Inductance testing device based on LC resonance principle
By using an inductance testing device based on the LC resonance principle, and utilizing an independently controlled charging circuit and an LC resonance circuit built-in testing system, the problems of large size, high price, and low accuracy of inductance testing instruments are solved, thus achieving both accuracy and economy in inductance measurement.
Patent Information
- Application Number
- CN202423291652.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-28
- Publication Date
- 2026-01-30
- Estimated Expiration
- 2034-12-28
AI Technical Summary
Existing inductance testing instruments are bulky, expensive, and their accuracy is affected by parasitic parameters, resulting in large differences in inductance values at different test frequencies.
An inductance testing device based on the LC resonance principle is adopted, which includes an independently controlled charging circuit and an LC resonant circuit. The built-in testing system of the LC resonant circuit is used to measure the inductance L2 through the LC resonant circuit formed by capacitor C1 and inductor L1, thereby reducing the influence of parasitic parameters.
It achieves both accuracy and economy in inductance measurement, and the device is compact in size, reducing production costs.
Smart Images
Figure CN223857307U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to inductance test equipment technical field, specifically related to a kind of inductance testing device based on LC resonance principle. BACKGROUND
[0002] LRC tester is the instrument for measuring the corresponding physical parameters of capacitor, resistance, inductance element. Compared with commonly used multimeter, LRC tester not only has higher measurement accuracy, but also can measure various parameters of element, such as impedance, quality factor and the like.
[0003] Currently, the inductance testing instrument on the market is usually LRC testing equipment, which usually applies a standard alternating voltage to the measured object, then collects current amplitude and phase, and then measures inductance by impedance meter method. Although this method is convenient to operate, it is bulky and expensive, but the accuracy is affected by parasitic parameters. In actual work, the phenomenon is that inductance value is very different under different test frequencies. UTILITY MODEL CONTENTS
[0004] To solve the above technical problems, the utility model adopts the following technical solutions:
[0005] A kind of inductance testing device based on LC resonance principle, comprising:
[0006] Both contain charging circuit and LC resonance circuit composed of capacitor C1 and independently controlled, the charging circuit, LC resonance circuit form built-in test system to external inductance L2;
[0007] To be measured end, with the interface of LC resonance circuit electric connection and the parasitic capacitance C2 in parallel with inductance L2.
[0008] Further, the charging circuit includes resistance R1 in series with capacitor C1, power supply V1 and switch S1 for controlling on-off.
[0009] Further, the LC resonance circuit includes inductance L1 in series with capacitor C1 and switch S2 for controlling on-off.
[0010] Further, after the switch S1 is closed and the switch S2 is opened, the power supply V1, the switch S1, the resistance R1, the capacitor C1 form charging circuit, after the switch S2 is closed and the switch S1 is opened, the capacitor C1, the inductance L1, the inductance L2, the switch S2 form the LC resonance circuit.
[0011] Further, the capacity of the capacitor C1 is greater than the capacity of the capacitor C2.
[0012] Further, the capacitor C1 includes any one of CBB capacitor, NPO capacitor and COG capacitor.
[0013] Further, the inductor L1 comprises a hollow coil inductor.
[0014] Further, the built-in test system is externally provided with a magnetic field shielding box.
[0015] Compared with the prior art, the utility model has the following beneficial effects:
[0016] The utility model discloses a test method of inductor changes with circuit, and inductance measurement is carried out with LC resonance principle, is not sensitive to parasitic parameter, and the measurement result is more accurate, so that the inductance test device adopting the circuit is affordable, small in size, can be equipped in large quantities, and can effectively reduce the production and development cost of enterprises. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is the structural schematic diagram of the test circuit of the utility model embodiment;
[0018] Figure 2 It is the schematic diagram of the test waveform of the utility model embodiment. DETAILED DESCRIPTION
[0019] In order to make those skilled in the art can better understand the utility model, the utility model technical scheme is further explained below in combination with the drawings and examples.
[0020] Wherein, the drawing is only used for example explanation, and the representation is only schematic diagram, and not physical drawing, and can not be understood as the limitation of the patent of the utility model;In order to better illustrate the embodiment of the utility model, some components of the drawing can be omitted, enlarged or reduced, and do not represent the size of actual product;For those skilled in the art, it is understandable that some known structures and their description in the drawing can be omitted, and the same or similar components in the drawing of the embodiment of the utility model are corresponding;In the description of the utility model, it is understood that if the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and not indicate or imply that the device or element must have a particular orientation, configuration and operation, therefore the positional relationship of the terms in the drawing is only used for example explanation, and can not be understood as the limitation of the patent of the utility model, and for those skilled in the art, the specific meaning of the above terms can be understood according to specific circumstances.
[0021] As Figure 1 - Figure 2 The utility model discloses an inductance test device based on LC resonance principle, including:
[0022] The charging circuit and the LC resonant circuit are formed by a capacitor C1 and are independently controlled, and the charging circuit and the LC resonant circuit form a built-in test system for an external inductor L2.
[0023] The to-be-tested end has an interface electrically connected with the LC resonant circuit and a parasitic capacitor C2 connected in parallel with the inductor L2.
[0024] The inductance testing method of the utility model changes the circuit, measures the inductance by using the LC resonant principle, solves the problem that the inductance value cannot be correctly measured due to the influence of the inductance parasitic parameter, and makes the inductance testing device adopting the circuit affordable and small in size.
[0025] As shown in Figure 1 The interface is divided into interface 1 and interface 2, and both are external, which are responsible for the inductor L2 to be measured externally, and the series connection of the resistor R1 and the capacitor C1 is controlled by the switch S1, and the series connection of the inductor L1 and the capacitor C1 is controlled by the switch S2.
[0026] The inductor L2 is an inductor to be measured externally.
[0027] Specifically, the charging circuit comprises the resistor R1, the power supply V1 and the switch S1 connected in series with the capacitor C1.
[0028] The LC resonant circuit comprises the inductor L1 connected in series with the capacitor C1 and the switch S2.
[0029] Specifically, after the switch S1 is closed and the switch S2 is opened, the power supply V1, the switch S1, the resistor R1 and the capacitor C1 form a charging circuit, and after the switch S2 is closed and the switch S1 is opened, the capacitor C1, the inductor L1, the inductor L2 and the switch S2 form an LC resonant circuit.
[0030] In the specific use of the device, the switch S2 is first opened and the switch S1 is closed, and the power supply V1 charges the capacitor C1.
[0031] After the charging is completed, the switch S1 is opened and the switch S2 is closed. Figure 2 At this time, if the interface 1 and the interface 2 are connected with the inductor L2 to be tested externally, a waveform diagram as shown in
[0032] According to the measured period T, the frequency The capacitor C1 and 2π are known quantities, and because the capacitor C1 is much larger than the capacitor C2, the inductance of the inductor L can be directly calculated by the formula .
[0033] Since the inductance L at this time is the inductance L1 and the inductance L2 in series, the inductance of the inductance L1 also needs to be subtracted to obtain the inductance of the inductance L2, which is completed in the debugging process, and only the inductance of the inductance L2 is displayed on the screen in the device.
[0034] Among them, the inductance L1 is used as a basic element to start the circuit, and the resistance R1 plays a role in limiting current when charging the inductance C1.
[0035] In addition, in order to ensure the accuracy of the measurement results, the capacity of the capacitor C1 should be much larger than the capacity of the capacitor C2, and the influence of the parasitic capacitor C2 on the resonance should be reduced, and the inductance L1 should be matched to make the measurement circuit work within a more appropriate frequency range.
[0036] The capacitor C1 should be selected as a high-stability non-polar capacitor as much as possible, such as CBB capacitor, NPO capacitor, COG capacitor or mica capacitor.
[0037] In addition, the inductance L1 should be selected as a high-stability inductance with small parasitic parameters, such as a hollow coil inductance.
[0038] In order to ensure the normal operation of the entire circuit, a certain external magnetic field shielding is required, and a shielding box is arranged outside the built-in test system.
[0039] The above shielding box can use existing technology and is easy to implement, and does not belong to the protection range of the present application, so it has the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described here.
[0040] The above is only an embodiment of the present application, and the specific structure and characteristics of the scheme are not described in detail here, and the ordinary technical personnel in the art know all the ordinary technical knowledge in the technical field of the present application before the application date or the priority date, can know all the prior art in this field, and have the ability to apply conventional experimental means before that date, and the ordinary technical personnel in the art can improve and implement the present scheme under the inspiration of the present application, and some typical known structures or known methods should not be an obstacle for the ordinary technical personnel to implement the present application. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection range of the present application, and these will not affect the effect and practicality of the patent.
Claims
1. An inductance testing device based on the LC resonance principle, characterized in that, Comprise: Both contain charging circuit composed of capacitor C1 and independent control, and LC resonant circuit, the charging Circuit, LC resonant circuit forms the built-in test system of external inductance L2; The terminal to be measured has an interface electrically connected to the LC resonant circuit and a parasitic capacitor C2 connected in parallel with the inductance L2.
2. The inductance testing device based on the LC resonance principle according to claim 1, characterized in that: The charging circuit comprises a resistor R1 connected in series with the capacitor C1, a power supply V1, and a switch S1 for controlling the on-off.
3. The inductance testing device based on the LC resonance principle according to claim 2, characterized in that: The LC resonant circuit comprises an inductance L1 connected in series with the capacitor C1 and a switch S2 for controlling the on-off.
4. The inductance testing device based on the LC resonance principle according to claim 3, characterized in that: After the switch S1 is closed and the switch S2 is opened, the power supply V1, the switch S1, the resistor R1, and the capacitor C1 form a charging circuit. After the switch S2 is closed and the switch S1 is opened, the capacitor C1, the inductance L1, the inductance L2, and the switch S2 form the LC resonant circuit.
5. The inductance testing device based on the LC resonance principle according to claim 1, characterized in that: The capacity of the capacitor C1 is greater than that of the capacitor C2.
6. The inductance testing device based on the LC resonance principle according to claim 1, characterized in that: The capacitor C1 comprises any one of CBB capacitor, NPO capacitor, and COG capacitor.
7. The inductance testing device based on the LC resonance principle according to claim 3, characterized in that: The inductance L1 comprises a hollow coil inductance.
8. The inductance testing device based on the LC resonance principle according to claim 1, characterized in that: The built-in test system is externally provided with a shielding box.