A resistor for fine adjustment of the balance of a four-bridge resistor circuit

Abstract

The application discloses a resistor for fine adjustment of balance of a four-bridge resistance circuit, and belongs to the technical field of resistance adjusters.The resistor comprises a substrate, and conductive lines in S-shaped distribution are arranged on the substrate;insulation areas on the inner sides of the left and right corner of the conductive lines are set as inner-side soldering short-circuit points; and insulation areas on the outer sides of the left and right corner of the conductive lines are set as outer-side soldering short-circuit points.The resistor for fine adjustment of balance of the four-bridge resistance circuit has low manufacturing cost, is convenient to adjust, and has high adjustment reliability and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of resistance regulators, and in particular to a resistor for finely regulating the balance of a four-bridge resistance circuit. Background Art

[0002] The four-bridge resistance circuit is a bridge circuit that uses the change of resistance to measure the change of physical quantity, such as Figure 1 As shown, the voltage across the resistor is collected by a voltage acquisition device, and then corresponding processing is performed to calculate the corresponding change in physical quantity. This is a measurement method that requires very high precision.

[0003] However, even resistors with high precision will have certain errors. Moreover, due to the limitation of PCB wiring, the lengths of the four bridge arms are not equal. This leads to slight differences in the resistance of the four bridge arms. Although the deviation may be only a few milliohms, it will cause a certain amplitude offset of the measured signal over a long time span. Figure 2 As shown, the measured resistance does not experience disturbances, but the measurement results gradually show larger and larger deviations over time. This situation will further lead to inaccurate physical quantities calculated accordingly, causing deviations in the calculation. Summary of the Invention

[0004] The object of the present invention is to provide a resistor for finely adjusting the balance of a four-bridge resistance circuit, which has low manufacturing cost, is easy to adjust and has high adjustment reliability and stability.

[0005] To achieve the above-mentioned objectives, the present invention provides a resistor for finely adjusting the balance of a four-bridge resistance circuit, comprising a substrate on which an S-shaped conductive circuit is laid, wherein the insulating areas inside the left and right corners of the conductive circuit are set as inner solder short-circuits, and the insulating areas outside the left and right corners of the conductive circuit are set as outer solder short-circuits.

[0006] Preferably, the lines on the upper and lower sides of the conductive circuit are centrally symmetrically distributed about the center point, wherein the upper part is the upper half-bridge resistance adjustment area, and the lower part is the lower half-bridge resistance adjustment area; the upper end of the upper half-bridge resistance adjustment area is provided with an upper half-bridge resistance connection point; the lower end of the lower half-bridge resistance adjustment area is provided with a lower half-bridge resistance connection point, and a voltage signal acquisition point is provided at the connection position of the upper half-bridge resistance adjustment area and the lower half-bridge resistance adjustment area.

[0007] Preferably, two voltage signal collection points are symmetrically arranged on the left and right.

[0008] Preferably, a solder resist layer is laid above the conductive circuit in areas other than the upper half-bridge resistor connection point, the lower half-bridge resistor connection point, the voltage signal collection point, the inner solder short-circuit point and the outer solder short-circuit point.

[0009] Preferably, the insulating areas of the inner solder short-circuit point and the outer solder short-circuit point are configured as a circuit structure with uneven top and bottom surfaces.

[0010] Preferably, the resistance calculation formula of a single transverse line of the conductive line is: ;

[0011] Where ρ represents the resistivity of copper, L represents the length of the wire, and A represents the cross-sectional area of ​​the wire;

[0012] The calculation formula for the cross-sectional area of ​​the conductor is:

[0013] ;

[0014] Where W represents the wire width and T represents the copper layer thickness;

[0015] Short-circuiting an inner solder short-circuit point will result in a resistance change of 2R, and short-circuiting an outer solder short-circuit point will result in a resistance change of 4R.

[0016] Therefore, the beneficial effects of the present invention using the above-mentioned resistor for finely adjusting the balance of the four-bridge resistance circuit are as follows:

[0017] (1) Low cost, can be achieved directly using conventional PCB manufacturing process.

[0018] (2) Compared with the use of multiple independent adjustable resistors for adjustment, the resistor structure of the present invention does not require additional adjustable resistor devices, is free of wear and vibration caused by mechanical parts, and has higher reliability.

[0019] (3) Users can change the wire length, width, copper thickness, number of loops and the position of the adjustment point in the structure according to their own needs, thereby changing the adjustable resistance range and the minimum adjustment amount, which is flexible and convenient.

[0020] (4) High stability. The temperature coefficient of pure copper is about 0.00393 / ℃ at room temperature, and is minimally affected by temperature.

[0021] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a four-bridge resistor circuit diagram;

[0023] Figure 2 It is a schematic diagram of the measurement signal deviation of the four-bridge resistor circuit;

[0024] Figure 3 is a structural schematic diagram of the embodiment of the resistor for fine adjustment of the balance of the four-bridge resistance circuit when no short circuit is performed;

[0025] Figure 4 is a simulation diagram of the resistor for fine adjustment of the balance of the four-bridge resistance circuit connected in the four-bridge resistance circuit;

[0026] Figure 5 is a structural schematic diagram of the embodiment of the resistor for fine adjustment of the balance of the four-bridge resistance circuit when short circuit is performed;

[0027] Figure 6 is a structural diagram of the resistor for fine adjustment of the balance of the four-bridge resistance circuit, in which (a) is the resistor structure adopted in the embodiment, (b) is the resistor structure for increasing the horizontal length of the conductive line, and (c) is the resistor structure for increasing the number of the vertical arrangement of the conductive line. DETAILED DESCRIPTION

[0028] The technical solutions of the present application are further described below by means of the accompanying drawings and embodiments.

[0029] Unless otherwise defined, the technical terms or scientific terms used in the present application shall have the meanings commonly understood by those skilled in the art to which the present application belongs. The terms "first", "second", and similar terms used in the present application do not represent any order, number, or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the components or objects before the terms cover the components or objects listed after the terms and their equivalents, without excluding other components or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like only represent relative positional relationships, which can change accordingly when the absolute positions of the described objects change.

[0030] Embodiment One

[0031] As shown in Figure 3 , the present application provides a resistor for fine adjustment of the balance of the four-bridge resistance circuit, which comprises a substrate, and the substrate is paved with conductive lines in S-shaped distribution, as shown in Figure 3 , the conductive lines on the upper and lower sides are centrally symmetrically distributed about the center point, in which the upper side is the upper half-bridge resistance adjustment area, and the lower side is the lower half-bridge resistance adjustment area.

[0032] The upper end of the upper half-bridge resistance adjusting area is provided with an upper half-bridge resistance connection point, i.e. point A in Figure 3 , for connecting with the upper half-bridge resistance in the four-bridge resistance circuit, and the lower end of the lower half-bridge resistance adjusting area is provided with a lower half-bridge resistance connection point, i.e. point C in Figure 3 , for connecting with the lower half-bridge resistance in the four-bridge resistance circuit, and the connection position of the upper half-bridge resistance adjusting area and the lower half-bridge resistance adjusting area is provided with a voltage signal collection point, i.e. point B in Figure 3 , for connecting with a voltage measuring device, as shown in Figure 4 . The voltage signal collection point is symmetrically provided with two points, which can facilitate the connection of the resistor and the voltage measuring device.

[0033] In the later use process, the resistance value of the upper half-bridge resistance adjusting area can be changed by adjusting the connection mode of the conductive circuit, thereby realizing the adjustment of the resistance value of the upper half-bridge connection resistance. Similarly, the resistance value of the lower half-bridge resistance adjusting area can be changed by adjusting the connection mode of the conductive circuit, thereby realizing the adjustment of the resistance value of the lower half-bridge connection resistance.

[0034] As shown in Figure 3 , the inner side of the insulating area of the conductive circuit at the left and right corners is provided with an inner solder short connection point, and the outer side of the insulating area of the conductive circuit at the left and right corners is provided with an outer solder short connection point, which is used for short connection of the line layout of the conductive circuit in the later stage. The insulating area of the inner solder short connection point and the outer solder short connection point is provided with an up-and-down uneven line structure, which can facilitate the connection of the upper and lower conductive circuits by soldering in the later stage, as shown in Figure 5 .

[0035] The area above the conductive circuit except the upper half-bridge resistance connection point, the lower half-bridge resistance connection point, the voltage signal collection point, the inner solder short connection point and the outer solder short connection point is provided with a solder mask layer, which can effectively improve the reliability of the resistor and prevent the easy connection between the horizontally adjacent conductive circuits, thereby improving the stability in the use process.

[0036] In addition, in this embodiment, the conductive medium selected for the conductive circuit is copper, and other materials can also be used according to actual needs. In this embodiment, the overall structure of the conductive circuit is designed as shown in Figure 6 (a). In different use scenarios, the horizontal length of the conductive circuit can be increased according to the use requirements, as shown in Figure 6 (b), or the number of vertically arranged conductive circuits can be increased, as shown in Figure 6 (c).

[0037] The resistance calculation formula of the single horizontal line of the conductive line is:

[0038] ;

[0039] In the formula, p represents the resistivity of copper, L represents the length of the wire, and A represents the cross-sectional area of the wire.

[0040] The calculation formula of the cross-sectional area of the wire is:

[0041] ;

[0042] In the formula, W represents the width of the wire, and T represents the thickness of the copper layer.

[0043] In this embodiment, the length of the conductive line on the substrate is 4 mm, the width is 0.235 mm, and 1 oz copper is used for copper thickening (PCB copper thickness is usually expressed in ounces, and 1 oz of copper is approximately 0.035 mm). The resistivity of copper is 1.68 x 10 -8 Ω·m, and the resistance calculation formula is:

[0044] ;

[0045] The final calculation of the resistance of a single horizontal wire is about 8.17 mΩ, as shown in the formula: Figure 5 When the conductive line is short-circuited, one of the inner solder short-circuit points is short-circuited, and the resistance change is 2R, so the minimum resistance adjustment amount of the conductive line is 2R. When one of the outer solder short-circuit points is short-circuited, the resistance change is 4R. In this embodiment, the resistance of a single horizontal wire is about 8.17 mΩ, so the minimum resistance adjustment amount of the resistor in this embodiment is 16.34 mΩ, and the entire resistor can achieve a resistance adjustment of about 163.40 mΩ.

[0046] Therefore, the resistor for fine adjustment of the balance of the four-bridge resistance circuit according to the present application has low manufacturing cost, is easy to adjust, and has high adjustment reliability and stability.

[0047] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A resistor for finely adjusting the balance of a four-bridge resistor circuit, characterized in that: The invention comprises a substrate on which a conductive circuit is laid in an S-shaped distribution, wherein the insulating areas inside the left and right corners of the conductive circuit are set as inner solder short-connections, and the insulating areas outside the left and right corners of the conductive circuit are set as outer solder short-connections; The conductive circuit has upper and lower sides that are symmetrically distributed about a central point, wherein the upper side is an upper half-bridge resistance adjustment area and the lower side is a lower half-bridge resistance adjustment area; an upper half-bridge resistance connection point is provided at the upper end of the upper half-bridge resistance adjustment area; a lower half-bridge resistance connection point is provided at the lower end of the lower half-bridge resistance adjustment area; a voltage signal collection point is provided at the connection position between the upper half-bridge resistance adjustment area and the lower half-bridge resistance adjustment area; and two voltage signal collection points are symmetrically provided on the left and right sides; The insulating areas of the inner solder short-circuit point and the outer solder short-circuit point are configured as a circuit structure with uneven top and bottom surfaces.

2. A resistor for finely adjusting the balance of a four-bridge resistor circuit according to claim 1, characterized in that: A solder resist layer is laid above the conductive circuit in areas other than the upper half-bridge resistor connection point, the lower half-bridge resistor connection point, the voltage signal acquisition point, the inner solder short-circuit point and the outer solder short-circuit point.

3. The resistor for finely adjusting the balance of a four-bridge resistor circuit according to claim 1, characterized in that: The calculation formula for the resistance of a single transverse line of the conductive line is: ； Where, ρ represents the resistivity of copper, L represents the length of the wire, and A represents the cross-sectional area of ​​the wire; The calculation formula for the cross-sectional area of ​​the conductor is: ； Where W represents the wire width and T represents the copper layer thickness; Short-circuiting an inner solder short-circuit point will result in a resistance change of 2R, and short-circuiting an outer solder short-circuit point will result in a resistance change of 4R.

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