Current control method, hysteresis current controller, transmitting circuit and device

Abstract

The invention provides a current control method, a hysteresis current controller, a transmitting circuit and a device, and relates to the technical field of wireless charging. The method comprises the following steps: when the coil current of a wireless charging transmitting module reaches a preset fixed threshold current every time, generating a variable threshold current according to the fixed threshold current and a random number; generating a first control signal aiming at the wireless charging transmitting module so as to control the coil current to change from the fixed threshold current to the variable threshold current; and when the coil current reaches the variable threshold current, generating a second control signal for the wireless charging transmitting module so as to control the coil current to change from the variable threshold current to the fixed threshold current. According to the invention, radiation energy can be reduced and an EMI problem can be improved.

Description

Technical Field

[0001] The present application relates to the field of wireless charging technology, and in particular to a current control method, a hysteresis current controller, a transmitting circuit and a device. Background Art

[0002] In the wireless charging transmitter module, the full-bridge circuit or the half-bridge circuit is used to transmit energy to the load network, and the first threshold current and the second threshold current are used as judgment conditions for controlling the on and off of the switch tube in the full-bridge circuit or the half-bridge circuit.

[0003] For example, Figure 1 This is a current waveform diagram of the transmitting coil of an existing wireless charging transmitting module, such as Figure 1 As shown, the first threshold current and the second threshold current of the prior art are fixed values ​​preset in advance, and the rising time and falling time of the current value on the transmitting coil of the wireless charging transmitting module will be a fixed period T, so that a specific frequency F=1 / T is seen on the spectrum, and its radiation energy peak is large, which will face potential electromagnetic interference (EMI) radiation problems. Summary of the invention

[0004] The purpose of this application is to provide a current control method, a hysteresis current controller, a transmitting circuit and a device to reduce the radiation energy and improve the EMI problem in view of the above-mentioned deficiencies in the prior art.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a current control method, which is applied to a hysteresis current controller, wherein the hysteresis current controller is used to connect to a control end of a wireless charging transmitter module, and the method includes:

[0007] Each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current, generating a variable threshold current according to the fixed threshold current and a random number;

[0008] generating a first control signal for the wireless charging transmitter module to control the coil current to change from the fixed threshold current to the variable threshold current;

[0009] When the coil current reaches the variable threshold current, a second control signal is generated for the wireless charging transmitter module to control the coil current to change from the variable threshold current to the fixed threshold current.

[0010] Optionally, generating a variable threshold current according to the fixed threshold current and a random number includes:

[0011] generating a hysteresis current according to the random number;

[0012] The variable threshold current is generated according to the fixed threshold current and the hysteresis current.

[0013] Optionally, each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current, generating a variable threshold current according to the fixed threshold current and a random number includes:

[0014] Each time the coil current rises to a first fixed threshold current, generating a first variable threshold current according to the first fixed threshold current and a random number, wherein the first variable threshold current is less than the first fixed threshold current;

[0015] The generating a first control signal for the wireless charging transmitting module to control the coil current to change from the fixed threshold current to the variable threshold current includes:

[0016] generating a reverse control signal for the wireless charging transmitting module to control the coil current to decrease from the first fixed threshold current to the first variable threshold current;

[0017] When the coil current reaches the variable threshold current, generating a second control signal for the wireless charging transmitter module to control the coil current to change from the variable threshold current to the fixed threshold current, comprising:

[0018] When the coil current drops to the first variable threshold current, a positive control signal is generated for the wireless charging transmitter module to control the coil current to rise from the first variable threshold current to the first fixed threshold current.

[0019] Optionally, each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current, generating a variable threshold current according to the fixed threshold current and a random number includes:

[0020] Each time the coil current drops to a second fixed threshold current, generating a second variable threshold current according to the second fixed threshold current and a random number, wherein the second variable threshold current is greater than the second fixed threshold current;

[0021] The generating a first control signal for the wireless charging transmitting module to control the coil current to change from the fixed threshold current to the variable threshold current includes:

[0022] generating a forward control signal for the wireless charging transmitter module to control the coil current to increase from the second variable threshold current to the second fixed threshold current;

[0023] When the coil current reaches the variable threshold current, generating a second control signal for the wireless charging transmitter module to control the coil current to change from the variable threshold current to the fixed threshold current, comprising:

[0024] When the coil current rises to the second fixed threshold current, a reverse control signal is generated for the wireless charging transmitting module to control the coil current to drop from the second fixed threshold current to the second variable threshold current.

[0025] In a second aspect, the present application further provides a hysteresis current controller, the hysteresis current controller comprising: a random number generation module, a calculation module, a comparison module and a control module;

[0026] The output end of the random number generating module is connected to the input end of the calculating module, and is used to provide a random number for the calculating module;

[0027] The first input terminal of the comparison module receives a preset fixed threshold current, the output terminal of the calculation module is connected to the second input terminal of the comparison module, and is used to provide a variable threshold current for the comparison module. The third input terminal of the comparison module receives the coil current of the wireless charging transmitter module, and the comparison module is used to compare the coil current with the fixed threshold current and the variable threshold current to obtain a current comparison result;

[0028] The output end of the comparison module is connected to the input end of the control module, and is used to provide the current comparison result to the control module;

[0029] The output end of the control module is connected to the control end of the wireless charging transmitter module, and is used to control the coil current change of the wireless charging transmitter module according to the current comparison result, and the hysteresis current controller executes the current control method as described in any one of the first aspects.

[0030] Optionally, an input end of the random number generating module is connected to an output end of the comparing module to generate the random number according to the current comparison result.

[0031] In a third aspect, the present application further provides a wireless charging transmitting circuit, which comprises: a wireless charging transmitting module and a hysteresis current controller as described in any one of the second aspects, wherein the hysteresis current controller is connected to the control end of the wireless charging transmitting module.

[0032] Optionally, the wireless charging transmitting module is a wireless charging transmitting module including a half-bridge circuit.

[0033] Optionally, the wireless charging transmitting module is a wireless charging transmitting module including a full-bridge circuit.

[0034] In a fourth aspect, the present application further provides a wireless charging device, comprising: a wireless charging transmitting circuit as described in any one of the third aspects.

[0035] The beneficial effects of this application are:

[0036] The current control method, hysteresis current controller, transmitting circuit and device provided by the present application can generate a random variable threshold current through the random number generated by the random number generation module, so that the comparison module and the control module can control the coil current of the wireless charging transmitting module to change between a fixed threshold current and multiple different variable threshold currents in multiple cycles. Due to the different variable threshold currents, the time required for the coil current to change is different, that is, the cycle lengths of multiple cycles are different, and the frequency of the transmitting coil is also changed, so that multiple frequency points can be provided on the spectrum, and the energy of each frequency point will be reduced, thereby effectively improving the EMI of the wireless charging transmitting module. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 The current waveform diagram of the transmitting coil of the existing wireless charging transmitting module;

[0039] Figure 2 A schematic diagram of the structure of a hysteresis current controller provided in an embodiment of the present application;

[0040] Figure 3 A principle block diagram of a wireless charging transmitting circuit provided in an embodiment of the present application;

[0041] Figure 4 A circuit diagram of a wireless charging transmitting circuit provided in an embodiment of the present application;

[0042] Figure 5 Schematic diagram of the current control method provided in the embodiment of the present application Figure 1 ;

[0043] Figure 6 Schematic diagram of the current control method provided in the embodiment of the present application Figure 2 ;

[0044] Figure 7The current waveform of the transmitting coil provided in this embodiment Figure 1 ;

[0045] Figure 8 Schematic diagram of the current control method provided in the embodiment of the present application Figure 3 ;

[0046] Fig. 9 The current waveform of the transmitting coil provided in this embodiment Figure 2 ;

[0047] Fig.10 This is a frequency energy diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0049] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0050] In addition, the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] It should be noted that, in the absence of conflict, the features in the embodiments of the present application may be combined with each other.

[0052] The present application provides a current control method, a hysteresis current controller, a transmitting circuit and a device. In order to better understand the present application, the implementation method of the hysteresis current controller and the transmitting circuit including the hysteresis current controller is first described.

[0053] Figure 2A schematic diagram of the structure of the hysteresis current controller provided in the embodiment of the present application is shown in FIG. Figure 2 As shown, the hysteresis current controller 10 includes: a random number generating module 11 , a calculating module 12 , a comparing module 13 and a controlling module 14 .

[0054] The output end of the random number generating module 11 is connected to the input end of the calculating module 12, so as to provide a random number for the calculating module 12; the first input end of the comparing module 13 receives a preset fixed threshold current, the output end of the calculating module 12 is connected to the second input end of the comparing module 13, so as to provide a variable threshold current for the comparing module 13, the third input end of the comparing module 13 receives the coil current of the wireless charging transmitting module, and the comparing module 13 is used to compare the coil current with the fixed threshold current and the variable threshold current to obtain a current comparison result.

[0055] The output end of the comparison module 13 is connected to the input end of the control module 14, which is used to provide the control module 14 with a current comparison result. The output end of the control module 14 is connected to the control end of the wireless charging transmitter module, which is used to control the coil current change of the wireless charging transmitter module according to the current comparison result.

[0056] Specifically, the random number generating module 11 is triggered to generate a random number according to a preset random number triggering condition, and the condition for being triggered to generate a random number is that the coil current of the wireless charging transmitting module reaches a fixed threshold current.

[0057] In some embodiments, the hysteresis current controller 10 also includes: a current detection module, which is used to detect the coil current of the wireless charging transmitter module. When the coil current of the wireless charging transmitter module reaches a fixed threshold current, a random number generation signal is sent to the random number generation module 11, and the random number generation module 11 generates a random number based on the random number generation signal.

[0058] The calculation module 12 generates a variable current threshold value based on the random number generated by the random number generation module 11 and the fixed threshold current, wherein the random number generation module 11 generates a different random number each time based on the coil current of the wireless charging transmitter module, and the calculation module 12 generates a different variable current threshold value based on the random number, that is, each time the coil current of the wireless charging transmitter module reaches the fixed threshold current, the calculation module 12 generates a different variable current threshold value each time.

[0059] In a possible implementation, the calculation module 12 generates a hysteresis current according to a random number, and generates a variable current threshold according to a fixed threshold current and the hysteresis current.

[0060] In some embodiments, the calculation module 12 generates a hysteresis current according to a random number, subtracts the hysteresis current from the fixed threshold current, and generates a variable current threshold that is less than the fixed threshold current, so that the coil current of the wireless charging transmitter module increases from a variable current threshold to a fixed threshold current, and then decreases from the fixed threshold current to another variable threshold current.

[0061] In other embodiments, the calculation module 12 generates a hysteresis current according to a random number, adds the hysteresis current to the fixed threshold current, and generates a variable current threshold greater than the fixed threshold current, so that the coil current of the wireless charging transmitter module decreases from a variable threshold current to a fixed threshold current, and then increases from the fixed threshold current to another variable threshold current.

[0062] The three input ends of the comparison module 13 respectively input a fixed threshold current, a variable threshold current and a coil current of the wireless charging transmitter module, and compare the fixed threshold current, the variable threshold current and the coil current of the wireless charging transmitter module. When the coil current of the wireless charging transmitter module reaches the fixed threshold current, a first comparison result is generated, and the control module 14 controls the coil current to reverse according to the first comparison result to change toward the variable threshold current. When the coil current of the wireless charging transmitter module reaches the variable threshold current, the comparison module 13 generates a second comparison result, and the control module 14 controls the coil current to reverse again according to the second comparison result to change toward the fixed threshold current.

[0063] Since the random number generation module 11 and the calculation module 12 generate a new random number and a new variable threshold current each time the coil current of the wireless charging transmitter module reaches the fixed threshold current, the variable current threshold that the coil current can reach is different each time the control module 14 controls the coil current to be reversed according to the first comparison result, that is, the time period in which the coil current changes from the fixed threshold current to the variable current threshold, and then from the variable threshold current to the fixed threshold current (or from the variable current threshold to the fixed threshold current, and then from the fixed threshold current to the variable threshold current) in each cycle is different.

[0064] In one possible implementation, Figure 2 As shown, the input end of the random number generating module 11 is connected to the output end of the comparing module 13 to generate a random number according to the current comparison result.

[0065] In this embodiment, in order to simplify the structure of the hysteresis current controller 10, the current detection module is not used to trigger the random number generation module 11 to generate a random number. The current comparison result of the comparison module 13 is used to trigger the random number generation module 11 to generate a random number. Specifically, when the current comparison result of the comparison module 13 indicates that the coil current of the wireless charging transmitter module reaches a fixed threshold current, the random number generation module 11 generates a random number.

[0066] In some embodiments, if the fixed threshold current is set to be greater than the variable threshold current, when the current comparison result of the comparison module 13 is 1, indicating that the coil current of the wireless charging transmitter module is greater than the fixed threshold current, the random number generation module 11 is triggered to generate a random number.

[0067] In other embodiments, if the fixed threshold current is set to be smaller than the variable threshold current, when the current comparison result of the comparison module 13 is 0, indicating that the coil current of the wireless charging transmitter module is smaller than the fixed threshold current, the random number generation module 11 is triggered to generate a random number.

[0068] The hysteresis current controller provided in the above embodiment can generate a random variable threshold current through the random number generated by the random number generation module, so that the comparison module and the control module can control the coil current of the wireless charging transmitter module to change between a fixed threshold current and multiple different variable threshold currents in multiple cycles. Due to the different variable threshold currents, the time required for the coil current to change is different, that is, the cycle lengths of multiple cycles are different, and the frequency of the transmitting coil is also changed, so that multiple frequency points can be provided on the spectrum, and the energy of each frequency point will be reduced, thereby effectively improving the EMI of the wireless charging transmitter module.

[0069] Based on the above hysteresis current controller, Figure 3 The principle block diagram of the wireless charging transmitting circuit provided in the embodiment of the present application is as follows: Figure 3 As shown, the wireless charging transmitting circuit includes: a wireless charging transmitting module 20 and a hysteresis current controller 10 , and the hysteresis current controller 10 is connected to the control end of the wireless charging transmitting module 20 .

[0070] In this embodiment, the wireless charging transmitter module 20 at least includes: a transmitting coil, a charging capacitor and a bridge control circuit. The control end of the bridge control circuit serves as the control end of the wireless charging transmitter module 20. The hysteresis current controller 10 controls the current direction on the transmitting coil by controlling the conduction state of the bridge control circuit.

[0071] In some embodiments, the wireless charging transmitter module 20 is a wireless charging transmitter module including a half-bridge circuit. In other embodiments, the wireless charging transmitter module 20 is a wireless charging transmitter module including a full-bridge circuit.

[0072] The working principles of the half-bridge circuit and the full-bridge circuit are basically the same. This embodiment takes the full-bridge circuit as an example to illustrate the working principle of the wireless charging transmitter module provided in the embodiment of the present application.

[0073] Figure 4 A circuit diagram of a wireless charging transmitting circuit provided in an embodiment of the present application, such as Figure 4As shown, the output end of the hysteresis current controller 10 is connected to the control end of the switch tubes Q1, Q2, Q3 and Q4 of the full-bridge circuit. When the switch tubes Q1 and Q3 are turned on and Q2 and Q4 are turned off, the coil current flows from AC1 to AC2. When the switch tubes Q2 and Q4 are turned on and Q1 and Q3 are turned off, the coil current flows from AC2 to AC1.

[0074] Assuming that the switch tubes Q1 and Q3 are turned on, and Q2 and Q4 are turned off, the coil current changes to the fixed threshold current. When the coil current reaches the fixed threshold current, the hysteresis current controller 10 controls the switch tubes Q1 and Q3 to turn off, and Q2 and Q4 to turn on, so that the coil current changes from the fixed threshold current to the variable threshold current. When the coil current reaches the variable threshold current, the hysteresis current controller 10 controls the switch tubes Q1 and Q3 to turn on again, and Q2 and Q4 to turn off, so that the coil current changes to the fixed threshold current again. After the coil current reaches the fixed threshold current each time, the hysteresis current controller 10 will generate a new variable threshold current, so that the variable threshold current of each change of the coil current is different.

[0075] The wireless charging transmitting circuit provided in the above embodiment controls the coil current of the wireless charging transmitting module to change between a fixed threshold current and multiple different variable threshold currents in multiple cycles based on the variable threshold current generated by the hysteresis current controller. Due to the different variable threshold currents, the time required for the coil current to change is different, that is, the cycle lengths of the multiple cycles are different, and the frequency of the transmitting coil is also changed. In this way, multiple frequency points can be provided on the spectrum, and the energy of each frequency point will be reduced, thereby effectively improving the EMI of the wireless charging transmitting module.

[0076] Based on the above-mentioned hysteresis current controller and wireless charging transmitting circuit, an embodiment of the present application also provides a current control method applied to the above-mentioned hysteresis current controller.

[0077] Figure 5 Schematic diagram of the current control method provided in the embodiment of the present application Figure 1 ,like Figure 5 As shown, the method may include:

[0078] S301. Each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current, a variable threshold current is generated according to the fixed threshold current and a random number.

[0079] In this embodiment, the current detection module in the hysteresis current controller detects the coil current of the wireless charging transmitter module, or the comparison module in the hysteresis current controller compares the coil current of the wireless charging transmitter module with the fixed threshold current. When the coil current of the wireless charging transmitter module reaches a preset fixed threshold current, the random number generation module is triggered to generate a random number, and the calculation module generates a variable threshold current according to the random number and the fixed threshold current and provides it to the comparison module.

[0080] In a possible implementation, the process of generating a variable threshold current according to a fixed threshold current and a random number in S301 may include:

[0081] A hysteresis current is generated according to a random number; and a variable threshold current is generated according to a fixed threshold current and a hysteresis current.

[0082] In some embodiments, the calculation module generates a hysteresis current based on a random number, subtracts the hysteresis current from the fixed threshold current, and generates a variable current threshold that is less than the fixed threshold current, so that the coil current of the wireless charging transmitter module increases from a variable current threshold to a fixed threshold current, and then decreases from the fixed threshold current to another variable threshold current.

[0083] In other embodiments, the calculation module generates a hysteresis current based on a random number, adds the hysteresis current to the fixed threshold current, and generates a variable current threshold that is greater than the fixed threshold current, so that the coil current of the wireless charging transmitter module decreases from a variable threshold current to a fixed threshold current, and then increases from the fixed threshold current to another variable threshold current.

[0084] S302: Generate a first control signal for the wireless charging transmitter module to control the coil current to change from a fixed threshold current to a variable threshold current.

[0085] In this embodiment, the comparison module generates a first comparison result when the coil current of the wireless charging transmitting module reaches a preset fixed threshold current, and the control module generates a first control signal according to the first comparison result to control the switch tube in the wireless charging transmitting module to switch the conduction state, so that the coil current on the transmitting coil flows in the reverse direction, and the coil current changes from the fixed threshold current to the variable threshold current.

[0086] S303: When the coil current reaches the variable threshold current, generate a second control signal for the wireless charging transmitting module to control the coil current to change from the variable threshold current to the fixed threshold current.

[0087] In this embodiment, the comparison module compares the coil current of the wireless charging transmitter module with the variable threshold current, and generates a second comparison result when the coil current of the wireless charging transmitter module reaches the variable threshold current. The control module generates a second control signal according to the second comparison result, and controls the switch tube in the wireless charging transmitter module to switch on and load again, so that the flow direction of the coil current on the transmitting coil is reversed again, and the coil current changes from the variable threshold current to the fixed threshold current.

[0088] When the coil current changes to reach the fixed threshold current, the above S301 to S303 are executed again. Each time S301 is executed, a new variable threshold current will be generated, so that the time taken for the coil current to change from the fixed threshold current to the variable threshold current, and then from the variable threshold current to the fixed threshold current (or from the variable threshold current to the fixed threshold current, and then from the fixed threshold current to the variable threshold current) is different each time.

[0089] In one possible implementation, Figure 6 Schematic diagram of the current control method provided in the embodiment of the present application Figure 2 ,like Figure 6 As shown, the process of generating a variable threshold current according to the fixed threshold current and a random number in the above S301 each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current may include:

[0090] S401. Each time the coil current rises to a first fixed threshold current, a first variable threshold current is generated according to the first fixed threshold current and a random number, wherein the first variable threshold current is smaller than the first fixed threshold current.

[0091] The process of generating a first control signal for the wireless charging transmitter module in S302 to control the coil current to change from a fixed threshold current to a variable threshold current may include:

[0092] S402: Generate a reverse control signal for the wireless charging transmitter module to control the coil current to drop from a first fixed threshold current to a first variable threshold current.

[0093] The above S303 generates a second control signal for the wireless charging transmitter module when the coil current reaches the variable threshold current to control the coil current to change from the variable threshold current to the fixed threshold current, which may include:

[0094] S403: When the coil current drops to the first variable threshold current, generate a forward control signal for the wireless charging transmitter module to control the coil current to rise from the first variable threshold current to the first fixed threshold current.

[0095] In this embodiment, a first fixed threshold current is set. When the current direction on the transmitting coil of the wireless charging transmitting module is positive, the coil current rises. When the coil current rises to the first fixed threshold current, the random number generation module is triggered to generate a random number. The calculation module generates a first variable threshold current that is less than the first fixed threshold current according to the random number and the first fixed threshold current.

[0096] After comparing that the coil current of the wireless charging transmitting module is greater than the first fixed threshold current, the comparison module generates a high-level comparison result. The control module generates a reverse control signal according to the high-level comparison result, and controls the bridge control circuit in the wireless charging transmitting module to switch the conduction state, so that the current direction on the transmitting coil becomes reverse, and decreases from the first fixed threshold current to the first variable threshold current.

[0097] After comparing that the coil current of the wireless charging transmitting module is less than the first variable threshold current, the comparison module generates a low-level comparison result. The control module generates a positive control signal according to the low-level comparison result, and controls the bridge control circuit in the wireless charging transmitting module to switch the conduction state, so that the current direction on the transmitting coil is switched to the positive direction again, and rises from the first variable threshold current to the first fixed threshold current.

[0098] When the coil current rises to the first fixed threshold current, the above steps S401 to S403 are executed again to generate a new first variable threshold current.

[0099] For example, Figure 7 The current waveform of the transmitting coil provided in this embodiment Figure 1 ,like Figure 7 As shown, when the coil current is greater than the first fixed threshold current for the first time, the calculation module generates a hysteresis current A1 according to a random number, and generates a first variable threshold current A1 according to the first fixed threshold current and the hysteresis current A1, and controls the coil current to drop from the first fixed threshold current to the first variable threshold current A1.

[0100] When the coil current is less than the first variable threshold current A1, the coil current is controlled to rise from the first variable threshold current A1 to the first fixed threshold current. When the coil current is greater than the first fixed threshold current for the second time, the calculation module generates a hysteresis current B1 according to a random number, and generates a first variable threshold current B1 according to the first fixed threshold current and the hysteresis current B1, and controls the coil current to drop from the first fixed threshold current to the first variable threshold current B1.

[0101] When the coil current is less than the first variable threshold current B1, the coil current is controlled to rise from the first variable threshold current B1 to the first fixed threshold current. When the coil current is greater than the first fixed threshold current for the third time, the calculation module generates a hysteresis current D1 according to a random number, and generates a first variable threshold current D1 according to the first fixed threshold current and the hysteresis current D1, and controls the coil current to drop from the first fixed threshold current to the first variable threshold current D1.

[0102] When the coil current is less than the first variable threshold current D1, the coil current is controlled to rise from the first variable threshold current D1 to the first fixed threshold current. When the coil current is greater than the first fixed threshold current for the fourth time, the calculation module generates a hysteresis current C1 according to a random number, and generates a first variable threshold current C1 according to the first fixed threshold current and the hysteresis current C1, and controls the coil current to drop from the first fixed threshold current to the first variable threshold current C1.

[0103] It can be seen that the time for the coil current to rise from the first fixed threshold current and then fall to the first variable threshold current A1 is t1, the time for the first variable threshold current A1 to rise to the first fixed threshold current and then fall to the first variable threshold current B1 is t2, the time for the first variable threshold current B1 to rise to the first fixed threshold current and then fall to the first variable threshold current D1 is t3, and the time for the first variable threshold current D1 to rise to the first fixed threshold current and then fall to the first variable threshold current C1 is t4. t1≠t2≠t3≠t4, then the signal transmission frequency F1≠F2≠F3≠F4 of the transmitting coil, and multiple frequency points can be seen on the spectrum. The energy of each frequency point will be reduced, which effectively improves EMI.

[0104] In one possible implementation, Figure 8 Schematic diagram of the current control method provided in the embodiment of the present application Figure 3 ,like Figure 8 As shown, the process of generating a variable threshold current according to the fixed threshold current and a random number in the above S301 each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current may include:

[0105] S501. Each time the coil current drops to a second fixed threshold current, a second variable threshold current is generated according to the second fixed threshold current and a random number, and the second variable threshold current is greater than the second fixed threshold current.

[0106] The process of generating a first control signal for the wireless charging transmitter module in S302 to control the coil current to change from a fixed threshold current to a variable threshold current may include:

[0107] S502: Generate a forward control signal for the wireless charging transmitter module to control the coil current to increase from a second variable threshold current to a second fixed threshold current.

[0108] The above S303 generates a second control signal for the wireless charging transmitter module when the coil current reaches the variable threshold current to control the coil current to change from the variable threshold current to the fixed threshold current, which may include:

[0109] S503: When the coil current rises to the second fixed threshold current, generate a reverse control signal for the wireless charging transmitter module to control the coil current to drop from the second fixed threshold current to the second variable threshold current.

[0110] In this embodiment, a second fixed threshold current is set. When the current direction on the transmitting coil of the wireless charging transmitting module is reversed, the coil current decreases. When the coil current decreases to the second fixed threshold current, the random number generation module is triggered to generate a random number. The calculation module generates a second variable threshold current greater than the second fixed threshold current according to the random number and the second fixed threshold current.

[0111] After comparing that the coil current of the wireless charging transmitting module is less than the second fixed threshold current, the comparison module generates a low-level comparison result. The control module generates a positive control signal according to the low-level comparison result, and controls the bridge control circuit in the wireless charging transmitting module to switch the conduction state, so that the current direction on the transmitting coil becomes positive, and rises from the second fixed threshold current to the second variable threshold current.

[0112] After comparing that the coil current of the wireless charging transmitting module is greater than the second variable threshold current, the comparison module generates a high level comparison result. The control module generates a reverse control signal according to the high level comparison result, and controls the bridge control circuit in the wireless charging transmitting module to switch the conduction state, so that the current direction on the transmitting coil is switched to the reverse direction again, and decreases from the second variable threshold current to the second fixed threshold current.

[0113] When the coil current drops to the second fixed threshold current, the above steps S501 to S503 are executed again to generate a new second variable threshold current.

[0114] For example, Fig. 9 The current waveform of the transmitting coil provided in this embodiment Figure 2 ,like Fig. 9 As shown, when the coil current is less than the second fixed threshold current for the first time, the calculation module generates a hysteresis current A2 according to a random number, and generates a second variable threshold current A2 according to the second fixed threshold current and the hysteresis current A2, and controls the coil current to rise from the second fixed threshold current to the second variable threshold current A2.

[0115] When the coil current is greater than the second variable threshold current A2, the coil current is controlled to go down from the second variable threshold current A2 to the first fixed threshold current. When the coil current is less than the second fixed threshold current for the second time, the calculation module generates a hysteresis current B2 according to a random number, and generates a second variable threshold current B2 according to the second fixed threshold current and the hysteresis current B2, and controls the coil current to rise from the first fixed threshold current to the second variable threshold current B2.

[0116] When the coil current is greater than the second variable threshold current B2, the coil current is controlled to decrease from the second variable threshold current B2 to the second fixed threshold current. When the coil current is less than the second fixed threshold current for the third time, the calculation module generates a hysteresis current D2 according to a random number, and generates a second variable threshold current D2 according to the second fixed threshold current and the hysteresis current D2, and controls the coil current to increase from the second fixed threshold current to the second variable threshold current D2.

[0117] When the coil current is greater than the second variable threshold current D2, the coil current is controlled to decrease from the second variable threshold current D2 to the second fixed threshold current. When the coil current is less than the second fixed threshold current for the fourth time, the calculation module generates a hysteresis current C2 according to a random number, and generates a second variable threshold current C2 according to the second fixed threshold current and the hysteresis current C2, and controls the coil current to increase from the second fixed threshold current to the second variable threshold current C2.

[0118] It can be seen that the time for the coil current to rise from the second variable threshold current A2 and then fall to the second fixed threshold current is t1, the time for the second fixed threshold current to rise to the second variable threshold current B2 and then fall to the second fixed threshold current is t2, the time for the second fixed threshold current to rise to the second variable threshold current D2 and then fall to the second fixed threshold current is t3, and the time for the second fixed threshold current to rise to the second variable threshold current C2 and then fall to the second fixed threshold current is t4. t1≠t2≠t3≠t4, then the signal transmission frequency F1≠F2≠F3≠F4 of the transmitting coil, and multiple frequency points can be seen on the spectrum. The energy of each frequency point will be reduced, which effectively improves EMI.

[0119] For example, Fig.10 The frequency energy diagram provided in the embodiment of the present application is as follows: Fig.10 As shown, the frequency of the transmitting coil is variable, the number of frequency points on the spectrum increases, the energy of each frequency point decreases, the interference of each frequency point decreases, and the EMI is effectively improved.

[0120] The current control method provided in the above embodiment generates a random variable threshold current based on a fixed threshold current and a random number to control the coil current of the wireless charging transmitter module to change between a fixed threshold current and multiple different variable threshold currents in multiple cycles. Due to the different variable threshold currents, the time required for the coil current to change is different, that is, the cycle lengths of the multiple cycles are different, and the frequency of the transmitting coil is also changed. In this way, multiple frequency points can be provided on the spectrum, and the energy of each frequency point will be reduced, thereby effectively improving the EMI of the wireless charging transmitter module.

[0121] Based on the above hysteresis current controller, wireless charging transmitting circuit and current control method, the present application also provides a wireless charging device, which includes the wireless charging transmitting circuit in the above embodiment.

[0122] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A current control method, characterized in that: Applied to a hysteresis current controller, the hysteresis current controller is used to connect to the control end of a wireless charging transmitter module, the method comprises: Each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current, generating a variable threshold current according to the fixed threshold current and a random number; generating a first control signal for the wireless charging transmitter module to control the coil current to change from the fixed threshold current to the variable threshold current; When the coil current reaches the variable threshold current, a second control signal is generated for the wireless charging transmitter module to control the coil current to change from the variable threshold current to the fixed threshold current.

2. The method according to claim 1, characterized in that The generating a variable threshold current according to the fixed threshold current and a random number comprises: generating a hysteresis current according to the random number; The variable threshold current is generated according to the fixed threshold current and the hysteresis current.

3. The method according to claim 1, characterized in that The method of generating a variable threshold current according to a preset fixed threshold current and a random number each time the coil current of the wireless charging transmitter module reaches the preset fixed threshold current comprises: Each time the coil current rises to a first fixed threshold current, generating a first variable threshold current according to the first fixed threshold current and a random number, wherein the first variable threshold current is less than the first fixed threshold current; The generating a first control signal for the wireless charging transmitting module to control the coil current to change from the fixed threshold current to the variable threshold current includes: generating a reverse control signal for the wireless charging transmitting module to control the coil current to decrease from the first fixed threshold current to the first variable threshold current; When the coil current reaches the variable threshold current, generating a second control signal for the wireless charging transmitter module to control the coil current to change from the variable threshold current to the fixed threshold current, comprising: When the coil current drops to the first variable threshold current, a positive control signal is generated for the wireless charging transmitter module to control the coil current to rise from the first variable threshold current to the first fixed threshold current.

4. The method according to claim 1, characterized in that: The method of generating a variable threshold current according to the fixed threshold current and a random number each time the coil current of the wireless charging transmitter module reaches a preset fixed threshold current comprises: Each time the coil current drops to a second fixed threshold current, generating a second variable threshold current according to the second fixed threshold current and a random number, wherein the second variable threshold current is greater than the second fixed threshold current; The generating a first control signal for the wireless charging transmitting module to control the coil current to change from the fixed threshold current to the variable threshold current includes: generating a forward control signal for the wireless charging transmitter module to control the coil current to increase from the second variable threshold current to the second fixed threshold current; When the coil current reaches the variable threshold current, generating a second control signal for the wireless charging transmitter module to control the coil current to change from the variable threshold current to the fixed threshold current, comprising: When the coil current rises to the second fixed threshold current, a reverse control signal is generated for the wireless charging transmitter module to control the coil current to drop from the second fixed threshold current to the second variable threshold current.

5. A hysteresis current controller, characterized in that: The hysteresis current controller comprises: a random number generation module, a calculation module, a comparison module and a control module; The output end of the random number generating module is connected to the input end of the calculating module, and is used to provide a random number for the calculating module; The first input terminal of the comparison module receives a preset fixed threshold current, the output terminal of the calculation module is connected to the second input terminal of the comparison module, and is used to provide a variable threshold current for the comparison module. The third input terminal of the comparison module receives the coil current of the wireless charging transmitter module, and the comparison module is used to compare the coil current with the fixed threshold current and the variable threshold current to obtain a current comparison result; The output end of the comparison module is connected to the input end of the control module, and is used to provide the current comparison result to the control module; The output end of the control module is connected to the control end of the wireless charging transmitter module, and is used to control the coil current change of the wireless charging transmitter module according to the current comparison result, and the hysteresis current controller executes the current control method according to any one of claims 1 to 4.

6. The hysteresis current controller according to claim 5, characterized in that: The input end of the random number generating module is connected to the output end of the comparing module to generate the random number according to the current comparison result.

7. A wireless charging transmitting circuit, characterized in that: The wireless charging transmitting circuit comprises: a wireless charging transmitting module and a hysteresis current controller as claimed in any one of claims 5 to 6, wherein the hysteresis current controller is connected to a control end of the wireless charging transmitting module.

8. The wireless charging transmitting circuit according to claim 7, characterized in that: The wireless charging transmitting module is a wireless charging transmitting module including a half-bridge circuit.

9. The wireless charging transmitting circuit according to claim 7, characterized in that: The wireless charging transmitting module is a wireless charging transmitting module including a full-bridge circuit.

10. A wireless charging device, characterized in that: The wireless charging device comprises: a wireless charging transmitting circuit as described in any one of claims 7 to 9.

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