JP2011080973A - Coreless current sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coreless current sensor which has little influence on an electric component caused by heat generation from a primary conductor, can connect the primary conductor to a substrate easily and highly accurately, and optimizes easily intensity of a magnetic field applied to a magnetosensitive element. <P>SOLUTION: A terminal 5 for soldering provided on the primary conductor 4 is inserted into a through hole provided in a substrate 1, and soldered and fixed with a prescribed gap 7 between the substrate and the primary conductor by allowing a projection part provided on the primary conductor to abut on the substrate. Hereby, the primary conductor can be fixed accurately and easily, and while reducing an influence of heat generation from the primary conductor, the intensity of the magnetic field applied to the magnetosensitive element 2 can be optimized. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a current sensor, and more particularly to a coreless current sensor having no magnetic core.

  As a conventional coreless current sensor, there is one in which a magnetosensitive element is mounted on a component mounting surface of a board and a primary conductor is attached in close contact with the back surface of the board. (For example, see Patent Document 1)

Published Utility Model 3-8770

  In the coreless current sensor disclosed in Patent Document 1, a magnetosensitive element is mounted on a component mounting surface of a substrate, and a primary conductor is disposed in close contact with the substrate on the back surface. The generated magnetic field is detected by a magnetosensitive element mounted on the board component mounting surface, and converted into a signal such as a voltage to measure the magnitude of the primary current.

  Since such a coreless current sensor directly measures the magnetic field from the primary conductor with a magnetosensitive element, it is sensitive to changes in the relative positions of the primary conductor and the magnetosensitive element and securely fixes the primary conductor and the magnetosensitive element. There is a need. For this reason, the primary conductor is bonded and fixed in a state of being in close contact with the substrate.

  However, the method of adhering the primary conductor to the substrate has the problems that positioning at the time of bonding is difficult and workability is poor because it takes time to cure the adhesive.

  In addition, since the primary conductor and the substrate are in close contact with each other, there is a problem that the magnetosensitive element and other electronic components are heated by the heat generated by the primary conductor, which adversely affects characteristics and reliability.

  In order to change the sensitivity of the current sensor, it is necessary to change the distance between the primary conductor and the magneto-sensitive element. However, the method of adhering the primary conductor to the board only changes the thickness of the board, so the current range depends on the current range to be measured. There is a problem that it is difficult to optimize the strength of the magnetic field applied to the magnetosensitive element.

  One of the objects of the present invention is to provide a coreless current sensor capable of easily and accurately fixing a primary conductor and a substrate.

  Another object of the present invention is to provide a coreless current sensor in which the influence on electronic components due to heat generated by the primary conductor is suppressed.

  Another object of the present invention is to provide a coreless current sensor that can easily optimize the strength of the magnetic field applied to the magnetosensitive element by the current to be measured.

  According to the present invention, a magnetosensitive element is disposed on a component mounting surface of a substrate, and a primary conductor is disposed on the back surface thereof, and a magnetic field generated by a current flowing through the primary conductor is detected by the magnetosensitive element and converted into a signal such as a voltage. In the coreless current sensor configured to measure the magnitude of the primary current, a soldering terminal provided on the primary conductor is inserted into a through-hole provided on the substrate, and between the primary conductor and the substrate. It is characterized by being fixed by soldering with a predetermined gap.

  Further, when the primary conductor is soldered and fixed to the substrate, a protrusion for ensuring a predetermined gap by contacting with the substrate can be provided on the primary conductor.

  According to the coreless current sensor of the present invention, the connection between the primary conductor and the substrate can be easily performed with high accuracy. Further, according to the coreless current sensor of the present invention, it is possible to suppress the influence on the electronic component due to the heat generation of the primary conductor. Further, according to the coreless current sensor of the present invention, the strength of the magnetic field applied to the magnetosensitive element can be easily optimized according to the magnitude of the current to be measured.

It is a top view of the coreless current sensor in this embodiment. It is a side view of the coreless current sensor in this embodiment. It is a perspective view which shows the primary conductor of the coreless current sensor in this embodiment.

    Hereinafter, embodiments of a coreless current sensor according to the present invention will be described with reference to the drawings. First, in FIG. 1 and FIG. 2, the peripheral circuit component 3 for constituting the magnetosensitive element 2 and the amplifier circuit is mounted on the component mounting surface of the substrate 1. The primary conductor 4 (partially indicated by a broken line in FIG. 1) is inserted into the through holes 6 of the substrate 1 with the terminals 5 provided at three locations of the primary conductor 4 with a predetermined distance 7 from the back surface of the substrate 1. And it is fixed by soldering. With this configuration, the primary conductor 4 and the substrate 1 can be fixed with high accuracy and easily in a short time. Further, by providing an interval 7 between the substrate 1 and the primary conductor 4, the space between the substrate 1 and the primary conductor 4 can be achieved. Therefore, the heat generated by the primary conductor 4 is less likely to be transmitted to the magnetosensitive element 2 and other electronic components 3, and the influence of the heat generated by the primary conductor can be suppressed.

3, the primary conductor 4 is provided with a protrusion 8, and when the terminal 5 of the primary conductor 4 is inserted into the through hole 6 of the substrate 1, the latter half is inserted until the protrusion 8 contacts the substrate 1. By performing the padding, the predetermined interval 7 can be ensured accurately and easily. Further, by changing the dimension of the protrusion 8 in accordance with the magnitude of the current flowing through the primary conductor 4, the dimension of the distance 7 between the primary conductor 4 and the substrate 1, that is, the distance between the primary conductor 4 and the magnetosensitive element 2. Changes, and the strength of the magnetic field applied to the magnetosensitive element 2 can be optimized.
In this embodiment, three terminals 5 are provided on the primary conductor 4, but the number of terminals 5 may be two or less or four or more as long as the primary conductor 4 can be stably fixed to the substrate 1. .

DESCRIPTION OF SYMBOLS 1 Board | substrate, 2 Magnetic sensing element, 3 Peripheral circuit components, 4 Primary conductor, 5 Terminal, 6 Through hole, 7 Gap, 8 Protrusion

Claims (2)

A magnetic sensitive element is disposed on the component mounting surface of the board, and a primary conductor is disposed on the back surface thereof. A magnetic field generated by a current flowing through the primary conductor is detected by the magnetic sensitive element and converted into a signal such as a voltage, thereby generating a primary current. In a coreless current sensor configured to measure the size, at least one soldering fixing terminal is provided on the primary conductor, and the fixing terminal is inserted into the hole of the board, and between the primary conductor and the board. A coreless current sensor configured to be fixed by soldering in a state where a predetermined interval is provided. 2. The coreless current sensor according to claim 1, wherein when a protrusion is provided at least at one location of the primary conductor and the primary conductor is fixed to the substrate, the protrusion can be brought into contact with the substrate to obtain a predetermined interval. A coreless current sensor characterized by the above.

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