JP2544930Y2 - Surface mount type current transformer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current transformer for detecting a current flowing through a circuit, which is used in an electronic device.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view of a conventional current transformer.
Shown in This current transformer 11 has a bobbin 10 having flanges 2 and 3 at both ends of a winding core 1, and one flange 3 integrally formed with a one-turn coil 5 and a terminal 4 for connecting a terminal of a winding 12. , Windings 12 are wound, the core 7 is mounted, and the cores 8 are fixed.

[0003] This current transformer has a structure that can be surface-mounted. The one-turn coil 5 and the terminal 4 of the bobbin 10 are formed in a lead frame shape. The U-shaped one-turn coil 5 and the terminal 4 are formed integrally with the lead frame 12. The one-turn coil 5 and the terminal 4 of the lead frame 12 are connected to the bobbin 1.
The bobbin is formed by resin molding so as to be inserted into the zero flange 3.

[0004]

In a conventional surface mount current transformer, a one-turn coil and a terminal are formed on a flange of a bobbin using a lead frame. However, in the conventional lead frame, the U-shaped one-turn coil moves up and down and is unstable, and when the bobbin is formed by resin molding, the thickness of the bobbin in the one-turn coil portion is not constant, It was difficult to satisfy safety standards.

In view of the above, an object of the present invention is to provide a surface mount type current transformer that can easily satisfy safety standards.

[0006]

[Means for Solving the Problems] The present invention is directed to a vertical direction.
Thick collars are provided on the upper and lower ends of a cylindrical core with through holes
A U-shaped one-turn coil surrounding the through-hole of the winding core was formed on the flange below the winding frame, and a pin terminal for tying up the secondary winding coil was formed in the opposite direction of the one-turn coil. In a surface mount type current transformer in which a core having a high magnetic permeability is incorporated in a bobbin, the U-shaped one-turn coil and a pin terminal for binding a secondary winding coil are formed in a lead frame shape in advance. U-shaped tip of one-turn coil of lead frame
And a bridge connected to the other lead frame .

[0007]

FIG. 1 shows a lead frame according to an embodiment of the present invention, and FIG. 2 shows a bobbin. The appearance is similar to that of FIG. In this embodiment, a lead frame 23 in which a U-shaped one-turn coil 21 and a terminal 22 for binding a secondary winding coil are integrally formed is used. In the lead frame 23, the end of the U-shaped tip of the one-turn coil 21
To connect to the other lead frame on which the element 22 is formed.
And a bridge 24 is formed.
The one-turn coil 21 having a substantially U-shape has three substantially Y-shaped points.
The connection to both the lead frames 23 prevents the U-shaped one-turn coil 21 from moving up and down.

The lead frame 23 is formed by resin molding to form a bobbin 25. At this time, the U-shaped one-turn coil 21 and the terminal 22 are implanted in the lower flange 26. Then, a block formed at the U-shaped tip of the one-turn coil 21 is formed.
The ridge 24 is cut along the outer peripheral surface of the flange 26 of the bobbin 25.
Has been refused. The U-shaped one-turn coil 21 and the terminal 22 for binding the secondary winding coil are processed so as to be surface mountable. The bobbin 25 has a core 28
Flanges 26 and 27 are formed at both ends thereof, a through hole 29 into which a core is inserted is formed in the winding core 28, and a concave groove 30 into which the core is mounted is formed in the flanges 26 and 27.

Then, a secondary winding coil is wound around the bobbin 25, its terminal is entangled with the terminal 22, a core is attached,
The core was fixed with metal fittings to form a surface-mounted current transformer.

[0010]

According to the present invention, the U on the lead frame
The bobbin can be formed without the vertical one-turn coil moving up and down. Therefore, the bobbin can be formed with a predetermined thickness, and the designed safety can be obtained. As a result, a surface-mounted current transformer that easily satisfies safety standards can be configured.

[Brief description of the drawings]

FIG. 1 is a plan view of a lead frame according to an embodiment of the present invention.

FIG. 2 is a front view of the bobbin according to the embodiment of the present invention;

FIG. 3 is a plan view of a conventional lead frame.

FIG. 4 is a perspective view of a conventional example.

[Explanation of symbols]

 21 U-shaped one-turn coil 22 Terminal 23 Lead frame 24 Bridge 25 Bobbin 26, 27 Flange 28 Core 29 Through-hole 30 Groove

Claims (1)

(57) [Scope of request for utility model registration] 1. A cylindrical core having a through hole in a vertical direction is provided with thick flanges on both upper and lower ends thereof, and a lower flange of the core is provided with a thick flange .
A U-shaped one-turn coil surrounding the through-hole is formed, and a high-permeability core is incorporated in a bobbin in which a pin terminal for tying a secondary winding coil is formed in a direction opposite to the one-turn coil. In the surface mount type current transformer, the U-shaped 1
Turn coil and the pin terminal Karageru the secondary winding is formed in advance on the lead frame shape, 1 of the lead frame
Connect the U-shaped tip of the turn coil to the other lead frame.
A surface mounted current transformer characterized by forming a continuous bridge .