resistance value of the series circuit, such as the length of the barbed wire 3.

In the detection holding relay 17, when the relay is turned on by the detection output output from the resistance detection device 13, the detection holding relay 17 holds the closed state until it is reset by the reset switch 16 and is connected to the detection holding relay 17. And the lighting device 23 are driven, and the alarm device 18 and the lighting device 23 are driven when the relay is turned on, or the switches of the alarm device 18 and the lighting device 23 are set to a predetermined state when the relay is turned on. It can be configured to turn on after time.

Further, between the DC stabilized power supply circuit 12 and the resistance detection device 13 and between the battery 15 and the reset switch 16, a two-circuit one-contact main power switch 1 that is normally closed.
9 is interposed. The control box 10 made of a metal box is locked,
Only the person who owns the key can unlock it, and the intruder cannot operate the reset switch 16 or the main power switch 19.

Next, an intruder detection operation by the crime prevention device according to the embodiment will be described.
First, when either the barbed wire 3 or the covered electric wires 5, 6, 8 is cut by an intruder, the current flowing through the series circuit including the barbed wire 3 is cut off and detected by the resistance detection device 13. When the resistance value of the series circuit becomes infinite and the resistance detection device 13 detects that the resistance value of the series circuit is outside the reference resistance value range, a detection output for turning on the detection holding relay 17 is output. The detection holding relay 17 is turned on by the detection output, the alarm device 18 and the lighting device 23 are driven, and the intruder is threatened and repulsed by sound and light. In addition, the intruder's invasion action is recorded as a whole video by the imaging device 25.

Next, if the intruder bypasses a certain section of the barbed wire 3 with an electric wire prepared by the intruder in order to prevent the current flowing in the series circuit from becoming zero even if the barbed wire 3 is cut, it is bypassed. Since this section becomes a parallel circuit, the resistance value of the series circuit detected by the resistance detection device 13 decreases, and the resistance detection device 13 detects that the resistance value of the series circuit is out of the reference resistance value range. ,
A detection output for turning ON the detection holding relay 17 is output, and the detection holding relay 1 is output by the detection output.
7 is turned on, and the alarm device 18 and the illumination device 23 are driven in the same manner as described above.

If an intruder pulls up the barbed wire 3 and tries to move it forcibly, the barbed wire 3
The wire 9 passed through the hollow portion is pulled, and the movable piece 7c of the switch element 7 is switched from the NC terminal to the NO terminal, and the contact is opened. Therefore, barbed wire 3 or covered wire 5
, 6 and 8, the current flowing in the series circuit including the barbed wire 3 is cut off, and the resistance value of the series circuit detected by the resistance detection device 13 becomes infinite, The detection device 13 detects that the resistance value of the series circuit is out of the reference resistance value range, and outputs a detection output for turning on the detection holding relay 17, and the detection holding relay 17 is turned on by the detection output.
Then, the alarm device 18 and the lighting device 23 are driven.

Further, when the power supply from the AC power supply 20 is cut off, the power supply to the resistance detection device 13 is cut off, and no voltage is applied to the series circuit including the barbed wire 3.
Thus, the normal resistance value cannot be detected, and this state is detected by the resistance detection device 13, and a detection output for turning on the detection holding relay 17 is output. 18 and the lighting device 23 are driven.

According to the crime prevention device according to the above embodiment, the barbed wire 3 that is a cord-like member is configured as a part of the electric circuit, and a change in the resistance value of the electric circuit is detected by the resistance detection device 13. Therefore, an action in which the resistance value of the electric circuit is changed, that is, the barbed wire 3 and the covered electric wires 5, 6, 8
It is possible to detect not only the cutting action but also a bypass action using another electric wire for evading the detection of the cutting action.

In addition, when a tension greater than a predetermined value is applied to the covered electric wire 9 in an attempt to move the barbed wire 3,
The movable piece 7c of the switch element 7 is switched from the NC terminal to the NO terminal, the contact is opened,
Since the resistance value of the electric circuit changes to infinity, it is possible to detect the act of forcibly moving the barbed wire 3 and the act of covering the mat etc. to get over the barbed wire 3. Various intrusions by intruders can be detected.

Even when the application of voltage from the DC stabilized power supply circuit 12 to the electric circuit including the barbed wire 3 is interrupted by an accident such as a lightning strike or an illegal act of an intruder, the alarm device 18 or the lighting Since the notification is performed by driving the device 23, it is possible to enhance the effect of suppressing illegal intrusion at the time of power failure.

In addition, the detection holding relay 17 holds the state in which the alarm device 18 and the lighting device 23 are driven until reset by the reset switch 16 based on the detection output of the resistance value change output from the resistance detector 13. Until the administrator or the like unlocks the control box 10 and operates the reset switch 16, the alarm device 18 and the lighting device 23 can be driven, and the threat to the intruder and the repelling effect can be enhanced. It can be set as the crime prevention apparatus with a high effect which prevents an illegal invasion by structure.

Further, since the driving power is supplied from the battery 15 to the alarm device 18 and the lighting device 23, the power supplied from the outside such as the AC power source 20 is caused by illegal actions of the intruder after the intrusion. Even if it is cut off, the alarm device 18 and the lighting device 23 can be reliably driven by the power supplied from the battery 15.

In addition, since the driving power is supplied from the battery 15 to the imaging device 25, the power supplied from the outside such as the AC power supply 20 is cut off by an accident such as a lightning strike or an illegal act of an intruder. Even in such a case, it is possible to reliably drive the imaging device 25 with the power supplied from the battery 15, and it is possible to record the entire invasion action as a video or an image.

Moreover, since the barbed wire 3 is used as the cord-like member for preventing intrusion, a visually robust impression can be given, and the effect of deterring invasion can be enhanced psychologically. Also,
When the main wire of the barbed wire 3 is configured to have a different resistance value for each unit length, the intruder measures the resistance value per unit length of the barbed wire 3. Even if it is an attempt to perform a bypass action with an electric wire prepared based on the resistance value, since the resistance value for each unit length of the barbed wire 3 is different, it is extremely difficult to match the resistance value, The illegal intrusion due to the bypass action can be almost completely prevented, and the effect of preventing the illegal invasion can be further enhanced.

In the crime prevention device according to the above-described embodiment, the case where the barbed wire 3 wound in a coil shape is used has been described. However, the extending form of the barbed wire 3 is in an insulated state from a column, a fence, and the like. Any stretched form such as a meandering shape may be used as long as it is ensured. Moreover, it is applicable also to cable-like members other than barbed wire, for example, a wire. In addition, the barbed wire 3
It is also possible to use a structure that is colored, or to which a decoration made of a non-conductive synthetic resin or the like is attached. For example, as shown in FIG. A rose flower (artificial flower) 3 made of synthetic resin, etc.
d can also be configured to be attached to the barbed wire 3, and according to such a configuration, it is possible to achieve harmony with a private house, a housing complex, etc. without giving the impression that the barbed wire 3 is slaughtered, It can have aesthetics as an exterior.

In the crime prevention device according to the above embodiment, the switch element 7 is arranged so that the electric circuit is opened when a tension of a predetermined value or more is applied to the covered wire 9 by moving the barbed wire 3 or the like. However, in another embodiment, as shown in FIG. 3, the other end 3b of the barbed wire 3 is connected to one end of the covered electric wire 6a, and the other end of the covered electric wire 6a is formed of a microswitch. Connected to the NC terminal of the switch element 7A, one end of the covered wire 6b is connected to the COM terminal of the switch element 7A, the other end of the covered wire 6b is connected to the NC terminal of the switch element 7B, and the COM terminal of the switch element 7B The covered electric wire 8 is connected to the covered electric wire 6 and the covered electric wire 6 is connected to the covered electric wire 5.
The c may be connected to the NO terminal of the switch element 7A and the NO terminal of the switch element 7B.

According to such a circuit configuration, in a normal state, as shown in FIG. 3A, the covered electric wire 5, the barbed wire 3, the covered electric wire 6a, the NC terminal of the switch element 7A, the COM terminal, the covered electric wire 6b, A current flows through the NC terminal, the COM terminal, and the covered electric wire 8 of the switch element 7B. Then, as shown in FIG. 3 (b), when the covered wire 9 is pulled by an illegal intrusion action and the spring member 9a 'is extended, the thread member connected to the covered wire 9 and the lever 7a of the switch element 7A. 9b 'is pulled, the lever 7a of the switch element 7A is actuated, the plunger 7b is pushed into the inside, the movable piece 7c is switched from the NC terminal to the NO terminal, and the current paths are covered wire 5 and covered wire 6c. The switch is switched to the route of the switch terminal 7A NO terminal, COM terminal, covered wire 6b, switch element 7B NC terminal, COM terminal, and covered wire 8.

Further, as shown in FIG. 3C, when the covered wire 9 is pulled by an illegal intruding action and the spring member 9a is extended, the thread member connected to the covered wire 9 and the lever 7a of the switch element 7B. 9b is pulled, the lever 7a of the switch element 7B is actuated, the plunger 7b is pushed into the inside, the movable piece 7c is switched from the NC terminal to the NO terminal, and the current paths are covered wire 5, covered wire 6c, NO terminal, COM terminal of switch element 7B, and covered electric wire 8C
The current flows through the path of the switch element 7A, and tension is applied to the covered electric wire 9 to switch the element 7A.
Alternatively, when the movable piece 7c of the switch element 7B is switched from the NC terminal to the NO terminal, a closed circuit without the barbed wire 3 is formed, and the resistance value of the circuit changes (becomes smaller), and the resistance value changes. Can be detected by the resistance detection device 13.

Further, the covered electric wire 5 or the covered electric wire 8 in FIG. 1 is extended, and one or more switch elements having the same configuration as the switch element 7 are interposed between the covered electric wires 5 or the covered electric wires 8, or an extended covering is provided. A covered electric wire is wired in parallel to the electric wire 5 or the covered electric wire 5, and a switch element having the same configuration as that of the switch element 7 is interposed between the covered electric wires connected in parallel and stretched on the ground. According to such a configuration, it is also possible to detect that an intruder has caught a foot on an electric wire stretched on the ground by opening an electric circuit or changing a resistance value of the circuit,
By devising the lengths of the covered electric wires 5 and 8 and the intervening places of the switch elements 7, it is possible to detect various intrusion actions.

Moreover, in the crime prevention device according to the above-described embodiment, the case where a micro switch is employed as the switch element 7 interposed between the covered electric wire 6 and the covered electric wire 8 has been described. In another embodiment, A switch having a configuration in which an internal contact is opened when the covered electric wire 6 or the covered electric wire 8 is pulled can be employed. Moreover, it can also be set as the structure which connects the other end of the covered electric wire 6 to the connection terminal 11b, without providing the switch element 7. FIG.

Moreover, in the security device according to the above embodiment, an AC power source (
(AC100V) 20 is configured to apply a DC power supply (DC12V) obtained by converting DC stabilized power supply circuit 12; however, in another embodiment, without using AC power supply (AC100V), battery 15 It is good also as a structure which applies a DC power supply to the electric circuit containing the barbed wire 3. FIG. Moreover, it is good also as a structure which switches the power supply from the direct current | flow stabilized power supply circuit 12 and the power supply from the battery 15 according to a condition.

In addition to the alarm device 18 that emits sound and the lighting device 23 that emits light, it is also possible to provide a transmitter that transmits an alarm signal to the receiver as an alarm means that is driven when the detection holding relay 17 is turned on. It is. Further, based on the detection output of the resistance detection device 13, a configuration is added in which the power supply to the imaging device 25 is stopped or stopped after a certain time. For example, it may be configured to prevent data erasure due to overwrite recording of the imaging device 25.

It is the block diagram which showed schematic structure of the crime prevention apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the barbed wire in the crime prevention apparatus which concerns on another embodiment. (A)-(c) is a figure for demonstrating the switching operation | movement of the circuit containing a barbed wire in the crime prevention apparatus which concerns on another embodiment.

Explanation of symbols

3 Barbed wire 5, 6, 6a, 6b, 6c, 8, 9 Covered wire 7, 7A, 7B Switch element
12 DC stabilized power supply circuit
13 Resistance detector
14 Battery Charger 15 Battery 16 Reset Switch 17 Detection Holding Relay 18 Alarm Device 19 Main Power Switch 20 AC Power Supply 23 Illumination Device 25 Imaging Device

Claims (8)

A cord-like member having conductivity for preventing intrusion;
A power source for applying a predetermined voltage to an electric circuit formed by connecting the cord-shaped member and the electric wire;
Resistance value detecting means for detecting a change in resistance value of the electric circuit;
Alarm means for notifying the intruder,
A crime prevention device, comprising: an alarm driving unit that drives the alarm unit when a change in resistance value is detected by the resistance value detecting unit. The resistance value detection means can be detected even in a state where application of voltage from the power source to the electric circuit is interrupted,
The alarm driving means drives the alarm means when the resistance value detecting means detects a state in which application of voltage from the power source to the electric circuit is cut off. The crime prevention device according to 1. Contact opening / closing means is interposed in the cord-like member and / or the electric wire,
2. The contact opening / closing means is arranged so that a connection state of the electric circuit changes when a tension of a predetermined value or more is applied to the cord-like member or the electric wire.
Or the crime prevention apparatus of Claim 2. The alarm driving means is configured to include a drive holding means for holding a state in which the alarm means is driven until reset based on a detection output of a resistance value change output from the resistance value detection means. The crime prevention device according to any one of claims 1 to 3. It has an auxiliary power source that can store electricity,
The crime prevention device according to any one of claims 1 to 4, wherein driving power is supplied from the auxiliary power source to the alarm means. The imaging means is configured to be connectable,
The crime prevention device according to claim 5, wherein driving power is supplied from the auxiliary power source to the imaging unit. The crime prevention device according to any one of claims 1 to 6, wherein the cord-like member is configured to have a different resistance value for each unit length. The crime prevention device according to any one of claims 1 to 7, wherein the cord-like member is a barbed wire.

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