KR101705090B1 - A power protection device of checking ground - Google Patents

Abstract

The present invention relates to an apparatus for detecting a ground short circuit and protecting power, constantly detecting whether a power supply device or a power distribution device providing alternating current (AC) power is grounded to a ground terminal or not, checking ground continuity, and, if not grounded, sending an alarm and cutting off power from the power supply device or the power distribution device. According to the present invention, the apparatus comprises: a power input unit including two input lines receiving AC power, which is input power, and a grounded ground line; a direct current (DC) power generation unit rectifying the input power to generate the DC power; a power line detection unit outputting a detection signal by voltage between each input line and the ground line; a control unit receiving the outputted detection signal to determine the ground continuity, and outputting a control signal according to the ground continuity; and a relay unit connecting or cutting off the input line of the power input unit according to the control signal. According to the present invention, when a ground role is not performed since the ground terminal (or ground line) of the power supply or distribution device is discontinuous, power input to an electric device or equipment is blocked, so an electric shock accident due to a short circuit can be prevented, and accordingly, a short circuit disaster can be efficiently prevented and occurrence of a fatal disaster due to electricity can be reduced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention provides a power supply device or a power distribution device that provides an alternating current power to the ground terminal or the power distribution device at all times to detect whether the ground terminal is grounded or ungrounded and to check grounding continuity, A ground fault detection and a power protection device for shutting off the power supply.

Electricity is an indispensable resource in modern life, but it can cause fatal injuries to people if they are damaged by electricity. In addition, when the electric equipment is operated or maintenance is performed in the industrial field, the electric power line of the electric machine and the ground are discontinuously generated, so that the worker is often exposed to electric shock or burns. Particularly, when performing inspection and maintenance work in the live state of an extra-high voltage transmission and distribution line or equipment, if there is a discontinuity with the ground in the electric machine, it may cause a fatal accident to the human body and equipment failure.

According to recent electric shock analysis, approximately 60% of disasters occur in small construction industry, and electric shock accidents caused by insulation failure of electric equipment account for about 30%. Especially, there are many electric shock deaths and scattering / contact injuries caused by portable electric equipment at the construction site. Therefore, a countermeasure for reducing the electric hazard in the moving electrical machine / apparatus is required.

In order to prevent such electric shock accidents, it is essential to install a grounding facility and an earth leakage breaker. In the case of grounding, it shall be ensured that the grounding condition is always maintained continuously. In addition, in the case where the grounding and the non-grounding are mixed, a blind spot may be generated for preventing the electric shock, such as an inability to operate the earth leakage breaker.

As a method for preventing such electric shock disaster, various devices for confirming the continuity of the ground wire are used. [Patent Document 1], a device for displaying a resistive ground state [Patent Document 2], an apparatus for detecting a ground fault of an electronic product [Patent Document 3], a device for absorbing or removing electromagnetic waves And a ground check socket [Patent Document 4].

Further, conventional ground continuity checking apparatuses include an ohmmeter and a multimeter, a plug type apparatus having a check lamp attached thereto, and an apparatus for confirming continuity by grounding a portable apparatus. Such a ground continuity checking device is useful for confirming the continuity of grounding during the electric work, maintenance, and inspection of industrial sites and construction sites.

However, the above-mentioned conventional devices have a problem that the price is high and the meter structure is complicated. In addition, the plug type confirmation device can not be used while the electric device is operating. In addition, the device for checking the continuity of grounding for electrostatic discharge in a mobile facility is not only expensive, but also has a problem in that it is inconvenient to carry because of its large size.

Korean Registered Patent No. 10-0941962 (2010.02.12. Announcement) Korean Patent Publication No. 10-2003-0083472 (published on October 30, 2003) Korean Patent Registration No. 10-0689032 (2007.03.08) Korean Patent Registration No. 10-0407770 (published on Dec. 1, 2003)

Disclosure of the Invention An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a ground disconnection detection and power protection device for confirming ungrounded state or ground continuity in order to prevent electric shock from an electric device .

It is also an object of the present invention to provide a ground fault detection and power protection device which not only cuts off the power supply of the electric equipment but also prevents the power supply to the electric equipment when the ground terminal (or the ground wire) is discontinuous .

Also, an object of the present invention is to provide a ground disconnection detection and power protection device that integrates a power interrupter for confirming ground continuity with a conventional portable, stationary earth fault circuit breaker, and overload circuit breaker, will be.

According to an aspect of the present invention, there is provided a ground fault detection and power protection apparatus comprising: a power input unit configured by two input lines for receiving AC power as input power and a ground line to be grounded; A DC power generator for rectifying the input power to generate a DC power; A power line sensing unit outputting a sensing signal by a voltage between each input line and a ground line; A control unit for receiving the output sensed signal to determine whether or not the sensor is connected to ground, and outputting a control signal according to the continuity of the ground; And a relay unit for connecting or disconnecting an input line of the power input unit according to the control signal.

According to another aspect of the present invention, there is provided a ground line disconnection detection and power protection device, wherein the power line sensing unit includes: a first line sensing unit for sensing a voltage between a first line, which is one of the two input lines, And a second line sensing unit outputting a sensing signal by a voltage between the second line and the ground line, wherein the first or second line sensing unit is provided between the first or second line and the ground line A rectifying unit and a photocoupler are connected in series, and the output of the photocoupler is output as a sensing signal.

Further, the present invention is a ground disconnection detection and power protection device, wherein the rectifying part is composed of a diode and allows only a voltage of one direction to pass therethrough.

According to another aspect of the present invention, there is provided an apparatus for sensing a ground disconnection and a power protection device, the control unit receiving a first sensing signal output from the first line sensing unit and a second sensing signal output from the second line sensing unit, And when the first sensing signal and the second sensing signal are both off and on, if the first sensing signal and the second sensing signal are both on and off, .

According to another aspect of the present invention, there is provided an apparatus for detecting disconnection of a ground line and a power protection device, wherein the relay unit includes a relay for connecting or disconnecting an input power source, and a driving unit for driving the relay, wherein the driving unit includes a photocoupler, The light emitting unit is caused to emit light by a control signal of the control unit. The light receiving unit of the photocoupler is connected to the base of the transistor included in the relay, and the relay is driven when a current flows through the transistor.

According to another aspect of the present invention, there is provided a ground fault detection and power protection apparatus comprising: a power input unit configured by two input lines for receiving AC power as input power and a first ground line to be grounded; A power output unit comprising two output lines for outputting the AC power to an electronic device and a second ground line to be grounded; A power cutoff unit provided between the power input unit and the power output unit for connecting or disconnecting the input line and the output line; A DC power generator for rectifying the input power to generate a DC power; A first and a second sensing signals are output by the voltage between each input line and the first ground line and a third and a fourth sensing signal are output by voltages between the respective output lines and the second ground line, A line sensing unit; A control unit for receiving the first to fourth sensing signals to determine whether there is continuity of ground and whether or not there is a short circuit, and outputting a control signal according to whether there is a continuity of ground or a short circuit; And a relay unit for connecting or disconnecting the input line or the output line according to the control signal.

According to another aspect of the present invention, there is provided a ground line disconnection detection and power protection device, wherein the power line sensing unit includes a first line sensing unit for outputting a first sensing signal by a voltage between one of the two input lines and the first ground line, A second line sense unit for outputting a second sense signal by a voltage between the other one of the two input lines and the first ground line, And a fourth line sensing unit for outputting a fourth sensing signal by a voltage between the other one of the two output lines and the second ground line, The second, third, or fourth line sensing unit connects the rectification unit and the photocoupler in series between the input line or the output line and the first or second ground line, and outputs a logic negative gate to the output of the photocoupler And outputs the output of the logic undefined gate as a sense signal.

As described above, according to the present invention, if the ground terminal (or the ground wire) of the power supply device or the power distribution device is discontinuous and does not serve as a ground, the power supply to the electric device or the electric equipment It is possible to prevent an electric shock accident caused by a short circuit or the like, thereby effectively preventing an electric shock accident and reducing the occurrence of a serious disaster caused by electricity.

In addition, according to the ground disconnection detection and power protection device of the present invention, a power cutoff device for preventing electric shock from an electric device (or a moving electric device) is miniaturized so as to be portable, It is possible to obtain an effect of increasing.

Particularly, according to the ground disconnection detection and power protection device according to the present invention, it is possible to use the ground disconnection detection and power protection device in combination with the portable fixed earth leakage circuit breaker and the overload circuit breaker by adding the functions of the ground fault continuity function, Effect is obtained.

1 is a circuit diagram of a ground disconnection detection and power protection device according to a first embodiment of the present invention;
2 is a graph illustrating sensed signals sensed for an input power source according to a first embodiment of the present invention.
3 is a table showing state determination and control signals according to the detection signal according to the first embodiment of the present invention.
FIG. 4 is an external view of a ground disconnection detection and power protection device according to a first embodiment of the present invention; FIG.
5 is a circuit diagram of a ground disconnection detection and power protection device according to a second embodiment of the present invention;
6 is a table showing status determination and control signals according to a sensing signal according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

In the description of the present invention, the same parts are denoted by the same reference numerals, and repetitive description thereof will be omitted.

First, the configuration of the ground disconnection detecting and power protecting apparatus according to the first embodiment of the present invention will be described with reference to FIG.

1, the power cutoff device according to the first embodiment of the present invention includes a power input unit 10, a DC power generation unit 20, a power line sensing unit 30, a control unit 40, (50). In addition, it may further comprise a display unit 60. Fig.

The power input unit 10 receives an AC power source (for example, AC 200 V) as an input power source. The power input unit 10 is composed of power input lines N and P and a ground line (or neutral line) G. Preferably, the input lines N and P are lines in which AC power is input as two lines, and the ground line G is a line which causes earth.

Preferably, the power input unit 10 is formed in the form of a plug and is inserted into a power supply unit or a power distribution unit (not shown) to which AC power is supplied, and is connected to a power supply unit or a power distribution unit Is supplied with AC power. That is, an input terminal and a ground terminal are provided at the ends of the input lines N and P and the ground line G. The input terminal and the ground terminal are connected to the power supply terminal of the power supply device or the power distributing device (not shown) Terminal. The ground line G is connected to the ground terminal of the power supply or power distribution device (not shown) and is grounded.

Next, the DC power generating unit 20 receives the AC power from the power input unit 10 and converts it into a DC voltage (preferably, 5 V, 12 V) to supply power to the electronic circuit such as a semiconductor device. The DC power generator 20 includes a transformer 21 for converting an AC power source to a DC voltage and a rectifier 22 for rectifying and removing noise from an output voltage of the transformer 21.

That is, the DC power generating unit 20 supplies the rectified DC power to the relay unit 50, the signal processing unit 50, or the like.

Next, the power line sensing unit 30 discriminates a normal state (normal or negative phase) of the power line, and detects normal, reverse, and power application states. In particular, the power line sensing unit 30 senses a current or voltage between each of the input lines N and P and the ground line G, and outputs a sensing signal. That is, an On signal is output when the ground line G is normally grounded (or ground continuous), and an Off signal is output when the ground line G is abnormal (or when the ground is discontinuous).

The power line or the input line N or P connected to the power input unit 10 is connected to a lead line or an incoming line P through which electric current flows into the electric device when the ground potential is viewed as neutral, And a return line or a return line (N).

The power line sensing unit 30 configures the line sensing units 30a and 30b according to the input lines N and P, respectively. The first line sensing unit 30a and the second line sensing unit 30b will be referred to as a first line sensing unit 30a and a second line sensing unit 30b, respectively. The first line sensing unit 30a senses a voltage between one of the input lines N and P and the ground line G and the second line sensing unit 30b senses a voltage between the other line P ) And the ground line (G). That is, the first and second line sensing units 30a and 30b sense the ground continuity by the potential difference between the input lines N and P and the ground line G. [

The first line sensing unit 30a connects the rectifying unit 31a and the photocoupler 32a in series between the input line N and the ground line G and outputs the output of the photocoupler 32a And outputs it as a detection signal In-A. The rectifying part 31a is composed of a diode D1 and allows only the reverse-phase current of the AC power source to pass therethrough. The current passed by the rectifying unit 31a causes the light emitting unit of the photocoupler 32a to emit light, receives the light by the light receiving unit, and outputs the detection signal In-A as On. Accordingly, the first line sensing unit 30a outputs the sensing signal In-A in the ON state only when the reverse-phase power is input to the input line N. The sensing signal at this time will be referred to as a first sensing signal. Particularly, since the first line sensing unit 30a receives a current between the input line N and the ground line G only when the ground line G is in the ground continuity state (grounded state), only the ground continuous state And outputs the first sensing signal In-A. In other words, in the case of the ground discontinuous state (the state not grounded), since no current flows between the input line N and the ground line G, the first sensing signal In-A is outputted as off.

The second line sensing unit 30b connects the rectifying unit 31b and the photocoupler 32b in series between the input line P and the ground line G and outputs the output of the photocoupler 32b ) As a sensing signal (In-B). The rectifying unit 31b is composed of a diode D4 and allows only the normal current of the AC power supply to pass therethrough. The current passed through the rectifying part 31b causes the light emitting part of the photocoupler 32b to emit light, receives the light by the light receiving part, and outputs the sensing signal In-B as On. Accordingly, the second line sensing unit 30b outputs the sensing signal In-B in the ON state only when the normal power is input to the input line P. [ Since the current flows between the input line P and the ground line G only when the ground line G is in the ground continuity state (grounded state), the second line sensing unit 30b is provided only in the ground continuous state 2 sense signal In-B. In other words, in the case of the ground discontinuous state (the state not grounded), since no current flows between the input line P and the ground line G, the second sensing signal In-B is outputted as off.

The first and second line sensing units 30a and 30b which sense the power supply between each of the two input lines N and P and the ground line G are connected in a normal case Or a reverse phase) and outputs an On signal. This is shown in FIG. 2 shows the first and second sensing signals In-A and In-B outputted by the first and second line sensing units 30a and 30b with respect to the AC power inputted in the ground continuity state . As shown in FIG. 2, if the input power source is an AC power source, the first and second line sensing units 30a and 30b cross the on / off signals. That is, when the supplied power is in the reverse phase, the first sensing signal is outputted as On and the second sensing signal is outputted as off. When the power source is normal, the first sensing signal is output in off state and the second sensing signal is outputted in on state.

Next, the control unit 40 receives the detection signals In-A and In-B from the power line sensing unit 30 and detects the ground continuity or the ground discontinuity (ungrounded, ungrounded, and ungrounded) . Also, the control unit 40 outputs the control signal RY-OUT to the relay unit 50 depending on whether the ground is continuous or not. Also, preferably, the control unit 40 outputs an on / off indication signal to the display unit 60 in accordance with whether it is ungrounded (ungrounded or ungrounded) or whether it is continuity of grounding.

In addition, the control unit 40 is a microcontroller unit (MCU), which is composed of one control chip. The MCU receives a detection signal as an input signal, and outputs a control signal (RY-OUT) as an output signal. Also, the MCU receives the DC power generated by the DC power generator 20 as a power source.

Particularly, the control unit 40 receives the ON / OFF (or 1/0) sensing signal from the power line sensing unit 30 and determines whether or not the ground continuity is established according to the signal value of the sensing signals. The logic operation of determining the ground continuity according to the detection signal in the control unit 40 is shown in FIG.

As shown in FIG. 3, when one of the two sensing signals In-A and In-B is on (1) or the other is off (0), the ground continuity state is determined. Particularly, when the first sensing signal In-A is 0 and the second sensing signal In-B is 1, the input power is in a normal state. In the opposite case, that is, when the first sensing signal In-A is 1 and the second sensing signal In-B is 0, the input power is in a reverse phase state. When both of the first and second sensing signals In-A and In-B are off (0), it is judged to be a non-grounded state, that is, a ground discontinuity state. In this case, the ground line G is not grounded and no detection signal is detected.

The control unit 40 outputs a control signal RY-OUT to the relay unit 50 to control the relay unit 50 to cut off the input power when the ground state of the input power source is judged as the ground discontinuity. That is, as shown in Fig. 3, the control signal RY-OUT outputted to the relay unit 50 is outputted as off (0).

Also, the control unit 40 outputs a display signal to the display unit 60 in accordance with the grounded state of the input power source. The display unit 60 displays the state of the power supply line (or input line) and the ground continuity state (or ungrounded state) through an indicator light (LED).

Next, the relay unit 50 includes a relay 51 for turning on / off the input power, and a driving unit 52 for driving the relay 51.

The driving unit 52 outputs a driving signal for controlling the relay 51 in accordance with the control signal RY-OUT of the control unit 40. [ The driving unit 52 may include a photo coupler (ISO3) that transmits a signal by light. That is, the light emitting portion of the photocoupler ISO3 is emitted by the control signal RY-OUT of the control portion 40, and the light receiving portion of the photocoupler ISO3 is connected to the base of the transistor Q4 provided in the relay 51 do. Thus, when light is emitted by the control signal RY-OUT, the driving signal is transmitted to the relay 51 through the transistor Q4.

The relay 51 is connected to the power input unit 10 and the driving unit 52. The switch 51 is controlled in response to the output of the driving unit 52 to selectively supply power to the header. Therefore, the controller 50 cuts off the input power source 220V through the relay 51 when the state of the power source line is ungrounded (ground discontinuity) during use of the electric device. That is, the control unit 50 controls the input power source through the prevention circuit when the power source line is in a non-grounded state (ground discontinuity) before the electric device is turned on. If the power line is in the normal state, control is returned to the previous state.

The present invention can be integrated and miniaturized through the merging of technologies with existing portable type earth leakage breakers. Accordingly, the present invention can contribute to the prevention of electric shock accident caused by short-circuiting from all the electricity costs including the moving electric machine / mechanism. In addition, the present invention can always check the continuity of the grounding from an electric device such as a moving electric machine / mechanism, and can detect a danger of electric shock which may occur due to disconnection / disconnection of a grounding line even during operation. In addition, when the grounding discontinuity occurs, the input power of the electric device is cut off, thereby early detection of a short circuit and proactive measures can be taken to reduce an electric shock disaster. The ground disconnection detection and power protection device according to the present invention can be applied to mobile devices such as a water pump, a hot air fan, a mobile generator, a reinforcing bar, and a compressor.

Next, the external configuration of the ground disconnection detection and power protection apparatus according to an embodiment of the present invention will be described.

As shown in FIG. 4, the power-off device according to the present invention includes an insertion terminal connected to a power supply or a power distribution device, input terminals N and P, and an earth. The input terminal can be integrated into a conventional portable type earth leakage breaker.

Further, the power cutoff device of the present invention includes a display unit 60 such as a power off indicator, a liquid crystal display, a power indicator, and the like, which indicates that the power is off. Accordingly, the present invention can display and confirm the power supply line when the power supply apparatus or the power supply apparatus power supply is energized, and can confirm the state of the power supply apparatus or the power supply apparatus when the power supply apparatus is short-circuited or disconnected.

In addition, in the case of disconnection of the ground wire in the continuity of the ground, it is possible to display and confirm the function of disabling the power supply and disabling the power supply. And display and confirmation of power source and center line (L1, N phase and L1, L2, L3, N phase) are possible.

Although not shown in the drawing, the present invention has a function return switch (resetting) function for resetting the power source. Accordingly, the present invention can be miniaturized so that the user can carry it individually.

Next, the configuration of the ground disconnection detection and power protection apparatus according to the second embodiment of the present invention will be described with reference to FIG.

5, the power cut-off device according to the second embodiment of the present invention includes a power input unit 110, a DC power generation unit 120, a power line sensing unit 130, a control unit 140, a relay unit 150, a power output unit 170, and a power shutoff unit 180. In addition, the display unit 160 may be further included.

The power input unit 110 receives AC power as input power. The power input unit 110 includes power input lines N and P and a ground line (or a neutral line) G. Preferably, the input lines N and P are lines in which AC power is input as two lines, and the ground line G is a line which causes earth.

Also, the power input unit 110 includes a connection terminal J2 for connecting to an external AC power source. Preferably, the connection terminal J2 is formed in a plug-like shape and is inserted into a power supply device or a power distribution device (not shown) to which AC power is supplied, and a power supply device or a power distribution device (not shown) Is supplied with AC power. That is, the input terminals N and P and the ground line G are connected to the input terminal or the ground terminal of the connection terminal J2 at the ends thereof, and the input terminal and the ground terminal are connected to the power supply device or the power distribution device ) And the ground terminal. The ground line G is connected to the ground terminal of the power supply or power distribution device (not shown) and is grounded.

Next, the DC power generating unit 120 receives the AC power from the power input unit 110, converts the AC power into a DC voltage, and supplies power to an electronic circuit such as a semiconductor device. The DC power generating unit 120 includes a transformer 121 for converting an AC power source to a DC voltage and a rectifying unit 122 for rectifying and removing noise from an output voltage of the transformer 121. The DC power generation unit 120 supplies the rectified DC power to the relay unit 150, the signal processing unit 150, and the like.

Also, the power output unit 170 is configured to output the inputted AC power to the electronic equipment. The power output unit 170 is composed of power output lines N 'and P' and a ground line (or neutral line) G. The ground line of the power input unit 110 is referred to as an input ground line and the ground line of the power output unit 170 is referred to as an output ground line. In order to distinguish between them, they can be generally described as ground lines. In particular, since the input ground line and the output ground line are connected to each other, they are used without distinction as the ground line.

The power output unit 170 has a connection terminal J4 for connecting with an electronic device (not shown). As an example, the connection terminal J4 is configured in the form of an outlet so that the plug of the electronic device is inserted to supply the AC power to the electronic device. Further, the connection terminal J4 can constitute additional grounding separately from the grounding line.

The power cutoff unit 180 is disposed between the power input unit 110 and the power output unit 170 and connects or disconnects between the input lines N and P and the output lines N 'and P' . Preferably, the power shutoff unit 180 is composed of a balance relay BR. In particular, the power cut-off unit 18 cuts off between the input lines N and P and the output lines N 'and P' when the balance of the current between the output line and the input line is broken due to a short circuit or the like.

Next, the power line sensing unit 130 determines whether the power line is in a normal state (normal or negative phase) and a short circuit state, and detects normal, ungrounded, short circuit, power supply, and the like. In particular, the power line sensing unit 130 senses a current or voltage between the input lines N and P and the ground line G, and outputs a sensing signal. The power sensing unit 130 senses a current, a voltage, and a potential difference between the output lines N 'and P' and the ground line G to output a sensing signal.

That is, when the ground line G is normally grounded (or in the case of ground continuous) by the detection of the input lines N and P, an On signal is outputted. In case of abnormal (or grounding disconnection) And outputs an Off signal. It is also possible to detect a short circuit on the output lines N 'and P' by detecting the output lines N 'and P', to output an On signal in the case of a short circuit, ) Signal.

Preferably, the power line sensing unit 130 negates the output of each of the input lines N and P or each of the output lines N 'and P', and outputs the on / off signal inversely.

The power line sensing unit 130 configures the line sensing units 130a and 130b according to the input lines N and P, respectively. The first line sensing unit 130a and the second line sensing unit 130b will be referred to as a first line sensing unit 130a and a second line sensing unit 130b, respectively. The first line sensing unit 130a senses the voltage between one of the input lines N and P and the ground line G and the second line sensing unit 130b senses the voltage between the other line P ) And the ground line (G). That is, the first and second line sensing units 130a and 130b sense the ground continuity by the potential difference between the input lines N and P and the ground line G. [

Also, the power line sensing unit 130 configures the line sensing units 130c and 130d according to the output lines N 'and P'. These are referred to as a third line sensing unit 130c and a fourth line sensing unit 130d, respectively. The third line sensing unit 130c senses the voltage between one line N of the output lines N 'and P' and the ground or ground line G, and the fourth line sensing unit 130d senses the voltage between the other The voltage between the line P 'and the ground line G is detected. That is, the third and fourth line sensing units 130c and 130d sense a short circuit by a potential difference between the output lines N 'and P' and the ground G. Specifically, if the current, voltage, or potential difference is detected in all of the third and fourth line sensing units 130c and 130d, it is determined that there is a short circuit. If not, it is determined to be in a normal state. That is, if at least one of the third and fourth line sensing units 130c and 130d does not sense a current flow, it is determined to be in a normal state.

The first line sensing unit 130a connects the rectifying unit 131a and the photocoupler 132a in series between the input line N and the ground line G and outputs the output of the photocoupler 132a Connects the logic negative gate 133a, and outputs the output of the logic negative gate 133a as the sense signal In-A. At this time, the logic gating gate 133a uses the NAND gate and outputs the output of the photocoupler 132a to the NAND gate as two inputs.

The rectifying unit 131a is composed of a diode D1 and allows only the reverse-phase voltage of the AC power source to pass therethrough. The voltage passed by the rectifying unit 131a causes the light emitting unit of the photocoupler 132a to emit light and receive the light by the light receiving unit to output the sensing signal In-A as On, and the sensing signal In- And is output as the opposite signal Off by the logic negative gate 133a.

Therefore, the first line sensing unit 130a outputs the sensing signal In-A in off state only when the reverse-phase power is input to the input line N. The sensing signal at this time will be referred to as a first sensing signal. Particularly, when the voltage is generated between the input line N and the ground line G only when the ground line G is in the ground continuous state (grounded state), the first line sensing unit 130a only detects the ground continuous state And outputs the first sensing signal In-A. In other words, since no voltage is generated between the input line N and the ground line G in the case of a ground discontinuous state (a state not grounded), the first sense signal In-A is off, And finally outputted as On.

The second line sensing unit 130b connects the rectifying unit 131b and the photocoupler 132b in series between the input line P and the ground line G and outputs the output of the photocoupler 132a , And outputs the output of the logical NOT gate 133b as a sense signal In-B. At this time, the logical NOT gate 133b uses a NAND gate.

The rectifying part 131b is composed of a diode D4 and allows only the steady voltage of the AC power source to pass therethrough. The voltage passed by the rectifying unit 131b causes the light emitting unit of the photocoupler 132b to emit light and receive the light by the light receiving unit to output the detection signal In-B as On, .

Accordingly, the second line sensing unit 130b outputs the sensing signal In-B in an off state only when the normal power is input to the input line P. [ The second line sensing unit 130b generates a voltage between the input line P and the ground line G only when the ground line G is in the ground continuity state 2 sense signal In-B. That is, in the case of the ground discontinuous state (the state not being grounded), since no voltage is generated between the input line P and the ground line G, the second sensing signal In-B is finally turned on .

The first and second line sensing units 130a and 130b that sense the power supply between each of the two input lines N and P and the ground line G are in a normal state Or a reverse phase) and outputs an On signal. This is the same as the first embodiment. The only difference is that the output signal is the opposite signal.

Next, the third line sensing unit 130c connects the rectifying unit 131c and the photocoupler 132c in series between the output line N 'and the ground line G, and outputs the output of the photocoupler 132c And outputs the output of the logic undefined gate 133c as a sense signal In-C. At this time, the logical NOT gate 133c uses a NAND gate. The ground line G may be a ground provided on the ground line G of the input power source, the ground line G 'of the output power source, or the output side connection terminal J4. The rectification part 131c, the photocoupler 132c and the logic gates 133c of the third line sensing part 130c are the same as those of the first or second line sensing part 130a or 130b. Accordingly, the third line sensing unit 130c outputs the sensing signal In-C in off state only when power is input to the input line P '.

The fourth line sensing unit 130d connects the rectifying unit 131d and the photocoupler 132d in series between the output line P 'and the ground line G and outputs the output of the photocoupler 132d And outputs the output of the logic undefined gate 133d as the sense signal In-D. The configuration of the fourth line sensing unit 130d is the same as that of the third line sensing unit 130c. However, there is a difference only in the output lines N 'and P'.

The output power source is a power source supplied to an electronic device (not shown). If a short circuit occurs in an electronic device (not shown), current will flow in both of the two output lines N 'and P'. Therefore, when a short circuit is detected, it will be detected that all the power flows in the third and fourth line sensing units 130c and 130d. That is, the third line sensing unit 130c and the fourth line sensing unit 130d sense the voltage of the output power source (electronic device), respectively.

The control unit 140 receives the sensing signals In-A, In-B, In-C and In-D from the power line sensing unit 130 and detects a ground continuity do. Also, the control unit 40 outputs the control signals RY-OUT1 and RY-OUT2 to the relay unit 150 according to the continuity of the ground or the short circuit. Also, preferably, the control unit 140 outputs a display signal to the display unit 160 in accordance with whether there is continuity of grounding or a short circuit.

In addition, the control unit 140 is a microcontroller unit (MCU), and is composed of one control chip. The MCU receives a detection signal or the like as an input signal, and outputs a control signal or the like as an output signal. Also, the MCU receives the DC power generated by the DC power generator 120 as a power source.

In particular, the control unit 140 receives the ON / OFF (or 1/0) sensing signal from the power line sensing unit 130 and determines whether the ground continuity or the short circuit is present according to the signal value of the sensing signals. The control unit 140 determines the grounding continuity according to the detection signal and the logical calculation of the leakage determination as shown in FIG.

As shown in FIG. 6, if the first and second sensing signals In-A and In-B are ON (1) or the other is OFF (0), the ground continuity state is determined. Particularly, when the first sensing signal In-A is 1 and the second sensing signal In-B is 0, the input power is in a normal state. In the opposite case, that is, when the first sensing signal In-A is 0 and the second sensing signal In-B is 1, the input power is in a reverse phase state. If both of the first and second sensing signals In-A and In-B are on (1), it is judged to be a non-grounded state, that is, a grounding discontinuity state. In this case, the ground line G is not grounded and no detection signal is detected.

If all of the third and fourth sensing signals In-C and In-D are off (0), it is judged as a short circuit state. That is, since current flows through all of the input lines output to the electronic device (not shown), it is judged that there is a short circuit. If at least one of the third and fourth sensing signals In-C and In-D is on (1), it is determined as a normal state or a soap state.

The control unit 140 outputs the first control signal RY-OUT1 to the relay unit 150 to control the relay unit 150 to shut off the input power, if the ground state of the input power source is determined as the ground discontinuity do. That is, as shown in FIG. 6, the first control signal RY-OUT1 to be output to the relay unit 150 is output as OFF (0).

The control unit 140 outputs a second control signal RY-OUT2 to the relay unit 150 to control the relay unit 150 to cut off the output power when the output power source is judged to be a short circuit state. That is, as shown in FIG. 6, the second control signal RY-OUT2 to be output to the relay unit 150 is outputted as OFF (0).

In addition, the control unit 140 outputs a display signal to the display unit 160 according to the grounded state of the input power source or the leakage state of the output power source. The display unit 160 displays the state of the power supply line (or input line), the ground continuity state (or ungrounded state), and the light leakage state via the indicator light (LED).

Next, the relay unit 150 includes a first relay 151a for turning on / off the input power, and a first driver 152a for driving the first relay 151a. In addition, the relay unit 150 further includes a second relay 151b that connects or disconnects the output power, and a second driver 152b that drives the second relay 151b.

The first driving unit 152a outputs a driving signal for controlling the first relay 151a according to the first control signal RY-OUT1 of the controller 140. [ The first driver 152a may include a photo coupler (ISO4) that transmits a signal by light. That is, the light emitting unit of the photocoupler ISO4 is emitted by the first control signal RY-OUT1 of the control unit 140, and the light receiving unit of the photocoupler ISO4 is connected to the transistor Q5 of the first relay 151a. As shown in FIG. Thus, when light is emitted by the first control signal RY-OUT1, the driving signal is transmitted to the first relay 151a through the transistor Q5.

The first relay 151a turns off the switch RL1 of the input lines N and P between the power input unit 110 and the power cutoff unit 180 to cut off the output power. The first relay 151a is connected to the power input unit 110 and the first driving unit 152a and the switch state is controlled corresponding to the output of the first driving unit 152a to selectively supply power to the header . Therefore, the controller 150 cuts off the input power through the first relay 151a when the electric power line of the electric device is in a non-grounded state (ground discontinuity). That is, the control unit 150 controls the input power source through the prevention circuit when the power line is not grounded (ground discontinuity) before the electric device is turned on. If the power line is in the normal state, control is returned to the previous state.

The second driving unit 152b outputs a driving signal for controlling the second relay 151b according to the second control signal RY-OUT1 of the controller 140. [ The second driving unit 152b may include a photo coupler (ISO4) that transmits a signal by light. That is, the light emitting unit of the photocoupler ISO5 is emitted by the second control signal RY-OUT2 of the control unit 140, and the light receiving unit of the photocoupler ISO4 is illuminated by the transistor Q5 of the second relay 151b. As shown in FIG. Thus, when light is emitted by the second control signal RY-OUT2, the driving signal is transmitted to the second relay 151b through the transistor Q5.

The second relay 151b turns off the switch RL2 of the output lines N 'and P' between the power cutoff unit 180 and the power output unit 170 to cut off the output power. That is, the controller 150 cuts off the output power through the second relay 151b when the electric device is in a short circuit state during use of the electric device. If the output power is in a normal state, control is returned to the previous state.

Although the present invention has been described in detail with reference to the above embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

10, 110: power input unit 20, 120: DC power generation unit
30, 130: Power line sensing unit 40, 140:
50, 150: relay unit 60, 160: display unit
170: power output unit 180: power cutoff unit

Claims (8)

A power input unit comprising two input lines for receiving AC power as input power, and a ground line to be grounded;
A DC power generator for rectifying the input power to generate a DC power;
A power line sensing unit outputting a sensing signal by a voltage between each input line and a ground line;
A control unit for receiving the output sensed signal to determine whether or not the sensor is connected to ground, and outputting a control signal according to the continuity of the ground; And
And a relay unit for connecting or disconnecting an input line of the power input unit according to the control signal,
The power line sensing unit may include a first line sensing unit that outputs a sensing signal by a voltage between a first line of the two input lines and the ground line and a second line sensing unit that outputs a voltage between the second line and the ground line And a second line sensing unit outputting a sensing signal,
The first or second line sensing unit connects the rectifying unit and the photocoupler in series between the first or second line and the ground line, outputs the output of the photocoupler as a sensing signal,
The control unit receives the first sensing signal output from the first line sensing unit and the second sensing signal output from the second line sensing unit, and when either one of the first sensing signal and the second sensing signal is on And if the first and second sensing signals are all off, it is determined that the first and second sensing signals are in a non-grounded state, .
delete The method according to claim 1,
Wherein the rectifying unit comprises a diode to allow only one directional current to pass therethrough.

delete The method according to claim 1,
The relay unit includes a relay for connecting or disconnecting an input power source, and a driving unit for driving the relay,
Wherein the driving unit includes a photocoupler, a light emitting unit of the photocoupler is caused to emit by a control signal of the control unit, a light receiving unit of the photocoupler is connected to a base of a transistor provided in the relay, Wherein the relay is driven.
A power input unit comprising two input lines for receiving AC power as input power and a first ground line to be grounded;
A power output unit comprising two output lines for outputting the AC power to an electronic device and a second ground line to be grounded;
A power cutoff unit provided between the power input unit and the power output unit for connecting or disconnecting the input line and the output line;
A DC power generator for rectifying the input power to generate a DC power;
A first and a second sensing signals are output by the voltage between each input line and the first ground line and a third and a fourth sensing signal are output by voltages between the respective output lines and the second ground line, A line sensing unit;
A control unit for receiving the first to fourth sensing signals to determine whether there is continuity of grounding and whether or not there is a short circuit, and outputting a control signal according to whether there is a continuity of grounding or a short circuit; And
And a relay unit for connecting or disconnecting the input line or the output line according to the control signal.
The method according to claim 6,
The power line sensing unit may include a first line sensing unit outputting a first sensing signal by a voltage between one of the two input lines and the first ground line, A third line sensing unit for outputting a third sensing signal by a voltage between one of the two output lines and the second ground line, And a fourth line sensing unit for outputting a fourth sensing signal by the voltage between the other one of the two output lines and the second ground line,
The first, second, third or fourth line sensing unit connects the rectifying unit and the photocoupler in series between the input line or the output line and the first or second ground line, and the output of the photocoupler And connects the logic negative gates and outputs the output of the logic negative gates as a sense signal.
8. The method of claim 7,
The control unit receives the first sensing signal output from the first line sensing unit and the second sensing signal output from the second line sensing unit, and when either one of the first sensing signal and the second sensing signal is on And if the other of the first and second sensing signals is on, it is determined that the first and second sensing signals are non-grounded,
A third sensing signal output from the third line sensing unit and a fourth sensing signal output from the fourth line sensing unit, and when the third sensing signal and the fourth sensing signal are both off, And the ground fault detection and power protection device.

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