JP2009210366A - Current sensing resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a current sensing resistor that is surface-mounted and has a simple structure to cut costs. <P>SOLUTION: The current sensing resistor 10 is formed by bending one metal resistance wire into a gate-shaped side 11 comprising a pair of left/right leg sides 13a, 13b and a connecting side 14 connecting the leg sides 13a, 13b with each other and foot sides 12. The leg sides 13a, 13b are bent at a right angle with respect to the connecting side 14 and in the same direction. The foot sides 12 are arranged at the lower ends of the leg sides 13a, 13b and are bent into a rectangular shape on a plane which forms a right angle with respect to the leg sides 13a, 13b. The current sensing resistor 10 is thereby stabilized when it is allowed to stand on its own. The current sensing resistor 10 has a simple structure comprising one metal resistance wire and can be surface-mounted, thereby cutting costs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resistor, and more particularly to a fixed resistor made of a metal wire.

Conventionally, a precision resistor in which an alloy such as a copper-manganese alloy is formed into a wire or strip has a predetermined volume resistivity, a temperature coefficient of resistance close to 0, and a low thermoelectric power against copper. And circuit elements of precision electrical instruments and current adjustments that require precision.
The current detection resistor disclosed in Japanese Utility Model Laid-Open No. 5-43502 discloses a configuration of a known current detection resistor as shown in FIGS. In FIG. 6, reference numeral 1 denotes a circuit board made of an insulator, and ends of the resistance wires 2a and 2b are connected to conductors 3a and 3b provided on the circuit board 1 by soldering or the like. Further, as shown in FIG. 7, in order to eliminate the difference in thermoelectromotive force that causes an error in the detected current value, the resistance wires 4a and 4b are, for example, U-shaped, and a portion connected to the conductor 5a By reducing the distance from the portion connected to the conductor 5b, the temperatures at both ends of the resistance wires 4a and 4b are made substantially equal. These current detection resistors are surface-mounted by soldering to conductors 5 a and 5 b provided on the circuit board 1.

  On the other hand, an electronic component disclosed in JP-A-10-177901 is composed of an electronic component main body and a pair of terminals provided so as to protrude from the electronic component main body, and the pair of terminals are provided below the electronic component main body. The terminals are bent substantially parallel to each other, and one side of the bent pair of terminals is located on the same plane and is provided so as to be able to stand by itself. At this time, the terminal is bent in a direction orthogonal to the central axis of the electronic component main body and formed in a V shape. The outside of the portion bent in the V shape is formed in a shape that is crushed widely in the vicinity of the center so as to be in contact with the circuit board, and by soldering the part in contact with the land on the surface of the circuit board, The electronic component is surface-mounted on the circuit board.

When the above-described current detection resistor and electronic component are surface-mounted on a circuit board, conductors 3a, 3b, 5a, 5b and terminals (hereinafter referred to as “terminals”) are initially attached by an action called self-alignment. Move from a position to an appropriate position.
Self-alignment means that the terminal or the like automatically moves to a position where the force acting on the terminal or the like is balanced in the liquid solder. Here, the force acting on the terminals, etc., includes the buoyancy that the terminals in the liquid solder receive from the pressure of the solder acting on the surfaces of the terminals and the like, and the liquid solder reduces the liquid surface on the land. Thus, it consists of surface tension generated along the liquid surface when trying to take a substantially hemispherical shape.
Since self-alignment can facilitate positioning of terminals and the like, the surface mounting structure can increase the density and efficiency of the circuit board and reduce the size of mounted electronic components and the like. it can.
Japanese Utility Model Publication No. 5-43502 Japanese Patent Laid-Open No. 10-177901

However, since the electronic component has a special shape in which the terminal is crushed so as to widen the portion in contact with the circuit board, it is necessary to form a press die corresponding to the portion, resulting in high cost. In addition, it is time-consuming to form a miniaturized press die for electronic components.
On the other hand, the current detection resistor has a large number of parts because it is composed of a plurality of resistance wires and conductors. Further, since the resistance wires are cut to a predetermined length, there is a risk that the material is wasted. Since the resistance wires are respectively attached to the conductors by soldering or welding, the number of manufacturing processes is large and the cost is increased. Furthermore, when a resistor for current detection using solder when attaching a resistance wire to the conductor is soldered to a land of a circuit board, heat for melting the solder is transferred to the conductor, and the conductor is The solder that fixes the resistance wire may melt.

  In order to solve the above-described problems, an object of the present invention is to provide a current detection resistor having a simple structure that can be surface-mounted and cost-cut.

  The current detection resistor according to claim 1, wherein one metal resistance wire is bent at a gate-shaped side composed of a pair of left and right leg sides and a connecting side connecting the both leg sides. Then, a foot side that is bent in the same plane that is substantially perpendicular to each leg side is formed at the lower end of each leg side.

  According to a second aspect of the present invention, in the invention of the first aspect, the foot side is formed in a rectangular shape or a ring shape.

  According to a third aspect of the present invention, the current detection resistor according to the first aspect of the present invention has a shape substantially the same as that of the gate-shaped side, and a sub-portion-shaped side continuous from one leg side of the gate-shaped side. , And formed in parallel with the portal side.

According to the invention described in claim 1, since the current detection resistor has a simple structure that is bent from one metal resistance wire, the number of parts is small, and the manufacturing process is simple. Cost cut can be realized.
In addition, the current detecting resistor bent at the gate-shaped side having a pair of left and right leg sides is bent at the lower end of the leg side on a plane perpendicular to the leg pieces. . Therefore, the current detection resistor can be made independent. Since the current detection resistor is self-supporting, it is possible to easily mount the current detection resistor on the surface of the circuit board.

  According to the second aspect of the present invention, the foot side formed at the lower end of the leg piece is bent into a rectangular or ring shape. Therefore, since the leg sides are stabilized, the current detection resistor can be easily set up.

  According to the third aspect of the present invention, the sub-portion side having substantially the same shape as the portal side is bent so as to be parallel to the gate side. Therefore, when the surface mounting is performed on the lands of the circuit board, the pair of opposed lands can be connected by the two metal resistance lines including the gate-shaped side and the sub-gate-shaped side. Therefore, since the resistance load of the current detection resistor is halved, the current flowing through the current detection resistor can be increased if the voltage applied to the current detection resistor is the same.

  A first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the current detection resistor according to the first embodiment.

The current detection resistor 10 includes a gate-shaped side 11 and a foot side 12 formed by bending a single metal resistance wire.
The metal resistance wire is made of a wire having a constant diameter, and is made of a metal such as a copper manganese alloy (manganin), a copper nickel alloy, or a nickel chromium aluminum alloy. It is preferable that the metal resistance wire has a resistance temperature coefficient close to 0, a small electromotive force against copper, and a material with little secular change in characteristics such as volume resistivity.
In addition, you may use the metal resistance wire which consists of copper with low volume resistivity as a short circuit wire (jumper or zero ohm resistor).

The gate-shaped side 11 includes a pair of left and right leg sides 13a and 13b and a straight connection side 14 that connects the leg sides 13a and 13b. The leg sides 13a and 13b are perpendicular to the connecting side 14 and are bent in the same direction.
The connecting side 14 may be formed in a semi-arc shape, and the gate-shaped side 11 may be formed in an inverted U shape. Alternatively, the leg sides 13a and 13b and the connecting side 14 may be integrally formed to form the portal side 11 in a semicircular shape.
The volume of the metal resistance wire is obtained from the cross-sectional area of the metal resistance wire having a constant diameter and the gate-shaped side 11 adjusted to a predetermined length. From the predetermined volume resistivity of the copper manganese alloy or the like, the current The resistance value of the detection resistor 10 can be obtained. Therefore, in the manufacturing process, the current detecting resistor 10 can be mass-produced by making the length of the gate side 11 constant.

  The foot side 12 is disposed at the lower ends of the leg sides 13a and 13b and is bent in a rectangular shape on a plane perpendicular to the leg sides 13a and 13b. The rectangular foot side 12 is composed of a pair of parallel vertical sides 12a, 12b, 12c and a pair of horizontal sides 12d, 12e. The vertical side includes a first vertical side 12a, a second vertical side 12b, and a third vertical side 12c, and the horizontal side includes a first horizontal side 12d and a second horizontal side 12e.

The first vertical side 12a is bent at a right angle to the lateral direction continuously to the leg side.
The first horizontal side 12d is bent at a right angle continuously to the first vertical side 12a.
The second vertical side 12b is bent at a right angle continuously to the first horizontal side 12d and parallel to the first vertical side 12a.
The second horizontal side 12e is bent at a right angle continuously to the second vertical side 12b and parallel to the first horizontal side 12d.
The third vertical side 12c is bent at a right angle continuously to the second horizontal side 12e and is arranged on the same straight line as the first vertical side 12a. The end of the third vertical side 12c faces the leg sides 13a and 13b, and a gap 15 is formed between the leg sides 13a and 13b.
The gap 15 is not welded because it is buried in the solder 21 when the current detection resistor 10 is soldered to the circuit board 20 as will be described later. However, the gap 15 may be welded to ensure the rigidity of the foot side.

As described above, since the rectangular foot 12 is bent on a plane perpendicular to the legs 13a and 13b, it can be stabilized when the current detecting resistor 10 is made independent.
The first vertical side 12a provided at the lower end portion of the leg side 13b is bent in a direction opposite to the direction in which the first vertical side 12a provided at the lower end portion of the leg side 13a is bent. Therefore, the foot side 12 provided at the lower end portion of the leg side 13b is formed in the reverse direction with respect to the foot side 12 provided at the lower end portion of the leg side 13a. Therefore, the rigidity of the gate-shaped side 11 can be increased when the current detection resistor 10 is made independent.
The surface portion defined by the foot side 12 is similar to the shape of the land 22 of the circuit board 20 and is formed slightly smaller than the area of the land 22. Therefore, since the distance between the side surface of the foot 12 and the edge of the land 22 can be shortened, the surface tension that the liquid solder 21 works to minimize the liquid surface when soldering is performed. Can be made to act strongly on the foot side 12, and self-alignment can be made easy to act.

The current detection resistor 10 having the above configuration is used as follows.
In the current detection resistor 10, the leg side 12 on the leg side 13 a side is arranged on the land 22, and the leg side 12 on the leg side 13 b side is arranged on the other land 22. To be placed on their own. Then, the solder 21 in the portion surrounded by the foot 12 on the land 22 is melted, so that the circuit board 20 is surface-mounted by soldering.
Since the current detection resistor 10 can be surface-mounted, the step of forming a through hole (through hole) for fixing the end of the metal resistance wire in the circuit board 20 can be omitted, and the cost can be reduced. Can be suppressed.
Furthermore, by performing surface mounting, after inserting the metal resistance wire into the through hole and soldering, it is not necessary to cut out the metal resistance wire protruding from the solder 21 on the back surface of the circuit board 20. Therefore, it is possible to prevent the metal resistance wire from being cut off.

  When the portion of the solder 21 surrounded by the foot 12 on the land 22 is melted, the buoyancy acts on the foot 12 before the liquid solder 21 is solidified, and the foot 12 floats on the solder 21. Further, surface tension acts on the liquid solder 21. Therefore, self-alignment that automatically moves to the position where the buoyancy and the surface tension are balanced acts on the foot 12. Here, the self-alignment is more strongly applied to the rectangular foot side 12 in the two directions of the direction along the vertical sides 12a, 12b, and 12c and the direction along the horizontal sides 12d and 12e.

Next, a second embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a perspective view of a current detection resistor 10A according to the second embodiment.
The current detection resistor 10 </ b> A includes a gate side 30 and a foot side 31 formed by bending a single metal resistance wire.
Since the metal resistance wires are the same as those in the first embodiment, the description thereof is omitted.

The gate-shaped side 30 includes a pair of left and right leg sides 32a and 32b and a semi-arc shaped connection side 33 that connects the leg sides 32a and 32b, and is formed in an inverted U shape. The leg sides 32a and 32b are perpendicular to the connecting side 33 and are bent in the same direction.
The foot side 31 is arranged at the lower end of the leg sides 32a and 32b, and is bent in a ring shape on a plane perpendicular to the leg sides 32a and 32b. The foot side 31 is continuous with the leg sides 32 a and 32 b and is bent at a right angle with respect to the direction along the gate side 30. Thereafter, the foot side 31 is wound into a circle or an ellipse, and the end of the foot side 31 faces the leg sides 32a and 32b. A gap 34 is formed between the end and the leg sides 32a and 32b.
The gap 34 is not welded because it is buried in the solder 21 when the current detection resistor 10A is soldered to the circuit board 20 as will be described later. However, the gap 34 may be welded to ensure the rigidity of the foot side 31.

Thus, since the ring-shaped foot side 31 is bent on a plane perpendicular to the leg sides 32a and 32b, it can be stabilized when the current detection resistor 10A is self-supporting.
The start end of the foot side 31 provided at the lower end portion of the leg side 32b is bent in the direction opposite to the start end of the foot side 31 provided at the lower end portion of the leg side 32a. Therefore, the ring-shaped foot side 31 formed at the lower end portion of the leg side 32b is formed in the reverse direction with respect to the ring-shaped foot side 31 formed at the lower end portion of the leg side 32a. Therefore, when the current detection resistor 10 </ b> A is self-supporting, the rigidity of the gate-shaped side 30 can be increased.
The area of the circular shape or the oval shape defined by the foot sides 31 is slightly smaller than the area of the rectangular land 22 of the circuit board. Therefore, since the distance between the outer surface of the foot 31 and the edge of the land 22 can be shortened, the surface where the liquid solder 21 works to minimize the liquid surface when soldering. Tension can be applied strongly to the foot side 31, and self-alignment can be easily applied.

Since the current detection resistor 10A having the above-described configuration is used in the same manner as in the first embodiment, description thereof is omitted.
According to the present embodiment, the self-alignment that automatically moves to the position where the buoyancy and the surface tension are balanced acts on the foot side 31 formed in the ring shape. Here, the self-alignment acts radially on the ring-shaped foot side 31 from the center of the foot side 31.

Next, a third embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 3 is a perspective view of the current detection resistor according to the third embodiment.
The current detection resistor 10 </ b> B includes a gate-shaped side 11 and a foot side 40 formed by bending a single metal resistance wire. The metal resistance wire is the same as that of the first embodiment, and the gate side 11 is formed in the same shape as that of the first embodiment, so that the description thereof is omitted.

  The foot side 40 is arranged at the lower end of the leg sides 13a, 13b and is bent in an L shape on a plane perpendicular to the leg sides 13a, 13b. The foot side 40 includes a horizontal side 40a that is bent at right angles from the leg sides 13a and 13b along the horizontal direction, and a vertical side 40b that is bent at a right angle continuously to the horizontal side 40a.

  The vertical side 40b of the foot side 40 provided at the lower end portion of the leg side 13b is bent in the opposite direction with respect to the vertical side 40b of the foot side 40 provided at the lower end portion of the leg side 13a. For this reason, the foot side 40 provided at the lower end portion of the leg side 13a and the foot side 40 provided at the lower end portion of the leg side 13b are alternately bent and formed. it can.

Since the current detection resistor 10B having the above-described configuration is used in the same manner as in the first embodiment, description thereof is omitted.
According to the present embodiment, the self-alignment that automatically moves to a position where the buoyancy and the surface tension are balanced acts on the foot side 40 formed in a U-shape. Here, the self-alignment acts more strongly on the U-shaped foot side 40 in the two directions of the direction along the vertical side 40b and the direction along the horizontal side 40a.

Next, a fourth embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 4 is a perspective view of a current detection resistor 10C according to the fourth embodiment.
The current detection resistor 10 </ b> C includes a gate side 50 a formed by bending a single metal resistance wire, a sub-gate side 50 b, and a foot side 51. Since the metal resistance wire is the same as that of the first embodiment, the description is omitted.

Similarly to the first embodiment, the gate-shaped side 50a is composed of a pair of left and right leg sides 13a and 13b and a linear connecting side 14 that connects the leg sides 13a and 13b. The leg sides 13a and 13b are perpendicular to the connecting side 14 and are bent in the same direction.
The sub-portion side 50b is formed in the same shape as the portal side 50a, and includes a pair of left and right leg sides 13a and 13b and a connecting side 14 that connects the leg sides 13a and 13b. The gate side 50a and the sub-gate side 50b are arranged in parallel.
The connecting side 14 may be formed in a semi-arc shape, and the gate side 50a and / or the sub-gate side 50b may be formed in an inverted U shape. Alternatively, the leg sides 13a, 13b and the connecting side 14 may be integrally formed to form the gate-shaped side 50a and / or the sub-gate-shaped side 50b in a semicircular shape.

The foot side 51 is continuous with the leg sides 13a and 13b of the portal side 50a and the sub-gate side 50b, and is bent on a plane perpendicular to the leg sides 13a and 13b. The foot side 51 includes a vertical side composed of a first vertical side 51a, a second vertical side 51b, and a third vertical side 51c, a first horizontal side 51d, a second horizontal side 51e, and a third horizontal side 51f. , And a fourth side 51g.
The foot sides 51a and 51d provided at the lower end of the leg side 13a of the portal side 50a are continuous with the first side 51d and the first side 51d bent at right angles from the leg side 13a along the horizontal direction. The first vertical side 51a bent at a right angle is formed in an L shape.
The foot sides 51b, 51e, 51f connecting the gate-shaped side 50a and the sub-gate-shaped side 50b have a second horizontal side 51e bent at a right angle from the leg side 13b of the gate-shaped side 50a along the horizontal direction, and a second side 51e. The second vertical side 51b bent at a right angle continuously to the horizontal side 51e and the third horizontal side 51f bent at a right angle continuous to the second vertical side 51b are formed in a U-shape. The end of the third lateral side 51f is continuous with the leg side 13b of the sub-portion side 50b.
The foot sides 51c and 51g provided at the lower end portion of the leg side 13a of the sub-portion side 50b are continuous with the fourth side 51g and the fourth side 51g bent at right angles from the leg 13a along the horizontal direction. The third vertical side 51c bent at a right angle is formed in an L shape. An end portion of the third vertical side 51c is opposed to an end portion of the first vertical side 51a, and a gap 52 is formed.
The gap 52 is not welded because it is buried in the solder 21 when the current detection resistor 10C is soldered to the circuit board 20 as will be described later. However, in order to ensure the rigidity of the foot side 51, the gap 52 may be welded.

Since the current detection resistor 10C having the above-described configuration is used in the same manner as in the first embodiment, the description thereof is omitted.
According to the present embodiment, the foot side 51 formed in a U shape between the gate side 50a and the sub-gate side 50b is automatically moved to a position where buoyancy and surface tension are balanced. Self-alignment that works. Here, the self-alignment acts on the U-shaped foot side 51 more strongly in the two directions of the vertical direction and the horizontal direction.
Further, by soldering the foot side 51 to the land 22 of the circuit board 20, two metal resistance wires of the gate-shaped side 50 a and the sub-gate-shaped side 50 b are installed between the lands 22. By using two metal resistance wires, the resistance load can be halved. Therefore, the resistance load is halved as compared with the case where one metal resistance wire is installed between the lands 22, so that the current flowing through the same circuit can be doubled.
Moreover, if the electric current to flow is the same, the heat_generation | fever of the resistor 10C for electric current detection can be suppressed.

Next, a fifth embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 5 is a perspective view of a current detection resistor 10D according to the fifth embodiment.
The current detection resistor 10 </ b> D includes a first portal side 60 a, a second portal side 60 b, a third portal side 60 c, and a foot side 61 formed by bending one metal resistance wire. Since the metal resistance wire is the same as that of the first embodiment, the description is omitted.

The first portal side 60a, the second portal side 60b, and the third portal side 60c are the leg sides 13a and 13b formed in a pair of left and right straight lines, like the portal side 11 of the first embodiment. And the straight connection side 14 connecting the leg sides 13a and 13b. The leg sides 13a and 13b are perpendicular to the connecting side 14 and are bent in the same direction. The first portal side 60a, the second portal side 60b, and the third portal side 60c are arranged in parallel.
The connecting side 14 may be formed in a semi-arc shape, and the first portal side 60a, the second portal side 60b, and the third portal side 60c may be formed in an inverted U shape. Alternatively, the leg sides 13a and 13b and the connecting side 14 may be integrally formed to form the first portal side 60a, the second portal side 60b, and the third portal side 60c in a semicircular shape.

  The foot side 61 is continuous with the leg sides 13a and 13b of the first portal side 60a, the second portal side 60b, and the third portal side 60c, and is bent on a plane perpendicular to the leg sides 13a and 13b. Has been. The foot side 61 includes a vertical side and a horizontal side. The vertical side includes a first vertical side 61a, a second vertical side 61b, a third vertical side 61c, and a fourth vertical side 61d, and the horizontal sides include a first horizontal side 61e and a second horizontal side 61f. The third horizontal side 61g, the fourth horizontal side 61h, the fifth horizontal side 61i, and the sixth horizontal side 61j.

The foot sides 61a and 61e arranged at the lower end of the leg side 13a of the first gate side 60a are continuous with the first side 61e bent at a right angle from the leg side 13a along the horizontal direction and the first side 61e. The first vertical side 61a bent at a right angle is formed in an L shape.
The leg sides 61b, 61f, 61g connecting the first portal side 60a and the second portal side 60b are second lateral sides bent at right angles from the leg sides 13b of the first portal side 60a along the horizontal direction. 61f, a second vertical side 61b bent at a right angle continuously to the second horizontal side 61f, and a third horizontal side 61g bent at a right angle continuous to the second vertical side 61b in a U-shape Is formed. The end of the third lateral side 61g is continuous with the leg side 13b of the second portal side 60b.

  The leg sides 61c, 61h, 61i connecting the second portal side 60b and the third portal side 60c are fourth lateral sides bent at right angles from the leg sides 13a of the second portal side 60b along the horizontal direction. 61h, a third vertical side 61c bent at a right angle continuously to the fourth horizontal side 61h, and a fifth horizontal side 61i bent at a right angle continuous to the third vertical side 61c in a U-shape Is formed. The end of the fifth lateral side 61i is continuous with the leg side 13a of the third portal side 60c. The end of the first vertical side 61a is opposed to the bent portion of the fourth horizontal side 61h and the third vertical side 61c.

  The foot sides 61d and 61j arranged at the lower end of the leg side 13b of the third gate side 61c are continuous with the sixth side 61j bent at right angles from the leg side 13b along the horizontal direction and the sixth side 61j. Thus, it is formed in an L shape from the fourth vertical side 61d bent at a right angle. The end of the fourth vertical side 61d faces the bent portion between the second vertical side 61b and the third horizontal side 61g.

Between the end of the first vertical side 61a, the bent portion of the fourth horizontal side 61h and the third vertical side 61c, the bent portion of the fourth vertical side 61d, the second vertical side 61b and the third horizontal side 61g. A gap 62 is formed between them.
The gap 62 is not welded because it is buried in the solder 21 when the current detection resistor 10D is soldered to the circuit board 20 as will be described later. However, in order to ensure the rigidity of the foot side 61, the gap 62 may be welded.

Since the current detection resistor 10D having the above-described configuration is used in the same manner as in the first embodiment, the description thereof is omitted.
According to the present embodiment, the foot side 61 formed in a U shape between the first portal side 60a, the second portal side 60b, and the third portal side 60c has buoyancy and surface tension. Self-alignment, which automatically moves to a balanced position, works. Here, the self-alignment acts on the U-shaped foot side 61 more strongly in the two directions of the vertical direction and the horizontal direction.
In addition, by soldering the foot side 61 to the land 22 of the circuit board 20, three metal resistors composed of the first gate side 60 a, the second gate side 60 b, and the third gate side 60 c are disposed between the lands 22. A line is erected. By using three metal resistance wires, the resistance load can be reduced to one third. Therefore, compared with the case where one metal resistance wire is installed between the lands 22, the resistance load is reduced to one third, so that the current flowing through the same circuit can be tripled.
Moreover, if the electric current to flow is the same, the heat_generation | fever of the resistor 10D for electric current detection can be suppressed.

According to the current detection resistors 10, 10A, 10B, 10C, and 10D according to the above-described embodiment, since the single metal resistance wire is bent and formed in the manner of one stroke, the manufacturing cost is reduced. Can be suppressed.
Further, since the current detection resistors 10, 10A, 10B, 10C, and 10D are formed so as to be self-supporting, they can be surface-mounted on the circuit board 20. For this reason, since it is not necessary to form through holes (through holes) for fixing terminals in the circuit board 20, the manufacturing process of the circuit board 20 can be simplified, and the manufacturing cost of the circuit board 20 can be suppressed. .
When the diameter of the metal wire is precisely processed to have a uniform thickness, the cross-sectional area of the metal wire becomes constant. Therefore, only the lengths of the gate side, the sub-gate side, the first gate side, the second gate side, and the third gate side of the current detection resistors 10, 10A, 10B, 10C, and 10D are adjusted. Thus, precise current detection resistors 10, 10A, 10B, 10C, and 10D can be manufactured.
Further, the gaps formed in the current detection resistors 10, 10A, 10B, 10C, and 10D are not necessarily welded, and the gate side, the sub-gate side, the first gate side, and the second gate side Since there is no seam or welded part on the third gate side, the resistance value of the metal resistance wire does not change, so that it is possible to provide the current detection resistors 10, 10A, 10B, 10C, 10D with high reliability. it can.

It is a perspective view which shows the resistor for electric current detection which concerns on 1st Example. It is a perspective view which shows the resistor for electric current detection which concerns on 2nd Example. It is a perspective view which shows the resistor for electric current detection which concerns on 3rd Example. It is a perspective view which shows the resistor for electric current detection which concerns on 4th Example. It is a perspective view which shows the resistor for electric current detection which concerns on 5th Example. It is a perspective view which shows the conventional resistor for electric current detection. It is a perspective view which shows the conventional resistor for electric current detection.

Explanation of symbols

10, 10A, 10B, 10C, 10D ... Current detection resistors, 11 ... Portal side, 12, 12a, 12b, 12c, 12d, 12e ... Foot sides, 13a, 13b ... Leg sides, 14 ... Connection sides, 15 ... Gap,
20 ... Circuit board, 21 ... Solder, 22 ... Land,
30 ... Portal side according to the second embodiment, 31 ... Foot side, 32a, 32b ... Leg side, 33 ... Connection side, 34 ... Gap,
40, 40a, 40b ... foot sides according to the third embodiment,
50a, 50b ... portal side according to the fourth embodiment, 51, 51a, 51b, 51c, 51d, 51e, 51f, 51g ... foot side, 52 ... gap,
60a, 60b, 60c,... Gate-like sides according to the fifth embodiment, 61, 61a, 61b, 61c, 61d, 61e, 61f, 61g, 61h, 61i, 61j ... foot sides, 62 ... gap.

Claims (3)

A current detecting resistor formed by bending one metal resistance wire into a gate-shaped side consisting of a pair of left and right leg sides and a connecting side connecting the both leg sides,
A resistor for detecting a current, wherein a foot side that is bent in the same plane that is substantially perpendicular to each leg side is formed at a lower end portion of each leg side.   The current detecting resistor according to claim 1, wherein the foot side is formed in a rectangular shape or a ring shape.   2. The sub-portion side that has substantially the same shape as the gate-shaped side and that is continuous from one leg side of the gate-shaped side is formed in parallel with the gate-shaped side. Resistor for current detection.

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