KR102096482B1 - Semiconductor integrated circuit for leakage current detection and earth leakage circuit breaker having the same - Google Patents

Abstract

The present invention relates to an earth leakage breaker having a leakage current detection semiconductor integrated circuit (110) for determining whether an electrical leakage occurs in an electrical line by an induced voltage input from a leakage current detection unit installed in the electrical line. The leakage current detection semiconductor integrated circuit (110) includes: a signal amplification unit (110) for amplifying an induced voltage; a blocking determination unit (130) comparing an output voltage output by the signal amplification unit and a preset reference voltage for blocking determination and outputting a blocking signal that cuts off the electric line when the output voltage of the signal amplification unit is higher than the reference voltage; and a sudden current stabilization unit (150) installed between the signal amplification unit and the blocking determination unit and delaying the operation of the blocking determination unit by a predetermined operation delay time when the output voltage of the signal amplification unit is higher than or equal to a predetermined value.

Description

SEMICONDUCTOR INTEGRATED CIRCUIT FOR LEAKAGE CURRENT DETECTION AND EARTH LEAKAGE CIRCUIT BREAKER HAVING THE SAME}

The present invention relates to a semiconductor integrated circuit for detecting leakage current and an earth leakage breaker having the semiconductor integrated circuit.

Detects a short circuit due to ground faults of various electric lines or load-side devices (hereinafter referred to as "electrical lines, etc." in the present specification), and when a short-circuit is detected, power supplied to the electric line or load-side devices Earth leakage breakers are widely used as devices to cut off the power supply to electric lines or equipment by cutting off the supply.

FIG. 1 is a block diagram showing the configuration of a general earth leakage breaker, and as shown in FIG. 1, in general, when an earth leakage breaker occurs such as an electric line, the leakage current detection unit 20 installed in the electric line detects and induces it. When a current is output, this induced current is converted from an input resistance (Rin) to an induced voltage, and is input to the signal amplification section (11) of the semiconductor integrated circuit (10) for leak current detection, and is received by the signal amplification section (11). The mV-sized input induced voltage is outputted to the blocking determination unit 13 through a process such as amplification.

The blocking determining unit 13 determines whether or not the electric line is short-circuited by an input signal from the signal amplifying unit 11, and when it is determined as a result of the leakage, the blocking signal for blocking the electric line is blocked 30 ) To perform the blocking operation.

In addition. The rectifying part 40 step-downs the AC power supplied from the electric line to a voltage required for each part and converts it into direct current (exactly pulse current) and supplies it to the filter part 50 and the blocking part 30. In addition, the filter unit 50 removes the ripple component from the output of the rectifying unit 40, converts it to DC, and supplies it to the signal amplifying unit 11 and the blocking determining unit 13 of the semiconductor integrated circuit 10 for leakage current detection. do.

On the other hand, when power is applied to the electric line, etc. in the off (off) state of the earth leakage breaker, or due to instability of the power source due to various other factors (hereinafter referred to as "when the earth leakage breaker is on", etc.) The sudden current to be flowed for a few seconds is normally, and the signal amplification unit 11 of the semiconductor integrated circuit 10 for detecting leakage current amplifies the input signal by the sudden current and outputs it to the blocking determination unit 13.

At this time, as shown in Fig. 4 (a), if the magnitude of the input voltage input from the signal amplification unit 11 to the blocking determination unit 13 by an unexpected current is greater than or equal to the blocking voltage (trip voltage in FIG. 4), the blocking determination unit In the case of (13), there is a problem that a malfunction occurs in which the electric line is cut off as soon as the sudden current is input (time t1 in FIG. 4) by incorrectly determining the sudden current as a short circuit.

As a solution to this problem, Patent Literature 1 discloses a technique for preventing malfunction of an earth leakage breaker that can prevent a malfunction of an earth leakage breaker due to surge inflow.

However, the technology of Patent Document 1 has a problem that the configuration of the malfunction preventing device is very complicated, and the number of components for the device configuration is large, which can lead to an increase in cost as a result.

In addition, a test button for testing whether a normal operation is performed is installed in the circuit breaker, and when the test button is operated, the circuit breaker 30 of the circuit breaker is turned off by the leakage current for testing, and the semiconductor integrated circuit for detecting leakage current (10) must also be turned off.

However, the filter unit 50, which removes the ripple component from the output of the rectifying unit 40 and converts it into direct current, usually uses an RC circuit composed of a resistor and a capacitor as a device for removing ripple, and is constant in discharging the charge charged in the capacitor. Since it takes time, the semiconductor integrated circuit 10 for detecting leakage current is delayed and turned off later than the time when the blocking unit 30 is turned off.

The off-time of the semiconductor integrated circuit 10 for detecting leakage current is usually required to be within 50 µs. If the semiconductor integrated circuit 10 for leakage current detection is not turned off even after this time, the earth leakage breaker is turned on again. When the semiconductor integrated circuit 10 for detecting leakage current latches the power-off signal, a malfunction occurs in which the earth leakage breaker is immediately turned off instead of being turned on, which leads to problems such as an increase in the test time of the earth leakage breaker.

As one of the methods to solve this problem, there may be a method of reducing the capacity of the capacitor of the filter unit 50, but if the capacity of the capacitor decreases, the ripple increases, so that the stability of the semiconductor integrated circuit 10 for detecting leakage current is improved. Deterioration, which may lead to a decrease in the operational reliability of the earth leakage breaker.

Patent Publication No. 10-2008-0078757 (published on August 28, 2008)

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a semiconductor integrated circuit for detecting leakage current and a circuit breaker having the semiconductor integrated circuit, which can prevent malfunction of an earth leakage breaker due to a sudden current by a simple configuration. It is aimed at.

In addition, an object of the present invention is to provide a leakage current detection semiconductor integrated circuit capable of preventing an operation delay of a semiconductor integrated circuit for detecting leakage current during a test operation of an earth leakage breaker, and a circuit breaker having the semiconductor integrated circuit.

The semiconductor integrated circuit for detecting leakage current of the present invention for solving the above problems is a semiconductor integrated circuit for detecting leakage current by determining whether or not a short circuit occurs in the electric line by an induced voltage input from the leakage current detection means installed in the electric line. By comparing the signal amplifying unit for amplifying the induced voltage with the output voltage output from the signal amplifying unit and a preset reference voltage for blocking determination, cut off the electric line when the output voltage of the signal amplifying unit is greater than or equal to the reference voltage It is installed between the blocking determination unit for outputting a cutoff signal and the signal amplification unit and the blocking determination unit, and if the output voltage of the signal amplification unit is greater than or equal to a predetermined value, the operation of the blocking determination unit is delayed by a predetermined operation delay time. And an unexpected current stabilization unit, wherein the sudden current stabilization unit generates an unexpected current stabilization signal from the output voltage of the signal amplification unit and outputs an unexpected current stabilization signal, and determines the blocking when the sudden current stabilization signal is input. And a reset time control unit delaying a negative operation by the operation delay time. The reset time control unit further delays the operation of the blocking determination unit by a predetermined delay time when the sudden current stabilization signal is input, and the operation delay time is It is the time that the sudden current stabilization signal generator adds the time until the sudden current stabilization signal is generated and output from the output voltage of the signal amplification unit and the predetermined delay time.

In addition, the earth leakage detector of the present invention for solving the above problems includes a semiconductor integrated circuit for detecting the leakage current and a blocking unit for blocking the electric line according to the blocking signal of the semiconductor integrated circuit for detecting the leakage current.

ADVANTAGE OF THE INVENTION According to this invention, the semiconductor integrated circuit for leak current detection which can prevent the malfunction of the earth leakage circuit breaker by a sudden current with a simple structure, and the earth leakage circuit breaker which have this semiconductor integrated circuit can be obtained.

In addition, according to the present invention, it is possible to obtain a leakage current detection semiconductor integrated circuit capable of preventing an operation delay of a semiconductor integrated circuit for detecting leakage current during a test operation of a circuit breaker, and a circuit breaker having the semiconductor integrated circuit.

1 is a block diagram showing the configuration of a conventional general earth leakage breaker,
Fig. 2 is a block diagram showing the construction of an earth leakage breaker in a preferred embodiment of the present invention,
3 is a view showing the configuration of a breakthrough current stabilization unit in a preferred embodiment of the present invention,
4 is a waveform diagram illustrating an operation for preventing a malfunction of an earth leakage breaker due to an unexpected current;
5 is a circuit diagram showing an example of the implementation of the lowest operating voltage upward part of the preferred embodiment of the present invention.

Hereinafter, a semiconductor integrated circuit for detecting leakage current and a circuit breaker having the semiconductor integrated circuit in a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, a schematic configuration of an earth leakage breaker of a preferred embodiment of the present invention will be described. 2 is a block diagram showing the configuration of an earth leakage breaker in a preferred embodiment of the present invention.

As shown in Fig. 2, the earth leakage breaker of the preferred embodiment of the present invention has a leakage current detection unit 20, a signal amplification unit 110, a blocking determination unit 130, a sudden current stabilization unit 150, and a minimum operating voltage. The semiconductor integrated circuit 100 for detecting leakage current including the upward portion 170 and the blocking portion 30 and the rectifying portion 40 that cut off the electric line when it is determined as a short circuit as a result of determination by the blocking determining portion 130 And a filter unit 50.

When a leakage current occurs in an electric line, etc., when the leakage current detection unit 20 installed in the electric line detects this and outputs an induced current, the induced current is converted into an induced voltage by an input resistance Rin, and the semiconductor for leakage current detection is integrated. It is input to the signal amplifying unit 110 of the circuit 100.

The leakage current detection unit 20 detects a leakage current generated in an electric line or a load-side electric device, and may be, for example, a video current transformer (ZCT) installed in an electric line or a load-side electric device. However, the present invention is not limited thereto, and any means that can detect a leakage current generated in an electric line or a load-side electric device in which the earth leakage breaker of the present invention is installed is all included.

The signal amplifying unit 110 amplifies the induced voltage of several mV in which the induced current output from the leakage current detection unit 20 is converted from the input resistance Rin into a voltage when a leakage occurs in an electric line, etc. (150).

The sudden current stabilization unit 150 prevents malfunction of the earth leakage circuit breaker that blocks the electric line by incorrectly determining the sudden current generated when the earth leakage breaker, which is the subject of the present invention is turned on, as the leakage current due to the ground leakage. It will be described later.

The blocking determination unit 130 compares the output voltage of the signal amplification unit 110 input through the sudden current stabilization unit 150 with a preset blocking determination reference voltage, and the output voltage of the signal amplification unit 110 is referenced. When the voltage is greater than or equal to the voltage value, a blocking signal for performing a blocking operation such as an electric line is output to the blocking unit 30.

The minimum operating voltage upward unit 170 increases the minimum operating voltage of the blocking determination unit 130, and details will be described later.

The blocking unit 30 is composed of an output unit including an unillustrated coil, an unillustrated actuator or a plunger, and an unillustrated opening / closing mechanism. When the coil is magnetized by a blocking signal output from the blocking determination unit 130 The output unit is moved by the magnetic force, and the opening / closing mechanism automatically performs a blocking operation such as an electric line.

The rectifying part 40 and the filter part 50, as well as the signal amplifying part 110, the blocking determining part 130, and the blocking part 30, all use a well-known configuration, and thus detailed description thereof will be omitted.

Next, the sudden current stabilization unit 150 will be described in detail with reference to the accompanying drawings. Figure 3 is a circuit diagram showing the configuration of the breakthrough current stabilizing unit of the preferred embodiment of the present invention, (a) is the configuration of the analog system of the sudden current stabilization unit 150a, (b) is a digital system of the sudden current stabilization unit ( 150b). 4 is a waveform diagram illustrating an operation for preventing a malfunction of an earth leakage breaker due to an unexpected current.

Normally, the leakage current to the ground fault has a long duration, whereas the sudden current generated when the earth leakage breaker is turned on has a characteristic that the duration is very short, usually within a few ㎳, and the sudden current stabilization unit 150 of this embodiment has The same difference is used to prevent malfunction of the earth leakage breaker due to an unexpected current.

First, while referring to FIGS. 3 (a) and 4, an analog-type sudden current stabilization unit 150a will be described.

As shown in FIG. 3 (a), the analog-type sudden current stabilization unit 150 includes a pulse generator PG, a switching unit 1511, a constant current source Is, a charging capacitor C11, and a comparator 1512. It consists of a sudden current stabilization signal generating unit 151a, a reset time control unit 153 and a switch (SW).

The pulse generator PG is connected to the output terminal of the signal amplification unit 110, and when a voltage equal to or higher than the cutoff voltage is input from the signal amplification unit 110, a pulse signal is generated and output to the switching unit 1511.

The switching unit 1511 includes two transistors of the switching transistor TR1 and the switching transistor TR2 having opposite polarities, and the bases of the two transistors are commonly connected to the pulse generator PG. Further, the emitter of the switching transistor TR1 is connected to the constant current source Is, the emitter of the switching transistor TR2 is connected to the ground side, and the collector of the switching transistor TR1 and the switching transistor TR2 is a comparator 1512 ).

A charging capacitor C11 is connected in parallel between one end of the comparator 1512 and a collector of the switching transistor TR1 and the switching transistor TR2, and a reference voltage Vref is input to the other end of the comparator 1512. do.

The reset time control unit 153 operates according to the output of the comparator 1512 to control the switch SW. In addition, although not shown in FIG. 3, the reset time control unit 153 may be configured to control the operation of the pulse generator PG by being connected to the pulse generator PG of the sudden current stabilization signal generator 151a.

The switch SW is connected between the output terminal of the signal amplification unit 110 and the blocking determination unit 130, and is set to block between the signal amplification unit 110 and the blocking determination unit 130 in the initial state, and reset Under the control of the time control unit 153, the signal amplification unit 110 and the blocking determination unit 130 are connected (on) or blocked (off). The switch SW may be configured using, for example, a switching element such as a transistor, or may be configured using a switch having a physical contact.

Next, the operation of the sudden current stabilization unit 150a will be described.

When an output signal (a trip voltage in FIG. 4) of a cutoff voltage or higher is input from the signal amplifying unit 110 to the pulse generator PG (time t1 in FIG. 4), the pulse generator PG generates a pulse signal to generate a switching signal 1511. ), And accordingly, the switching transistor TR1 is turned on and the switching transistor TR2 is turned off. Therefore, the charging capacitor C11 is charged by the current flowing from the constant current source Is.

When the charging capacitor C11 starts to be charged, the charging voltage is input to one end of the comparator 1512, and the comparator 1512 compares and compares the voltage input from the charging capacitor C11 and the reference voltage Vref. The result is output to the reset time controller 153.

As the charging capacitor C11 is charged, the voltage input to the comparator 1512 gradually increases, and after a certain period of time, the charging capacitor C11 is charged to a predetermined voltage and is input to one end of the comparator 1512. The comparator 1512 outputs an output signal (the BCS output in FIG. 4) to the reset time control unit 153 when the voltage to be applied becomes greater than or equal to the reference voltage Vref (time t2 in FIG. 4).

Here, the time at which the sudden current stabilization signal is output from the sudden current stabilization signal generator 151a, that is, the time when the charging capacitor C11 is charged to the reference voltage Vref is the sudden current stabilization time (BCS time in FIG. 4). ), And when the sudden current stabilization signal is input from the sudden current stabilization signal generating unit 151a (time t2 in FIG. 4), delays by a predetermined time from the moment the sudden current stabilization signal is input (times t2 to t3 in FIG. 4). The reset time control unit 153 determines whether or not the sudden current stabilization signal is continuously output from the comparator 1512 at the time t3, which is the time between).

As shown in FIG. 4 (b), the leakage current due to a ground fault continues to flow between the electric line and the ground even after time, so the induced current input from the leakage current detection unit 20 to the signal amplification unit 110 continues. Is entered. On the other hand, unlike the leakage current, the breakthrough current is not continuous, and gradually decreases over time and disappears within a few seconds as shown at the top of FIG. 4 (c).

Therefore, as shown in FIG. 4 (b), even though a predetermined time has elapsed since the sudden current stabilization signal generator 151a outputs the sudden current stabilization signal, the sudden current from the comparator 1512 of the sudden current stabilization signal generator 151a. When the stabilization signal is continuously output, the reset time control unit 153 determines that the signal output from the signal amplification unit 110 is an induced voltage due to leakage current due to short circuit and stops operation by controlling the pulse generator PG. At the same time, the switch SW is controlled to release the blocking between the signal amplifying unit 110 and the blocking determining unit 130.

Therefore, the output voltage of the signal amplifying unit 110 is normally output to the blocking determining unit 130, and the blocking determining unit 130 compares the output voltage of the signal amplifying unit 110 with a preset reference voltage for blocking determination, When the output voltage of the signal amplifying unit 110 is greater than or equal to the reference voltage value, the blocking signal is output to the blocking unit 30 (time t3 in FIG. 4 (b)).

Conversely, if the sudden current stabilization signal is not continuously input from the comparator 1512 after a predetermined delay time after the sudden current stabilization signal is input to the reset time controller 153, the reset time controller 153 is a signal amplification unit. It is determined that the signal above the blocking voltage output from 110 is caused by an unexpected current, and the switch SW is controlled to maintain the blocking between the signal amplifying unit 110 and the blocking determining unit 130 so that the blocking voltage is not output. Does not.

The breakdown current stabilization time of the breakthrough current stabilization unit 150a can be changed by adjusting the capacity of the charging capacitor C11.

Next, the digital-type sudden current stabilization unit 150b will be described. As shown in FIG. 3 (b), the digital-type sudden current stabilization unit 150a includes an oscillator (OSC), a counter 1513 and a comparator 1514, and a reset current stabilization signal generator 151b, and a reset time. It includes a control unit 153 and a switch (SW).

One end of the counter 1513 is connected to the output terminal of the signal amplification unit 110, and when a voltage equal to or higher than the cutoff voltage is input from the signal amplification unit 110, the counter 1513 is a clock CLK input from the oscillator OSC. Is counted and output to one end of the comparator 1514.

The comparator 1514 outputs an emergency current stabilization signal to the reset time control unit 153 when the count of the counter 1513 is equal to or greater than a predetermined value ref. When the sudden current stabilization signal is input, the reset time control unit 153 continues from the comparator 1542 at time t3, which is the time delayed by a predetermined time from the input of the sudden current stabilization signal (between time t2 to t3 in FIG. 4). Therefore, it is determined whether or not the sudden current stabilization signal is input, and subsequent operations are the same as those of the sudden current stabilization unit 150a described above.

As described above, the sudden current stabilization unit 150 of the present embodiment is installed between the signal amplification unit 110 and the blocking determination unit 130, and a signal input from the signal amplification unit 110 (signal amplification unit 110) Check whether the output signal of the signal is greater than or equal to a predetermined voltage (trip voltage in FIG. 4), and if the output signal of the signal amplification unit 110 is greater than or equal to a predetermined cutoff voltage, the signal amplification unit 110 determines the blocking After the output of the voltage output to 130 is delayed by a predetermined operation delay time (in this embodiment, the sudden current stabilization time + the delay time of the reset time control unit 153), it is continuously blocked even after the operation delay time has elapsed. When a signal having a voltage or higher is output from the signal amplifying unit 110, the output signal of the signal amplifying unit 110 is output to the blocking determining unit 130.

The breakdown current stabilization time of the breakdown current stabilization unit 150b can be changed by adjusting the reference count number ref of the comparator 1514 or the frequency of the oscillator OSC.

Next, with reference to Figs. 2 and 5, a description will be given of a method of preventing the operation delay of the semiconductor integrated circuit for detecting leakage current during the test operation of the earth leakage breaker.

As described above, the earth leakage breaker of the present embodiment determines the blocking during the test by allowing the charge charged in the ripple elimination capacitor of the filter unit 50 to be discharged and at the same time the blocking determining unit 130 of the earth leakage breaker also operates. The blocking signal output of the unit 130 and the off-operation of the semiconductor integrated circuit 100 for detecting leakage current are caused to occur simultaneously.

To this end, in this embodiment, the rectifier 40 is installed between the filter unit 50 and the blocking determination unit 130 to remove the ripple component from the rectified DC voltage (pulsation), and the voltage applied to the blocking determination unit 130 By increasing the (operation voltage of the blocking determining unit 130), the blocking determining unit 130 is quickly turned off as a result.

 5 is a circuit diagram showing an example of the implementation of the lowest operating voltage upward part of the preferred embodiment of the present invention, wherein (a) is a minimum operating voltage upward means, a resistance element, (b) a transistor, and (c) a diode. Each example is shown.

First, in the example of FIG. 5 (a), a resistance element is used as the lowest operating voltage upward means, and the voltage drop generated in the resistor R11 is caused by the current flowing from the filter unit 50 to the blocking determination unit 130. Use to increase the minimum operating voltage of the blocking determining unit 130.

Here, the minimum operating voltage upward value of the blocking determining unit 130 may be adjusted by changing the resistance R11 value.

Next, in the example of FIG. 5 (b), the transistor is used as the lowest operating voltage upward means, and the NPN type bipolar transistor TR11 having the base and the collector in common is connected to the filter unit 50 and the blocking determination unit 130. Connected to, the minimum operating voltage of the blocking determining unit 130 is increased by the threshold voltage Vbe of the transistor TR11.

Here, the minimum operating voltage upward value of the blocking determining unit 130 may be adjusted by a method of connecting two or more transistors TR11 in series.

Next, in the example of FIG. 5 (c), a diode is used as the lowest operating voltage upward means, and the anode terminal of the diode D11 is connected to the filter unit 50 and the cathode terminal is connected to the blocking determination unit 130. The minimum operating voltage of the blocking determining unit 130 is increased by the threshold voltage Vth of the diode D11.

Here, the minimum operating voltage upward value of the blocking determining unit 130 may be adjusted by a method of connecting two or more diodes D11 in series.

Although the present invention has been described by the preferred embodiments, it is not limited thereto, and it is natural that various changes or modifications can be carried out without departing from the scope of the invention described in claims.

For example, in the above embodiment, the sudden current stabilization unit 150 induces an abnormality of the cutoff voltage from the signal amplification unit 110 even after an operation delay time equal to (the sudden current stabilization time + the delay time of the reset time controller 153) has elapsed. When the voltage is input to the blocking determining unit 130, the blocking determining unit 130 outputs a blocking signal to prevent malfunction of the earth leakage breaker due to an unexpected current.

However, it is not limited thereto, and the capacity of the charging capacitor C11 of the sudden current stabilization signal generating unit 151a of the sudden current stabilization unit 150 is increased, or the oscillator (OSC) of the sudden current stabilization unit 150b is increased. By increasing the stabilization time of the breakdown current by a method such as adjusting the frequency, it may be possible to prevent a malfunction of the earth leakage breaker due to the breakdown current without a separate delay time by the reset time control unit 153.

In addition, in the above-described embodiment, it has been described that the sudden current stabilization unit 150 controls the switch SW to connect or block the signal amplification unit 110 and the blocking determination unit 130, but is not limited thereto.

Without a switch (SW), the signal amplification unit 110 and the blocking determination unit 130 are always connected, and the sudden current stabilization unit 150 performs the operation of the blocking determination unit 130 depending on whether an unexpected current flows. It may be controlled to be on or off.

In addition, the prevention of malfunction due to the sudden current described in the above-described embodiments and the prevention of malfunction due to the increase in the minimum operating voltage of the blocking determining unit may be performed separately or in combination with each other. Moreover, the said embodiment and the said modified example may be implemented separately, respectively, and may be implemented in combination with each other.

20 Leakage current detector
100 leakage integrated semiconductor integrated circuit
110 signal amplification unit
130 interception decision unit
151 sudden current stabilization signal generator
153 reset time control
150 Breakdown Current Stabilizer
170 Minimum operating voltage upward

Claims (9)

A semiconductor integrated circuit for leakage current detection, which determines whether a short circuit occurs in the electric line by an induced voltage input from the leakage current detection means installed in the electric line,
A signal amplifying unit for amplifying the induced voltage,
A blocking determination unit for comparing an output voltage output from the signal amplification unit with a preset reference voltage for blocking determination, and outputting a blocking signal for blocking the electric line when the output voltage of the signal amplification unit is greater than or equal to the reference voltage;
It is provided between the signal amplification unit and the blocking determination unit, and if the output voltage of the signal amplification unit is greater than or equal to a predetermined value, includes an unexpected current stabilization unit that delays the operation of the blocking determination unit by a predetermined operation delay time,
The sudden current stabilization unit,
A sudden current stabilization signal generator for generating and outputting a stabilizing current stabilization signal from the output voltage of the signal amplifying unit;
And a reset time control unit delaying the operation of the blocking determination unit by the operation delay time when the sudden current stabilization signal is input.
The reset time control unit further delays the operation of the blocking determination unit by a predetermined delay time when the sudden current stabilization signal is input,
The operation delay time is the time until the sudden current stabilization signal generator generates and outputs the sudden current stabilization signal from the output voltage of the signal amplification unit and the predetermined delay time, the semiconductor integrated circuit for leakage current detection. delete The method according to claim 1,
The sudden current stabilization signal generating unit,
A pulse generator connected to the output terminal of the signal amplification unit and generating a pulse signal when the output voltage of the signal amplification unit is greater than or equal to a predetermined value;
A switching element that operates by the pulse signal to open and close the current flowing from the constant current source,
A capacitor connected to the output terminal of the switching element to charge the current of the constant current source,
And a comparator outputting the sudden current stabilization signal when the charging voltage of the capacitor is greater than or equal to a reference voltage. The method according to claim 1,
The sudden current stabilization signal generating unit,
An oscillator generating a clock signal,
A counter which is connected to the output terminal of the signal amplification unit and counts the clock signal generated by the oscillator when the output voltage of the signal amplification unit is greater than or equal to a predetermined value;
And a comparator that outputs the sudden current stabilization signal when the number of counts of the counter is equal to or greater than a predetermined number of counts. delete The method according to claim 1,
Further comprising a switch connected between the signal amplifying unit and the blocking determining unit,
The reset time control unit controls the switch to open and close the signal amplification unit and the blocking determination unit to delay the operation of the blocking determination unit by the operation delay time. The method according to claim 1,
A semiconductor integrated circuit for detecting leakage current further comprising a filter unit for removing a ripple component from the DC voltage of the rectifying unit rectifying the power supply voltage and a minimum operating voltage upward unit connected between the blocking determination unit to increase the minimum operating voltage of the blocking determination unit. Circuit. The method according to claim 7,
The minimum operating voltage upward part is a semiconductor integrated circuit for detecting leakage current, which is any one of a resistor, transistor, or diode connected between the filter part and the blocking decision part. The semiconductor integrated circuit for detecting leakage current according to any one of claims 1, 3, 4, 6, 7, and 8,
An earth leakage breaker including a blocking unit for blocking the electric line according to the blocking signal of the semiconductor integrated circuit for detecting leakage current.

Images