JPH09251921A - Current transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a current transformer having a structure which never causes the short circuiting in a side of a coil bobbin mounted on a substrate at low cost, superior in withstand voltage property and allowing the size to be reduced. SOLUTION: U-shaped single-turn pin 3 for prim. coil is inserted into prim. coil grooves 11 from a lower side, connectors of fastening terminals, etc., are connected to fixing grooves formed at the ends 4a, 4b of the pins 3 on the upper face of the bobbin 1, and a U-shaped magnetic core 10 is mounted in a center hole of the coil 1 from both sides. Then dummy pins formed on the lower face of a flange 2a and multiply-wound sec. coil terminals 5a, 5a are mounted on the board. Thus, no current flows in the board, and hence a current transformer superior in withstand voltage property and allowing the size to be reduced is obtained.

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 circuit current used in electronic equipment and the like.

[0002]

2. Description of the Related Art FIG. 3 shows an external perspective view of a conventional current transformer, and FIG. 4 shows a side view thereof. As shown in FIGS. 3 and 4, in the conventional current transformer, the U-shaped pin is inserted in the recessed groove 8 provided in one of the flanges 2a and 2b at both ends from the upper side so as to be fitted in the opposite direction. A magnetic core 10 is assembled to a U-shaped pin 3 for a primary coil and a coil bobbin 1 around which a secondary coil 7 is wound in the center. Further, the end portion 4 of the U-shaped pin 3 for the primary coil and the secondary coil terminal 5 are directly mounted on the substrate 6 which is a device side circuit.

[0003]

During operation of the current transformer, a current of several tens of amperes flows through the primary coil, so that dielectric breakdown occurs on the substrate 6 to which the end 4 of the primary coil U-shaped pin 3 is connected. As a result, a short circuit is likely to occur.

Therefore, it is necessary to use a substrate material having excellent pressure resistance for the substrate, which makes the substrate expensive, or is formed between the end portions 4 of the U-shaped pin 3 for the primary coil and on the substrate. In order to ensure the insulation of the circuit pattern, it is necessary to widen the pattern interval, which has been an obstacle to miniaturization of the substrate itself.

A technical object of the present invention is to solve the above-mentioned drawbacks as a structure in which a short circuit does not occur on a substrate, and to provide a current transformer which is inexpensive, has an excellent withstand voltage and can be miniaturized. To do.

[0006]

In the current transformer according to the present invention, the U-shaped pin for the primary coil is inserted from the lower side of the coil bobbin on the board mounting side so that the current does not flow on the board, and the U-shaped pin is provided on the upper part of the transformer. A connector or the like can be connected to the two ends of the exposed U-shaped pin, and a dummy pin for board mounting is embedded in the lower flange of the coil bobbin.

That is, according to the present invention, in a current transformer in which a magnetic core is assembled to a coil bobbin wound with a one-turn primary coil and a secondary coil by a U-shaped pin, to a groove provided on the board mounting side of the collar of the coil bobbin. The U-shaped pin is inserted from the board mounting side and both ends thereof are projected to opposite sides, and stop grooves are formed at both ends of the coil bobbin, and dummy pins for mounting are provided on the board mounting side of the coil bobbin. It is a current transformer.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of a current transformer of the present invention, and FIG. 2 is a side view thereof.

As shown in FIGS. 1 and 2, the primary coil U-shaped pin 3 for the primary coil is a primary coil for inserting and positioning the primary coil U-shaped pin 3 on the lower end face of the collar 2a of the coil bobbin 1. The groove 11 is provided, and the groove 11 for the primary coil is provided.
U-shaped pin 3 for 1-turn primary coil formed in U shape
Is inserted from the lower side, and the ends 4a and 4b of the U-shaped pin 3 for the primary coil are formed on the upper surface of the coil bobbin 1. It has a structure in which a connector such as a faston terminal is connected to a stop groove (not shown) provided in the end portions 4a and 4b.

Further, after the U-shaped magnetic core 10 is assembled into the central hole of the coil bobbin 1 from both sides, the dummy pin 9 provided on the lower surface of the collar 2a and the secondary coil at the lower end of the secondary coil 7 which is wound a lot. The terminals 5a and 5b are mounted on the substrate 6.

[0011]

As described above, according to the present invention,
Since the U-shaped pin terminal for the primary coil is not mounted on the mounting board, no current flows in the board, and it is possible to obtain a current transformer excellent in withstand voltage and capable of being downsized.

[Brief description of drawings]

FIG. 1 is an external perspective view of a current transformer of the present invention.

FIG. 2 is a side view of the current transformer of the present invention.

FIG. 3 is an external perspective view of a conventional current transformer.

FIG. 4 is a side view of a conventional current transformer.

[Explanation of symbols]

 1 Coil bobbin 2a, 2b Tsuba 3 (for primary coil) U-shaped pin 4, 4a, 4b Pin end 5,5a, 5b Secondary coil terminal 6 Substrate 7 Secondary coil 8 Groove 9 Dummy pin 10 Magnetic core 11 Groove for primary coil

Claims (1)

[Claims] 1. A current transformer in which a magnetic core is assembled to a coil bobbin in which a primary coil and a secondary coil are wound by a U-shaped pin, and the U-shaped groove is provided on a board mounting side of a flange of the coil bobbin. A current transformer characterized in that a pin is inserted from a board mounting side, both ends thereof are projected to opposite sides, and stop grooves are formed at the both ends and mounting dummy pins are provided on the board mounting side of the coil bobbin.