JP2002214272A - Electric leak detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized, lightweight and inexpensive electric leak detector hard to receive the effect of noise. SOLUTION: The electric leak detector comprises a current sensor 2 constituted of a magnetic core 6 having a magnetic gap 6a and the switching output type Hall IC 7 arranged in the magnetic gap 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric leakage detector, and more particularly to an electric leakage detector suitable for a vehicle.

[0002]

2. Description of the Related Art As a conventional leakage detecting device, Japanese Patent Laid-Open Publication No.
Some are disclosed in Japanese Patent No. 30774 and Japanese Patent Application Laid-Open No. 10-232259.

[0003] For example, in a leak detection device disclosed in Japanese Patent Application Laid-Open No. 6-30774, a magnetic field generated in a magnetic core 21 at the time of a leak is converted into an induced electromotive force by a coil 22 as shown in FIG. It is of the form. That is, inside the magnetic core 21 around which the coil 22 is wound,
Wirings 24 and 25 connected to the load unit 23 are inserted. When the load current I2 flows through the primary wiring in the direction of the arrow and the ground fault current I3 flows due to a ground fault,
The current I1 flowing through the wiring 24 increases by I3 and becomes I2 + I
3, and the current flowing through the wiring 25 becomes I2. Then, Φ (I2 +
I3) The magnetic flux of Φ (I2) is generated in the direction of the arrow as the wiring 25, but the directions are opposite to each other, so that the portion corresponding to I2 is canceled out and the magnetic flux corresponding to I3 is generated. And the ground fault current I3
The presence or absence and the size are measured.

[0004] The leakage detecting device is characterized in that the magnetic core can be assembled and disassembled into a half-cylindrical, large-diameter magnetic core so that the device can be fixed to an arbitrary portion. .

As shown in FIG. 8, a leakage detection device disclosed in Japanese Patent Application Laid-Open No. 10-232259 uses a magnetic impedance element 33 to generate a magnetic field generated in a gap portion of a magnetic core 32 at the time of leakage. It has a format to detect. That is, the leakage is detected by the difference between the current flowing from the electric wire A into the load L and the electric current flowing from the load L into the electric wire B. First, the electric wires A and B are passed through the ring-shaped sensor 31 composed of the magnetic body 32. Next, when a leakage occurs, the ring-shaped magnetic body 32
Detects a magnetic field change. Then, a change in the magnetic field generated in the magnetic body 32 is detected by the magnetic impedance element 33 as a change in impedance. The detected impedance change is oscillated by an oscillating circuit 35 in order to improve sensitivity in the detector 34, or after waveform shaping is performed by a filter circuit and an amplifier circuit 36, and then detected by a signal detecting circuit 37 to output an output signal. I do.

In this leakage detecting device, the detector 3
4 and the sensor 31 are separate bodies, and the signal processing is performed by providing an oscillation circuit 35 and the like in the detector 34.

[0007]

However, since the former of the above-described leakage detection devices uses a sensor of the type that measures the induced electromotive force of the coil 22, it is necessary to use an engine or the like in an application in a vehicle. It is susceptible to generated noise and the like. Therefore, it is considered that accurate leakage detection is difficult. In addition, since this leakage detection device is not premised on a vehicle, it uses a split magnetic core, but if a split magnetic core is used, the correct leakage current value will be obtained due to the magnetic resistance of the junction. There is a problem that cannot be detected.

On the other hand, in the latter of the above-described leakage detection devices, the magnetic field detection capability of the magneto-impedance element 33 is extremely high, and there is a high possibility of reacting to a minute magnetic field change other than the leakage. . Further, since the minute change in impedance is amplified by the oscillator 35, a malfunction may occur due to the influence of noise or the like.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a small-sized, light-weight, and low-cost electric leakage detection device that is not easily affected by noise, focusing on the above problems.

[0010]

According to a first aspect of the present invention, there is provided a magnetic core having a magnetic gap, and a switching output type Hall IC disposed in the magnetic gap. The current leakage detection device comprises a current sensor 2.

According to the first aspect of the present invention, the leakage detecting device comprises a current sensor comprising a magnetic core having a magnetic gap and a switching output type Hall IC disposed in the magnetic gap. As a result, the state of electric leakage can be reliably grasped, and it is hardly affected by noise, so that the size, weight and cost are reduced. Further, since the output signal is digital, signal processing in a subsequent circuit becomes easy.

According to a second aspect of the present invention, there is provided a current sensor comprising a magnetic core having a magnetic gap and a switching output type Hall IC disposed in the magnetic gap. A first electric wire connected from a positive terminal of the battery mounted on the vehicle to a load, and a second electric wire connected from the load to a negative terminal of the battery through the magnetic core; A leakage detection device is characterized in that a change in a magnetic field generated in a core is detected as a change in the output of the switching output type Hall IC.

According to a second aspect of the present invention, there is provided an earth leakage detecting device comprising: a magnetic core having a magnetic gap; and a switching output type Hall IC disposed in the magnetic gap.
Consisting of a current sensor. Then, the first terminal connected to the load from the plus terminal of the battery mounted on the vehicle.
And the second electric wire connected from the load to the negative terminal of the battery is passed through the magnetic core, and a change in the magnetic field generated in the magnetic core is detected as a change in the output of the switching output type Hall IC. . As a result, it is possible to reliably grasp the presence or absence of the leakage in the vehicle. In addition, it is hardly affected by noise from the engine etc.
Lightweight and low cost.

According to a third aspect of the present invention, there is provided a magnetic core having a magnetic gap, a Hall element disposed in the magnetic gap, a small magnetic piece provided in the Hall element, And a current sensor comprising a comparator to which a detection output of the Hall element is input.

According to the third aspect of the present invention, there is provided an earth leakage detecting device comprising: a magnetic core having a magnetic gap; a Hall element arranged in the magnetic gap; a small magnetic piece installed in the Hall element; It consists of a current sensor composed of a comparator to which the detection output is input. As a result, the inexpensive configuration of the Hall element and the comparator makes it possible to surely grasp the state of electric leakage, is less susceptible to noise, and is small, lightweight and low-cost. Further, since the output signal is digital, signal processing in a subsequent circuit becomes easy.

According to a fourth aspect of the present invention, there is provided a magnetic core having a magnetic gap, a Hall element arranged in the magnetic gap, a small magnetic piece installed in the Hall element, And a current sensor composed of a comparator to which the detection output of the Hall element is input. The first wire is connected from the plus terminal of the battery mounted on the vehicle to the load, and is connected to the minus terminal of the battery from the load. And a second electric wire passing through the magnetic core and detecting a change in a magnetic field generated in the magnetic core as a change in the output of the comparator.

According to the fourth aspect of the present invention, there is provided an earth leakage detecting device comprising: a magnetic core having a magnetic gap; a Hall element disposed in the magnetic gap; a small magnetic piece disposed in the Hall element; It consists of a current sensor composed of a comparator to which the detection output is input. Then, a first electric wire connected from the positive terminal of the battery mounted on the vehicle to the load and a second electric wire connected from the load to the negative terminal of the battery are passed through the magnetic core. A change in the generated magnetic field is detected as a change in the output of the comparator. Thus, it is possible to reliably grasp the presence or absence of leakage in the vehicle with an inexpensive configuration including the Hall element and the comparator. In addition, it is hardly affected by noise from the engine or the like, and is small, lightweight, and low in cost.

[0018]

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

FIG. 1 is a block diagram showing an embodiment of a leakage detection device according to the present invention. As an example, the leakage detection device shows a case where the presence or absence of leakage in a vehicle is confirmed. In FIG. 1, a first electric wire 3 connected from a plus terminal of the battery 1 to a load 5 and a load 5 are included in a current sensor 2 serving as an insulation type leakage detection sensor in the immediate vicinity of a vehicle-mounted battery 1. Then, the electric wire 4 connected to the negative terminal of the battery 1 is inserted.

FIG. 2 is a configuration diagram showing the configuration of the current sensor 2 in FIG. In FIG. 2, the current sensor 2 is
A magnetic core 6 having a magnetic gap 6a in a part of a ring shape, a switching output type Hall IC (integrated circuit) 7 disposed in the magnetic gap 6a, and an output converter for supplying an output of the switching output type Hall IC 7 And an output terminal 9 connected to the output of the output converter 8.

FIG. 3 shows the switching hall IC 7 of FIG.
FIG. 3 is a circuit diagram showing a configuration example of the present invention. Switching Hall IC
Reference numeral 7 denotes a Hall element H having a control electrode, transistors Q1 to Q6, resistors R1 to R10, and a diode D1. The output terminal Vout is connected as shown in FIG. Can be obtained.

FIG. 4 shows the switching hall IC 7 of FIG.
3 shows the output characteristics. As shown in FIG. 4, the output terminal Vou
The output voltage from t shows a switching characteristic that changes from a high (H) level to a low (L) level at a certain threshold value T1 as the magnetic flux density increases, and conversely, the magnetic flux density decreases. And a threshold T lower than the above threshold
2, the switching characteristic changes from the low (L) level to the high (H) level, and the characteristic has hysteresis.

As the output converter 8 to which the output of the switching output type Hall IC 7 is supplied, an impedance converter, a VI converter, or the like can be used depending on the application at the subsequent stage.

In the earth leakage detecting device having the above-described configuration, during normal operation (ie, when there is no earth leakage), the current flowing from the battery 1 to the first electric wire 3 and the second electric wire 4
Since the current flowing from the magnetic sensor 6 is the same, the magnetic field generated in the magnetic gap 6a of the magnetic core 6 of the current sensor 2 is kept substantially zero.

On the other hand, the GND directly from the load 5 or the electric wire portion
When a leakage current flowing into (ground) occurs, the current flowing into the battery 1 through the second electric wire 4 becomes smaller than the current flowing out of the battery 1 through the first electric wire 3, The balance of the magnetic field in the magnetic core 6 is not maintained.

As a result, due to the difference between the outflow current and the inflow current, the magnetic flux Φ based on the above-mentioned current difference is generated in the magnetic gap 6a.
Occurs. When the density of the magnetic flux Φ exceeds the above-described threshold value T1, an output that changes from a high (H) level to a low (L) level is generated from the switching Hall IC 7 according to the characteristic shown in FIG.

Higher than switching Hall IC 7 (H)
The output that changes from the level to the low (L) level is converted into an appropriate output form by the output converter 8 and output from the output terminal 9.

Thus, the switching output type Hall I
By giving a threshold value of the magnetic flux density to the current at the time of leakage using C7, the leakage state can be reliably grasped. In addition, compared to the conventional method using a coil or a magneto-impedance element (FIGS. 7 and 8), it is less affected by noise from an engine or the like. Further, since the output signal is digital, signal processing in a subsequent circuit becomes easy.

As described above, the embodiments of the present invention have been described. However, the present invention is not limited thereto, and various modifications and applications are possible.

For example, as another embodiment, a Hall element 10 may be used instead of the switching output type Hall IC 7 as shown in FIG. 5 and a partially enlarged view thereof.
That is, an inexpensive Hall element such as a GaAs Hall element is arranged as the Hall element 10 in the magnetic gap 6a of the magnetic core 6, and a small magnetic field such as a ferrite magnet is applied so that a predetermined magnetic field is applied to the Hall element 10 in advance. The piece 11 is set. The output of the Hall element 10 is supplied to a comparator 12, and the output signal of the comparator 12 is output to an output terminal 13
Output from

Therefore, as shown in FIG. 1, the first electric wire 3 and the second electric wire 4 are provided in the magnetic core 6 of the current sensor 2 shown in FIG.
To detect a leakage when a magnetic field is generated in the magnetic gap 6a that cancels the Hall voltage of the Hall element 10 offset by the small magnetic piece 11.

FIG. 6 shows the output characteristics of the current sensor 2 of FIG. In FIG. 6, the Hall voltage A output from the Hall element 10 is the offset voltage Vo due to the magnetic field of the small magnetic piece 11 when the magnetic flux density in the magnetic gap 6a is zero.
Has occurred. The difference between the outflow current from the first electric wire 3 and the inflow current from the second electric wire 4 causes the magnetic gap 6
When the density of the magnetic flux .PHI. generated in a exceeds the threshold value T3 for canceling the Hall voltage of the offset Hall element 10, the comparator 12 generates an output that changes from a high (H) level to a low (L) level. , A leak is detected.

As described above, since the comparator 12 detects the positive or negative output from the output terminal of the Hall element 10, the zero point of the Hall voltage, that is, the positive / negative reversal point between the output terminals serves as a reference. Only with the configuration, the current sensor 2 is established.

Also in this configuration, since a threshold value of the magnetic flux density with respect to the current at the time of leakage is provided, the state of leakage can be grasped with certainty, and it is hardly affected by noise from the engine or the like. Small size, light weight and low cost. Further, since the output signal is digital, signal processing in a subsequent circuit becomes easy.

In the above description, the case of confirming the presence or absence of a leakage in the vehicle has been described. However, the present invention is not limited to this, and can be applied to various uses.

[0036]

According to the first aspect of the present invention, by using a switching output type Hall IC to provide a threshold value of the magnetic flux density with respect to the current at the time of leakage, it is possible to grasp the leakage state reliably. It is. In addition, compared to a conventional device using a coil or a magnetic impedance element, the device is less affected by external noise, and is small, lightweight, and low in cost.
Further, since the output signal is digital, signal processing in a subsequent circuit becomes easy.

According to the second aspect of the present invention, the presence or absence of a leakage in the vehicle can be reliably grasped. In addition, it is less susceptible to noise from the engine or the like, and is small, lightweight, and low in cost.

According to the third aspect of the present invention, the inexpensive configuration of the Hall element and the comparator makes it possible to reliably detect the leakage state, and is less susceptible to noise.
Small size, light weight and low cost. Further, since the output signal is digital, signal processing in a subsequent circuit becomes easy.

According to the fourth aspect of the present invention, it is possible to reliably grasp the presence or absence of the leakage in the vehicle with an inexpensive configuration including the Hall element and the comparator. In addition, it is hardly affected by noise from the engine or the like, and is small, lightweight, and low in cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a leakage detection device according to the present invention.

FIG. 2 is a configuration diagram showing a configuration of a current sensor in FIG. 1;

FIG. 3 is a circuit diagram showing a configuration example of a switching hall IC in FIG. 2;

FIG. 4 is a diagram showing output characteristics of the switching Hall IC in FIG. 2;

FIG. 5 is a block diagram showing another embodiment of the earth leakage detecting device according to the present invention.

FIG. 6 is a diagram showing output characteristics of the current sensor in FIG.

FIG. 7 is a configuration diagram illustrating a configuration example of a conventional leakage detection device.

FIG. 8 is a configuration diagram illustrating another configuration example of a conventional leakage detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Current sensor 3 1st electric wire 4 2nd electric wire 5 Load 6 Magnetic core 6a Magnetic gap 7 Switching output type Hall IC 8 Output converter 9 Output terminal 10 Hall element 11 Small magnetic piece 12 Comparator 13 Output terminal

Claims (4)

[Claims] 1. An earth leakage detecting device comprising: a magnetic core having a magnetic gap; and a current sensor including a switching output type Hall IC disposed in the magnetic gap. 2. A current sensor comprising a magnetic core having a magnetic gap and a switching output type Hall IC disposed in the magnetic gap, and a current sensor connected to a load from a positive terminal of a battery mounted on the vehicle. 1 wire and a second wire connected from the load to the negative terminal of the battery through the magnetic core, and a change in a magnetic field generated in the magnetic core is detected by the switching output type Hall IC. An earth leakage detecting device characterized by detecting a change in output. 3. A magnetic core having a magnetic gap, a Hall element disposed in the magnetic gap, a small magnetic piece installed in the Hall element, and a comparator to which a detection output of the Hall element is input. A leakage detecting device comprising a current sensor. 4. A magnetic core having a magnetic gap, a Hall element disposed in the magnetic gap, a small magnetic piece installed in the Hall element, and a comparator to which a detection output of the Hall element is input. A first electric wire connected to a load from a positive terminal of a battery mounted on the vehicle and a second electric wire connected to a negative terminal of the battery from the load. And detecting a change in the magnetic field generated in the magnetic core as a change in the output of the comparator.