Variable resistance adjusting device for power module

Abstract

This utility model relates to the field of power module electrical performance testing technology, specifically to a variable resistor adjustment device for power modules, including a front-end circuit; a driving resistor circuit connected between the front-end circuit and the driven power module, the driving resistor circuit including a potentiometer, the first pin of the potentiometer being connected to the first terminal of the front-end circuit, the third pin of the potentiometer being connected to the signal g terminal of the power module, and the second pin of the potentiometer sliding along the potentiometer; and a resistance control device connected to the front-end circuit and the potentiometer for adjusting the potentiometer. This utility model replaces the traditional relay-fixed resistor combination scheme with a combination of potentiometer and resistance control device, achieving continuous adjustment of Rg by precisely adjusting the potentiometer resistance value, significantly reducing the size and complexity of the testing device, and improving the flexibility and accuracy of dynamic testing.

Description

Technical Field

[0001] This utility model relates to the field of power module electrical performance testing technology, specifically to a variable resistor adjustment device for power modules. Background Technology

[0002] Power modules, as core components of power electronic devices, are widely used in home appliances, industrial control, new energy vehicles, photovoltaic and wind power, and other fields. To ensure their performance reliability and factory quality, they must undergo rigorous testing and screening, including static testing, dynamic testing, and insulation withstand voltage testing. Among these, dynamic testing (such as single / double pulse testing, short-circuit testing, etc.) is a key step in evaluating the switching characteristics and anti-interference capabilities of power modules. The performance of dynamic testing is highly dependent on the value of the drive resistor (Gate Resistance, Rg). Different test items (such as single pulse and double pulse) or different models of power modules often require different Rg values ​​to meet the test requirements.

[0003] In traditional dynamic testing, switching of Rg primarily relies on combinations of various fixed-value resistors connected in series with relays: different resistors are selected by controlling the on / off state of the relays to adjust Rg. However, with the rapid iteration of power modules and increasingly stringent testing conditions, the range of Rg values ​​required for testing is gradually expanding, and the accuracy requirements are increasing. In traditional solutions, the number of relays surges with the demand for Rg combinations, leading to an increase in the size of the testing equipment and significant space occupation. Furthermore, traditional fixed-resistor combinations can only provide a limited number of resistor values ​​with fixed intervals, making it difficult to meet the needs of refined testing for richer and more densely distributed resistor values. Utility Model Content

[0004] To solve the above technical problems, this utility model provides a variable resistor adjustment device for power modules.

[0005] The technical problem solved by this utility model can be achieved by the following technical solution:

[0006] A variable resistor adjustment device for a power module, comprising:

[0007] Front-end circuitry;

[0008] A driving resistor circuit is connected between the front-end circuit and the driven power module. The driving resistor circuit includes:

[0009] A potentiometer, wherein the first pin of the potentiometer is connected to the first terminal of the front-end circuit, the third pin of the potentiometer is connected to the signal g terminal of the power module, and the second pin of the potentiometer slides along the potentiometer;

[0010] A resistance control device, connected to the front-end circuit and the potentiometer, is used to adjust the potentiometer.

[0011] Preferably, when the potentiometer is a knob-type structure, the resistance control device is configured as an angle control device, and the rotating part of the angle control device is connected to the knob of the potentiometer.

[0012] Preferably, the rotation range of the angle control device matches the adjustable range of the potentiometer's knob.

[0013] Preferably, the angle control device is mounted on the circuit board via a bracket, and an insulating thermally conductive pad is provided between the bracket and the circuit board.

[0014] Preferably, when the potentiometer has a sliding structure, the resistance control device is configured as a linear drive device, and the sliding part of the linear drive device is mechanically connected to the slider of the potentiometer.

[0015] Preferably, the sliding stroke of the linear drive device matches the adjustable range of the potentiometer's slider.

[0016] Preferably, the linear drive device is fixed to the circuit board via a guide rail, and photoelectric limit switches are installed at both ends of the guide rail of the linear drive device.

[0017] Preferably, when the potentiometer and the resistance control device are an integrated structure, the potentiometer and the resistance control device are integrated and packaged into a single component.

[0018] Preferably, the single component integrates a digital communication interface and a resistance control circuit.

[0019] Preferably, the digital communication interface is I. 2 C-bus, SPI serial peripheral interface or single-wire digital interface.

[0020] Beneficial Effects: By adopting the above technical solution, this utility model replaces the traditional relay-fixed resistor combination with a potentiometer and resistor control device. The driving resistor (Rg) is continuously adjustable through precise adjustment of the potentiometer value. This solution significantly reduces the size and complexity of the testing device, avoiding space occupation issues caused by an increase in the number of relays. Simultaneously, the continuous adjustment characteristic of the potentiometer allows Rg to achieve high-precision, stepless variation within the target range, thus meeting the diverse requirements of different test items and power module models for Rg values. This improves the flexibility and accuracy of dynamic testing, providing reliable technical support for efficient power module testing. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a partial circuit of the gate drive of the power module;

[0022] Figure 2 This is a circuit diagram of the relay switching drive resistor Rg in the prior art;

[0023] Figure 3 This is a circuit diagram of the relay switching drive resistor Rg in the existing technology;

[0024] Figure 4 This is a structural diagram of the potentiometer-based Rg switching circuit of this utility model;

[0025] Figure 5 This is the circuit diagram of the potentiometer-based Rg switching circuit of this utility model.

[0026] Explanation of reference numerals in the attached diagram: 1. Front-end circuit; 2. Potentiometer; 3. Servo motor; 4. Knob groove; 5. Rotation shaft; 6. Circuit board; 7. First pin; 8. Second pin; 9. Third pin. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0030] Reference Figure 1 The gate drive circuit structure of the power module mainly consists of three parts: front-end circuit 1, the drive resistor (Rg) adjustment circuit (the part within the dashed box in the figure), and the driven power module. In actual testing, whether in R&D experiments or mass production testing, the most frequently adjusted part is the Rg adjustment circuit, and its precise resistance configuration directly affects the dynamic performance test results of the power module.

[0031] Reference Figure 2 In traditional solutions, the switching of Rg during dynamic testing of power modules is mainly achieved through a combination of fixed-value resistors and relays connected in series. Specifically, multiple fixed resistors are connected to relays, and different resistor combinations (such as parallel or a hybrid series-parallel connection) are selected by controlling the on / off state of the relays (K1, K2, K3, K4), thereby adjusting the Rg value. For example, refer to... Figure 3When relays K1 and K3 are closed and the others are open, then Rg = R1 / / R3, meaning Rg is the parallel resistance of R1 and R3. However, this approach has significant limitations: as testing demands increase, the range and accuracy requirements of Rg continuously expand, leading to a surge in the number of relays required. This not only occupies a large amount of circuit board space but also only provides a limited number of fixed-interval resistance values, making it difficult to meet the demands of refined testing for diverse and densely distributed resistance values. Furthermore, the complexity and size expansion of traditional solutions also limit their application efficiency in rapidly iterating power module testing.

[0032] To address the aforementioned problems in the existing technology, referring to Figure 4 and Figure 5 This utility model provides a variable resistor adjustment device for a power module, comprising:

[0033] Front-end circuit 1;

[0034] A driving resistor circuit is connected between the front-end circuit 1 and the driven power module. The driving resistor circuit includes:

[0035] Potentiometer 2 (Rp), the first pin 7 of the potentiometer 2 is connected to the first terminal of the front-end circuit 1, the third pin 9 of the potentiometer 2 is connected to the signal g terminal of the power module, and the second pin 8 of the potentiometer 2 slides along the potentiometer 2;

[0036] A resistance control device is connected to the front-end circuit 1 and the potentiometer 2, and is used to adjust the potentiometer 2.

[0037] Specifically, in this embodiment of the invention, potentiometer 2 is used as a variable resistor element. The sliding end of potentiometer 2 is precisely adjusted by a resistor control device, thereby achieving continuous and finely adjustable driving resistor Rg. This design abandons the traditional approach of relying on multiple fixed-value resistors combined with relays, effectively solving the problem of large device size and serious space occupation caused by the surge in the number of relays. At the same time, it breaks through the limitations of fixed resistor combination in terms of the number and distribution density of resistor values, meeting the requirements of a wider range and higher accuracy of Rg values ​​in dynamic testing of power modules.

[0038] In a preferred embodiment of this utility model, when the potentiometer 2 is a knob-type structure, the resistance control device is configured as an angle control device, and the rotating part of the angle control device is connected to the knob of the potentiometer 2; the rotation range of the angle control device matches the adjustable range of the knob of the potentiometer 2.

[0039] Specifically, in this embodiment of the invention, when the potentiometer 2 adopts a knob-type structure, the resistance control device is selected from angle control devices such as a servo motor 3 or a stepper motor. During installation, the output shaft of the angle control device is mechanically coupled to the knob of the potentiometer 2 via a coupling or directly to ensure effective transmission of rotational torque. The rotation range of the angle control device needs to precisely match the adjustable range of the knob of the potentiometer 2. An external control signal drives the angle control device to rotate a specified angle, causing the knob of the potentiometer 2 to rotate synchronously, thereby precisely adjusting the resistance value. This structure achieves stepless continuous adjustment of the resistance value, which is significantly better than the discrete resistance value switching method of traditional relays. At the same time, the rigid connection design between the angle control device and the potentiometer 2 avoids backlash errors during transmission, ensuring the real-time performance and repeatability of resistance value adjustment.

[0040] In a preferred embodiment of the present invention, the angle control device is mounted on the circuit board 6 via a bracket, and an insulating thermally conductive pad is provided between the bracket and the circuit board 6.

[0041] Specifically, in this embodiment of the invention, the angle control device is mounted on the circuit board 6 via a bracket. The bracket supports and fixes the angle control device, ensuring that it can function stably on the circuit board 6. An insulating and thermally conductive pad is provided between the bracket and the circuit board 6. During installation, the insulating and thermally conductive pad is first accurately placed at the corresponding position on the circuit board 6, and then the bracket is attached to the pad. The bracket is then firmly installed on the circuit board 6 using screws or other fixing methods, thus forming a stable connection structure between the angle control device and the circuit board 6.

[0042] The use of insulating thermally conductive pads offers several advantages. Firstly, their excellent insulation properties effectively isolate current conduction between the angle control device and circuit board 6, preventing equipment malfunctions or safety hazards caused by leakage and ensuring the safety and stability of the entire device. Secondly, the pads possess good thermal conductivity, rapidly transferring heat generated by the angle control device during operation to circuit board 6, which then dissipates the heat, preventing overheating that could affect the performance and lifespan of the angle control device and improving the device's heat dissipation efficiency and reliability. Furthermore, the insulating thermally conductive pads also provide shock absorption and sealing, reducing the impact of external vibrations on the angle control device and circuit board 6, while preventing dust and moisture from entering the device and protecting the normal operation of internal components.

[0043] Reference Figure 4 Taking servo 3 as an example, the specific implementation steps are as follows:

[0044] Step 1: Determine the required Rg resistance range as 0 to 20Ω based on the testing requirements;

[0045] Step 2: Select potentiometer 2 with an adjustable resistance of 0 to 20Ω and an adjustable knob range of 180°, according to the required Rg resistance range;

[0046] Step 3: Select a servo motor 3 with a rotation range of 180° and a minimum rotation angle of 1° based on the adjustable range of the potentiometer 2 knob;

[0047] Step 4: Install the servo motor 3 on the circuit board 6 and mechanically couple its rotating shaft 5 with the knob groove 4 of the potentiometer 2 to ensure that the servo motor 3 can accurately drive the knob of the potentiometer 2 to rotate without slippage or free travel when it rotates.

[0048] Step 5: After receiving the control command from the front-end circuit 1, the servo motor 3 rotates the rotating shaft 5 by the corresponding angle, causing the knob of the potentiometer 2 to rotate to the target position, thereby adjusting the Rg value from the current value to the target resistance value.

[0049] Calculations show that for every 1° rotation of servo motor 3, the resistance of potentiometer 2 changes by approximately 0.11Ω (calculation formula: 20Ω / 180°≈0.11Ω / °). Therefore, when a 1Ω resistance adjustment is needed, servo motor 3 only needs to rotate precisely 9° (1Ω / 0.11Ω / °≈9°).

[0050] Clearly, this solution achieves high-precision continuous adjustment of the driving resistor Rg, with a minimum adjustment resolution of 0.11Ω, far superior to the discrete resistance characteristics of traditional relay-fixed resistor combinations. Through precise angle control of the servo motor 3, the system can quickly and accurately set the target resistance value, meeting the refined requirements of Rg values ​​in different testing scenarios.

[0051] In a preferred embodiment of this invention, when the potentiometer 2 has a sliding structure, the resistance control device is configured as a linear drive device, and the sliding part of the linear drive device is mechanically connected to the slide rod of the potentiometer 2. The sliding stroke of the linear drive device matches the adjustable range of the slide rod of the potentiometer 2.

[0052] Specifically, in this embodiment of the invention, the linear drive device is linked with the slider of the potentiometer 2 via a precision guide rail mechanism to ensure the motion accuracy and stability during the sliding process. During installation, the main body of the linear drive device is first fixed to a preset position on the circuit board 6. Then, its sliding output end is mechanically coupled to the slider of the potentiometer 2 via a coupling or rigid connector, ensuring that the motion axes of both are strictly aligned. The linear drive device incorporates a high-precision stepper motor or linear motor, which receives control signals from the front-end circuit 1 to drive the sliding part to perform linear reciprocating motion along the guide rail, thereby synchronously displacing the slider of the potentiometer 2 and achieving linear adjustment of the resistance value.

[0053] In a preferred embodiment of the present invention, the linear drive device is fixed to the circuit board 6 by a guide rail, and photoelectric limit switches are installed at both ends of the guide rail of the linear drive device.

[0054] Specifically, in this embodiment of the invention, the linear drive device is fixed to the circuit board 6 via a guide rail. The guide rail provides precise sliding guidance for the linear drive device, ensuring its motion trajectory is stable and reliable. During installation, screws or other fasteners are used to firmly fix the guide rail to the preset installation position on the circuit board 6. Then, the sliding component of the linear drive device is precisely engaged with the guide rail to form a smooth linear motion mechanism. Photoelectric limit switches installed at both ends of the guide rail can monitor the displacement position of the linear drive device in real time. When the sliding component approaches the travel limit, the photoelectric limit switch will trigger a signal to stop the drive in time, preventing damage caused by mechanical overshoot.

[0055] The use of photoelectric limit switches offers multiple advantages. First, their non-contact detection method avoids mechanical wear, significantly improving the durability and reliability of the device. Second, photoelectric switches offer fast response and high precision, enabling millimeter-level positioning control and ensuring accurate resistance adjustment of potentiometer 2. Third, the design incorporates overload protection, immediately cutting off power in case of system malfunction to protect the drive unit and potentiometer 2 from damage. Furthermore, the installation position of the photoelectric limit switch is flexibly adjustable, facilitating adaptation to the travel requirements of different potentiometer models, enhancing the device's versatility. The entire mechanism, through the rigid support of the guide rail and the intelligent limit function of the photoelectric switch, achieves high-precision, long-life linear adjustment, significantly improving the stability and maintainability of the testing system.

[0056] In a preferred embodiment of this utility model, when the potentiometer 2 and the resistance control device are integrated into a single structure, the potentiometer 2 and the resistance control device are integrated and packaged into a single component; the single component integrates a digital communication interface and a resistance control circuit. The digital communication interface adopts an industry-standard communication protocol, including but not limited to I... 2 Various general digital communication standards, such as C-bus, SPI serial peripheral interface, or single-wire digital interface.

[0057] Specifically, in this embodiment of the invention, the single component adopts a modular design, highly integrating the potentiometer 2 with the resistance control device, and forming a compact functional unit through precision packaging. During installation, the component can be directly soldered or fixed to the circuit board 6 via connectors, ensuring reliable electrical connection with the front-end circuit 1 and the power module. The component integrates a digital communication interface (such as I...). 2(C, SPI or single-wire digital interface) supports standard communication protocols and can be quickly connected to the system control bus; the resistance control circuit adopts digital processing technology, which can accurately parse external commands and adjust the resistance value of potentiometer 2 in real time.

[0058] The adjustment steps for this integrated component are as follows:

[0059] Step 1: Receive external control commands via digital communication interface. The commands include the target resistance value parameter.

[0060] Step 2: The resistance control circuit decodes and processes the instruction to generate the corresponding control signal;

[0061] Step 3: Drive the adjustment mechanism inside potentiometer 2 to achieve rapid and accurate setting of resistance value.

[0062] The integrated design adopted in this embodiment of the invention highly integrates the potentiometer 2 with the resistance control device, achieving a compact package while significantly optimizing system performance. This innovative modular structure not only greatly reduces the space occupied by the circuit board 6, but also enables rapid and accurate adjustment of the resistance value through digital communication, with significantly improved response speed and adjustment accuracy compared to traditional solutions. The modular design concept makes installation and maintenance more convenient, while the built-in intelligent control circuit has automatic calibration and temperature compensation functions, effectively ensuring the accuracy and reliability of test data.

[0063] Of particular note is the component's innovative real-time resistance feedback mechanism, which provides the system with closed-loop control capabilities. Combined with the anti-interference characteristics of the digital communication interface, the entire device can maintain a stable operating state even in complex working environments, fully meeting the stringent requirements of modern power module testing for accuracy, efficiency, and reliability.

[0064] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A variable resistance adjusting device for a power module, characterized by, include: Front-end circuitry; A driving resistor circuit is connected between the front-end circuit and the driven power module. The driving resistor circuit includes: A potentiometer, wherein the first pin of the potentiometer is connected to the first terminal of the front-end circuit, the third pin of the potentiometer is connected to the signal g terminal of the power module, and the second pin of the potentiometer slides along the potentiometer; A resistance control device, connected to the front-end circuit and the potentiometer, is used to adjust the potentiometer.

2. The variable resistance adjusting device for a power module according to claim 1, characterized by When the potentiometer is a knob-type structure, the resistance control device is set as an angle control device, and the rotating part of the angle control device is connected to the knob of the potentiometer.

3. A variable resistance adjusting device for a power module according to claim 2, characterized in that, The rotation range of the angle control device matches the adjustable range of the potentiometer knob.

4. The variable resistance adjusting device for a power module according to claim 3, characterized by The angle control device is mounted on the circuit board via a bracket, and an insulating thermally conductive pad is provided between the bracket and the circuit board.

5. The variable resistance adjusting device for a power module according to claim 1, wherein When the potentiometer has a sliding structure, the resistance control device is configured as a linear drive device, and the sliding part of the linear drive device is mechanically connected to the slider of the potentiometer.

6. A variable resistance adjusting device for a power module according to claim 5, wherein The sliding stroke of the linear drive device is matched with the adjustable range of the potentiometer's slider.

7. A variable resistance adjusting device for a power module according to claim 6, characterized by The linear drive device is fixed to the circuit board via a guide rail, and photoelectric limit switches are installed at both ends of the guide rail of the linear drive device.

8. The variable resistance adjusting device for a power module according to claim 1, wherein When the potentiometer and the resistance control device are integrated into a single structure, the potentiometer and the resistance control device are integrated and packaged into a single component.

9. A variable resistance adjusting device for a power module according to claim 8, characterized by The single component integrates a digital communication interface and a resistance control circuit.

10. The variable resistance adjusting device for a power module according to claim 9, wherein The digital communication interface is an I 2 C bus, SPI serial peripheral interface or single wire digital interface.

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