JPH08201438A - Current detecting circuit module - Google Patents

Abstract

PURPOSE: To provide a current detecting circuit module of a current detecting circuit which detects the magnitude of an electric current flowing through a current line, has a small size and light weight, and can be mounted on the surface of a circuit board. CONSTITUTION: A current detecting conductor 16 is wound around a magnetic core 14 which is fixed to one surface of a circuit board 11 mounted with electronic parts 13 and becomes free against the other surface of the board 11 and the front end section of the conductor 16 is formed. Then the front end section 17a of a connecting lead terminal electrically connected to the parts 13 on the board 11 is formed and sealed with an external case 18. Therefore, a current detecting circuit module which has a small size and light weight and can be mounted on the surface of the circuit board 11 can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current detection circuit module for detecting the magnitude of current flowing in a current line.

[0002]

2. Description of the Related Art In recent years, the demand for high-precision detection of current flowing through a motor has become an essential requirement for high-precision motor control and power saving. Moreover, a current detection circuit having a structure capable of surface mounting is demanded as an important electronic component.

A conventional current detection circuit module will be described below with reference to the drawings. FIG. 2 is a perspective view of a conventional current detection circuit module. In FIG. 2, reference numeral 1 denotes a circuit board on which various electronic components 2 constituting a module are mounted and connected on the front surface or the back surface. Reference numeral 3 denotes a magnetic core that constitutes a closed magnetic field of the current flowing through the current detection electric wire 4, and gives a magnetic field proportional to the current flowing through the current detection electric wire 4 to the magnetoelectric conversion element 5. The current detection electric wire 4 is arranged separately from the circuit board 1. Reference numeral 5 denotes a magnetoelectric conversion element, which generates a voltage in proportion to a current flowing through the current detection electric wire 4, and an output amplified and molded by a circuit composed of an amplifier circuit 6 and various electronic components 2 is externally connected by a connection lead 7. Output to a circuit motherboard for controlling external motors, etc.
Connection is made by a soldering iron or a jet solder reflow method.

[0004]

However, in the above-mentioned conventional configuration, the current detection wire 4 is arranged separately from the circuit board 1 on which the amplifier circuit 6 and various electronic components 2 are mounted and connected,
Since the connection is also separated from the connection lead 7 that outputs the amplified signal, the overall configuration is large and the weight is large, and after the connection lead 7 is inserted into a mother board to be connected to the outside, a soldering iron or a jet There was a problem that solder connection had to be made by solder reflow or the like.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a current detection circuit module that is small in size and light in weight and capable of surface mounting.

[0006]

In order to solve the above-mentioned conventional problems, the present invention provides a circuit board having electronic parts mounted on the front surface or the back surface and having a circuit portion, and one end fixed to one surface of the circuit board. And the other end is provided on the other surface of the circuit board so as to be a free end to form a closed magnetic circuit, and a magnetic conversion element is provided in the closed magnetic circuit of the magnetic core and the end is wound around the magnetic core. And a connection lead terminal electrically connected to the circuit portion on the circuit board and having a tip portion formed. The current detection conductor and the connection lead are formed. And an outer case that is sealed except for the end portion.

[0007]

[Operation] With this configuration, the product can be picked up by vacuum suction or the like on the upper surface of the outer case by the mounting machine, the current detection wire and the output connection lead can be positioned on the cream solder printing surface, and highly accurate automatic surface mounting can be performed. Became.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A current detection circuit module according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a perspective view showing a current detection circuit module according to an embodiment of the present invention, and FIG. 1B is a sectional view of the same.

In the figure, reference numeral 11 denotes a circuit board, which has a conductor layer (not shown) formed on the front surface or the back surface by conductor foil or conductor printing, and various types having at least an amplifier circuit 12 on the conductor layer. A circuit including the electronic component 13 is mounted and connected. Reference numeral 14 is a magnetic core made of ferrite, permalloy, silicon steel plate or the like so that one end is fixed to one surface of the circuit board 11 and the other end is a free end on the other surface of the circuit board 11. It consists of a closed magnetic circuit,
A notch for inserting a magnetoelectric conversion element 15 described later is provided in a part thereof. 16 is a current detection conductor,
A copper wire coated with polyurethane, polyester, or the like is wound in a coil shape (0.5 to 25 turns), and the tip portion 16a protruding from the end surface of the circuit board 11 can be surface-mounted. The circuit board 11 is bent so as to be parallel to the surface on which the electronic component 13 is mounted, and for example, an L-shaped product is fixed to the circuit board 11 with epoxy resin, high-temperature solder, or the like. Reference numeral 15 denotes a magnetoelectric conversion element, which is composed of a Hall element or a ferromagnetic magnetic sensitive resistance, is arranged in a closed magnetic circuit of the magnetic core 14, and can obtain a voltage output proportional to the strength of the magnetic field. Reference numeral 12 is an amplifier circuit, and various electronic components 13
The circuit section is formed by the combination with. Reference numeral 17 is a connection lead terminal, which is an F-type lead, a flat lead, a connection lead terminal 1
Similarly to the tip portion 16a of the current detection conductor 16, the tip portion 17a of No. 7 is formed into, for example, an L shape to have a surface mountable shape, and is connected to an external circuit. Reference numeral 18 denotes an outer case, which is made of resin such as ABS, PBT, PPS, etc., and seals other portions except the tip portion 16a of the current detection conductor 16 and the tip portion 17a of the connection lead terminal 17. is there.

The operation of the current detecting module having the above structure according to the embodiment of the present invention will be described below.

The detection current flows through the winding which is the current detection conductor 16 and forms a coil of 0.5 to 25 turns with respect to the magnetic core 14, and the magnetic field is generated by the current applied to the winding. The magnetic field generated in the closed magnetic circuit of the magnetic core 14 is applied to the magnetoelectric conversion element 15 in proportion to the detected current, and a voltage output proportional to the detected current is obtained from the magnetoelectric conversion element 15.
Since this voltage output has a small level, it is amplified by the amplifier circuit 12, is further appropriately processed by the circuit including the other electronic component 13, and is output from the connection lead terminal 17 formed into an L shape.

[0013]

As described above, according to the present invention, the current detection conductor and the magnetic core are integrated on the circuit board, and the current detection conductor and the output signal connection lead are formed into an L-shape. It is possible to provide a current detection circuit module that can handle the above.

Further, by using the outer case, the mounting machine can be vacuum-sucked and the mounting machine can realize automatic surface mounting.

[Brief description of drawings]

FIG. 1A is a perspective view of a current detection module according to an embodiment of the present invention, and FIG.

FIG. 2 is a perspective view of a conventional current detection module.

[Explanation of symbols]

 11 circuit board 14 magnetic core 15 magnetoelectric conversion element 16 current detection conductor 17 connection lead terminal 18 outer case

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidefumi Nakamura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A circuit board having a circuit part on which electronic components are mounted on a front surface or a back surface, and one end is fixed to one surface of the circuit board and the other end is a free end on the other surface of the circuit board. A magnetic core that forms a closed magnetic path provided in the magnetic core, a current detection conductor that has a magnetoelectric conversion element in the closed magnetic path of the magnetic core, and is wound around the magnetic core to form a tip portion, and a circuit on the circuit board. A connecting lead terminal formed by electrically forming a tip portion and electrically connected to the portion, and an outer case formed by sealing the current detecting conductor and the connection lead excluding the formed tip portion. Current detection circuit module.