JPH09293601A - Resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a resistor having stable quality by simplifying the shape of a resistance unit for cutting down the material cost. SOLUTION: A resistor 20 wherein a pair of input and output terminals 21, 22 and detecting terminals 23, 24 are inserted into through holes of a printed substrate for a package provided with a sheet metallic resistance unit for measuring the current running between the input and output terminals 21, 22 by detecting the potential difference between the detecting terminals 23, 24, the resistor 20 is to be packaged by forming the resistance unit in a flat shape. Besides, the resistor 20 is composed of the resistance unit formed of almost a semicircular flat shape. Furthermore, the insertion gaps between the detecting terminals 23, 24 of the resistor 20 are to be made as narrow as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor including a metal resistor.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory diagram of a conventional resistor structure, and FIG.
Is a block diagram of a control circuit in which resistors of resistors are connected, and FIG. 6 is a perspective view showing the structure of another conventional resistor. FIG.
In the figure, 20 is a resistor, 3 is a printed circuit board, and 4 is a through hole formed in the printed circuit board 3. Resistor 2
As shown in FIG. 0, a wide plate-shaped resistance material is bent into a substantially M-shape as shown in the drawing using a mold jig or the like, and the connecting portions at both ends are connected to the printed circuit board 3
It is inserted into the through hole 4 and soldered.

In FIG. 5, reference numeral 2 is a resistor using a resistor 20. Further, B is a battery power source, F is a fail relay, D is a drive circuit, and M is a motor. The resistor 2 is connected to the control circuit of FIG. 5, and the current I supplied from the battery power source B flows between the terminals 21 and 22. Then, the potential difference V between the detection terminals 23 and 24 is detected, and the current I flowing through the resistor 20 is calculated from the formula (I = V / R). In addition, another conventional resistor 20 has a structure as shown in FIG. FIG. 6 (a) shows a U-shaped plate-shaped resistance material bent, and FIG. 6 (b) shows an inverted U-shaped molding.

[0004]

As described above, each of the conventional resistors 20 is formed by bending a wide plate-shaped resistance material into an M-shape or a U-shape. Therefore, since it is mounted over the printed circuit board 3, the mounting is stable,
Since the cross-sectional area can be relatively wide, the resistor 2 has a small resistance value.
Can be configured. In addition, it has a feature that it has a large surface area and a high heat dissipation function so that a circuit that is advantageous in terms of heat generation can be designed.

However, since the resistor 20 is formed by bending the press using a die jig, there is a drawback that the processing cost becomes high. Further, the resistance value may change and become non-uniform due to variations in the shape of the resistor 20 during bending. As a result, the conventional resistor 20 has a problem that it is difficult to stabilize the product.

The present invention has been made in order to solve the above-mentioned problems of the conventional resistor, and realizes a resistor having a stable quality by simplifying the shape of the resistor to reduce the processing cost. That is the purpose.

[0007]

According to the present invention, a pair of input / output terminals and a detection terminal are mounted by being inserted into a through hole of a printed circuit board, and a potential difference between the detection terminals is detected to connect the input / output terminals to each other. In a resistor having a metal plate-shaped resistor for measuring a flowing current, the resistor is formed in a flat plate shape and is mounted on a printed board. Also,
This is a resistor formed by forming a resistor into a substantially semi-circular flat plate shape. Further, the resistor is configured such that the insertion gap between the resistor and the detection terminal through hole is made as small as possible.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is an explanatory view showing the configuration of Embodiment 1 of the present invention, FIG. 1 (a) is a plan view, FIG. 1 (b) is a side view, and FIG. 2 is an enlarged sectional view of a portion of FIG. . In FIGS. 1 and 2, 20 is a resistor. The resistor 20 is made of a resistance material whose quality-specific resistance value is stable (for example, CNP ... copper-nickel plate for electrical resistance).
Is used, and is made by stamping and molding a metal plate material into a slightly wider arch shape as shown in the figure.

Reference numerals 21 and 22 denote input and output terminals of the resistor 20,
23 and 24 are detection terminals. A pair of input / output terminals 21,
22 has a wide width and is provided so as to protrude downward from the outside of the resistor 20. Similarly, the detection terminals 23 and 24 have a narrower width and are formed inside thereof. The resistor 20 according to the first embodiment of the present invention is also mounted on the printed board 3 in the same manner as the conventional resistor described above.

At the time of soldering, it is necessary to hold the resistor 20 upright on the printed circuit board 3, but if it is an ordinary through hole, it will be greatly inclined. As a countermeasure against this, the minimum gap between the corners of the detection terminals 23 and 24 and the through hole 4 is set to about 0.1 mm with respect to the board thickness of 1 mm [see FIG. 2 (b)]. As a result, as shown in FIG. 2, the detection terminals 23 and 24 are inserted into the through holes 4 of the printed circuit board 3 so that the inclination angle θ is small and the resistor 20 is held substantially perpendicular to the printed circuit board 3. Has become. Then, similarly to the above, the resistor 20 is connected between the terminals 21 and 22, and a control circuit that controls the input current by calculating the current I from the detected potential difference V in FIG. 5 is configured.

In the first embodiment of the present invention having such a configuration, the power source current of the battery B shown in FIG. 5 is supplied to the motor M via the drive circuit D to be rotated forward and backward. even here,
The potential difference V between the detection terminals 23 and 24 is constantly detected, and the current I flowing through the resistor 20 is calculated from the detected voltage. The calculated current value is fed back to the control circuit, and the current flowing through the circuit is controlled to a constant value.

Further, a fail relay F is connected to the preceding stage of the drive circuit D, and a protection circuit for protecting the load side from overcurrent is constructed by utilizing the calculated accurate resistance value. When an accident such as a short circuit occurs on the load side and an overcurrent flows, the fail relay F is turned off to protect the FET and the like for driving the motor M. For example, the control circuit is controlled so that the rated current of the motor M is 70A and the overcurrent is 100A or less.

As described above, the resistor according to the embodiment of the present invention is formed as a punching flat plate without bending. Therefore, the machining for bending is eliminated as compared with the conventional resistor, and the machining cost is reduced accordingly. Moreover, since there is no cause of variation in the resistance value based on R (R) that tends to become non-uniform during bending, the calculated current is accurate and the control accuracy can be improved.
Further, the occupied area A of the mounting surface of the printed circuit board 3 is only the product of the length L and the width W (A = L × W), which is remarkably reduced as compared with the conventional resistor 2 and the miniaturization of the device can be achieved. be able to.

Embodiments 2 and 3 FIGS. 3A and 3B show other Embodiments 2 and 3 of the present invention. 3 (a) and 3 (b) both show a resistor 20 having a different shape. In FIG. 3 (a), the entire contour shape is a rectangle with a low height H. In (b), the contour shape of the resistor 20 is connected to the upper portions of the left and right parallel portions 25 by a semicircular arc portion 26. It was done.

A second embodiment in which the height H is a rectangle.
According to FIG. 3A, the resistor 2 suitable for an electronic device having a thin case can be configured.

In the above-described embodiment of the present invention, only the case of the arch-shaped resistor has been described as an example, but the shape may be a semicircle having the same radius or a polygonal arch having rounded corners. . If necessary, the through holes of the printed circuit board may be formed as square holes, and the number and shape of terminals are not necessarily limited to those in the embodiment.

[0017]

According to the present invention, a pair of input / output terminals and a detection terminal are mounted by being inserted into a through hole of a printed circuit board, a potential difference between the detection terminals is detected, and a current flowing between the input / output terminals is measured. In the resistor provided with the metal plate-shaped resistor, the resistor is formed in a flat plate shape and mounted on a printed circuit board. Further, the resistor is formed by forming the resistor into a substantially semi-circular flat plate shape.
Further, the resistor is configured such that the insertion gap between the resistor and the detection terminal through hole is made as small as possible.

As a result, there is no need for the conventional mechanical machining for bending as in the case of the resistor, and the machining cost can be reduced accordingly. Further, there is no variation in the resistance value due to the variation of the shape that occurs during bending, and the calculated current value is accurate, so that the control accuracy can be improved. Further, the occupied area on the printed circuit board becomes extremely narrow, which contributes to downsizing of the product.

Therefore, according to the present invention, it is possible to provide a small-sized and highly-accurate resistor for a resistor, which has a low manufacturing cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional explanatory view of a part of FIG.

FIG. 3 is an explanatory diagram showing a configuration of another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a configuration of a conventional resistor.

FIG. 5 is a block diagram of a control circuit in which resistors of resistors are connected.

FIG. 6 is a perspective view showing the configuration of another conventional resistor.

[Explanation of symbols]

 2 resistors, 3 printed circuit boards, 4 through holes, 20 resistors, 21 input terminals, 22 output terminals, 23 detection terminals, 24 detection terminals, 25 parallel parts 26 arc parts 27 notches B battery power supply, D drive circuit, F fail relay, H height I current, L length, M motor, V voltage (potential difference), W width, θ tilt angle.

Claims (3)

[Claims] 1. A metal plate mounted with a pair of input / output terminals and a detection terminal inserted into a through hole of a printed circuit board to detect a potential difference between the detection terminals and measure a current flowing between the input / output terminals. A resistor having a rectangular resistor, wherein the resistor is formed in a flat plate shape and mounted on the printed board. 2. The resistor according to claim 1, wherein the resistor is formed in a substantially semi-circular flat plate shape. 3. The resistor according to claim 1, wherein the insertion gap between the detection terminal of the resistor and the through hole is made as small as possible.