Withstand voltage testing device

Abstract

The invention discloses a withstand voltage testing device which comprises a current module, a voltage measuring module and a control module. The current module is configured to intermittently apply a test current to the coil element multiple times during a test period. The voltage measurement module is configured to be connected with the coil element and measure the terminal voltage of the coil element so as to obtain a plurality of measurement voltage values after the corresponding coil element is subjected to the test current each time. The control module is configured to be connected with the current module and the voltage measurement module and generate a test passing result according to the measurement voltage values.

Description

Technical Field

[0001] The present invention relates to a withstand voltage test device, in particular to a withstand voltage test device which can perform a withstand voltage test on a coil element and judge the withstand voltage test result by measuring the back electromotive force of the coil element. Background Art

[0002] Generally speaking, if a coil component (such as an inductor) in an electronic product with a coil element deteriorates, it can affect the stability and service life of the electronic product. Therefore, all coil components must undergo a withstand voltage test to detect whether the coil component has deteriorated. Current withstand voltage test circuits cannot control the current input to the coil component during withstand voltage testing. This causes the withstand voltage test circuit to measure a voltage that is too high or too low when the switch module is closed, making it impossible to accurately determine whether the coil component has deteriorated. Summary of the Invention

[0003] In view of this, some embodiments provide a withstand voltage test apparatus comprising a current module, a voltage measurement module, and a control module. The current module is configured to intermittently apply a test current to a coil element multiple times during a test period. The voltage measurement module is configured to connect to the coil element and measure the terminal voltage of the coil element, thereby obtaining a plurality of measured voltage values ​​corresponding to each application of the test current to the coil element. The control module is configured to connect to the current module and the voltage measurement module and generate a test pass result based on these measured voltage values.

[0004] In some embodiments, the control module obtains voltage difference values ​​according to the difference between each measured voltage value and the voltage setting value, and the test pass result is determined based on whether each voltage difference value falls within a threshold value.

[0005] In some embodiments, the control module subtracts the maximum voltage value measured during the test period from another subsequent voltage value to obtain a voltage difference value, and the test pass result is determined based on whether the voltage difference value falls within a threshold value.

[0006] In some embodiments, the control module performs the test during the current increasing period, which includes a plurality of test periods. During the current increasing period, the current module gradually increases the current value of the test current with each test period as a stage.

[0007] In some embodiments, the control module subtracts the maximum voltage value measured during the test period from another subsequent voltage value to obtain a voltage difference value, and the test pass result is determined based on whether the voltage difference value falls within a threshold value.

[0008] In some embodiments, the control module subtracts two consecutive measured voltage values ​​during the current increase period to obtain a voltage difference, and the test pass result is determined based on whether the voltage difference falls within a threshold.

[0009] In some embodiments, the control module subtracts two consecutive measured voltage values ​​during the test period to obtain a voltage difference, and the test pass result is determined based on whether the voltage difference falls within a threshold.

[0010] In some embodiments, the control module obtains the inductance variation according to the measured voltage value during the first current increase period and the measured voltage value during any subsequent current increase period, and the test pass result is determined based on whether the inductance variation falls within a threshold.

[0011] In some embodiments, the control module subtracts the inductance changes during two consecutive current increase periods from each other based on the inductance changes of the measured voltage value during the first current increase period and the measured voltage value during the subsequent current increase period to obtain an inductance change difference. The test pass result is determined based on whether the inductance change difference falls within a threshold.

[0012] In some embodiments, the measured voltage value is a voltage peak value in a voltage bounce waveform caused by a back electromotive force generated in response to the disappearance of the test current.

[0013] In summary, in some embodiments, the withstand voltage test device includes a current module, a voltage measurement module and a control module. The control module can perform a withstand voltage test in a set test environment, wherein when the control module sets the test environment, the control current module outputs a test current of a specified current value during the test period, or gradually increases the test current of each test period during the current increase period. This allows the control module to measure the back electromotive force fed back by the coil element under a variety of test environments according to product testing requirements. When the withstand voltage test device performs a withstand voltage test on the coil element, it detects whether the coil element has passed the test. The control module obtains a voltage peak value based on the back electromotive force of the coil element, and determines whether the coil element has passed the test based on the measured voltage value and the judgment condition. In this way, the withstand voltage test device can ensure that the back electromotive force measured under the test environment is stable, and then accurately determine whether the withstand voltage test result of the coil element is a pass result.

[0014] Various embodiments are presented below for detailed description. However, these embodiments are intended for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, some elements are omitted from the drawings to clearly illustrate the technical features of the present invention. The same reference numerals will be used throughout the drawings to indicate identical or similar elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1FIG. 4 is a block diagram of a withstand voltage testing device in some embodiments of the present invention.

[0016] Figure 2 FIG. 4 is a circuit diagram of a withstand voltage test device in some embodiments of the present invention.

[0017] Figure 3 In some embodiments of the present invention, a voltage waveform caused by the back electromotive force of the coil element is detected.

[0018] Figure 4 In some embodiments of the present invention, a voltage bounce waveform caused by back electromotive force is detected during the current ramp-up period.

[0019] Wherein, the reference numerals:

[0020] 10: Withstand voltage test device

[0021] 102: Current module

[0022] 103: Current Source

[0023] 104: switch module

[0024] 1041: First End

[0025] 1042: Second end

[0026] 1043: Control terminal

[0027] 106: Voltage measurement module

[0028] 108: Control module

[0029] 110: Coil element

[0030] 112: Peak detection circuit

[0031] I: Test current

[0032] P1: Output path

[0033] S1: Current source switching signal

[0034] S2: Current source adjustment signal

[0035] S3: control signal

[0036] T1: Charging period

[0037] T2, T21, T22, T23: Testing period

[0038] T3: Current increase period

[0039] Vp, Vp1, Vp2, Vp3, Vp4: Peak voltage

[0040] W,W1,W2,W3,W4: Voltage bounce waveform DETAILED DESCRIPTION

[0041] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this does not limit the present invention.

[0042] See also Figure 1 、 Figure 2 and Figure 3 . Figure 1 FIG. 1 is a block diagram of a withstand voltage testing device 10 in some embodiments of the present invention. Figure 2 FIG. 1 is a circuit diagram of a withstand voltage testing device 10 in some embodiments of the present invention. Figure 3 In some embodiments of the present invention, the voltage waveform caused by the back electromotive force of the coil element 110 is detected. Figure 1 、 Figure 2 and Figure 3 As shown, the withstand voltage test device 10 includes a current module 102, a voltage measurement module 106, and a control module 108. The withstand voltage test device 10 is used to provide a test environment for performing a withstand voltage test on a coil element 110. In some embodiments, the test environment is determined by parameters such as a test current I output by the current module 102 and / or the timing of activation of the switch module 104 (described later).

[0043] Coil component 110 is, for example, a motor, inductor, transformer, generator, or other component having a coil. The withstand voltage test performed by the withstand voltage test apparatus 10 on the coil component 110 involves determining the extent of degradation of the coil component 110 after being subjected to voltage based on electrical information fed back by the coil component 110 after the withstand voltage test apparatus 10 has established a test environment. (Degradation may refer to a decrease in the inductance of the coil component 110.)

[0044] The current module 102 is configured to output a test current I. The current module 102 can adjust the current value of the test current I outputted by it according to requirements. In some embodiments, the current module 102 includes a current source 103 and a switch module 104. After receiving a setting signal, the current source 103 outputs a test current I of a specified current value corresponding to the setting signal, so that the current source 103 can output a test current I of a specified current value required in response to the requirements of different test environments. The setting signal can be generated and sent by the control module 108, so that the control module 108 generates a corresponding setting signal according to the preset working current of the coil element 110 or the test environment requirements to control the current source 103 to output a test current I of a specified current value. The current value of the test current I outputted by the current source 103 can be obtained according to a test voltage of the coil element 110. For example, before the withstand voltage test device 10 performs a withstand voltage test, the withstand voltage test device 10 can obtain the current value of the test current I through sampling after the withstand voltage test device 10 sets the test voltage of the coil element 110 according to the user. As Figure 2 As shown in FIG, the setting signal includes a current source switching signal S1 and a current source adjustment signal S2. The current source 103 outputs a test current I in response to the current source switching signal S1. The current source 103 adjusts the current value of the test current I in response to the current source adjustment signal S2. In some embodiments, the current source switching signal S1 includes a current start signal and a current end signal. The current source 103 outputs the test current I in response to the current start signal. The current source 103 stops outputting the test current I in response to the current end signal.

[0045] The switch module 104 is configured to be connected between the current source 103 and the coil element 110. In response to a control signal S3, the switch module 104 turns on during a charging period T1 to supply a test current I to the coil element 110 during the charging period T1. After the charging period T1 ends, the switch module 104 turns off, ceasing the supply of the test current I to the coil element 110, thereby generating a back electromotive force in the coil element 110. In some embodiments, the switch module 104 may be a semiconductor switch element, such as a metal-oxide semiconductor field-effect transistor (MOSFET), a bipolar transistor, or an insulated gate bipolar transistor (IGBT). In some embodiments, the charging period T1 starts at the time when the switch module 104 turns on, and ends at the time when the current source 103 charges the coil element 110 to a specified current value (which may be the time when the coil element 110 is charged to the current value of the test current I). In some embodiments, the switch module 104 has a first terminal 1041, a second terminal 1042, and a control terminal 1043. The first terminal 1041 is coupled to the current source 103, the second terminal 1042 is coupled to the coil element 110, and the control terminal 1043 is configured to receive a control signal S3 to conduct electricity between the first terminal 1041 and the second terminal 1042, thereby forming an output path P1, allowing the test current I to be input to the coil element 110 via the output path P1. In some embodiments, when the switch module 104 is closed in response to the control signal S3, the current source 103 stops outputting the test current I in response to a current end signal.

[0046] In some embodiments, the charging period T1 is the time during which the switch module 104 turns on the output path P1 after receiving the control signal S3 . Accordingly, the test current I can pass through the switch module 104 and be input to the input coil element 110 during the charging period T1 .

[0047] The voltage measurement module 106 is configured to connect to the coil element 110 and measure the terminal voltage of the coil element 110 to measure the back electromotive force generated by the coil element 110 in response to the disappearance of the test current I, thereby obtaining a measured voltage value. The control module 108 obtains the measured voltage value from the voltage measurement module 106. In some embodiments, the measured voltage value is a voltage peak value Vp in a voltage bounce waveform W caused by the back electromotive force generated by the coil element 110 in response to the disappearance of the test current I. Figure 3As shown, since the voltage bounce waveform W is caused by back electromotive force, the voltage peak Vp is the maximum negative amplitude within the voltage bounce waveform W. It should be noted that the voltage measurement module 106 measures the voltage bounce waveform W once each time the switch module 104 completes a test cycle (including the on-state operation during the charge maintenance period T1 and the subsequent off-state operation). Furthermore, the voltage bounce waveform W is a high-frequency signal. Capturing the complete waveform generally requires a voltage measurement device with high-speed voltage measurement capabilities, which is costly. Therefore, the voltage measurement module 106 may not have high-speed voltage measurement capabilities to save costs. The voltage measurement capability of the voltage measurement module 106 only needs to be sufficient to capture the voltage peak Vp within the voltage bounce waveform W, allowing the control module 108 to determine the degree of degradation of the coil element 110 based on the voltage peak Vp. It should be noted that the voltage measurement module 106 is not limited to not having high-speed voltage measurement capabilities. In other words, even if it has high-speed voltage measurement capabilities, it can still capture the voltage peak Vp and provide it to the control module 108 for determining the degree of degradation of the coil element 110. In some embodiments, the voltage measurement module 106 includes a peak detection circuit 112. The peak detection circuit 112 is used to capture and record a voltage peak value Vp in the voltage bounce waveform W, so that the control module 108 can determine the degree of degradation of the coil element 110 based on the voltage peak value Vp.

[0048] The control module 108 is configured to connect the switch module 104 and the voltage measurement module 106. The control module 108 generates a control signal S3 and receives a measured voltage value. The control module 108 generates a withstand voltage test result based on the measured voltage value. In some embodiments, the withstand voltage test result is a pass result or a fail result (described later). If the withstand voltage test result is a pass result, it indicates that the coil element 110 is a good product (the degree of degradation is within the tolerance range). If the withstand voltage test result is a fail result, it indicates that the coil element 110 is a defective product (the degree of degradation exceeds the tolerance range).

[0049] For example Figure 3 As shown, in some embodiments, the control module 108 intermittently generates multiple control signals S3 during a test period T2 to obtain multiple measured voltage values, and generates a withstand voltage test result based on these measured voltage values. Specifically, during the test period T2, the switch module 104 responds to the received multiple control signals S3 and turns on the output path P1 multiple times during the aforementioned charging period T1. For example Figure 3 As shown in FIG, four voltage bounce waveforms (W1 to W4) corresponding to four test cycles occurred during the test period T2. Figure 3For the sake of convenience, only four waveforms are shown, and some embodiments of the present invention are not limited to this number. In some embodiments, there are 512 test cycles in the test period T2.

[0050] For example Figure 3 As shown, in some embodiments, the current source 103 outputs substantially the same test current I during each charging period T1 within the test period T2. That is, each test cycle provides the same charging period T1 and test current I (i.e., the test environment is the same). Consequently, the control module 108 receives multiple measured voltage values ​​corresponding to these test cycles with the same test environment and uses these measured voltage values ​​to determine the withstand voltage test results.

[0051] For example Figure 3 As shown, in some embodiments, the control module 108 obtains a first voltage difference based on the voltage peak value Vp and a voltage setting value, and compares the first voltage difference with a judgment condition to generate a withstand voltage test result. The judgment condition can be to determine whether the voltage difference falls within a threshold value to determine the withstand voltage test result. It should be noted that the first voltage difference is the difference between each voltage peak value (Vp1, Vp2, Vp3, Vp4) during the test period T2 and the voltage setting value. In some embodiments, the control module 108 obtains a second voltage difference based on the maximum voltage peak value Vp detected during the test period T2 and at least one voltage peak value Vp detected thereafter (such as any one or more voltage peak values ​​or each voltage peak value thereafter), and compares the second voltage difference with the threshold value to generate the withstand voltage test result. The aforementioned "determining whether the voltage difference falls within the threshold value to determine the withstand voltage test result" can mean that the voltage difference is substantially equal to the threshold value, or it can mean that the voltage difference falls within the threshold value range (the range between the upper limit and the lower limit of one of the threshold values).

[0052] The following description assumes that the withstand voltage test apparatus 10 sets the test environment to output substantially the same current value during the same test period T2, and the control module 108 determines whether the coil element 110 is degraded based on the measured back electromotive force.

[0053] exist Figure 3In one embodiment, an upper limit of the threshold value is 0.5V and a lower limit of -0.5V. For example, when the difference between each voltage peak value (Vp1, Vp2, Vp3, Vp4) and the voltage setting value during the test period T2 is 0V (i.e., the first voltage difference is 0), the control module 108 compares the first voltage difference to fall within the threshold range and accordingly determines that the withstand voltage test result is a pass result. For another example, when the difference between any voltage peak value (Vp1, Vp2, Vp3, Vp4) and the voltage setting value during the test period T2 is 1V (i.e., the first voltage difference is 1), the control module 108 compares the first voltage difference to fall within the threshold range and accordingly determines that the withstand voltage test result is a fail result.

[0054] exist Figure 3 In another embodiment, the upper limit of the threshold is 0.5V and the lower limit is -0.5V. When the difference between the maximum voltage peak value Vp1 detected during the test period T2 and any subsequent voltage peak value Vp2 detected is 0V (i.e., the second voltage difference is 0), the control module 108 compares the second voltage difference to find that it falls within the threshold range and, accordingly, determines that the withstand voltage test result is a pass. For another example, when the difference between the maximum voltage peak value Vp1 detected during the test period T2 and any subsequent voltage peak value (Vp2, Vp3, Vp4) detected is 1V (i.e., the second voltage difference is 1), the control module 108 compares the second voltage difference to find that it exceeds the threshold range and, accordingly, determines that the withstand voltage test result is a fail.

[0055] Please also refer to Figure 2 and Figure 4 . Figure 4 In some embodiments of the present invention, the voltage bounce waveform caused by the back electromotive force is detected during the current increase period T3. Figure 2 and Figure 4 As shown, in some embodiments, the control module 108 performs a withstand voltage test (eg, breakdown voltage analysis) during a current increase period T3. Figure 4 As shown in FIG, the current increasing period T3 includes multiple test periods (T21, T22, T23), and the control module 108 can complete multiple withstand voltage tests within the current increasing period T3 (the end of each test period T2 indicates the completion of one withstand voltage test).

[0056] In some embodiments, the current source 103 can use each test period (T21, T22, and T23) as a stage and gradually increase the current value of the test current I. For example, during test period T21, the current source 103 outputs a test current I of a first current value and increases the current value of the next output at the end of test period T21. Therefore, during test period T22, the current source 103 can output a test current I of a second current value (the second current value is greater than the first current value). In this way, the withstand voltage testing device 10 can set the test environment to gradually increase the current value during the current increase period T3, allowing the control module 108 to measure a maximum withstand voltage value of the coil element 110 (the measured voltage value immediately before the measured voltage value is increased or decreased is used as the maximum withstand voltage value). In some embodiments, the current source 103 gradually increases the current value at the same ratio (5% to 20%).

[0057] For example Figure 4 As shown, in some embodiments, the current source 103 outputs substantially the same current value of the test current I during each charging period T1 within the test period T2. For example, the test current I output by the current source 103 during the charging period T1 and another charging period T1 within the test period T21 is substantially the same (within an allowable range error in measurement). Thus, the withstand voltage test device 10 can configure the test environment to output the test current I of substantially the same current value within the same test period T2 (i.e., between withstand voltage tests), allowing the control module 108 to detect whether the measured voltage value of the coil element 110 has increased or decreased.

[0058] The following description uses the withstand voltage test apparatus 10 to set the test environment to gradually increase the current value of the test period T2 within the current increasing period T3 , and the control module 108 determines whether the coil element 110 is degraded based on the measured back electromotive force.

[0059] exist Figure 4In one embodiment, the control module 108 subtracts the maximum voltage peak Vp1 measured during test period T2 from at least one subsequent voltage peak (Vp2, Vp3, Vp4) (e.g., one or more voltage peaks or each subsequent voltage peak) to obtain one or more third voltage differences (the third voltage difference being voltage peak Vp2 minus voltage peak Vp1, voltage peak Vp3 minus voltage peak Vp1, or voltage peak Vp4 minus voltage peak Vp1). The control module 108 determines a test pass result based on whether each third voltage difference falls within a threshold. For example, during test period T21, voltage peak Vp1 is measured to have a maximum voltage of 5.5V. Subsequently, voltage peak Vp2 is measured to be 5.2V, voltage peak Vp3 is measured to be 5.4V, voltage peak Vp3 is measured to be 5.5V, and voltage peak Vp4 is measured to be 5.4V. The control module 108 subtracts the voltage peak value Vp1 from any of the detected voltage peak values ​​(Vp2, Vp3, Vp4) to obtain third voltage differences of -0.3V, -0.1V, 0V, and -0.1V, respectively. When the threshold value is -0.5V, the control module 108 compares each of the third voltage differences to see if they fall within the threshold range, and accordingly determines that the withstand voltage test result is a pass result. For another example, if the voltage peak value Vp1 is measured to have a maximum voltage of 5.5V, and then the voltage peak value Vp2 is detected to be 4.5V, the voltage peak value Vp3 is 4.5V, and the voltage peak value Vp4 is 4.7V, the control module 108 subtracts the voltage peak value Vp1 from the voltage peak value Vp2 to obtain a third voltage difference of -1V (4.5V-5.5V). The control module 108 compares the third voltage difference to see if it falls within the threshold range, and accordingly determines that the withstand voltage test result is a fail result (i.e., the degree of degradation exceeds the allowable range).

[0060] exist Figure 4In another embodiment, the control module 108 subtracts the voltage peak values ​​Vp of two consecutive test periods (such as T21 and T22, or T22 and T23, etc.) to obtain a fourth voltage difference. The control module 108 determines whether the test is passed based on whether the fourth voltage difference falls within a threshold. For example, the upper limit of the threshold is 0.5V and the lower limit is -0.5V. The voltage measurement module 106 measures a voltage peak value Vp1 of 5V during the test period T21 and a voltage peak value Vp2 of 5.2V during the test period T22. The control module 108 subtracts the two voltage peak values ​​(Vp1, Vp2) to obtain a fourth voltage difference of 0.2V, and compares the fourth voltage difference (0.2V) to see if it falls within the range of the threshold (0.5V to -0.5V), thereby determining that the withstand voltage test result is a passed result. For another example, the voltage measurement module 106 measures a voltage peak value Vp1 of 5V during test period T21 and a voltage peak value Vp2 of 4.4V during test period T22. The control module 108 subtracts the two voltage peak values ​​(Vp1, Vp2) to obtain a fourth voltage difference of 0.6V. The control module 108 determines that the fourth voltage difference (0.6V) exceeds a threshold value (0.5V to -0.5V) and determines that the withstand voltage test result is a failure. It should be noted that in this embodiment, the control module 108 obtains the fourth voltage difference by subtracting any voltage peak value (Vp1, Vp2, Vp3, Vp4) during test period T21 from any voltage peak value (Vp1, Vp2, Vp3, Vp4) during test period T22 (this can also be the subtraction of subsequent test period T22 from test period T23). In other embodiments, the control module 108 obtains a fourth voltage difference by subtracting the average value of all voltage peak values ​​(Vp1, Vp2, Vp3, Vp4) in the test period T21 from the average value of all voltage peak values ​​(Vp1, Vp2, Vp3, Vp4) in the test period T22 (it may also be the subtraction of the subsequent test period T22 and the test period T23).

[0061] exist Figure 4In another embodiment, the control module 108 subtracts two consecutive voltage peaks Vp measured during two adjacent test cycles within the same test period T2 to obtain a fifth voltage difference. The control module 108 determines a test pass result based on whether the fifth voltage difference falls within a threshold. For example, the threshold has an upper limit of 0.5V and a lower limit of 0V. The voltage measurement module 106 measures a first voltage peak Vp1 of 5V and a second voltage peak Vp2 of 5V during test period T21. The control module 108 subtracts the measured voltage values ​​of the two consecutive voltage peaks (Vp1, Vp2) to obtain a fifth voltage difference of 0V. The control module 108 then checks whether the fifth voltage difference (0V) falls within the threshold range (0.5V to 0V) (the voltage peaks do not show a significant downward trend or do not show any downward trend during test period T21, indicating that the coil component 110 has not degraded). Based on this, the control module 108 determines that the withstand voltage test result has passed. For example, the voltage measurement module 106 measures a first voltage peak Vp1 of 5V and a second voltage peak Vp2 of 4.4V during test period T21. The control module 108 subtracts the measured voltage values ​​of the two consecutive voltage peaks (Vp1, Vp2) to obtain a fifth voltage difference of 0.6V. The control module 108 determines that the fifth voltage difference (0.6V) exceeds the threshold range (0.5V to 0V) and therefore determines that the withstand voltage test result is a failure (the voltage peaks show a significant downward trend during test period T21, indicating that the coil element 110 is functionally degraded).

[0062] exist Figure 4 In another embodiment, the control module 108 determines the test pass result based on whether an inductance change falls within a threshold. The control module 108 can apply the measured voltage value to the formula (1) described later to obtain the corresponding inductance change. The control module 108 obtains an inductance change based on the voltage peak value Vp of two adjacent test periods T2. For example, the upper limit value of the threshold is 5% and the lower limit value is -5%. The voltage measurement module 106 measures a measured voltage value of 5V for the voltage peak value Vp1 during the first test period T21 and a measured voltage value of 5V for the voltage peak value Vp1 during the second test period T22. The control module 108 obtains an inductance change of 0% based on the two voltage peak values ​​Vp1. The control module 108 can obtain the inductance change according to the following formula (1):

[0063]

[0064] Vs is the voltage peak value Vp1 measured during the first test period T21 ; Vx is the voltage peak value Vp2 measured during the test period T22 following the test period T21 (it may also be the voltage peak value during the test period T23 or its subsequent periods).

[0065] The control module 108 compares the inductance change of 0% to a threshold value (0% to 5%) (indicating that the inductance characteristics of the coil element 110 are normal), and accordingly determines that the withstand voltage test result is a pass. For another example, the voltage measurement module 106 measures a voltage peak value of 5V during the first test period T21 and a voltage peak value of 5.2V during the second test period T22 of the current ramp-up period T3. Based on the two voltage peaks (Vp1 and Vp2), the control module 108 determines that the inductance change is 8.16% (Vs is 5.2V, Vx is 5V, and the inductance change is 8.16% calculated according to formula (1)). The control module 108 compares the inductance change (8.16%) to a threshold value (5% to -5%) (the measured voltage value has increased, indicating that the inductance of the coil element 110 has decreased), and accordingly determines that the withstand voltage test result is a fail. It should be noted that in this embodiment, the control module 108 uses any voltage peak value (Vp1, Vp2, Vp3, Vp4) during the first test period T21 and any voltage peak value (Vp1, Vp2, Vp3, Vp4) during any subsequent test period (T22, T23) as parameters in the aforementioned formula (1) to obtain the inductance change. In other embodiments, the control module 108 uses the average value of all voltage peak values ​​(Vp1, Vp2, Vp3, Vp4) during the first test period T21 and the average value of all voltage peak values ​​(Vp1, Vp2, Vp3, Vp4) during any subsequent test period (T22, T23) as parameters in the aforementioned formula (1) to obtain the inductance change.

[0066] exist Figure 4In another embodiment, the control module 108 subtracts the calculated inductance changes during the two consecutive test periods T2 to obtain an inductance change difference. The control module 108 determines whether the test has passed based on whether the inductance change difference falls within a threshold. For example, the control module 108 determines an inductance change of 0% based on two consecutive voltage peaks Vp1 during the first set (test periods T21 and T22), and also determines an inductance change of 0% based on two consecutive voltage peaks Vp1 during the second set (test periods T22 and T23). The two sets of inductance changes are subtracted to obtain an inductance change difference of 0%. The control module 108 determines that the inductance change difference (0%) does not exceed a threshold (5% to -5%) (the increase in the measured voltage value is within an acceptable range, indicating that the inductance of the coil component 110 is normal), and thus determines that the withstand voltage test result has passed. For another example, the control module 108 obtains an inductance change of 0% based on the two voltage peaks Vp1 during the first set (test period T21 and test period T22), and obtains an inductance change of 6% based on the two voltage peaks Vp1 during the second set (test period T22 and test period T23). The two sets of inductance changes are subtracted to obtain an inductance change difference of -6%. The control module 108 compares the inductance change difference (-6%) and determines whether it falls within a threshold range (5% to -5%) (the increase in the measured voltage value exceeds the acceptable range, indicating that the inductance value of the coil element 110 has decreased), and accordingly determines that the withstand voltage test result is a failure.

[0067] In some embodiments, the control module 108 selectively uses any one or more of the aforementioned determination methods to determine the degree of degradation of the coil element 110. For example, the control module 108 determines an inductance change of 10% based on the first set of two voltage peaks Vp1 (test periods T21 and T22), and also determines an inductance change of 10% based on the second set of two voltage peaks Vp1 (test periods T22 and T23). The two sets of inductance changes are subtracted to obtain a difference in inductance change of 0%. Although the difference in inductance change is 0%, the control module 108 compares the inductance changes (10%) of the first and second sets and finds that they are within a threshold range (5% to -5%) (the increase in the measured voltage value exceeds the acceptable range, indicating that the inductance value of the coil element 110 has decreased). Therefore, the control module 108 determines that the withstand voltage test result still fails.

[0068] For example Figure 3 and Figure 4As shown, in some embodiments, the control module 108 intermittently generates multiple control signals S3 at the same time interval during test period T2. For example, the voltage bounce waveform W1 and the voltage bounce waveform W2 have a first time interval, while the voltage bounce waveform W2 and the voltage bounce waveform W3 have a second time interval, with the first time interval being substantially equal to the second time interval. This ensures that the interval between the switch being turned on again and the next time the switch is turned on remains consistent, ensuring that each voltage bounce waveform W2 detected during test period T2 is generated under the same test environment.

[0069] In summary, in some embodiments, the withstand voltage test device 10 includes a current module 102, a voltage measurement module 106, and a control module 108. The control module 108 can perform a withstand voltage test under a set test environment. When the control module 108 sets the test environment, it controls the current module 102 to output a test current I of a specified current value during test period T2, or to gradually increase the test current I during each test period T2 during current increase period T3. This allows the control module 108 to measure the back electromotive force (EMF) fed back by the coil element 110 under various test environments, depending on product testing requirements. When the withstand voltage test device 10 performs a withstand voltage test on the coil element 110, it detects whether the coil element 110 has passed the test. The control module 108 obtains a voltage peak value based on the back electromotive force of the coil element 110 and determines whether the coil element 110 has passed the test based on the measured voltage value and a judgment condition. The control module 108 determines whether the test passes according to the following criteria: A first voltage difference is obtained by measuring the difference between the peak voltage Vp measured during test period T2 and the set voltage value, and determining whether the voltage difference falls within a threshold; a second voltage difference is obtained by subtracting the maximum peak voltage Vp measured during test period T2 from at least one subsequent peak voltage Vp, and determining whether the voltage difference falls within the threshold; a fourth voltage difference is obtained by subtracting the peak voltage Vp values ​​of two consecutive test periods T2, and determining whether the voltage difference falls within the threshold; an inductance change is obtained based on the peak voltage Vp values ​​of two adjacent test periods T2, and determining whether the inductance change falls within the threshold; and a difference in inductance change is obtained by subtracting the inductance change values ​​of two consecutive test periods T2, and determining whether the difference in inductance change falls within the threshold. In this way, the withstand voltage test device 10 can ensure that the back electromotive force measured under the test environment is stable, thereby accurately determining whether the withstand voltage test result of the coil component 110 passes the test.

[0070] The embodiments described above are merely illustrative of the technical concepts and features of this application. Their purpose is to enable those familiar with the technology to understand the content of this application and implement it accordingly. They cannot be used to limit the patent scope of this application. In other words, any equivalent changes or modifications made based on the spirit disclosed in this application should still be included in the scope of the patent application of this application.

Claims

1. A withstand voltage test device, characterized in that: Suitable for testing a coil component, the withstand voltage testing device comprises: a current module configured to intermittently apply a test current to the coil element multiple times during a test period; a voltage measuring module configured to be connected to the coil element and measure a voltage at one end of the coil element to obtain a plurality of measured voltage values ​​corresponding to each time the coil element is subjected to the test current; and A control module is configured to connect the current module and the voltage measurement module and generate a test pass result according to the measured voltage values.

2. The withstand voltage test device according to claim 1, wherein: in, The control module obtains a voltage difference value according to the difference between each measured voltage value and a voltage setting value. The test pass result is determined according to whether each voltage difference value falls within a threshold value.

3. The withstand voltage test device according to claim 1, wherein: in, The control module obtains a voltage difference by subtracting the maximum measured voltage value from another measured voltage value measured during the test period. The test pass result is determined based on whether the voltage difference falls within a threshold.

4. The withstand voltage test device according to claim 2, wherein: in, The control module performs a test during a current increasing period, which includes a plurality of test periods. The current module gradually increases a current value of the test current during the current increasing period, taking each test period as a stage.

5. The withstand voltage test device according to claim 4, wherein: in, The control module obtains a voltage difference by subtracting the maximum measured voltage value from another measured voltage value measured during the test period. The test pass result is determined based on whether the voltage difference falls within a threshold.

6. The withstand voltage test device according to claim 4, wherein: in, The control module subtracts two consecutive measured voltage values ​​during the current increasing period to obtain a voltage difference. The test pass result is determined based on whether the voltage difference falls within a threshold.

7. The withstand voltage test device according to claim 4, wherein: in, The control module subtracts two consecutive measured voltage values ​​during the test period to obtain a voltage difference. The test pass result is determined based on whether the voltage difference falls within a threshold.

8. The withstand voltage test device according to claim 4, wherein: in, The control module obtains an inductance variation according to the measured voltage values ​​during two adjacent test periods. The test pass result is determined based on whether the inductance variation falls within a threshold.

9. The withstand voltage test device according to claim 4, wherein: in, The control module subtracts the inductance changes during two consecutive current increase periods from each other based on an inductance change of the measured voltage values ​​during two adjacent test periods to obtain an inductance change difference. The test pass result is determined based on whether the inductance change difference falls within a threshold.

10. The withstand voltage test device according to any one of claims 1 to 9, characterized in that: in, The measured voltage value is a voltage peak value in a voltage bounce waveform caused by a back electromotive force generated in response to the disappearance of the test current.

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