A power resistor with high power density and a wide resistance range

Abstract

This invention relates to the field of resistor technology, specifically to a high power density power resistor with a wide resistance range. It includes a housing and multiple resistor units stacked within the housing. Each resistor unit includes an insulating support substrate and a resistor sheet encased within the support substrate. The resistor sheet has conductive portions bent at both ends, extending to the outer surface of the support substrate. Adjacent resistor units are connected via these conductive portions. An air duct is provided between the support substrates of adjacent resistor units. The high power density allows the resistor unit spacing to be adjusted within any range based on the thickness of the support substrate, enabling forced air cooling heat exchange and minimizing the volume to the theoretical minimum. It also offers higher protection levels and corrosion resistance, achieving high levels of waterproofing and dustproofing; and meets the high requirements for large creepage distances and clearances even under high voltage conditions.

Description

Technical Field

[0001] This invention relates to the field of resistor technology, and more specifically to a power resistor with high power density and a wide resistance range. Background Technology

[0002] High power density metal resistors typically employ a combination of metal sheet resistors arranged in parallel and forced air cooling. Adjacent metal resistor sheets are separated by ceramic components. To enhance heat dissipation and increase power density, the thickness of the resistor sheets needs to be reduced to increase the heat dissipation area between the resistor sheets and the air.

[0003] However, reducing the thickness of metal resistor sheets results in insufficient self-support. During forced air cooling, the resistor sheets may deform and stick together, causing a short circuit in the resistor circuit and rendering the resistor unusable. Therefore, resistor sheets generally cannot be too thin. Furthermore, because metal resistors typically have low resistivity, manufacturing high-resistance resistors requires increasing their mass and size through series connection, which cannot simultaneously achieve high power density and makes miniaturization of high-power resistors difficult. Summary of the Invention

[0004] In view of the above-mentioned technical problems in the prior art, the present invention provides a power resistor with high power density and wide resistance range.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A power resistor with high power density and wide resistance range is provided, including a housing and multiple resistor units stacked in the housing. Each resistor unit includes an insulating support substrate and a resistor sheet wrapped inside the support substrate. The two ends of the resistor sheet are bent into conductive portions that extend to the outer surface of the support substrate. Adjacent resistor units are connected by the conductive portions. An air duct is provided between the support substrates of adjacent resistor units.

[0007] Specifically, the surface of the support substrate is provided with multiple rows of flow guiding protrusions, and flow guiding grooves are formed between adjacent flow guiding protrusions. After the support substrates of two adjacent resistor units are attached, the opposing flow guiding grooves are aligned to form the air duct.

[0008] Specifically, the conductive portion is U-shaped, and / or the conductive portion is flush with the surface of the supporting substrate.

[0009] Specifically, the support substrate is a glass body that is hot-melted and cast onto the resistor sheet.

[0010] Specifically, the support substrate consists of two ceramic or quartz sheets that are pressed and sandwiched together to hold the resistor sheet.

[0011] Specifically, the resistor film is a carbon film or a metal oxide film.

[0012] Specifically, the resistor sheet has a plate-like structure: its middle part is a complete sheet.

[0013] Specifically, the resistor sheet has a coil-like structure: it consists of multiple layers of spiral bands wrapped inside and out.

[0014] Specifically, the resistor sheet has a reciprocating structure: it includes continuous, meandering, S-shaped segments.

[0015] Specifically, the resistor sheet has a shunt structure: it is a sheet with multiple elongated holes arranged in parallel in the middle.

[0016] The beneficial effects of this invention are:

[0017] The present invention provides a high power density power resistor with a wide resistance range, which, compared with the prior art, offers the following advantages:

[0018] 1. High power density, the spacing between resistor units can be adjusted freely according to the thickness of the supporting substrate, which can reduce the volume to the theoretical minimum value of forced air cooling heat exchange to meet the ultimate forced air cooling heat exchange.

[0019] 2. Miniaturized unit design: The miniaturized array of resistor units can meet the arrangement requirements and can be placed in portable micro devices as load test units;

[0020] 3. Inductor-free design: The resistor sheet used is a low-inductance component. By optimizing the resistor circuit and the tight stacking arrangement, the inductor-free design can make the entire resistor component inductor-free, meeting the high-precision requirements (such as RF antenna) of analog load testing.

[0021] 4. The resistor sheet is encapsulated in an insulating support substrate. The metal resistor sheet can be made very thin while meeting the structural support requirements. Compared with the method of being exposed to air, the resistor sheet of the present invention has a higher protection level and corrosion resistance, and can achieve a high level of waterproof and dustproof. Moreover, it has higher insulation performance. While the structure is compact and stable, it can also meet the high requirements of large creepage distance and electrical clearance under high voltage conditions.

[0022] 5. High resistance to high current impact: Since the resistor sheet is encapsulated in the support substrate, when subjected to transient thermal stability current and dynamic stability current, the weight of the resistor sheet is increased in effect, which can absorb more impact energy. When multiple resistor units are stacked and pressed tightly against each other, they can achieve reliable support. They have good resistance to impact electromagnetic stress during current impact and will not cause structural deformation leading to electrical structural failure or abnormality. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a power resistor with high power density and wide resistance range in one of the embodiments.

[0024] Figure 2 This is a partial cross-sectional schematic diagram of a power resistor with high power density and wide resistance range in one embodiment.

[0025] Figure 3 This is a schematic diagram of the resistor unit in the embodiment.

[0026] Figure 4 This is a cross-sectional view of the resistor unit in the embodiment.

[0027] Figure 5 This is a schematic diagram of the plate structure of the resistor sheet in the embodiment.

[0028] Figure 6 This is a schematic diagram of the coil-type structure of the resistor sheet in the embodiment.

[0029] Figure 7 This is a schematic diagram of the reciprocating structure of the resistor sheet in the embodiment.

[0030] Figure 8 This is a schematic diagram of the shunt structure of the resistor sheet in the embodiment.

[0031] Figure label:

[0032] Support substrate 1, flow guiding protrusion 11;

[0033] 2. Resistor sheet 2, Conductive part 21.

[0034] 3. Housing 3, slot 31, resistor unit 4, air duct 5. Detailed Implementation

[0035] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0036] This embodiment provides a high power density, wide resistance range power resistor, such as... Figures 1 to 4 As shown, the device includes a housing 3 and multiple resistor units 4 stacked within the housing 3. Each resistor unit 4 includes an insulating support substrate 1 and a resistor sheet 2 encased inside the support substrate 1. The opposing side walls of the housing 3 are provided with slots 31, and the end of the support substrate 1 is embedded in the slots 31, thereby limiting the support substrate 1 in the vertical direction. During installation, an opening is left in one end plate of the housing 3, through which multiple resistor units 4 can be inserted. Disassembly is similar, thus facilitating maintenance. When individual resistor units 4 fail, the resistors can be quickly disassembled for replacement, resulting in higher reliability.

[0037] The resistor sheet 2 has U-shaped conductive portions 21 bent at both ends. These conductive portions 21 extend to the outer surface of the supporting substrate 1, and are flush with or slightly protruding a few millimeters from the surface of the supporting substrate 1. Adjacent resistor units 4 are tightly connected via the conductive portions 21, eliminating the need for additional soldering. It should be noted that the "thinness" of the resistor sheet 2 does not limit its specific thickness, but rather emphasizes its ability to be thinner than a bare resistor. The resistor sheet 2 can be made of carbon film or metal oxide film, formed by etching grooves on the film.

[0038] In practice, the support substrate 1 can be made of glass, ceramic, or quartz, all of which are high-temperature resistant and flame-retardant materials with high safety and thermal stability. If glass is used, the support substrate 1 is a glass body hot-melt cast onto the resistor sheet 2. If ceramic or quartz is used, the support substrate 1 consists of two ceramic or quartz sheets that are glued and pressed together to hold the resistor sheet 2.

[0039] In this embodiment, the surface of the support substrate 1 is provided with multiple rows of flow-guiding protrusions 11. Flow-guiding grooves are formed between adjacent flow-guiding protrusions 11 on the same side. After the support substrates 1 of two adjacent resistor units 4 are bonded together, the opposing flow-guiding grooves align to form an air duct 5, facilitating forced air cooling with a fan. The flow-guiding protrusions 11 on both sides of the support substrate 1 are staggered. This results in good heat dissipation uniformity and low thermal stress within the resistor's internal structure. The flow-guiding protrusions 11 on the support substrate 1 increase the air heat exchange area while supporting the resistor units 4, forming independent heat dissipation air ducts 5. This ensures uniform heat dissipation throughout the resistor, preventing uneven heat dissipation and localized thermal stress concentration.

[0040] In this embodiment, the resistor sheet 2 has four structures, including as follows: Figure 5 The structure shown is a plate-like structure: the middle part is a complete sheet, and elongated holes are opened near the conductive parts 21 at both ends; as shown Figure 6 The coiled structure shown includes multiple layers of loops with inner and outer spirals; such as... Figure 7 The reciprocating structure shown includes continuous, meandering, S-shaped segments; the diversion structure shown in Figure 8 is a sheet with multiple elongated holes arranged in parallel in the middle.

[0041] For resistors requiring high power density and low resistance, it is possible to follow... Figure 5 or Figure 8 In the form of.

[0042] For resistors requiring high power density and moderate resistance values, it is possible to follow... Figure 6 or Figure 7 form.

[0043] For resistors requiring high power density and high resistance, it is possible to follow... Figure 5 or Figure 6 form.

[0044] Depending on the requirements, a single resistor may contain a combination of two or more of the above four types of resistor units.

[0045] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A power resistor with high power density and a wide resistance range, characterized in that: The device includes a housing and multiple resistor units stacked within the housing. Each resistor unit includes an insulating support substrate and a resistor sheet encased inside the support substrate. The resistor sheet has conductive portions bent at both ends, extending to the outer surface of the support substrate. Adjacent resistor units are connected by these conductive portions. An air duct is provided between the support substrates of adjacent resistor units. The surface of the support substrate is provided with multiple rows of flow-guiding protrusions, forming flow-guiding grooves between adjacent flow-guiding protrusions. After the support substrates of adjacent resistor units are attached, the opposing flow-guiding grooves align to form the air duct.

2. The power resistor with high power density and wide resistance range according to claim 1, characterized in that: The conductive portion is U-shaped, and / or the conductive portion is flush with the surface of the supporting substrate.

3. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The support substrate is a glass body that is hot-melt cast onto a resistor sheet.

4. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The support substrate consists of two ceramic or quartz sheets that are pressed and sandwiched together to hold the resistor sheet.

5. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The resistor film is a carbon film or a metal oxide film.

6. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The resistor sheet has a plate-like structure: its middle part is a complete sheet.

7. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The resistor sheet has a coil-wound structure: it consists of multiple layers of spiral bands wrapped inside and out.

8. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The resistor sheet has a reciprocating structure: it includes continuous, meandering, S-shaped segments.

9. A power resistor with high power density and wide resistance range according to claim 1, characterized in that: The resistor sheet has a shunt structure: it is a sheet with multiple elongated holes arranged in parallel in the middle.

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