CN218071114U

CN218071114U - Single-coil vehicle-mounted wireless charger

Info

Publication number: CN218071114U
Application number: CN202222386801.9U
Authority: CN
Inventors: 吴佩申; 张军伟
Original assignee: Shanghai Xinyao Electronics Co Ltd
Current assignee: Shanghai Xinyao Electronics Co Ltd
Priority date: 2022-09-05
Filing date: 2022-09-05
Publication date: 2022-12-16
Anticipated expiration: 2032-09-05

Abstract

A single-coil vehicle-mounted wireless charger is provided with a calibration charging area and comprises a shell, wherein a circuit board is arranged in the shell, a wireless charging circuit is arranged on the circuit board and provided with an LC resonance circuit unit, the LC resonance circuit unit comprises a single resonance capacitor and a single transmitting coil, the single resonance capacitor is connected with the single transmitting coil in series, and the charging range of the single transmitting coil forms the calibration charging area. The utility model discloses a single transmitting coil, and this single transmitting coil's charging range just can constitute and mark the charging area territory (being equivalent to increased single transmitting coil's size), has left out two way resonant capacitance and transmitting coil and three routes coil selection circuit on the one hand like this, and the hardware is with low costs, and on the other hand can avoid among the prior art two transmitting coil to make a round trip to switch to being charged by the equipment of being filled, causes the problem that charging efficiency is low or even absolutely fills.

Description

Single-coil vehicle-mounted wireless charger

Technical Field

The utility model belongs to the technical field of on-vehicle wireless charging, especially, relate to an on-vehicle wireless charger of single coil.

Background

At present, the LC resonant circuit of the on-vehicle wireless charger on the market generally has two or more than two transmitting coils, and in order to facilitate the charging of the user, the user is prevented from needing to find the position of charging accurately in particular, and the on-vehicle wireless charger generally has a calibration charging area.

As shown in fig. 3 and fig. 4, taking three transmitting coils as an example, the three transmitting coils are arranged side by side, adjacent parts are overlapped, and the three transmitting coils are respectively connected in series with a resonant capacitor, each transmitting coil has its own charging range (for example, the area of the charging range is 20 × 20cm), when the mobile phone is in operation, as shown in fig. 4, the control unit of the vehicle-mounted wireless charger selects a corresponding transmitting coil to charge through the three coil selection circuit according to the position of the receiving coil of the mobile phone, for example, when the receiving coil is in the charging range of the middle transmitting coil, the middle transmitting coil charges, and when the receiving coil is in the charging range of the upper transmitting coil, the upper transmitting coil charges, and it can be seen that the charging ranges of the three transmitting coils are overlapped to form the above-mentioned calibration charging region (for example, the area of the calibration charging region is 20 × 60cm), as long as the receiving coil of the mobile phone can charge in the calibration charging region, the user does not need to specially find the charging position.

However, as can be seen from the above, when charging is actually performed, only one coil works, and the other two coils do not work, which causes waste of hardware resources, and when the receiving coil of the mobile phone is located at the junction of the two transmitting coils, the two transmitting coils can identify the receiving coil at the same time, which causes the problem of low charging efficiency and even charging interruption due to the fact that charging is switched back and forth between the two transmitting coils.

SUMMERY OF THE UTILITY MODEL

In view of the above, a single-coil vehicle-mounted wireless charger is provided to solve the technical problems.

In order to solve the technical problem, the utility model adopts the following technical scheme:

a single-coil vehicle-mounted wireless charger is provided with a calibration charging area and comprises a shell, wherein a circuit board is arranged in the shell, a wireless charging circuit is arranged on the circuit board and provided with an LC resonance circuit unit, the single-coil vehicle-mounted wireless charger is characterized in that the LC resonance circuit unit comprises a single resonance capacitor and a single transmitting coil, the single resonance capacitor is connected with the single transmitting coil in series, and the charging range of the single transmitting coil forms the calibration charging area.

The utility model discloses a single transmitting coil, and this single transmitting coil's charging range just can constitute and mark the charging area territory (being equivalent to increased single transmitting coil's size), has left out two way resonant capacitance and transmitting coil and three routes coil selection circuit on the one hand like this, and the hardware is with low costs, and on the other hand can avoid among the prior art two transmitting coil to make a round trip to switch to being charged by the equipment of being filled, causes the problem that charging efficiency is low or even absolutely fills.

Drawings

FIG. 1 is a schematic view of the present invention;

fig. 2 is a schematic structural diagram of the wireless charging circuit of the present invention;

FIG. 3 is a schematic structural diagram of a three-way transmitting coil of a conventional vehicle-mounted wireless charger;

fig. 4 is a schematic diagram of a conventional in-vehicle wireless charger.

Detailed Description

The embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that the embodiments mentioned in the present description are not exhaustive, and do not represent the only embodiments of the present invention. The following examples are given for the purpose of clearly illustrating the invention of the present invention and are not intended to limit the embodiments thereof. It is obvious to those skilled in the art that various changes and modifications can be made based on the description of the embodiment, and all changes and modifications which belong to the technical idea and the contents of the invention and are obvious are within the scope of the invention.

As shown in fig. 1, the present embodiment provides a single-coil onboard wireless charger having a nominal charging area a.

The charger includes a housing 110, a circuit board is disposed in the housing 110, and a wireless charging circuit 120 is disposed on the circuit board, as shown in fig. 2.

As shown in fig. 1, the housing 110 includes a cover case 111 and a cover plate 112 connected to the cover case 111.

The outer surface of the cover plate 112 has a positioning charging area B for placing the device to be charged and making the receiving coil of the device to be charged just inside the calibration charging area a, and the contour of the positioning charging area B is matched with that of the device to be charged.

As shown in fig. 2, the wireless charging circuit 120 includes an anti-filtering unit 121, a Buck-Boost unit 122, an LDO power supply unit 123, a sampling resistor 124, a full-bridge inverter unit 125, an LC resonant circuit unit 126, a Qi identity authentication chip 127, an NTC resistor 128, and a control unit 129.

The anti-filtering unit 121 is connected to the Buck-Boost unit 122 and the LDO power supply unit 123, the Buck-Boost unit 122 is connected to the full-bridge inverter unit 125 through the sampling resistor 124, the LDO power supply unit 123 is connected to the control unit 129, two ends of the sampling resistor 124 are connected to the control unit 129, the full-bridge inverter unit 125 is connected to the LC resonant circuit unit 126, the Qi authentication chip 127 and the NTC resistor 128 are connected to the control unit 129, and the control unit 129 is connected to the full-bridge inverter unit 125.

The LC resonant circuit unit 126 includes a single resonant capacitor 126a and a single transmitting coil 126b, which are connected in series, with the transmitting face of the single transmitting coil 126b facing the cover 112, and the charging range thereof constituting a nominal charging area a.

This application adopts single transmitting coil, and this single transmitting coil's charging range just can constitute the demarcation charging area (has increased single transmitting coil's size in other words), has saved two way resonant capacitance and transmitting coil and three routes coil selection circuit on the one hand like this, and the hardware is with low costs, and on the other hand, can avoid among the prior art two transmitting coil to make a round trip to switch to being charged equipment, causes the problem that charging efficiency is low even disconnected to be filled.

In the present embodiment, the operating frequency range of the single transmitting coil 126b is 112KHZ to 128KHZ, the area is 85.1 × 67mm, the area of the charging range is 20 × 60mm, and a calibration charging area with an area of 20 × 60mm is formed.

The anti-reverse filtering unit 121 is used for connecting a vehicle battery, and plays roles of reverse connection prevention and filtering.

The Buck-Boost unit 122 is configured to adjust an output voltage to adjust the charging output power, and the Buck-Boost unit 122 outputs a dc voltage to the full-bridge inverter unit 125.

The LDO power supply unit 123 provides a 5v operating voltage to the control unit 129.

The sampling resistor 124 is used to sample the output current value and the output voltage value of the Buck-Boost unit 122, and then input the values to the control unit 129, thereby calculating the input power of the wireless charger.

The Qi authentication chip 127 adopts a Q1.3 authentication chip, and based on the chip, before charging, authentication can be performed between the charger and the charged device, so that power transmission can be performed only after authentication is performed.

The NTC resistors 128 are two, which are packaged by 0603, and have a resistance value of 10K ohms, one NTC resistor is disposed on the circuit board and is used for detecting the temperature of the circuit board, the other NTC resistor is disposed right above the center of the transmitting coil 126b and is fixed to the inner surface of the cover plate 112 and is used for detecting the temperature of the transmitting coil 126b, and when the temperature is too high, the control unit 129 finishes charging, so that over-temperature protection is realized, and safety is improved.

The control unit 129 controls the full-bridge inverter unit 125, so that the full-bridge inverter unit 125 chops the direct-current voltage output by the Buck-Boost unit 122 into a 125kHz square wave, the square wave is input to the LC resonance circuit unit 126, and the single transmitting coil 126b of the LC resonance circuit unit 126 transmits energy to the receiving coil of the charged device through a magnetic field.

As shown in fig. 2, the 4 NMOS switching tubes generate square wave signals between the nodes of the bridge arms SW1 and SW2, the square wave signals are loaded at two ends of the LC resonant circuit unit 126 to generate alternating current, and the alternating current generates a magnetic field through the single transmitting coil 126 b.

In order to avoid magnetic leakage and improve charging efficiency, the other surface of the single transmitting coil 126b corresponding to the transmitting surface thereof is provided with a magnetic shield plate, and the magnetic shield plate is bonded with the transmitting coil 126 b.

It is obvious that a person skilled in the art should realize that the above embodiments are only used for illustrating the present invention, and not used as a limitation of the present invention, and that changes and modifications to the above embodiments will fall within the scope of the claims of the present invention as long as they are within the spirit of the present invention.

Claims

1. A single-coil vehicle-mounted wireless charger is provided with a calibration charging area and comprises a shell, wherein a circuit board is arranged in the shell, a wireless charging circuit is arranged on the circuit board and provided with an LC resonance circuit unit, the single-coil vehicle-mounted wireless charger is characterized in that the LC resonance circuit unit comprises a single resonance capacitor and a single transmitting coil, the single resonance capacitor is connected with the single transmitting coil in series, and the charging range of the single transmitting coil forms the calibration charging area.

2. The single-coil vehicle-mounted wireless charger according to claim 1, wherein the area of the calibration charging area is 20 × 60mm, the operating frequency range of the single transmitting coil is 112KHZ to 128KHZ, the area is 85.1 × 67mm, and the area of the charging range is 20 × 60mm.

3. The single-coil vehicle-mounted wireless charger according to claim 1 or 2, wherein the wireless charging circuit comprises an anti-filtering unit, a Buck-boost unit, an LDO power supply unit, a sampling resistor, a full-bridge inverter unit, an LC resonant circuit unit, a Qi identification authentication chip, an NTC resistor, and a control unit, the anti-filtering unit is connected to the Buck-boost unit and the LDO power supply unit, the Buck-boost unit is connected to the full-bridge inverter unit through the sampling resistor, the LDO power supply unit is connected to the control unit, two ends of the sampling resistor are connected to the control unit, the full-bridge inverter unit is connected to the LC resonant circuit unit, the Qi identification authentication chip and the NTC resistor are connected to the control unit, and the control unit is connected to the full-bridge inverter unit.

4. The single-coil vehicle-mounted wireless charger according to claim 3, wherein the transmitting coil is provided with a magnetic shield on the other surface corresponding to the transmitting surface of the transmitting coil, and the magnetic shield is bonded with the transmitting coil.

5. The single-coil vehicle-mounted wireless charger according to claim 4, wherein the NTC resistors are two, one NTC resistor is disposed on the circuit board, and the other NTC resistor is disposed right above the center of the transmitting coil and fixed with the housing.

6. The single-coil vehicle-mounted wireless charger according to claim 5, wherein the outer surface of the housing has a positioning charging area for placing the charged device and enabling the receiving coil of the charged device to be located in the calibration charging area, and the contour of the positioning charging area is matched with the contour of the charged device.

7. The single-coil vehicle-mounted wireless charger according to claim 6, wherein the housing comprises a housing and a cover plate connected to the housing, the transmitting surface of the transmitting coil faces the cover plate, the NTC resistor disposed right above the center of the transmitting coil is fixed to the inner surface of the cover plate, and the positioning charging area is disposed on the outer surface of the cover plate.