KR101299252B1 - Module for breaking abnomal current for camera - Google Patents

Abstract

The present invention relates to an abnormal current interruption module, the power input terminal receiving the power used for the operation of the camera, the power output terminal for supplying the received power to the camera, senses the magnitude of the current applied from the power input terminal And a current controller for controlling the flow and interruption of the current, and a switch connected between the current controller and the power output terminal and performing a flow and interruption of the current under control of the current controller. A blocking module can be provided to block overcurrent from flowing through the camera and to eliminate surge currents caused by lightning strikes.

Description

Module for breaking abnomal current for camera}

The present invention relates to a fault current interruption module, and more particularly to a fault current interruption module for a camera installed outdoors.

Surveillance cameras such as CCTV and other outdoor cameras generally need to be supplied with power from the outside, and also output the video signal photographed by the camera to the outside. However, when the length of the wiring is lengthened to supply power to the camera, voltage drop occurs due to the wire resistance of the wiring. Since a constant voltage is supplied from the power supply side, the voltage applied to the power input terminal of the camera becomes relatively small. In general, however, cameras are rated for rated voltage and current. Therefore, even if a proper voltage is supplied from the power supply side, a voltage lower than the rated voltage is applied at the camera input terminal. In addition, since the power consumption of the camera is constant, the current flowing inside the camera increases when the applied voltage is low. As a result, the current flowing inside the camera rises above the rated current, and the device inside the camera is damaged.

In general, when selling the camera, the manual indicates the proper length of the wiring so that this problem does not occur. 1 is a diagram illustrating a part of an actual manual of a surveillance camera for explaining resistance of wiring. Referring to Figure 1, it can be seen how many volts per unit length of the copper wire drops. In addition, the user is informed about a problem that may occur when the length of the wiring is increased.

In practice, however, camera installers fail to follow these precautions, resulting in many failures. In addition, when a failure occurs, the entire camera needs to be replaced, which causes a lot of cost, and there is a problem that the camera installed outdoors is not easy to replace.

On the other hand, in addition to the abnormal current caused by the length of the wiring, in the case of a camera installed outdoors, the abnormal current may be generated by lightning. Such abnormal currents may flow into the camera along the wiring, which eventually damages the internal elements of the camera.

Therefore, there is a need for a method of preventing abnormal current from entering the camera at a low cost.

The technical problem to be solved by the present invention is to provide a fault current blocking module that can detect when the fault current flows to the camera to prevent damage to the camera.

In order to solve the above technical problem, the present invention is to detect the power input terminal receives the power used for the operation of the camera, the power output terminal for supplying the received power to the camera, the magnitude of the current applied from the power input terminal And a current controller for controlling the flow and interruption of the current, and a switch connected between the current controller and the power output terminal and performing a flow and interruption of the current under control of the current controller. Provide a blocking module.

According to another aspect of the present invention, the current control unit may include a current sensing unit for sensing the magnitude of the current, and a switch control unit for controlling the switch according to the magnitude of the sensed current.

According to another feature of the present invention, the current sensing unit may include an op amp for amplifying and outputting a resistor and a voltage across the resistor.

According to another feature of the invention, the resistor may be a variable resistor.

According to another feature of the invention, the switch control unit includes a transistor in which a first electrode is connected to the switch, a second electrode is connected to the ground, a third electrode is connected to the output terminal of the current sensing unit, The on / off of the transistor may be controlled according to the output of the current sensing unit.

According to another feature of the present invention, the switch may block the current when the transistor is in the on state and allow the current to flow when the transistor is in the off state.

According to another feature of the invention, the switch can perform the flow and interruption of the current by physical contact.

According to another feature of the invention, it may further include a varistor connected between the power input terminal and the ground to remove a surge current.

In addition, according to another aspect of the invention, the signal input terminal to which the video signal from the camera is input, the signal output terminal for outputting the video signal, and between the signal input terminal and the signal output terminal, and connected between the ground It may further include a varistor to remove the surge current.

As mentioned above, when the camera is installed with the length of the wiring more than the prescribed length, it is possible to block the over-current flowing through the camera by installing an abnormal current blocking module between the camera and the power supply, and surge current due to lightning Can be removed.

In addition, it is possible to prevent damage to the camera by preventing overcurrent flow to the camera, thereby reducing the cost and reducing the effort of replacing the camera.

In addition, since the switch controls the flow and interruption of the current by physical contact, the switch is not completely damaged even when the overcurrent flows, thereby increasing the durability of the abnormal current interruption module.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 to 4.

2 is a block diagram showing an internal configuration of the abnormal current interruption module 100 for a camera according to an embodiment of the present invention. 2, the abnormal current interruption module 100 for a camera according to the present invention includes a power input terminal 110, a current controller 120, a switch 130, a power output terminal 140, and a first varistor 150. ). The camera current blocking module 100 may further include a signal output terminal 160, a signal input terminal 170, and a second varistor 180.

The power input terminal 110 receives power used for the operation of the camera from the outside. The power input terminal 110 may include a + terminal and a-terminal. In addition, VCC (supply voltage) is applied to the + terminal, and ground voltage may be applied to the-terminal.

The current controller 120 senses the magnitude of the current applied from the power input terminal. In addition, the current controller 120 controls the flow and blocking of current according to the sensed current. The current controller 120 may be connected between the power input terminal 110 and the switch 130 to be described later.

The current controller 120 may include a current detector 121 and a switch controller 122.

The current detector 121 detects the magnitude of the current applied from the power input terminal 110. The current sensing unit 121 may include an OP amplifier for amplifying and outputting a resistor and a voltage across the resistor. In addition, the resistor may be a variable resistor. Rated currents of the cameras are different from each other depending on the type of the camera. Therefore, when the resistor is made of a variable resistor, it is possible to set a reference current for shorting the switch 130 to be described later by adjusting the resistance.

The switch controller 122 controls the operation of the switch 130 to be described later according to the sensed current. The switch controller may include a transistor. That is, the output of the current sensing unit 121 may be connected to the control electrode of the transistor, and the on / off of the transistor may be controlled according to the output of the current sensing unit 121.

The switch 130 performs the flow and interruption of the current under the control of the current controller 120. The switch 130 may be configured as a switch that controls the short-circuit / opening by physical contact, such as a reed switch, for performing current flow and blocking by physical operation. The switch 130 may be connected between the current control unit 120 and the message output terminal 140 to be described later.

The power output terminal 140 supplies the power provided from the power input terminal 110 to the camera. Like the power input terminal 110, the power output terminal 140 may include a + terminal and a-terminal.

The first varistor 150 is connected between the power input terminal 110 and the ground. The first varistor 150 removes the surge current flowing to the camera by a lightning strike or the like.

Meanwhile, the signal output terminal 160 and the signal input terminal 170 respectively receive images captured by the camera and output them to the outside.

One terminal of the second varistor 180 is connected between the signal output terminal 160 and the signal input terminal 170, and the other terminal is connected to the ground. Like the first varistor 150, the second varistor 180 removes surge current flowing to the camera along the signal transmission line by lightning.

Hereinafter, an actual circuit diagram of the abnormal current interruption module 100 for a camera according to FIG. 2 will be described with reference to FIGS. 2 and 3.

The power input terminal 110 may include a first power input terminal 111 and a second power input terminal 112. The first power input terminal 111 is applied with the supply voltage VCC and is connected to the current controller 120. The second power input terminal 112 is connected to ground.

The current sensing unit 121 includes a resistor R1 and an OP amplifier Amp.

The resistor R1 may be made of a variable resistor. Both terminals of the resistor R1 are connected to the first node N1 and the second node N2, respectively.

In addition, the first node N1 is connected to the inverting input terminal Vin- of the OP amplifier Amp, and the second node N2 is connected to the non-inverting input terminal Vin + of the OP amplifier Amp. The OP amplifier Amp is provided with a power supply VDD for performing an operation of sensing and amplifying a voltage difference across the resistor R1.

The switch controller 122 includes resistors R2 and R3 and a transistor Tr. One end of the resistor R2 is connected to an output terminal of the OP amplifier Amp, and the other end is connected to a control electrode of the transistor Tr, that is, a base electrode. The emitter electrode of the transistor Tr is connected to ground, and the collector electrode is connected to the switch 130 through a resistor R3. In FIG. 3, the case where the transistor Tr is a BJT transistor has been described. However, the present invention is not limited thereto, and a MOS transistor may be used.

In the switch 130, an input terminal is connected to the second node N2 and a current flowing through the resistor R1 is applied. In the switch 130, there may be a reed switch LS that physically determines whether to pass or block a current applied through the resistor R1. The reed switch LS includes a coil, and wiring of the reed switch LS is alternatively connected to a or b terminals by a current flowing through the coil.

The power output terminal 140 may include a first power output terminal 141 and a second power output terminal 142. One end of the first power output terminal 141 is connected to a terminal of the switch 130, and the other end thereof is connected to the VCC terminal of the camera. One end of the second power output terminal 142 may be connected to the ground, and the other end thereof may be connected to the ground terminal of the camera.

One end of the first varistor 150 is connected to the first node N1 and the other end is connected to the ground.

The signal output terminal 160 and the signal input terminal 170 also have two terminals (161, 162, 171, and 172), respectively. Also, a second varistor 180 having one end connected between the first signal output terminal 161 and the first signal input terminal 171 of the signal output terminal 160 and the other end connected to the ground may be included.

Hereinafter, the operation of the abnormal current interruption module for a camera according to the present invention will be described.

Current is applied through the power input terminal 110 of the abnormal current interruption module 100. The magnitude of the current is determined according to the line resistance by the length of the wire connected from the power supply source to the abnormal current interruption module 100.

The current flows through the resistor R1, and the OP amplifier Amp senses a voltage across the resistor R1 generated by the current. When the current flowing through the OP amplifier increases and the voltage across the resistor R1 increases, the OP amplifier reflects this and increases the output voltage output from the output terminal.

When the output voltage is increased, current flows to the control electrode of the transistor Tr. In a normal state, that is, when the current is below the reference value, the transistor Tr is kept in the off state. That is, no current flows. However, when the current exceeds the reference value, the output voltage is increased, thereby turning on the transistor Tr. That is, the on / off of the transistor Tr is controlled according to the output of the current sensing unit 121. Determining whether the current is greater than or equal to the reference value may be performed by changing the size of the resistor R1 according to the type of the camera in which the abnormal current blocking module 100 is installed.

When the transistor Tr is turned on, current starts to flow in the coil provided in the switch 130. When a current flows in a coil, a magnetic field is generated around the coil. As such, when the magnetic field is generated, the physical switch provided in the switch 130 is connected from the a terminal to the b terminal. That is, in the normal state, the input terminal of the switch 130 is connected to the a terminal so that the input current flows to the power output terminal 140. On the contrary, when a current flows in the coil, the input terminal is connected to the b terminal to block the input current from being output to the power output terminal 140. That is, the current is interrupted when the transistor Tr is in the on state, and conversely, the current is passed when the transistor Tr is in the off state.

On the other hand, the first varistor 150 and the second varistor 160 is connected to the power input terminal 110 and the signal output terminal 160, respectively, to remove the surge current caused by lightning strike to block the flow of the surge current to the camera do.

4 is a conceptual diagram illustrating a state in which the abnormal current interruption module for the camera according to FIG. 2 is installed. The abnormal current blocking module 100 is installed between the power supply source 200 and the camera 300, and the abnormal current blocking module 100 is positioned between the display device 400 such as a monitor and the camera 300. To be installed.

In this way, when the camera is installed with the length of the wire longer than the prescribed length, the over current flow can be prevented from flowing through the camera by installing the abnormal current blocking module between the camera and the power supply and eliminating the surge current caused by lightning. You can do it.

In addition, it is possible to prevent damage to the camera by preventing the overcurrent flowing to the camera, thereby reducing the cost and the effort of replacing the camera can be reduced.

In addition, since the switch controls the flow and interruption of the current by physical contact, the switch is not completely damaged even when the overcurrent flows, thereby increasing the durability of the abnormal current interruption module.

The foregoing description and drawings are merely illustrative of the present invention and are used for the purpose of illustrating the present invention only and not for limiting the scope of the present invention described in the claims or the claims. Therefore, those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical protection scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1 is a diagram illustrating a part of an actual manual of a surveillance camera for explaining resistance of wiring.

2 is a block diagram illustrating an internal configuration of an abnormal current interruption module for a camera according to an exemplary embodiment of the present invention.

3 is a circuit diagram illustrating an embodiment of an actual configuration of an abnormal current interruption module for a camera according to FIG. 2.

4 is a conceptual diagram illustrating a state in which the abnormal current interruption module for the camera according to FIG. 2 is installed.

Claims (9)

A power input terminal provided with power used to operate the camera; A power output terminal for supplying the received power to the camera; A current controller which senses the magnitude of the current applied from the power input terminal and controls the flow and blocking of the current; And A switch connected between the current controller and the power output terminal, the switch configured to perform flow and interruption of the current under control of the current controller; The current control unit, A current sensing unit sensing the magnitude of the current; And It includes a switch control unit for controlling the switch in accordance with the magnitude of the sensed current, The current sensing unit, A resistor connected between the power input terminal and the switch; And An abnormal current interruption module for a camera comprising an OP amplifier to amplify and output the voltage across the resistor. delete delete Claim 4 has been abandoned due to the setting registration fee. The method of claim 1, The resistor is an abnormal current blocking module for a camera that is a variable resistor. Claim 5 was abandoned upon payment of a set-up fee. The method of claim 1, The switch controller includes a transistor having a first electrode connected to the switch, a second electrode connected to ground, and a third electrode connected to an output terminal of the current sensing unit. The abnormal current blocking module for controlling the on / off of the transistor in accordance with the output of the current sensing unit. Claim 6 has been abandoned due to the setting registration fee. The method of claim 5, wherein the switch Cut off the current when the transistor is on, An abnormal current interruption module for a camera that allows the current to flow when the transistor is in an off state. Claim 7 has been abandoned due to the setting registration fee. The method of claim 1, wherein the switch An abnormal current interruption module for a camera which performs the flow and interruption of the current by physical contact. Claim 8 was abandoned when the registration fee was paid. The method of claim 1, Claim 9 has been abandoned due to the setting registration fee. The method of claim 1, A signal input terminal to which an image signal from the camera is input; A signal output terminal for outputting the video signal; And And a varistor connected between the signal input terminal and the signal output terminal and between ground to remove a surge current.

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