CN208506230U - A kind of high quality factor difference coil combination for wireless charging foreign bodies detection - Google Patents

Abstract

The utility model discloses a kind of high quality factor difference coil combination for wireless charging foreign bodies detection, its lead-out wire accesses the ac input end of current rectifying and wave filtering circuit (2), direct current is obtained by current rectifying and wave filtering circuit (2), resistance 2 is divider resistance, resistance 1 is sampling resistor, sampling resistor is direct current sampling end, direct current sampling end accesses capture card (4), by the voltage value of single-chip microcontroller acquisition high quality factor difference coil combination, while collected data are sent to host computer (5) by single-chip microcontroller.The utility model whether there is metallic foreign body between can detect transmission coil, and will test result and feed back to host computer, if discovery metal, alarms, and judge the position of metallic foreign body in time, guarantee the safety of user and equipment.

Description

A High Quality Factor Differential Coil Combination for Wireless Charging Foreign Object Detection

technical field

The utility model belongs to the field of wireless power transmission, in particular to a high quality factor differential coil combination used for wireless charging foreign object detection.

Background technique

Due to the convenience and speed of wireless charging, more and more electrical devices use wireless charging. However, after metal foreign matter is mixed into the wireless charging coupling mechanism, metal heating will cause a series of problems.

The existing detection methods for metal foreign objects between wireless charging coupling mechanisms are divided into two categories: electrical parameter detection and auxiliary coil detection. The detection accuracy of the electrical parameter detection method is not high, and it is highly dependent on the stability of double-terminal communication, and can only detect large metals. The metal position cannot be accurately judged. The detection accuracy of the existing auxiliary coil detection method needs to be enhanced, and the position of the metal foreign object cannot be judged.

SUMMARY OF THE INVENTION

In view of this, the utility model designs a high-quality differential coil combination for metal foreign body detection, which can detect whether there is a metal foreign body between the transmission coils, and feedback the detection result to the upper computer. Determine the location of foreign metal objects to ensure the safety of users and equipment.

In order to achieve the above object, the technical scheme of the present utility model is achieved in this way:

A high quality factor differential coil combination used for wireless charging foreign object detection, including four identical square coils, namely No. 1 coil, No. 2 coil, No. 3 coil, No. 4 coil; No. 1 coil is placed in the forward direction, The No. 2 coil is placed in reverse, the No. 3 coil is placed in the forward direction, and the No. 4 coil is placed in reverse; the inner lead of the No. 1 coil is connected to the inner lead of the No. 2 coil, and the outer lead of the No. 2 coil is connected to the No. 3 coil. The outer leads are connected, the inner lead of the 4th coil is connected with the inner lead of the 3rd coil, and the outer leads of the 1st coil and the 4th coil are used as lead wires.

Further, the lead wire is connected to the AC input end of the rectification filter circuit (2), and is sequentially connected to the sampling circuit (3), the acquisition card (4), and the host computer (5) through the rectification filter circuit (2).

Further, the rectifier filter circuit (2) is composed of a rectifier circuit and a filter circuit; the rectifier circuit adopts full-bridge rectification; the filter circuit adopts a CCB capacitor and an electrolytic capacitor, wherein the CCB capacitor is connected in parallel behind the rectifier circuit, and the electrolytic capacitor and the sampling circuit ( The sampling resistors in 3) are connected in parallel.

Further, the sampling circuit (3) is composed of two high-precision resistors, which are divided into a voltage dividing resistor and a sampling resistor, which are connected in series to the circuit.

Further, the acquisition card (4) is mainly composed of a single-chip microcomputer and an analog-to-digital converter, the single-chip microcomputer adopts an STM32F104ZET6 type single-chip microcomputer, and the analog-to-digital converter adopts an AD7606 chip.

Compared with the prior art, the utility model has the following advantages:

(1) The utility model can detect whether there is a metal foreign body between the transmission coils, and feedback the detection result to the upper computer. If metal is found, it will alarm in time, and determine the position of the metal foreign body to ensure the safety of users and equipment.

(2) The utility model adopts the combination of high quality factor differential coils for detection, which can improve the detection accuracy, and accurately judge the position of metal foreign objects, which ensures the reliability and safety of wireless charging.

Description of drawings

Fig. 1 is the overall layout diagram of the present utility model;

Fig. 2 is the combined layout diagram of the high quality factor differential coil of the present invention;

Fig. 3 is the combined dimension drawing of the high quality factor differential coil of the present invention;

4 is a diagram of a rectifier filter device of the present invention;

Fig. 5 is the overall layout diagram of the detection device of the present invention;

Fig. 6 is the concrete experiment conclusion diagram of the detection device of the present utility model;

Fig. 7 is the experimental operation diagram of the detection device of the present utility model;

Fig. 8 is the operation diagram of the metal foreign body (aluminum sheet) of the present utility model when detecting different positions of the coil; (1), (2) and (3) of Fig. 8 are the experimental test sequence;

FIG. 9 is a waveform diagram of the detection device of the present utility model detecting metal foreign objects (aluminum sheets) at different positions of the detection coil.

in,

(1) High quality factor differential coil combination;

(2) Rectifier filter circuit;

(3) Sampling circuit;

(4) Capture card;

(5) The host computer.

Detailed ways

It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict.

The present utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

As shown in FIG. 1, it is an overall layout diagram of a high quality factor differential coil combination of a wireless charging foreign object detection device and method of the present invention, including: (1) a high quality factor differential coil combination; (2) a rectifier filter circuit; (3) sampling circuit; (4) acquisition card; (5) upper computer. The high quality factor differential coil combination (1) has a stable output voltage value of 0 under normal conditions. When a metal foreign body is introduced, the voltage of the differential coil combination changes, and the output is passed through the rectifier filter circuit (2); the sampling circuit (3) outputs The voltage value is collected by the acquisition card (4) and the data is transmitted to the host computer (5) for display. The host computer (5) displays the coil combination whose voltage changes and gives an alarm, which has high detection accuracy and strong stability. , the location of accurate judgment and other advantages.

As shown in Figure 2, it is a combination of high quality factor differential coils of the device of the present invention. The winding sequence of the coils is from the outer end to the inner end in a counterclockwise direction, and the coil is placed in the forward direction, and the winding sequence is clockwise from the outer end. The inward head is placed in the reverse direction, so the four coils are placed in the following way: No. 1 coil forward (positive 1), No. 2 coil reverse (reverse 1), No. 3 coil forward (positive 2), 4 The number coil is reversed (reverse 2). In Figure 2, the inner lead of coil 1 is connected to the inner lead of coil 2, the outer lead of coil 2 is connected to the outer lead of coil 3, and the inner lead of coil 3 is connected to the inner lead of coil 4. The outer leads of the No. 1 and No. 4 coils are the lead wires of the differential coil combination. The four coils are combined into a differential coil combination. When there is no foreign body disturbance, the voltage between the lead wires of the differential coil combination is 0. The voltage between the lead wires of the differential coil combination is a non-zero value.

As shown in Figure 3, it is the specific size parameters of the high quality factor differential coil combination (1) of the device of the present invention, the outer diameter of the coil is 23mm, the inner diameter is 9mm, the outer diameter is 23mm, the wire diameter is 1mm, and the thickness is 2mm. The copper wire wrapped by enameled wire is wound with 18 turns, the distance between the coil and the coil is 2mm, the distance between the coil and the bottom plate is 1mm, and the bottom plate is made of 50mm*50mm bakelite.

As shown in Figure 4, which is a diagram of the rectifier and filter device of the present invention, the lead wire of the high-quality differential coil combination is connected to the AC input end of the rectifier filter circuit (2), and the DC power is obtained through the rectifier filter circuit (2), and the resistance 2 is Voltage divider resistor, resistor 1 is the sampling resistor, the sampling resistor is the DC sampling terminal, the DC sampling terminal is connected to the acquisition card (4), the voltage value of the high quality factor differential coil combination is collected by the single-chip microcomputer, and the single-chip microcomputer sends the collected data to the The upper computer (5), the upper computer judges whether there is metal foreign matter mixed between the transmission coils through a series of logic, and displays the specific position of the metal.

As shown in FIG. 5 , which is the overall layout of the device of the present invention, the detection device of the present invention is composed of 16 sets of differential coils. The distance between the combination and the combination is 2mm.

As shown in Figure 6, it is the specific experimental conclusion obtained by the detection device of the utility model. 30mm*8mm). The specific operation steps of the effect achieved in Fig. 6 are: first, test the static state, put in aluminum sheet, one-yuan coin, five-cent coin, and paper clip in turn, each time the position is the center of the coil, without touching the coil, and the time of putting in is 5 Second; then test the jitter state, put in the jittering aluminum sheet, one-dollar coin, five-cent coin, and paper clip in turn, the direction of jittering is shown in Figure 7, and the jittering speed is 2 seconds per cycle (entering from one point and then exiting from the same point is a cycle ).

As shown in Figure 8, the test method of placing metal foreign objects in different positions of the detection coil is introduced. The serial numbers (1), (2) and (3) in the figure are the experimental test sequence. The microcontroller will detect different voltage values, such as Figure 9 shows the waveform diagram obtained by this test method.

The waveform diagram obtained by the test according to the above detection method can be obtained, the utility model can accurately detect whether metal foreign matter is mixed between the transmission coils during the wireless charging process, and the detection effect is obvious. The position of the foreign object is detected, and an alarm is performed, which proves that the high quality factor differential coil combination is suitable for use in the wireless charging metal foreign object detection device, and proves that the utility model has high practical value and good development prospects.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the within the protection scope of the present invention.

Claims (5)

1. A high quality factor differential coil combination for wireless charging foreign object detection, characterized in that it includes four identical square coils, which are respectively No. 1 coil, No. 2 coil, No. 3 coil, No. 4 coil; No. 1 coil; The coil is placed in the forward direction, the No. 2 coil is placed in the reverse direction, the No. 3 coil is placed in the forward direction, and the No. 4 coil is placed in the reverse direction; the inner lead of the No. 1 coil is connected to the inner lead of the No. 2 coil, and the outer lead of the No. 2 coil is connected. The lead wire is connected to the outer lead of the No. 3 coil, the inner lead of the No. 4 coil is connected to the inner lead of the No. 3 coil, and the outer leads of the No. 1 coil and the No. 4 coil are used as lead wires. 2. The high quality factor differential coil combination according to claim 1, characterized in that: the lead wire is connected to the AC input end of the rectifier filter circuit (2), and the sampling circuit (3) is sequentially connected through the rectifier filter circuit (2). ), capture card (4), and host computer (5). 3. high quality factor differential coil combination according to claim 2, is characterized in that: described rectifier filter circuit (2) is made up of rectifier circuit and filter circuit; rectifier circuit adopts full-bridge rectifier; filter circuit adopts CCB capacitor and electrolytic capacitor, wherein the CCB capacitor is connected in parallel behind the rectifier circuit, and the electrolytic capacitor is connected in parallel with the sampling resistor in the sampling circuit (3). 4 . The high quality factor differential coil combination according to claim 2 , wherein the sampling circuit ( 3 ) is composed of two high precision resistors, divided into a voltage dividing resistor and a sampling resistor, which are connected in series to the circuit. 5 . 5. The high quality factor differential coil combination according to claim 2, wherein the acquisition card (4) is mainly composed of a single-chip microcomputer and an analog-to-digital converter, the single-chip microcomputer adopts STM32F104ZET6 type single-chip microcomputer, and the analog-to-digital converter adopts AD7606 chip.