JPH09281149A - Magnetic transformer for sensor - Google Patents

Abstract

(57) Abstract: An external dimension of a primary winding and an external dimension of a secondary winding are made to be the same, thereby miniaturizing a magnetic transformer portion and achieving miniaturization of a sensor. SOLUTION: A part of a secondary winding 9 is wound around a primary side split core 4, and an outer dimension h _{3 of a} primary winding 5 and a secondary winding 9 wound around the primary side split core 4 is obtained. The outer dimensions h _{4 of the} secondary winding 9 wound around the secondary split core 7 are the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic transformer for a sensor used in a current sensor, a voltage sensor, etc., and particularly to a geometrical disadvantage and a cost due to a difference in the number of turns of a primary winding and a secondary winding. TECHNICAL FIELD The present invention relates to a magnetic transformer for a sensor that improves the disadvantages.

[0002]

2. Description of the Related Art As an example of a current sensor for measuring the value of current to be measured, there is conventionally known one that measures the value of current to be measured using a magnetic transformer for sensor. ing.

FIG. 3 is a perspective view showing an example of a magnetic transformer for a current sensor used in such a current sensor.

Magnetic transformer 1 for current sensor shown in this figure
Reference numeral 01 denotes the first and second input terminals 102 and 103 to which the measurement current to be measured is input, and the primary-side split core 10 made of a U-shaped high magnetic permeability material.
4, a primary winding 105 formed by winding the primary split core 104 a predetermined number of times (N ₁ turns), and a U-shaped high magnetic permeability material at each end. Is arranged so as to face each end of the primary-side split core 104, and has a slit 106 between each end, the part is magnetically coupled to the primary-side split core 104 to form the magnetic core 10.
Secondary split core 108 and primary winding 105 forming
The secondary winding 109 is formed by winding the secondary split core 108 a predetermined number of times (N ₂ turns) in the winding direction opposite to the winding direction, and is connected to each end of the secondary winding 109. The first and second output terminals 110 and 111, and a magnetic sensor (not shown) that is inserted in any of the slits 106 and detects the magnetic flux density in the magnetic core 107 are provided.

Then, the first and second input terminals 102, 10
When a measurement current to be measured is input to 3, magnetic flux is generated in the magnetic core 107 by the primary winding 105.
As a method for measuring this current, a magnetic flux canceling current (also called a compensating current) is caused to flow from the secondary winding 109 in a direction opposite to the direction of the secondary current by a current value measuring circuit (not shown). Then, the value of the measured current is determined based on the value of the magnetic flux canceling current when the magnetic flux passing through the magnetic sensor becomes zero.

[0006]

However, in the above-mentioned conventional magnetic transformer 101 for a current sensor,
There were the following problems.

That is, when manufacturing such a magnetic transformer 101 for a current sensor, the number of turns N _{1 of the} primary winding 105 wound around the primary split core 104 and the secondary split core 108. and the number of turns N ₂ of the secondary winding 109 often differ greatly.

Therefore, as shown in FIG. 4, the outer dimension h _{1 of the} primary winding 105 wound around the primary-side split core 104.
In many cases, the external dimension h ₂ of the secondary winding 109 becomes too large, resulting in imbalance.

Thus, the outer dimension h of the secondary winding 109 is
_{Based on 2} etc., decide the installation space etc.,
There is a problem that there are many restrictions on mounting, such as having to use a reinforcing structure for covering a weight imbalance.

The present invention has been made in view of the above circumstances, and an object thereof is to make the external dimensions of the primary winding and the secondary winding the same so that the magnetic The transformer part can be downsized and the current sensor can be downsized, and the weight of the primary split core side and the weight of the secondary split core side can be balanced to eliminate the need for a reinforcing structure or the like. In addition, the mounting structure can be simplified, and when the bobbin is used when the primary winding and the secondary winding are wound around the primary split core and the secondary split core, the primary winding is used. A bobbin common to the split core and the secondary split core can be used, thereby providing a magnetic transformer for a sensor that can suppress development investment funds.

[0011]

In order to achieve the above-mentioned object, the present invention is directed to a case where a current to be measured is input,
In a magnetic transformer for a sensor that generates a secondary current corresponding to this measured current, it is composed of a primary side split core and a secondary side split core, and is made of a material having a preset magnetic permeability characteristic. A magnetic core, a primary winding wound around the primary-side split core, and into which the measured current is input as a primary current, and a primary current passed through the primary winding. The secondary winding is wound around the secondary core so as to induce a secondary current that causes the magnetic flux to be generated in a direction that cancels the generated magnetic flux, and a part of the secondary winding is wound around the primary split core. And are provided.

According to the above structure, the outer dimensions of the primary winding and the outer dimensions of the secondary winding can be made equal to each other, whereby the magnetic transformer portion can be miniaturized and the current sensor can be miniaturized. In addition, the weight on the primary split core side and the weight on the secondary split core side are balanced to eliminate the need for a reinforcing structure and the like, and simplify the mounting structure. When the bobbin is used to wind the primary winding and the secondary winding around the side split core, the common bobbin can be used for the primary side split core and the secondary side split core, thereby suppressing development investment funds. .

[0013]

1 is a perspective view showing an embodiment of a magnetic transformer for a sensor according to the present invention.

Magnetic transformer 1 for current sensor shown in this figure
Is the first to which the measured current to be measured is input,
The second input terminals 2 and 3, the primary side split core 4 formed in a U-shape with a high magnetic permeability material, and the primary side split core 4
And a primary winding 5 formed by winding a predetermined number of times (N ₁ turns) into a U-shape and made of a material having a high magnetic permeability, and each end of the primary winding 5 has each end of the primary-side split core 4. A secondary side split core which is arranged so as to oppose to each other and is magnetically coupled to the primary side split core 4 with a slit 6 between each end to form a magnetic core (magnetic circuit) 8. 7, the secondary winding core 7 is wound a predetermined number of times (N ₂ turns) in the winding direction opposite to the winding direction of the primary winding 5, and the primary split core 4 is rotated a predetermined number of times (N ₂ turns). _The secondary winding 9 is formed by winding ₃ turns), and the first and second output terminals 10 and 11 connected to each end of the secondary winding 9 are provided. A magnetic sensor (not shown) that detects the magnetic flux density in the magnetic core 8 is inserted in any of the slits 6.

In the above structure, when a current to be measured is input to the first and second input terminals 2 and 3, a magnetic flux is generated in the magnetic core 8 by the primary winding 5, but in contrast to this, , A current value measuring circuit (not shown) causes a magnetic flux canceling current to flow through the secondary winding 9 in a direction opposite to the direction of the secondary current, and the magnetic flux passing through the magnetic sensor becomes zero. The value of the measured current is determined based on the value of the magnetic flux cancellation current at that time.

As described above, in this embodiment, a part of the secondary winding 9 is wound around the primary-side split core 4, and the primary winding is wound around the primary-side split core 4 as shown in FIG. Since the outer dimension h _{3 of the} wire 5 and the secondary winding 9 and the outer dimension h _{4 of the} secondary winding 9 wound around the secondary side split core 7 are made to be the same, downsizing of the magnetic transformer portion is achieved. It is possible to achieve the miniaturization of the current sensor and to balance the weight of the primary split core 4 side and the weight of the secondary split core 7 side, thereby eliminating the need for a reinforcing structure or the like. At the same time, the mounting structure can be simplified.

When the primary winding 5 and the secondary winding 9 are wound around the primary split core 4 and the secondary split core 7, the primary winding 5 and the secondary winding 9 are attached to each bobbin. After winding, each of these bobbins is attached to the primary split core 4 and the secondary split core 7.
, The bobbin of the same standard can be used as the bobbin around which the primary winding 5 and the secondary winding 9 are wound and the bobbin around which the secondary winding 9 is wound. Can be suppressed.

[0018]

As described above, according to the present invention, 1
The external dimensions of the secondary winding and the secondary winding can be made the same, which allows miniaturization of the magnetic transformer portion and miniaturization of the current sensor, as well as the primary coil. By balancing the weight of the split core side and the weight of the secondary split core side, it is possible to eliminate the need for a reinforcing structure and the like, and to simplify the mounting structure. When using a bobbin when winding the primary winding and the secondary winding around the secondary side split core,
A bobbin common to the primary side split core and the secondary side split core can be used, which can suppress development investment funds.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a magnetic transformer for sensors according to the present invention.

FIG. 2 is a cross-sectional view of the magnetic transformer for a current sensor shown in FIG. 1 when cut in the lateral direction.

FIG. 3 is a perspective view showing an example of a conventionally known magnetic transformer for a current sensor.

FIG. 4 is a cross-sectional view of the magnetic transformer for a current sensor shown in FIG. 3 when cut in the lateral direction.

[Explanation of symbols]

 1 current sensor magnetic transformer 2 first input terminal 3 second input terminal 4 primary split core 5 primary winding 6 slit 7 secondary split core 8 magnetic core 9 secondary winding 10 first output terminal 11th 2 output terminals

Claims (1)

[Claims] 1. When a current to be measured is input,
In a magnetic transformer for a sensor that generates a secondary current corresponding to this measured current, it is composed of a primary side split core and a secondary side split core, and is made of a material having a preset magnetic permeability characteristic. And a magnetic core that is wound around the primary split core, and the measured current is 1
A primary winding that is input as a secondary current, and a secondary that generates a magnetic flux in the opposite direction that cancels the magnetic flux generated in the magnetic core by the primary current flowing in the primary winding. 2 so that an electric current is induced
A magnetic transformer for a sensor, comprising: a secondary winding wound around the secondary core and part of the secondary winding wound around the primary split core.