Wireless charging circuit and wireless charging device
By using a wireless charging circuit with six power switches in a wireless charging device, the coil switching topology is simplified, and the problem of complex coil switching design in the prior art is solved, and a lighter, smaller size and high-performance wireless charging product is realized.
Patent Information
- Application Number
- CN202420326162.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-21
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-02-21
AI Technical Summary
The arrangement of multiple coils in existing wireless charging devices leads to complex coil switching topology design, increasing the number of circuit components, the number of control chip output signal ports and algorithm complexity.
A wireless charging circuit is adopted to realize the charging mode switching between two charging coils through six power switches, simplifying the coil switching topology.
Reduces the required number of power switches, circuit components, number of control chip output signal ports, and algorithm complexity on the control chip, helping to achieve lighter, smaller volume and high performance wireless charging products.
Smart Images
Figure CN222563532U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of wireless charging technology, and in particular to a wireless charging circuit and a wireless charging device. Background Art
[0002] Wireless charging technology has been widely used in the field of smartphones and portable devices. Users only need to place the device on a charging stand that supports wireless charging to charge it. Wireless charging solves the limitations and inconveniences brought by traditional charging cables and brings users a more comfortable and convenient charging experience.
[0003] With the development of wireless charging technology, users have higher and higher requirements for charging experience. Taking mobile phones with wireless charging function as an example, users hope to place their mobile phones on the wireless charging device at will for wireless charging, without causing the position deviation of the charging coil of the wireless charging device and the charging coil in the mobile phone to be too large due to the deviation of the position of the mobile phone, making it impossible to charge or reducing the charging efficiency. In a wireless charging device, two or more coils can be set to achieve wireless charging in different positions. When the user places the mobile phone on the wireless charging device at will, there will always be a coil that overlaps the mobile phone to a high degree, and the mobile phone can use this coil as the main coil for charging.
[0004] However, setting two or more coils in a wireless charging device will complicate the coil switching topology design. This not only increases the number of circuit elements necessary to implement the device, but also increases the number of output signal ports that need to be occupied by the control chip, and also increases the algorithm complexity on the control chip. Therefore, how to simplify the coil switching topology in a wireless charging device has become a key topic in this field. Summary of the invention
[0005] The present application provides a wireless charging circuit and a wireless charging device, which can help simplify the coil switching topology in the wireless charging device.
[0006] An embodiment of the present application provides a wireless charging circuit, the wireless charging circuit comprising: a first charging coil, a second charging coil, a first power switch, a second power switch, a third power switch, a fourth power switch, a fifth power switch and a sixth power switch; wherein the positive power terminal of the wireless charging circuit is respectively connected to the first end of the first power switch, the first end of the third power switch and the first end of the fifth power switch, the negative power terminal of the wireless charging circuit is respectively connected to the second end of the second power switch, the second end of the fourth power switch and the second end of the sixth power switch, the first end of the first charging coil is respectively connected to the second end of the first power switch, the first end of the second power switch and the first end of the second charging coil, the second end of the first charging coil is respectively connected to the second end of the third power switch and the first end of the fourth power switch, and the second end of the second charging coil is respectively connected to the second end of the fifth power switch and the first end of the sixth power switch; each of the power switches is configured to turn on or off a current path between its first end and its second end according to an electrical signal on its third end.
[0007] In some possible implementations, the first charging coil and the second charging coil are arranged in such a way that an induced current in the second charging coil induced by a charging current in the first charging coil has a current direction opposite to a current generated by interference in the second charging coil.
[0008] In some possible implementations, the first end of the first charging coil and the first end of the second charging coil are the same-named ends.
[0009] In some possible implementations, the first charging coil partially overlaps with the second charging coil.
[0010] In some possible implementations, the first charging coil is wound from the first end to the second end in a clockwise direction from the inside to the outside, and the second charging coil is wound from the first end to the second end in a counterclockwise direction from the outside to the inside.
[0011] In some possible implementations, the wireless charging circuit also includes a first capacitor and a second capacitor, the first capacitor is spaced between the first end of the first charging coil and the first node, the second capacitor is spaced between the first end of the second charging coil and the first node, and the first node is a circuit node connecting the second end of the first power switch and the first end of the second power switch.
[0012] In some possible implementations, each of the power switches includes a transistor, a gate of the transistor is connected to a third terminal of the power switch, one of the first terminal and the second terminal of the power switch is connected to a source of the transistor, and the other of the first terminal and the second terminal of the power switch is connected to a drain of the transistor.
[0013] In some possible implementations, each of the transistors is a metal-oxide semiconductor field effect transistor.
[0014] An embodiment of the present application also provides a wireless charging device, which includes any one of the above-mentioned wireless charging circuits.
[0015] In some possible implementations, the wireless charging device also includes a controller having six pulse width modulation signal output terminals respectively connected to the third terminal of the first power switch, the third terminal of the second power switch, the third terminal of the third power switch, the third terminal of the fourth power switch, the third terminal of the fifth power switch, and the third terminal of the sixth power switch.
[0016] In the embodiment of the present application, the wireless charging circuit can realize the switching of the charging mode between the two charging coils by only six power switches - when the first power switch and the fourth power switch are turned on and the other power switches are turned off, the power supply voltage is applied to both ends of the first charging coil in a forward manner; when the second power switch and the third power switch are turned on and the other power switches are turned off, the power supply voltage is applied to both ends of the first charging coil in a reverse manner; when the first power switch and the sixth power switch are turned on and the other power switches are turned off, the power supply voltage is applied to both ends of the second charging coil in a forward manner; when the second power switch and the fifth power switch are turned on and the other power switches are turned off, the power supply voltage is applied to both ends of the second charging coil in a reverse manner. Therefore, the wireless charging circuit of the embodiment of the present application can switch the charging coil powered and the direction of the power supply current only under the control of an external signal, and can reduce the number of power switches required, the number of related circuit elements required, the number of output signal ports of the control chip required to be occupied, and the algorithm complexity on the control chip compared to the related art, which helps to simplify the coil switching topology in the existing wireless charging device and help to achieve a more lightweight, small-volume and high-performance wireless charging product. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is a circuit diagram of a wireless charging circuit in one embodiment of the present application;
[0018] Figure 2 It is a schematic diagram of a coil winding method in a wireless charging circuit in one embodiment of the present application;
[0019] Figure 3 It is a structural block diagram of a wireless charging device in one embodiment of the present application. DETAILED DESCRIPTION
[0020] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.
[0021] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0022] Figure 1 is a circuit diagram of a wireless charging circuit in one embodiment of the present application. Figure 1 The wireless charging circuit includes a first charging coil L1, a second charging coil L2, a first power switch Q1, a second power switch Q2, a third power switch Q3, a fourth power switch Q4, a fifth power switch Q5 and a sixth power switch Q6. As an example, Figure 1 In the figure, each of the above-mentioned power switches is implemented by a metal-oxide semiconductor field effect transistor (MOSFET) type transistor, and the body diode of each transistor is drawn; when the electrical signal on the third terminal of the power switch (the gate of the transistor) provides a gate-on voltage that enables the transistor to operate in a linear region or a saturation region, the current path between the first terminal (drain) and the second terminal (source) of the power switch is in an on state; when the electrical signal on the third terminal of the power switch (the gate of the transistor) provides a gate-off voltage that enables the transistor to operate in a cut-off region, the current path between the first terminal (drain) and the second terminal (source) of the power switch is in an off state; in other examples, the power switch can be implemented by other types of transistors or circuit elements or components with switching functions, including but not limited to: gate turn-off thyristors (GTOs), power transistors (GTRs), insulated gate bipolar transistors (IGBTs), bipolar junction transistors (BJTs), integrated gate-commutated thyristors (IGCTs), and symmetrical gate-commutated thyristors (SGCTs).
[0023] See also Figure 1The positive power terminal V1 of the wireless charging circuit is respectively connected to the first end of the first power switch Q1, the first end of the third power switch Q3 and the first end of the fifth power switch Q5, and the negative power terminal V0 of the wireless charging circuit is respectively connected to the second end of the second power switch Q2, the second end of the fourth power switch Q4 and the second end of the sixth power switch Q6. The first end of the first charging coil L1 is connected to the first node P1 through the two ends of the first capacitor C1, and the first end of the second charging coil L2 is connected to the first node P1 through the two ends of the second capacitor. The first node P1 is a circuit node connecting the second end of the first power switch Q1 and the first end of the second power switch Q2. The second end of the first charging coil L1 is respectively connected to the second end of the third power switch Q3 and the first end of the fourth power switch Q4, and the second end of the second charging coil L2 is respectively connected to the second end of the fifth power switch Q5 and the first end of the sixth power switch Q6.
[0024] In one example, the positive power terminal V1 and the negative power terminal V0 of the wireless charging circuit are supplied with an AC power supply voltage, and the third terminal of each power switch is supplied with a separate switch control signal (for example, an electrical signal switching between a first level having the above-mentioned gate-on voltage and a second level having the above-mentioned gate-off voltage), for wirelessly charging a device to be charged that is equipped with a matching coil and a matching charging circuit through two charging coils.
[0025] Based on the above connection relationship, the wireless charging circuit can realize the switching of charging modes between the two charging coils with only six power switches. Figure 1 When the first power switch Q1 and the fourth power switch Q4 are turned on and the other power switches are turned off, the AC power supply voltage is applied to both ends of the first charging coil L1 in a forward manner (current flows from the first end to the second end of the first charging coil L1); when the second power switch Q2 and the third power switch Q3 are turned on and the other power switches are turned off, the AC power supply voltage is applied to both ends of the first charging coil L1 in a reverse manner (current flows from the second end to the first end of the first charging coil L1); when the first power switch Q1 and the sixth power switch Q6 are turned on and the other power switches are turned off, the AC power supply voltage is applied to both ends of the second charging coil L2 in a forward manner (current flows from the first end to the second end of the second charging coil L2); when the second power switch Q2 and the fifth power switch Q5 are turned on and the other power switches are turned off, the AC power supply voltage is applied to both ends of the second charging coil L2 in a reverse manner (current flows from the second end to the first end of the second charging coil L2).
[0026] It can be seen that the wireless charging circuit of the embodiment of the present application can switch the powered charging coil and the direction of the power supply current only under the control of an external signal. Compared with the related art (a circuit structure that requires at least eight or more power switches to achieve switching between two coils), it can reduce the number of required power switches, the number of related circuit elements required, the number of output signal ports of the control chip required to be occupied, and the algorithm complexity on the control chip, thereby helping to simplify the coil switching topology in the existing wireless charging device, and can help to achieve a more lightweight, small-volume and high-performance wireless charging product.
[0027] Figure 2 Schematic diagram of coil winding in a wireless charging circuit in one embodiment of the present application. Figure 1 and Figure 2 As an example, the first charging coil L1 and the second charging coil L2 partially overlap (the covered areas overlap each other), and the first end of the first charging coil L1 and the first end of the second charging coil L2 are the same end (the same end is in Figure 1 and Figure 2 In the figure, they are represented by an asterisk “*” and are all connected to the first node P1); for more details, see Figure 2 The first charging coil L1 is wound from the first end to the second end in a clockwise direction from the inside to the outside, and the second charging coil L2 is wound from the first end to the second end in a counterclockwise direction from the outside to the inside.
[0028] See also Figure 1 When the first power switch Q1 and the fourth power switch Q4 are turned on and the other power switches are turned off, the AC power supply voltage is applied to both ends of the first charging coil L1 in a forward manner. Since each power switch has a body diode, an interference current is formed in the second charging coil L2. The interference current flows through the first and second ends of the first power switch, the first node, the first and second ends of the second charging coil L2, and the positive and negative electrodes of the body diode of the fifth power switch Q5 in sequence. However, see Figure 1 and Figure 2 Since the first end of the first charging coil L1 and the first end of the second charging coil L2 are the same end, when the current direction of the charging current in the first charging coil L1 is from the first end (connected to the first node P1) to the second end (connected to the second node P2), since the first charging coil L1 and the second charging coil L2 are coupled, an induced current will be stimulated in the second charging coil L2, with the current direction flowing from the second end (connected to the third node P3) to the first end (connected to the first node P1), wherein the induced current is opposite to the current direction of the above-mentioned interference current, so the induced current and the interference current can offset each other to at least a certain extent, thereby helping to reduce efficiency loss.
[0029] In an experiment using a wireless charging module and an electronic load for loading, the same output voltage of 18V / current of 3A was set to test the charging efficiency of a wireless charging circuit containing only a single charging coil, a wireless charging circuit containing the first and second charging coils and whose first ends are opposite ends, and a wireless charging circuit containing the first and second charging coils and whose first ends are the same end. The test results are as follows: the actual input power of the wireless charging circuit containing only a single charging coil is 67.39W, the actual output power is 52.87W, and the efficiency is 78.45%; the actual input power of the wireless charging circuit containing the first and second charging coils and whose first ends are opposite ends is 75.44W, the actual output power is 52.30W, and the efficiency is 69.33%; the actual input power of the wireless charging circuit containing the first and second charging coils and whose first ends are the same end is 67.58W, the actual output power is 52.77W, and the efficiency is 78.09%. It can be seen from the test results that the wireless charging circuit in which the first and second charging coils are the same-named first ends is very close in efficiency to the wireless charging circuit in which only a single charging coil is included, and the efficiency is significantly better than the wireless charging circuit in which the first and second charging coils are the opposite-named first ends.
[0030] Taking this as an example, according to different application requirements, application scenarios and application environments, the current direction of the interference current in the charging coil in the wireless charging circuit can be predetermined, and the first charging coil and the second charging coil can be arranged through the settings of the same-name terminal / different-name terminal, winding direction, etc., so that: the induced current stimulated by the charging current in the first charging coil in the second charging coil has the opposite current direction to the current generated by the interference in the second charging coil, and / or the induced current stimulated by the charging current in the second charging coil in the first charging coil has the opposite current direction to the current generated by the interference in the first charging coil. In this way, the working efficiency of the wireless charging circuit can be further improved.
[0031] In addition, it should be noted that Figure 1The first capacitor C1 and the second capacitor C2 shown in the figure can absorb high-frequency noise signals, and at least one of the first capacitor C1 and the second capacitor C2 can be replaced by a section of wire (equivalent to removing the first capacitor C1 and / or the second capacitor C2) according to application requirements, or the first capacitor C1 and the second capacitor C2 can be replaced by other circuit elements or components, such as equivalently replaced by multiple capacitors in parallel, which is not limited in the embodiments of the present application. Taking this as an example, each circuit element or component in the structure described above can be replaced by a circuit with the same or similar function, so the circuit structure of the wireless charging circuit of the embodiment of the present application may not be limited to the form described above. Moreover, all the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of the present application, which will not be described one by one here.
[0032] Figure 3 This is a block diagram of a wireless charging device in one embodiment of the present application. The wireless charging device may be, for example, a separate vertical charger, a box charger, a disk charger, etc., or a wireless charging component integrated in furniture, vehicles, electrical appliances, portable devices, or similar products or product components. Figure 3 In one example, the wireless charging device includes a controller 31 and a wireless charging circuit 32 connected to each other, and the wireless charging circuit can be selected from any one of the wireless charging circuits described above; Figure 1 Taking the circuit structure shown as an example, the controller 31 may have six pulse width modulation (PWM) signal output terminals respectively connected to the third terminal of the first power switch Q1, the third terminal of the second power switch Q2, the third terminal of the third power switch Q3, the third terminal of the fourth power switch Q4, the third terminal of the fifth power switch Q5, and the third terminal of the sixth power switch Q6, so as to use the high level and low level in the high-frequency PWM signal to correspond to the above-mentioned gate-on voltage and gate-off voltage, thereby realizing high-performance and high-reliability coil switching control. Of course, the connection relationship between the controller 31 and the wireless charging circuit 32 may not be limited to the connection relationship described above, and the wireless charging device may also include other structures or components not shown, which are not limited in the embodiment of the present application.
[0033] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.
[0034] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims
1. A wireless charging circuit, characterized in that: The wireless charging circuit includes: a first charging coil, a second charging coil, a first power switch, a second power switch, a third power switch, a fourth power switch, a fifth power switch and a sixth power switch; wherein, The positive terminal of the power supply of the wireless charging circuit is respectively connected to the first end of the first power switch, the first end of the third power switch and the first end of the fifth power switch, the negative terminal of the power supply of the wireless charging circuit is respectively connected to the second end of the second power switch, the second end of the fourth power switch and the second end of the sixth power switch, the first end of the first charging coil is respectively connected to the second end of the first power switch, the first end of the second power switch and the first end of the second charging coil, the second end of the first charging coil is respectively connected to the second end of the third power switch and the first end of the fourth power switch, and the second end of the second charging coil is respectively connected to the second end of the fifth power switch and the first end of the sixth power switch; Each of the power switches is configured to open or close a current path between the first end and the second end thereof according to an electrical signal at the third end thereof.
2. The wireless charging circuit according to claim 1, characterized in that: The first charging coil and the second charging coil are arranged in such a manner that an induced current in the second charging coil induced by a charging current in the first charging coil has a current direction opposite to that of a current in the second charging coil generated by interference.
3. The wireless charging circuit according to claim 1, characterized in that: The first end of the first charging coil and the first end of the second charging coil are the same end.
4. The wireless charging circuit according to claim 1, characterized in that: The first charging coil partially overlaps with the second charging coil.
5. The wireless charging circuit according to claim 4, characterized in that: The first charging coil is wound from the first end to the second end in a clockwise direction from the inside to the outside, and the second charging coil is wound from the first end to the second end in a counterclockwise direction from the outside to the inside.
6. The wireless charging circuit according to claim 1, characterized in that: The wireless charging circuit also includes a first capacitor and a second capacitor, the first capacitor is spaced between the first end of the first charging coil and a first node, the second capacitor is spaced between the first end of the second charging coil and the first node, and the first node is a circuit node connecting the second end of the first power switch and the first end of the second power switch.
7. The wireless charging circuit according to claim 1, characterized in that: Each of the power switches includes a transistor, a gate of the transistor is connected to the third terminal of the power switch, one of the first terminal and the second terminal of the power switch is connected to the source of the transistor, and the other of the first terminal and the second terminal of the power switch is connected to the drain of the transistor.
8. The wireless charging circuit according to claim 7, characterized in that: Each of the transistors is a metal-oxide semiconductor field effect transistor.
9. A wireless charging device, characterized in that: The wireless charging device comprises the wireless charging circuit according to any one of claims 1 to 8.
10. The wireless charging device according to claim 9, characterized in that: The wireless charging device also includes a controller having six pulse width modulation signal output terminals respectively connected to the third terminal of the first power switch, the third terminal of the second power switch, the third terminal of the third power switch, the third terminal of the fourth power switch, the third terminal of the fifth power switch, and the third terminal of the sixth power switch.