DV / dt parameter testing device of multilayer ceramic dielectric capacitor
By designing a dV/dt parameter testing device for multi-layer porcelain dielectric capacitors, the problem that the prior art cannot test the capacitor's overvoltage or overcurrent resistance is solved, and the performance evaluation of the capacitor under high slope voltage is achieved, with high efficiency and simple operation characteristics.
Patent Information
- Application Number
- CN202421717044.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-07-19
AI Technical Summary
The prior art cannot perform dV/dt parameter testing on multi-layer porcelain dielectric capacitors, and cannot fully reflect the capacitor's ability to resist overvoltage or overcurrent.
A dV/dt parameter testing device for multi-layer porcelain dielectric capacitors is designed. Through the circuit design of the DC power supply unit, the pulse charge and discharge adjustment unit, the pulse number control unit, the oscilloscope and the capacitor to be tested, the charge and discharge control and voltage waveform monitoring of the capacitor are realized.
It can accurately test the capacitor dV/dt parameters, evaluate its withstand voltage ability under high slope voltage and its ability to suppress faults caused by high slope voltage, and has the advantages of simple structure, convenient operation and good stability.
Smart Images
Figure CN223038052U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of capacitor performance testing devices, and particularly to a dV / dt parameter testing device for multilayer ceramic capacitors. Background Art
[0002] Multilayer ceramic capacitors have the characteristics of small volume, large specific capacitance, long life, high reliability, etc. They are one of the most used components in current communication equipment, computer circuit boards, and household appliance remote controls, and are currently widely used in the whole machine electronic circuits of aerospace and aviation. However, the basic electrical performance test parameters of multilayer ceramic capacitors usually only include withstand voltage, insulation resistance, capacitance, and loss. Among them, the withstand voltage refers to the maximum voltage that a capacitor can withstand without breaking down its dielectric. This parameter is crucial for ensuring the safe operation of the capacitor in the circuit. Exceeding the withstand voltage may cause damage to the dielectric and result in capacitor breakdown; the insulation resistance refers to the resistance value between the two electrodes of the capacitor, which reflects the insulation performance of the dielectric. A high insulation resistance value means that the dielectric has good insulation characteristics and can effectively prevent current from passing through. Too low insulation resistance may lead to leakage current, affecting the performance and safety of the circuit; capacitance is the ability of the capacitor to store charge, usually measured in farads (F). Capacitance depends on the area of the two capacitor plates, the distance between the plates, and the dielectric constant of the dielectric. Capacitance is one of the most important parameters of the capacitor, which determines how much energy the capacitor can store in the circuit; loss refers to the fact that in an AC circuit, due to the non-ideality of the dielectric and the electrodes, part of the electrical energy will be lost in the form of heat. Loss is usually expressed by the dissipation factor (DF) or the tangent loss angle. DF is the ratio of the actual power loss of the capacitor in the AC circuit to the stored energy, which reflects the efficiency of the capacitor. The smaller the DF, the lower the loss and the higher the efficiency of the capacitor. When the capacitor is under the actual application conditions of the power system, large electrodynamic forces and energy losses will be generated inside the capacitor, which will further reduce the life of the capacitor or even cause breakdown.
[0003] Therefore, only testing the four parameters such as the capacitance and loss of the capacitor, without testing the dV / dt parameter of the capacitor, cannot fully reflect the ability of the capacitor to resist overvoltage or overcurrent.
[0004] In view of this, this application is specifically proposed. Content of the Utility Model
[0005] The purpose of the utility model is to provide a dV / dt parameter testing device for multilayer ceramic capacitors. By designing a circuit, cooperating the pulse number control unit with an oscilloscope, and then designing the circuit connection relationship of the charging adjustable variable resistor and the discharging adjustable variable resistor, the problem that the dV / dt parameter of the capacitor cannot be tested in the prior art is solved.
[0006] The embodiments of the present utility model are implemented through the following technical solutions: The embodiments of the present utility model provide a dV / dt parameter testing device for a multi-layer ceramic capacitor, including the following units:
[0007] DC power supply unit: provides a DC power supply;
[0008] Pulse charge and discharge adjustment unit: connected to the DC power supply unit;
[0009] Pulse number control unit: connected between the positive electrode of the DC power supply unit and the pulse charge and discharge adjustment unit;
[0010] Capacitor under test: one end thereof is connected to the pulse charge and discharge adjustment unit, and the other end is connected to the negative electrode of the DC power supply unit;
[0011] Oscilloscope: its probe is connected to both ends of the capacitor under test;
[0012] Among them, the pulse number control unit includes a charging adjustable variable resistor and a discharging adjustable variable resistor. The charging adjustable variable resistor is connected between the positive electrode of the DC power supply unit and the capacitor under test, the discharging adjustable variable resistor is connected in parallel with the capacitor under test, and a control switch is provided between the charging adjustable variable resistor and the positive electrode of the DC power supply unit.
[0013] Preferably, the DC power supply unit includes an energy storage capacitor and a DC adjustable voltage source connected in parallel with each other.
[0014] Preferably, the adjustable voltage range of the DC adjustable voltage source is 0 - 600V.
[0015] Preferably, the pulse number control unit includes a high-voltage relay.
[0016] Preferably, the charging adjustable variable resistor is connected to the output end of the high-voltage relay.
[0017] Preferably, a voltmeter is also connected in parallel with the capacitor under test.
[0018] Preferably, the minimum control time unit of the high-voltage relay is 1s.
[0019] Preferably, a capacitance meter is connected to the capacitor under test.
[0020] Preferably, the frequency of the capacitance meter is 120Hz or 1KHz or 1MHz.
[0021] Preferably, the DC adjustable voltage source can be continuously adjusted.
[0022] Compared with the prior art, the embodiments of the present utility model have the following advantages and beneficial effects:
[0023] A dV / dt parameter testing device for a multi-layer ceramic capacitor provided by an embodiment of the present utility model conducts a specific circuit design for a DC power supply unit, a pulse charge and discharge adjustment unit, a pulse number control unit, a capacitor under test, and an oscilloscope. The pulse charge and discharge adjustment unit can control the charging and discharging processes of the capacitor under test, including the charging and discharging rates, as well as the charging and discharging paths, including a charging adjustable resistor and a discharging adjustable resistor. The charging adjustable resistor is connected between the positive pole of the DC power supply unit and the capacitor under test to limit the charging current; the discharging adjustable resistor is connected in parallel with the capacitor under test to control the discharging current, and together with a control switch, it controls the detection operation of the entire testing device; the pulse number control unit controls the number of charge and discharge cycles of the capacitor to simulate the working conditions of the capacitor in actual applications; the oscilloscope can monitor and record the voltage waveform of the capacitor under test during the charging and discharging processes in real time to evaluate the response of the capacitor to rapid voltage changes.
[0024] Specifically, the testing device can simulate the rapid charge and discharge conditions that the capacitor may encounter in actual applications, and evaluate its tolerance and performance changes under high dV / dt. At the same time, through the monitoring of the oscilloscope, detailed voltage and current waveforms during the charging and discharging processes of the capacitor can be obtained, providing data support for performance analysis. The above-mentioned testing device can conduct pulse charge and discharge detection on the capacitor under test in a specific pulse charge and discharge circuit. As long as the operator measures and compares the performance parameters before and after charge and discharge, the quality of the capacitor under test can be detected. The testing device provided by the embodiment of the present utility model can accurately test the dV / dt parameter of the capacitor, and has the advantages of simple structure, convenient operation, good stability, and the ability to monitor the output current waveform diagram and the number of charge and discharge times in real time.
[0025] Generally speaking, the dV / dt parameter testing device for a multi-layer ceramic capacitor provided by the embodiment of the present utility model designs a circuit, coordinates the pulse number control unit with the oscilloscope, and then designs the circuit connection relationship of the charging adjustable resistor and the discharging adjustable resistor to achieve the purpose of evaluating the voltage withstand capacity of the multi-layer ceramic capacitor under a high-slope voltage and the ability to suppress faults caused by a high-slope voltage. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.
[0027] Figure 1 It is a schematic structural diagram of the dV / dt parameter testing device provided by the embodiment of the present utility model;
[0028] Figure 2 This is a schematic diagram of the circuit connection of the dV / dt parameter testing device provided by the embodiment of the present utility model.
[0029] Marks in the attached drawings and corresponding component names:
[0030] R1 - Charge adjustable variable resistor, R2 - Discharge adjustable variable resistor. Detailed implementation manners
[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and shown in the accompanying drawings here can be arranged and designed in various different configurations.
[0032] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the present utility model to be protected, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.
[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0034] In the description of the present utility model, it should be noted that the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.
[0035] Embodiment
[0036] As Figure 1-2 shown, the embodiment of the present utility model provides a dV / dt parameter testing device for a multilayer ceramic capacitor, including the following units:
[0037] DC power supply unit: provides DC power to charge the capacitor under test; Pulse charge and discharge adjustment unit: connected to the DC power supply unit, used to adjust the charge and discharge process of the capacitor, including a charge adjustable variable resistor R1 and a discharge adjustable variable resistor R2. The charge adjustable variable resistor R1 is connected between the positive pole of the DC power supply unit and the capacitor under test to limit the magnitude of the charging current from the DC power supply unit to the capacitor under test. The discharge adjustable variable resistor R2 is connected in parallel with the capacitor under test to limit the magnitude of the current and the discharge rate when the capacitor under test discharges; Pulse count control unit: connected between the positive pole of the DC power supply unit and the pulse charge and discharge adjustment unit, which can include a high-voltage relay or other electronic switching devices, used to control the number of charge and discharge cycles of the capacitor; Capacitor under test: one end is connected to the pulse charge and discharge adjustment unit, and the other end is connected to the negative pole of the DC power supply unit; Oscilloscope: its probe is connected to both ends of the capacitor under test, used to monitor the voltage waveform of the capacitor in real time during the charge and discharge cycle process. It should be noted that during the entire test process, the oscilloscope is not only used to monitor the voltage waveform, but also can be used to monitor the safety of the test to prevent the voltage from exceeding the withstand voltage value of the capacitor. A control switch is provided between the charge adjustable variable resistor R1 and the positive pole of the DC power supply unit to start and stop the charging process of the capacitor under test.
[0038] With the above structure, the test device can accurately simulate the rapid charge and discharge conditions encountered by the capacitor in actual applications and evaluate its performance under these conditions. The use of the charge adjustable variable resistor R1 and the discharge adjustable variable resistor R2 enables precise control of the current during the test process, while the pulse count control unit allows the tester to set the number of charge and discharge cycles as needed. The use of the oscilloscope provides an intuitive voltage waveform for the test, which helps to analyze the dynamic response characteristics of the capacitor.
[0039] Furthermore, the DC power supply unit includes an energy storage capacitor and a DC adjustable voltage source connected in parallel. The DC adjustable voltage source enables the operator to adjust the output voltage according to the test requirements to simulate different working conditions. The energy storage capacitor can quickly release or absorb energy when needed, providing energy support for the rapid charging and discharging of the capacitor under test. At the same time, it helps to smooth the output voltage of the DC power supply, especially when the load current changes significantly, reducing voltage fluctuations. When the capacitor under test requires rapid charging and discharging, the energy storage capacitor can provide transient high current to simulate the rapid voltage changes in actual applications. In the embodiment of the present invention, connecting the energy storage capacitor in parallel with the DC adjustable voltage source can combine the advantages of both to provide a stable and adjustable power supply. By adjusting the output of the DC adjustable voltage source, different capacitors under test can be tested, increasing the applicability of the test device. Generally speaking, the DC power supply unit not only provides the required DC voltage, but also enhances the response ability of the power supply to rapidly changing loads through the parallel use of the energy storage capacitor, which is crucial for testing the performance of multilayer ceramic capacitors under high dV / dt conditions.
[0040] Of course, a voltmeter can also be connected in parallel with the capacitor under test and used in conjunction with an oscilloscope to further improve the flexibility of the device. Since the voltmeter provides a static or average reading of the voltage across the capacitor, it can show the stable state or the trend of slow change of the voltage throughout the test process. The oscilloscope can record the detailed waveforms during the charge and discharge cycles, facilitating subsequent analysis and fault diagnosis. By using the oscilloscope and voltmeter simultaneously, comprehensive information about the charge and discharge behavior of the capacitor can be obtained, including transient response, long-term stability, and accurate voltage measurement. By observing the readings of the voltmeter, the charging and discharging processes can be controlled to ensure that the voltage of the capacitor meets the voltage requirements of the test process. To improve the comprehensiveness of the entire device for capacitive testing of the capacitor under test, a capacitance meter can be connected to the capacitor under test to measure the capacitance and loss before and after the test of the capacitor under test and observe whether the capacitance and loss change. If abnormal parameter changes are measured, this may indicate a problem with the capacitor, and timely further inspection and adjustment can be carried out.
[0041] Exemplarily, a dV / dt parameter testing device for a multilayer ceramic capacitor includes a DC power supply unit, a pulse charge and discharge adjustment unit, a pulse number control unit, an oscilloscope, and a capacitor under test. The DC power supply unit is a continuously adjustable DC power supply that can provide 0 to 600V. This range allows different levels of voltage to be applied to the capacitor under test to test its performance under different voltage conditions. The continuous adjustment function enables the operator to smoothly change the voltage for precise test settings, which is very useful when gradually increasing the voltage to find the breakdown point or tolerance limit of the capacitor. This power supply can simulate various voltage conditions that the capacitor may encounter in an actual circuit. The adjustable voltage source allows the operator to start testing from a low voltage and gradually increase the voltage to the rated value of the capacitor or until a fault occurs, helping to safely evaluate the voltage withstand capacity of the capacitor. The pulse charge and discharge adjustment unit includes a charge-adjustable variable resistor R1 and a discharge-adjustable variable resistor R2, and a voltmeter. The pulse number control unit includes a high-voltage relay. The high-voltage relay is connected to the positive pole of the DC power supply to control the charge and discharge frequency. The charge-adjustable variable resistor R1 is connected to the output terminal of the high-voltage relay, and the discharge-adjustable variable resistor R2 is connected in parallel across both ends of the capacitor under test. By adjusting the charge-adjustable variable resistor R1 and the discharge-adjustable variable resistor R2, the charge and discharge current of the capacitor under test is controlled, and the actual charge and discharge time of the capacitor under test is controlled.
[0042] During the test, a wire is connected to one end of the DC power supply unit and the capacitor under test. A DC voltage is applied to charge the capacitor under test through the DC adjustable power supply and the energy storage capacitor, applying a voltage signal with dV / dt from low to high to the capacitor under test until the breakdown voltage of the capacitor; the charge and discharge time is controlled by setting the on-off time of the high-voltage relay. Among them, the minimum time unit of the high-voltage relay is 1s. After the capacitor under test is fully charged, it is in the voltage holding stage; one end of the charge-adjustable variable resistor R1 is connected to the positive pole of the DC power supply unit, and the other end is connected to the capacitor under test; the discharge-adjustable variable resistor R2 is connected in parallel on both sides of the capacitor under test, jointly forming a pulse charge and discharge adjustment unit. The charge time of the capacitor under test is controlled by the charge-adjustable variable resistor R1, and the discharge time of the capacitor under test is controlled by adjusting the discharge-adjustable variable resistor R2; after charging is completed, the high-voltage relay is disconnected, and the capacitor under test discharges to the load resistor. The discharge time is controlled for about 3s; the other end of the capacitor under test is connected to the oscilloscope, and the oscilloscope is used to observe the change in the transient voltage across both ends of the capacitor under test to confirm that the waveform signal meets the test requirements. Before and after the test, the capacitor under test can be connected to a 120Hz / 1KHz / 1MHz capacitance meter to test its capacitance and loss, and observe whether the capacitance and loss change. By comparing the electrical performance parameters of the capacitor under test before and after the test under different dV / dt voltage signals, the data is analyzed to obtain the capacitance dV / dt parameter value.
[0043] Generally speaking, the dV / dt test device for a multi-layer ceramic capacitor provided by the embodiment of the present utility model has a simple structure, convenient operation and low later maintenance cost. When testing a capacitor of a certain specification, the charge and discharge time can be adjusted according to the actual use conditions of the product, the number of charge and discharge times and the charging voltage can be set, and the test can be automatically stopped when the number of times is reached. Moreover, during the test process, the voltage waveforms at both ends of the capacitor during the charge and discharge cycle can be monitored in real time. On the basis of the existing four-parameter detection, the ability of the multi-layer ceramic capacitor to withstand the surge during the switch-on process when used as a DC support can be further evaluated.
[0044] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model. It should be noted that the structures or components illustrated in the drawings are not necessarily drawn to scale, and the present utility model omits the description of well-known components and processing technologies and processes to avoid unnecessarily limiting the present utility model.
Claims
1. A dV / dt parameter test device for a multilayer ceramic capacitor, characterized in that: The following units are included: DC power supply unit: provides DC power; Pulse charge and discharge adjustment unit: connected to the DC power supply unit; Pulse number control unit: connected between the positive electrode of the DC power supply unit and the pulse charge and discharge adjustment unit; The capacitor to be tested: one end of which is connected to the pulse charge and discharge adjustment unit, and the other end of which is connected to the negative electrode of the DC power supply unit; Oscilloscope: its probe is connected to the two ends of the capacitor to be tested; Among them, the pulse number control unit includes a charging adjustable resistor and a discharging adjustable resistor, the charging adjustable resistor is connected between the positive electrode of the DC power supply unit and the capacitor to be tested, the discharging adjustable resistor is connected in parallel with the capacitor to be tested, and a control switch is arranged between the charging adjustable resistor and the positive electrode of the DC power supply unit.
2. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 1, characterized in that: The DC power supply unit comprises an energy storage capacitor and a DC adjustable voltage source which are connected in parallel.
3. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 2, characterized in that: The adjustable voltage range of the DC adjustable voltage source is 0-600V.
4. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 1, characterized in that: The pulse number control unit includes a high voltage relay.
5. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 4, characterized in that: The charging adjustable resistor is connected to the output end of the high voltage relay.
6. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 1, characterized in that: A voltmeter is also connected in parallel to the capacitor to be tested.
7. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 4, characterized in that: The minimum control time unit of the high voltage relay is 1s.
8. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 1, characterized in that: The capacitor to be tested is connected with a capacity meter.
9. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 8, characterized in that: The frequency of the capacity meter is 120 Hz or 1 KHz or 1 MHz.
10. The dV / dt parameter testing device of a multilayer ceramic capacitor according to claim 3, characterized in that: The DC adjustable voltage source can be continuously adjusted.