Magnetic core inductor characteristic testing device

Abstract

The utility model provides a device for testing the characteristics of a magnetic core inductor with superposed direct-current components. The device comprises an alternating-current bridge loop and a direct-current loop, the direct current loop comprises a direct current constant current source and an inductor; the alternating current bridge loop comprises a blocking capacitor, an adjustable resistor, an adjustable capacitor and an adjustable alternating current source; the direct-current loop and the alternating-current bridge loop are connected with two ends of the magnetic core inductor to be tested to form a loop; the inductor is used for isolating the interference of the AC bridge loop on the DC loop, and the blocking capacitor is used for isolating the interference of the DC constant current source on the AC bridge loop; the direct current loop is used for providing adjustable direct current for the magnetic core inductor to be tested; the alternating current bridge loop is used for providing adjustable alternating current for the magnetic core inductor to be tested. According to the utility model, the performance of the magnetic core inductor can be tested under the superposition of different alternating-current and direct-current voltages, the test result is accurate and comprehensive, and the operation reliability and stability of the magnetic core inductor under the actual working condition are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of inductance performance testing, in particular to a magnetic core inductor characteristic testing device. Background Art

[0002] Magnetic core inductors are mostly used in power supply circuits and filter circuits, and can also be used in ripple, noise and interference suppression circuits. In such applications, a certain working current always flows through the magnetic core inductor. When a certain DC current flows through the inductor, it may cause the magnetic material to approach the magnetic saturation state, and the inductance value will also decrease, affecting the safe and stable operation of the circuit.

[0003] The existing performance test of magnetic core inductors usually only applies AC voltage for testing, which leads to inaccurate and incomplete test results, affecting the reliability and stability of the magnetic core inductors under actual working conditions. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a magnetic core inductor characteristic test device with a superimposed DC component, comprising an AC bridge circuit and a DC circuit; the DC circuit comprises: a DC constant current source and an inductor; the AC bridge circuit comprises: a DC blocking capacitor, an adjustable resistor, an adjustable capacitor and an adjustable AC source; the DC circuit and the AC bridge circuit are both connected to the two ends of the magnetic core inductor to be tested to form a circuit; the inductor is used to isolate the interference of the AC bridge circuit to the DC circuit, and the DC blocking capacitor is used to isolate the interference of the DC constant current source to the AC bridge circuit; the DC circuit is used to provide an adjustable DC current for the magnetic core inductor to be tested; and the AC bridge circuit is used to provide an adjustable AC current for the magnetic core inductor to be tested.

[0005] Optionally, the DC constant current source and the inductor are connected in series, and the inductor is connected to the test terminal A, and the DC constant current source is connected to the test terminal B; during testing, the test terminal A and the test terminal B are used to connect the two ends of the magnetic core inductor to be tested.

[0006] Optionally, the AC bridge circuit also includes: a first resistor, a second resistor and an ammeter; the DC blocking capacitor, the first resistor, the adjustable resistor, the adjustable capacitor, and the second resistor are connected in series in sequence, and the DC blocking capacitor is connected to the test terminal A, and the second resistor is connected to the test terminal B; the two ends of the ammeter are respectively connected between the DC blocking capacitor and the first resistor, and between the adjustable capacitor and the second resistor; the two ends of the adjustable AC source are respectively connected between the first resistor and the adjustable resistor, and the test terminal B.

[0007] Optionally, the DC circuit further includes a current measuring element, and the current measuring element is used to measure the DC current of the DC circuit.

[0008] Optionally, the AC bridge loop further includes a current measuring element; the current measuring element is used to measure the AC current of the AC bridge loop.

[0009] Optionally, the inductor is a choke inductor.

[0010] Optionally, when no DC power supply is applied to the DC circuit and a voltage of a preset frequency is applied to the AC bridge circuit, the adjustable resistor and the adjustable capacitor balance the AC bridge circuit.

[0011] Optionally, the second resistor is an adjustable resistor.

[0012] Optionally, the first resistor is an adjustable resistor.

[0013] The device and system for testing the characteristics of a core inductor with a superimposed DC component provided in the embodiments of the utility model can perform performance tests on the core inductor under the superposition of different AC and DC voltages, simulate the operating conditions of the core inductor under different conditions, and obtain the saturation characteristics of the inductor under different DC superposition conditions. The test results are accurate and comprehensive, which improves the reliability and stability of the core inductor under actual operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0015] Figure 1 The circuit structure diagram of the magnetic core inductor characteristic testing device with superimposed DC component provided by an embodiment of the utility model is shown.

[0016] Description of reference numerals:

[0017] I-adjustable DC constant current source; A1, A2-ammeters; L1-choke inductor; C1-DC blocking capacitor; R2, R3, R4-adjustable resistors; C2-adjustable capacitor; G-galvanometer; U-adjustable AC source; A, B-test terminals. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific embodiments of the utility model are described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0019] In order to improve the reliability and stability of the core inductor under actual working conditions, it is very important to perform performance tests on the core inductor under the superposition of different AC and DC voltages.

[0020] The embodiment of the utility model provides a device and a test scheme with a reasonable and concise design, which can accurately analyze the performance test of a magnetic core inductor under the superposition of different AC and DC voltages.

[0021] The embodiment of the utility model provides a magnetic core inductor characteristic testing device with a superimposed DC component, which comprises an AC bridge circuit and a DC circuit.

[0022] The DC circuit includes a DC constant current source and an inductor; the DC constant current source and the inductor are connected in series, and the inductor is connected to the test terminal A, and the DC constant current source is connected to the test terminal B. During the test, the test terminals A and B are used to connect the two ends of the magnetic core inductor to be tested.

[0023] The DC constant current source is used to apply different DC currents to the magnetic core inductor to be tested, so as to test the drop rate of the magnetic core inductor value to be tested under given AC current amplitude and frequency conditions with different DC current superposition conditions, and obtain the relationship between the inductance and the DC component.

[0024] Optionally, the inductor is a choke inductor, which functions to isolate the interference of the AC bridge loop on the DC constant current source, so that all the AC current generated by the AC bridge flows through the magnetic core inductor to be tested.

[0025] The AC bridge circuit includes: a DC blocking capacitor, a first resistor, an adjustable resistor, a second resistor, an adjustable capacitor, a galvanometer and an adjustable AC source; the DC blocking capacitor, the first resistor, the adjustable resistor, the adjustable capacitor and the second resistor are sequentially connected in series, and the DC blocking capacitor is connected to the test terminal A, and the second resistor is connected to the test terminal B. The two ends of the adjustable AC source are respectively connected between the first resistor and the adjustable resistor and the test terminal B.

[0026] The AC bridge circuit is used to apply AC signals of different amplitudes and frequencies to the magnetic core inductor to be tested. The function of the DC blocking capacitor is to isolate the interference of the DC constant current source on the AC bridge, so that the DC current generated by the DC constant current source flows completely through the magnetic core inductor to be tested.

[0027] Under the condition that the DC current in the DC circuit is constant, by changing the amplitude and frequency of the given current in the AC bridge circuit, the relationship between the inductance and the AC component can be obtained.

[0028] The two ends of the galvanometer are respectively connected between the DC blocking capacitor and the first resistor, and between the adjustable capacitor and the second resistor. The galvanometer can detect weak electric quantity and serve as a zeroing instrument in the bridge. When no DC power supply is applied to the DC circuit and a voltage of a preset frequency is applied to the AC bridge circuit, the adjustable resistor and the adjustable capacitor balance the AC bridge circuit. The adjustable resistor and the adjustable capacitor are adjusted so that the galvanometer reading is 0, and the AC bridge is balanced at this time.

[0029] Based on the above-mentioned magnetic core inductor characteristic testing device, by changing the AC current under a given DC current, the relationship between the inductance and the AC component can be tested. By changing the DC current under a given AC current, the relationship between the inductance and the DC component can be tested. By repeating the above tests, the characteristics of the magnetic core inductor under various operating conditions can be obtained.

[0030] The AC bridge circuit and the DC circuit can realize the adjustment of the AC component and the DC component superimposed on the magnetic core inductor to be measured, and the AC bridge circuit can measure the inductance of the magnetic core inductor to be measured.

[0031] The magnetic core inductor characteristic testing device with superimposed DC component provided in the embodiment of the utility model can perform performance tests on the magnetic core inductor under the superposition of different AC and DC voltages, simulate the operating conditions of the magnetic core inductor under different conditions, and obtain the saturation characteristics of the inductor under different DC superposition conditions. The test results are accurate and comprehensive, which improves the reliability and stability of the magnetic core inductor under actual operating conditions.

[0032] Optionally, the DC circuit further includes a first ammeter connected between the DC constant current source and the inductor, and can display the current in the DC circuit in real time.

[0033] Optionally, the AC bridge loop further includes a second ammeter connected between the DC blocking capacitor and the first resistor. The second ammeter can display the current in the AC bridge loop in real time.

[0034] Optionally, the second resistor is an adjustable resistor, and the first resistor is an adjustable resistor. Based on the adjustable resistor being able to adjust the balance of the AC bridge loop, the AC component superimposed on the magnetic core inductor to be measured is used to calculate the inductance of the magnetic core inductor to be measured.

[0035] Figure 1 The circuit structure diagram of the magnetic core inductor characteristic testing device with superimposed DC component provided by an embodiment of the utility model is shown.

[0036] exist Figure 1The figure shows an adjustable DC constant current source I, an ammeter A1, a choke inductor L1, a DC blocking capacitor C1, an ammeter A2, an adjustable resistor R2 (i.e., the first resistor mentioned above), an adjustable resistor R3, an adjustable resistor R4 (i.e., the second resistor mentioned above), an adjustable capacitor C2, a galvanometer G and an adjustable AC source U. Figure 1 Also shown in the figure is a test terminal A and a test terminal B.

[0037] The DC constant current source I, the ammeter A1, the choke inductor L1 and the magnetic core inductor L to be tested are x The DC circuit LP1 is formed, which is the magnetic core inductor L to be tested. x Provides adjustable DC bias current; ammeter A2, adjustable resistor R2, adjustable resistor R3, adjustable resistor R4, adjustable capacitor C2, galvanometer G, adjustable AC source U and magnetic core inductor L to be tested x The AC bridge circuit LP2 is composed of the core inductor L to be tested. x It provides adjustable AC current, and on the other hand, by adjusting the bridge arms, it can calculate the inductor value and quality factor of the magnetic core to be measured.

[0038] The function of the DC blocking capacitor C1 is to isolate the interference of the DC constant current source on the AC bridge, so that the DC current generated by the DC constant current source flows through the magnetic core inductor L to be tested. x The function of the choke inductor L1 is to isolate the interference of the AC bridge circuit to the DC constant current source, so that all the AC current generated by the AC bridge flows through the magnetic core inductor L to be tested. x .

[0039] This embodiment provides a testing method based on the above-mentioned core inductor characteristics with superimposed DC components, which is as follows:

[0040] First, when no DC power is applied to the DC circuit, an AC current with a given amplitude and frequency is applied to the AC bridge circuit side to measure the initial inductance value L. s0 Among them, the adjustable resistor R3 and the adjustable capacitor C2 are adjusted to make the galvanometer G read 0. At this time, the AC bridge reaches balance. According to the formula (1) Lx = R2R4C2, the inductance value L is calculated. s0 .

[0041] Secondly, gradually increase the current value of the DC circuit and record the DC circuit current value I in turn. n The inductance value of the magnetic core to be measured is L sn Calculate and record the DC circuit current value I in turn according to formula (1) n The inductance value of the magnetic core to be measured is L sn (n=1, 2, 3, ...).

[0042] Then, based on the data recorded in the previous step, the curve of inductance changing with the DC component is obtained, and the rate of decrease of inductance as the DC superposition component increases is calculated. According to the formula (L s0 -L sn ) / L s0 *100% Calculate the drop rate of the inductor value of the magnetic core to be tested under different DC current superposition conditions under given preset AC current amplitude and frequency conditions, and obtain the curve of inductance changing with DC component.

[0043] Under the condition that the DC current in the DC circuit is constant, the amplitude and frequency of the given current in the AC bridge circuit are changed to obtain the curve of the inductance changing with the AC component. By repeating the above steps, the characteristics of the core inductor under various operating conditions can be obtained.

[0044] By means of the above-mentioned testing device provided in this embodiment, the operating conditions of the magnetic core inductor under different conditions can be simulated, and according to the above-mentioned testing method, the saturation characteristics of the inductor under different DC superposition conditions can be obtained.

[0045] The embodiment of the utility model provides a core inductor characteristic testing system with a superimposed DC component, comprising the above-mentioned core inductor characteristic testing device with a superimposed DC component and a core inductor to be tested; the above-mentioned test terminal A and test terminal B are connected to the two ends of the core inductor to be tested.

[0046] Although the utility model is disclosed as above, the utility model is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the scope defined by the claims.

[0047] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0048] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0049] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A core inductor characteristic testing device, characterized in that: Including AC bridge circuit and DC circuit; The DC circuit includes: a DC constant current source and an inductor; The AC bridge circuit includes: a DC blocking capacitor, an adjustable resistor, an adjustable capacitor and an adjustable AC source; The DC circuit and the AC bridge circuit are both connected to the two ends of the magnetic core inductor to be tested to form a circuit; the inductor is used to isolate the interference of the AC bridge circuit to the DC circuit, and the DC blocking capacitor is used to isolate the interference of the DC constant current source to the AC bridge circuit; The DC circuit is used to provide an adjustable DC current for the magnetic core inductor to be tested; and the AC bridge circuit is used to provide an adjustable AC current for the magnetic core inductor to be tested.

2. The magnetic core inductor characteristic testing device according to claim 1, characterized in that: The DC constant current source and the inductor are connected in series, and the inductor is connected to the test terminal A, and the DC constant current source is connected to the test terminal B; During testing, the test terminal A and the test terminal B are used to connect the two ends of the magnetic core inductor to be tested.

3. The magnetic core inductor characteristic testing device according to claim 2, characterized in that: The AC bridge circuit also includes: a first resistor, a second resistor and a galvanometer; The DC blocking capacitor, the first resistor, the adjustable resistor, the adjustable capacitor, and the second resistor are sequentially connected in series, and the DC blocking capacitor is connected to the test terminal A, and the second resistor is connected to the test terminal B; Two ends of the galvanometer are respectively connected between the DC blocking capacitor and the first resistor, and between the adjustable capacitor and the second resistor; Two ends of the adjustable AC source are connected to between the first resistor and the adjustable resistor and the test end B respectively.

4. The magnetic core inductor characteristic testing device according to claim 3, characterized in that: The DC circuit further includes a current measuring element, and the current measuring element is used to measure the DC current of the DC circuit.

5. The magnetic core inductor characteristic testing device according to claim 3, characterized in that: The AC bridge loop also includes a current measuring element; the current measuring element is used to measure the AC current of the AC bridge loop.

6. The magnetic core inductor characteristic testing device according to claim 3, characterized in that: The inductor is a choke inductor.

7. The magnetic core inductor characteristic testing device according to claim 3, characterized in that: When no DC power is applied to the DC circuit and a voltage of a preset frequency is applied to the AC bridge circuit, the adjustable resistor and the adjustable capacitor balance the AC bridge circuit.

8. The magnetic core inductor characteristic testing device according to any one of claims 3 to 7, characterized in that: The second resistor is an adjustable resistor.

9. The magnetic core inductor characteristic testing device according to any one of claims 3 to 7, characterized in that: The first resistor is an adjustable resistor.

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