Power supply circuit and charging device

Abstract

Disclosed are a power supply circuit and a charging device. The power supply circuit comprises: a transformer, a primary circuit connected to a primary winding of the transformer, a secondary circuit connected to a first secondary winding of the transformer, an isolation module, and a control module. The control module is connected to the secondary circuit and a transmitting end of the isolation module, and a receiving end of the isolation module is connected to a switching transistor of the primary circuit. The control module is used for generating a first switch control signal on the basis of an output voltage of the secondary circuit, and transmitting the first switch control signal to the switching transistor of the primary circuit by means of the isolation module, so as to control switching of the switching transistor of the primary circuit. In the present circuit, the primary side is directly controlled from the secondary side by means of the isolation module, thus eliminating the need for a PWM controller on the primary side and effectively reducing the volume of the power supply circuit, while eliminating the signal conversion process caused by optocoupler feedback and achieving improved timeliness.

Description

Power circuit and charging equipment

[0001] The present invention claims priority to the Chinese patent application filed with the Patent Office of China on September 18, 2023, with application number 202311206459.2 and application name “Power Circuit and Charging Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to the technical field of power supply, and in particular to a power supply circuit and a charging device. Background Art

[0003] As the application scope of electronic devices becomes wider and wider, the requirements for the lightness and thinness of electronic devices are also getting higher and higher, which also limits the requirements of electronic devices for the volume of power supply circuit structures.

[0004] In related technology, a flyback converter circuit is used to achieve fast charging of electronic devices. In this circuit, an output voltage detection circuit is set on the secondary side to detect the output voltage on the secondary side. The detected voltage is transmitted to the PWM controller on the primary side through an optocoupler. The PWM controller controls the primary side switch tube to adjust the primary side output voltage to achieve the purpose of fast charging.

[0005] However, this type of control of the primary and secondary sides through an optocoupler feedback loop not only requires the use of more components, resulting in a large power supply circuit, but also has poor timeliness of control.

[0006] Summary of the Invention

[0007] The present invention aims to at least partially address one of the technical problems in the related art. To this end, the first object of the present invention is to provide a power supply circuit that transmits a first switch control signal to a switch transistor in a primary circuit via an isolation module to control the switch transistor in the primary circuit. This achieves direct control of the primary side from the secondary side, eliminates the need for a PWM controller on the primary side, effectively reduces the size of the power supply circuit, and eliminates the signal conversion process caused by optocoupler feedback, resulting in high timeliness.

[0008] A second object of the present invention is to provide a charging device.

[0009] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a power supply circuit, including: a transformer, a primary circuit connected to the primary winding of the transformer, a secondary circuit connected to the first secondary winding of the transformer, an isolation module and a control module, the control module is connected to the transmitting end of the secondary circuit and the isolation module, and the receiving end of the isolation module is connected to the switching tube of the primary circuit, wherein the control module is used to generate a first switching control signal based on the output voltage of the secondary circuit, and transmit it to the switching tube of the primary circuit through the isolation module to perform switching control on the switching tube of the primary circuit.

[0010] According to the power supply circuit of an embodiment of the present invention, the first switch control signal is transmitted to the switch tube of the primary circuit through the isolation module to control the switch tube of the primary circuit, thereby realizing direct control of the primary side by the secondary side, eliminating the PWM controller on the primary side, effectively reducing the volume of the power supply circuit, and at the same time eliminating the signal conversion process caused by the optocoupler feedback, and having high timeliness.

[0011] In some embodiments, the isolation module includes a wireless communication module or an optical communication module.

[0012] In some embodiments, the optical communication module includes an infrared transceiver module or a millimeter wave transceiver module.

[0013] In some embodiments, the power supply circuit also includes a self-excited soft start circuit, which is connected to the receiving end of the isolation module and the switching tube of the primary circuit, and is used to control the switching tube of the primary circuit to enable the power supply circuit to self-excite and soft start, and after the startup is completed, the receiving end of the isolation module is controlled to be connected to the switching tube of the primary circuit.

[0014] In some embodiments, the self-excited soft start circuit includes: an oscillation circuit for generating a carrier signal; a comparison circuit, the comparison circuit is connected to the oscillation circuit, and is used to compare the carrier signal with the fundamental signal to generate a second switching control signal; a selection circuit, the selection circuit is connected to the comparison circuit, the receiving end of the isolation module and the switching tube of the primary circuit, and is used to control the comparison circuit to be connected to the switching tube of the primary circuit when the power supply circuit is self-excited soft started, so as to control the switching tube of the primary circuit through the second switching control signal to soft-start the power supply circuit, and when the power supply circuit startup is completed, control the receiving end of the isolation module to be connected to the switching tube of the primary circuit.

[0015] In some embodiments, the self-excited soft start circuit further includes a first power supply circuit, which is connected to the primary circuit, the oscillation circuit, the comparison circuit and the selection circuit, and is used to supply power to the oscillation circuit, the comparison circuit and the selection circuit.

[0016] In some embodiments, the first switch control signal and the second switch control signal are PWM control signals.

[0017] In some embodiments, the power supply circuit also includes a second power supply circuit connected to the second secondary winding of the transformer, and the second power supply circuit is connected to the receiving end of the isolation module for supplying power to the receiving end of the isolation module; wherein the secondary circuit is also connected to the transmitting end of the isolation module for supplying power to the transmitting end of the isolation module.

[0018] In some embodiments, the control module includes: a sampling unit, the sampling unit is connected to the secondary circuit and is used to sample the output voltage of the secondary circuit; a control logic unit, the control logic unit is connected to the sampling unit and is used to generate a first switch control signal based on the output voltage of the secondary circuit; and a feedback unit, the feedback unit is connected to the control logic unit and the transmitting end of the isolation module and is used to provide a first switch control signal adapted to the isolation module.

[0019] In some embodiments, the control module also includes: a control circuit, which is connected to the control logic unit and the switch tube of the secondary circuit, wherein the control logic unit is also used to generate a third switch control signal based on the output voltage of the secondary circuit, and the control circuit is used to control the switch tube of the secondary circuit based on the third switch control signal.

[0020] In some embodiments, the transformer, the primary circuit, and the secondary circuit constitute a flyback converter or a forward converter.

[0021] To achieve the above-mentioned object, a second embodiment of the present invention provides a charging device, comprising the aforementioned power supply circuit.

[0022] According to the charging device of an embodiment of the present invention, through the aforementioned power supply circuit, the first switch control signal is transmitted to the switch tube of the primary circuit through the isolation module to control the switch tube of the primary circuit, thereby realizing direct control of the primary side by the secondary side, eliminating the PWM controller on the primary side, effectively reducing the volume of the power supply circuit, and at the same time eliminating the signal conversion process caused by the optocoupler feedback, with high timeliness.

[0023] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of a power supply circuit in the related art;

[0025] FIG2 is a schematic structural diagram of a power supply circuit according to a first embodiment of the present invention;

[0026] FIG3 is a schematic structural diagram of a power supply circuit according to a second embodiment of the present invention;

[0027] FIG4 is a schematic structural diagram of a power supply circuit according to a third embodiment of the present invention;

[0028] 5 is a schematic structural diagram of a power supply circuit according to a fourth embodiment of the present invention;

[0029] FIG6 is a schematic structural diagram of a power supply circuit according to a fifth embodiment of the present invention;

[0030] 7 is a schematic structural diagram of a power supply circuit according to a sixth embodiment of the present invention;

[0031] FIG8 is a schematic structural diagram of a power supply circuit according to a seventh embodiment of the present invention;

[0032] FIG9 is a schematic structural diagram of a power supply circuit according to an eighth embodiment of the present invention;

[0033] FIG10 is a schematic structural diagram of another power supply circuit in the related art. DETAILED DESCRIPTION

[0034] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0035] In related technology, a flyback converter circuit is used to achieve fast charging of electronic devices. In this circuit, an output voltage detection circuit is set on the secondary side to detect the output voltage on the secondary side. The detected voltage is transmitted to the PWM controller on the primary side through an optocoupler. The PWM controller controls the primary side switch tube to adjust the primary side output voltage to achieve the purpose of fast charging.

[0036] Specifically, referring to Figure 1, the output voltage of the secondary side is sampled by sampling resistors R1 and R2, and the sampled voltage is stabilized by capacitor C. The optocoupler is turned on or off based on the sampled voltage by Zener diode Z, so that the output voltage of the secondary side is transmitted to the PWM controller on the primary side through the optocoupler. The PWM controller generates a PWM control signal with a corresponding duty cycle based on the feedback voltage, and controls the switch tube Q1 on the primary side based on the PWM control signal to adjust the output voltage of the primary side, thereby adjusting the output voltage of the secondary side.

[0037] In this circuit, the secondary side controls the primary side through an optocoupler feedback loop. This not only requires the use of more components, such as sampling resistors R1 and R2, capacitor C, voltage regulator diode Z, and PWM controller, resulting in a large power supply circuit, but also has poor control timeliness.

[0038] Based on this, in an embodiment of the present invention, the first switch control signal is transmitted to the switch tube of the primary circuit through the isolation module to control the switch tube of the primary circuit, thereby realizing direct control of the primary side by the secondary side, eliminating the PWM controller, voltage regulator diode Z, etc. on the primary side, effectively reducing the volume of the power supply circuit, and at the same time eliminating the signal conversion process brought about by the optocoupler feedback, and having higher timeliness.

[0039] The power supply circuit and charging device proposed in the embodiments of the present invention are described below with reference to the accompanying drawings.

[0040] Figure 2 is a schematic diagram of the structure of a power supply circuit according to one embodiment of the present invention. Referring to Figure 2 , the power supply circuit may include: a transformer T, a primary circuit 11 connected to the primary winding of transformer T, a secondary circuit 12 connected to the first secondary winding of transformer T, an isolation module 13, and a control module 14. The control module 14 is connected to the transmitting end of the secondary circuit 12 and the isolation module 13. The receiving end of the isolation module 13 is connected to the switch Q1 of the primary circuit 11. The control module 14 is configured to generate a first switching control signal based on the output voltage of the secondary circuit 12, and transmit the signal to the switch Q1 of the primary circuit 11 via the isolation module 13 to control the switching of the switch Q1 of the primary circuit 11.

[0041] For example, when the power supply circuit is operating, the primary circuit 11 can be used to rectify the AC power into DC power, and then the DC power can be inverted into AC power. After the AC power is stepped up or down by the transformer T, the secondary circuit 12 rectifies the target DC power for use by the load. In order to ensure that the voltage of the target DC power, i.e., the output voltage of the secondary circuit 12, meets the preset requirements, the control module 14 can generate a first switch control signal, such as a PWM control signal, based on the output voltage of the secondary circuit 12, and send it to the receiving end of the isolation module 13 through the transmitting end of the isolation module 13, and then transmit it to the switch tube Q1 of the primary circuit 11 to perform switching control (i.e., on-off control) on the switch tube Q1 of the primary circuit 11, so as to adjust the output voltage of the primary circuit 11 and then adjust the output voltage of the secondary circuit 12.

[0042] In this circuit, the first switch control signal is directly transmitted to the primary circuit's switch transistor via an isolation module to control the primary circuit's switch transistor. This achieves direct control of the primary side from the secondary side, eliminating the need for a primary-side PWM controller, Zener diode Z, and other components. This effectively reduces the size of the power supply circuit and eliminates the signal conversion process associated with optocoupler feedback (controlling the voltage level on the secondary side, receiving the voltage level on the primary side, adjusting the PWM reference voltage based on the received voltage level, and thereby changing the duty cycle of the PWM control signal to control the primary-side switch transistor). For example, the first switch control signal from the secondary side can be quickly fed back to the primary side, resulting in improved timeliness and safety (reduced components and increased reliability and safety). Furthermore, the switching frequency of the transmitted switch control signal is higher than the switching frequency generated by the PWM controller (there is no need to modulate the signal to a high frequency; the highest frequency of the primary circuit's switch transistor can be used directly). Furthermore, because the switch control signal is transmitted, the overall power supply circuit has a fast response speed, which in turn helps reduce the size of the transformer and the inductor (for circuits containing inductors), effectively reduces output ripple, and improves output efficiency. Furthermore, this approach can achieve better synchronous rectification.

[0043] In some embodiments, the isolation module 13 includes a wireless communication module or an optical communication module, wherein the optical communication module may include an infrared transceiver module or a millimeter wave transceiver module.

[0044] That is, the isolation module 13 can be a wireless communication module or an optical communication module. In the case of a wireless communication module, the first switch control signal can be isolated and transmitted via wireless signals, thereby enabling the secondary side to directly control the primary side switch. In the case of an optical communication module, it can specifically be infrared light or millimeter waves, thereby enabling the first switch control signal to be isolated and transmitted via infrared light or millimeter waves, thereby enabling the secondary side to directly control the primary side switch. Compared to the optocoupler feedback method, this method can transmit more data faster, thereby effectively reducing the size of the power supply circuit and improving timeliness.

[0045] In some embodiments, referring to Figure 3, the power supply circuit also includes a self-excited soft start circuit 15, which is connected to the receiving end of the isolation module 13 and the switch tube Q1 of the primary circuit 11, and is used to control the switch tube Q1 of the primary circuit 11 to enable the power supply circuit to self-excite and soft start. After the startup is completed, the receiving end of the isolation module 13 is controlled to be connected to the switch tube Q1 of the primary circuit 11.

[0046] It should be noted that the self-excited soft start of the power supply circuit refers to a starting method in which the output voltage of the power supply circuit gradually increases from zero without the action of a control signal.

[0047] For example, referring to FIG3 , after the power supply circuit is powered on, the self-excited soft-start circuit 15 begins operation. At this time, the receiving end of the isolation module 13 is disconnected from the switch Q1 of the primary circuit 11. That is, the switch Q1 of the primary circuit 11 does not receive the first switch control signal from the control module 14. Simultaneously, the self-excited soft-start circuit 15 generates a control signal in the absence of a control signal and controls the switch Q1 of the primary circuit 11 to gradually increase the output voltage of the secondary circuit 12. When the output voltage of the secondary circuit 12 reaches a preset value, the self-excited soft-start circuit 15 controls the receiving end of the isolation module 13 to connect to the switch Q1 of the primary circuit 11 to receive the first switch control signal from the control module 14, thereby controlling the switch on the primary side through the secondary side. In this way, the self-excited soft-start of the power supply circuit is achieved.

[0048] In some embodiments, referring to FIG4 , the self-excited soft-start circuit 15 includes an oscillator circuit 151, a comparison circuit 152, and a selection circuit 153. The oscillator circuit 151 is configured to generate a carrier signal; the comparison circuit 152 is connected to the oscillator circuit 151 and is configured to compare the carrier signal with the fundamental wave signal to generate a second switch control signal; and the selection circuit 153 is connected to the comparison circuit 152, the receiving end of the isolation module 13, and the switch Q1 of the primary circuit 11. The selection circuit 153 is configured to control the comparison circuit 152 to connect to the switch Q1 of the primary circuit 11 during the self-excited soft-start of the power supply circuit, so as to control the switch Q1 of the primary circuit 11 to be switched on and off by the second switch control signal, thereby enabling the self-excited soft-start of the power supply circuit. When the power supply circuit is fully started, the selection circuit 153 is configured to control the receiving end of the isolation module 13 to connect to the switch Q1 of the primary circuit 11.

[0049] Specifically, the oscillation circuit 151 may be an RC oscillation circuit, and a carrier signal may be generated by the RC oscillation circuit. For example, the carrier signal may be a triangular wave signal.

[0050] The comparison circuit 152 can be a comparator, a first input terminal of the comparator is connected to the oscillation circuit 151, and a second input terminal of the comparator is connected to the reference signal terminal. The reference signal terminal is used to provide a fundamental wave signal. If the fundamental wave signal is a fixed level signal, the carrier signal and the fundamental wave signal are compared by the comparator to generate a second switching control signal, such as performing an amplitude comparison between the triangular wave signal and the fixed level signal to generate a second switching control signal, such as a PWM control signal.

[0051] The selection circuit 153 may include an RC delay circuit and a controllable switch. Before the delay time determined by RC (i.e., resistance and capacitance) is reached, the RC delay circuit outputs a first control signal to control the controllable switch to connect the comparison circuit 152 to the switch Q1 of the primary circuit 11. This allows the switch Q1 of the primary circuit 11 to be switched on and off via a second switch control signal, thereby achieving a self-excited soft start for the power supply circuit. When the self-excited soft start of the power supply circuit is complete, i.e., when the delay time determined by RC is reached, the RC delay circuit outputs a second control signal to control the controllable switch to connect the receiving end of the isolation module 13 to the switch Q1 of the primary circuit 11. This allows the switch Q1 of the primary circuit 11 to be switched on and off via the first switch control signal sent by the control module 14. In this way, a self-excited soft start for the power supply circuit is achieved.

[0052] It should be noted that, based on the isolation module 13, data can be transmitted faster and in greater quantities. The control module 14 can also transmit the output voltage of the secondary circuit 12 to the self-excited soft-start circuit 15 through the isolation module 13. The selection circuit 153 in the self-excited soft-start circuit 15 determines whether to exit the soft-start state and the control module 14 takes over the control of the switch tube Q1 of the primary circuit 11 to adjust the output voltage.

[0053] 4 , the self-excited soft-start circuit 15 further includes a first power supply circuit 154, which is connected to the primary circuit 11, the oscillation circuit 151, the comparison circuit 152, and the selection circuit 153, and is configured to supply power to the oscillation circuit 151, the comparison circuit 152, and the selection circuit 153. Exemplarily, the first power supply circuit 154 may be a charge pump configured to boost the DC power of the primary circuit 11 to generate the required DC power to supply power to the self-excited soft-start circuit 15.

[0054] In some embodiments, referring to Figure 5, the power supply circuit also includes a second power supply circuit 16 connected to the second secondary winding of the transformer T, and the second power supply circuit 16 is connected to the receiving end of the isolation module 13 for supplying power to the receiving end of the isolation module 13; wherein the secondary circuit 12 is also connected to the transmitting end of the isolation module 13 for supplying power to the transmitting end of the isolation module 13.

[0055] Specifically, the isolation module 13 needs to be powered to enable it to operate. When powering, the receiving end of the isolation module 13 can be powered by the second power supply circuit 16, and the transmitting end of the isolation module 13 can be powered by the secondary circuit 12, thereby achieving independent isolated power supply for the transmitting end and the receiving end, thereby improving the safety of the isolation module 13. Exemplarily, the second power supply circuit 16 can be a rectifier circuit to convert the AC power of the transformer T into DC power to power the receiving end of the isolation module 13. Since the secondary circuit 12 connected to the transformer T is used to convert AC power into DC power, the DC power can be directly provided to the transmitting end of the isolation module 13. It is understandable that if the converted DC power does not match the voltage required by the transmitting end of the isolation module 13, a corresponding buck-boost circuit or a third power supply circuit can be added, and the specific details are not limited here.

[0056] In some embodiments, referring to Figure 6, the control module 14 includes: a sampling unit 141, a control logic unit 142 and a feedback unit 143, wherein the sampling unit 141 is connected to the secondary circuit 12 for sampling the output voltage of the secondary circuit 12; the control logic unit 142 is connected to the sampling unit 141 for generating a first switch control signal based on the output voltage of the secondary circuit 12; the feedback unit 143 is connected to the control logic unit 142 and the transmitting end of the isolation module 13 for providing a first switch control signal adapted to the isolation module 13.

[0057] Specifically, the sampling unit 141 may be an ADC analog-to-digital conversion unit, configured to sample the output voltage, output current, etc. of the secondary circuit 12 and provide the samples to the control logic unit 142 .

[0058] The control logic unit 142 serves as the control core of the power supply circuit and realizes the control of the entire power supply circuit, including but not limited to generating a first switch control signal based on the output voltage of the secondary circuit 12, judging whether the output power of the power supply circuit meets expectations based on the output voltage and output current of the secondary circuit 12, and sampling various protocol signals, such as obtaining a charging protocol signal when the power supply circuit is used for charging.

[0059] Feedback unit 143 is mainly used to provide wireless or optical communication corresponding to the first switch control signal required by isolation module 13 to directly control the primary-side switch tube and thus control the output voltage of the secondary side. It should be noted that the specific structure of feedback unit 143 is not limited here.

[0060] When the power supply circuit is powered on, the sampling unit 141 detects the output voltage of the secondary circuit 12 in real time. The control logic unit 142 generates a first switch control signal based on the output voltage of the secondary circuit 12, and provides it to the isolation module 13 through the feedback unit 143. The isolation module 13 transmits it to the switch tube Q1 of the primary circuit 11 to perform switch control on the switch tube Q1 of the primary circuit 11.

[0061] In some embodiments, referring to Figure 6, the control module 14 also includes a control circuit 144, which is connected to the control logic unit 142 and the switch tube Q2 of the secondary circuit 12, wherein the control logic unit 142 is further used to generate a third switch control signal based on the output voltage of the secondary circuit 12, and the control circuit 144 is used to control the switch tube Q2 of the secondary circuit 12 based on the third switch control signal.

[0062] Specifically, the control circuit 144 can be a PFC control circuit that, in conjunction with the sampling unit 141, can implement switching control of the switch Q2 of the secondary circuit 12 to align the output switching phase with the phase of the load fluctuation, thereby improving the overall output efficiency. For example, when the power supply circuit is powered on, the sampling unit 141 detects the output voltage of the secondary circuit 12 in real time. The control logic unit 142 generates a third switching control signal, such as a PWM control signal, based on the output voltage of the secondary circuit 12 and sends it to the control circuit 144. The control circuit 144 then drives and controls the switch Q2 of the secondary circuit 12 based on the third switching control signal to achieve power factor correction, thereby effectively improving the output efficiency of the power supply circuit.

[0063] It should be noted that in the embodiments of the present invention, there is no limitation on the specific circuit structures of the primary circuit 11 and the secondary circuit 12. For example, the primary circuit 11, the transformer T, and the secondary circuit 12 may constitute a flyback converter, a forward converter, or a push-pull converter.

[0064] Exemplarily, referring to Figure 7, the primary circuit 11 includes a rectifier bridge U1 and a switch tube Q1, the input end of the rectifier bridge U1 is connected to the AC power supply AC, the first output end of the rectifier bridge U1 is connected to one end of the primary winding of the transformer T, the other end of the primary winding of the transformer T is connected to the first end of the switch tube Q1, and the second end of the switch tube Q1 is connected to the second output end of the rectifier bridge U1.

[0065] The secondary circuit 12 includes a switch tube Q2 and a capacitor C1. One end of the first secondary winding of the transformer T is connected to the first voltage output terminal of the power supply circuit, the other end of the first secondary winding of the transformer T is connected to the first end of the switch tube Q2, and the second end of the switch tube Q2 is connected to the second voltage output terminal of the power supply circuit. In this example, the second voltage output terminal of the power supply circuit is grounded; the capacitor C1 is connected in parallel between the first voltage output terminal and the second voltage output terminal of the power supply circuit.

[0066] The detailed description of the isolation module 13 , the control module 14 and the self-excited soft start circuit 15 can be referred to above and will not be repeated here.

[0067] The first power supply circuit 16 may include a diode D1 and a capacitor C2. The anode of the diode D1 is connected to one end of the second secondary winding of the transformer T, the cathode of the diode D1 is connected to the receiving end of the isolation module 13, and the other end of the second secondary winding of the transformer T is connected to the second output end of the rectifier bridge U1. The capacitor C2 is connected between the cathode of the diode D1 and the other end of the second secondary winding of the transformer T. The transmitting end of the isolation module 13 is also connected to the secondary circuit 12.

[0068] After the power supply circuit is powered on, the rectifier bridge U1 converts the AC power provided by the AC power source AC into quasi-DC power. The self-excited soft-start circuit 15 periodically switches the switch Q1 on and off, stepping up or down the quasi-DC power via the transformer T before converting it to DC output via the secondary circuit 12. When the output voltage of the secondary circuit 12 reaches a preset value, the self-excited soft-start circuit 15 controls the receiving end of the isolation module 13 to connect to the switch Q1. At this point, the control module 14 periodically switches the switch Q1 on and off to adjust the output voltage of the secondary circuit 12. During this process, the control module 14 also switches the switch Q1 of the secondary circuit 12 on and off to achieve rectification and power factor correction.

[0069] As can be seen from the comparison between Figure 7 and Figure 1, the power supply circuit of the embodiment of the present invention omits the voltage-stabilizing diode Z, capacitor C, voltage-dividing resistors R1 and R2, power correction chip and PWM controller, and the secondary side can communicate with the primary side more efficiently and quickly.

[0070] It should be noted that the power supply circuit of the embodiment of the present invention can be used to charge electronic devices. Taking the power supply circuit shown in Figure 7 as an example, when it is used to charge an electronic device, the power supply circuit may also include a charging interface. For example, referring to Figure 8, the power supply circuit may include a USB port, through which an electronic device can be charged, which is suitable for single-port fast charging application scenarios.

[0071] For example, referring to FIG9 , the power supply circuit may include multiple USB ports, enabling charging of multiple electronic devices through the multiple USB ports. It is understood that when the power supply circuit includes multiple USB ports, one of the USB ports can be directly connected to the output of the secondary circuit 12, thereby eliminating a buck or boost circuit and reducing charging losses. The other USB ports can be provided with corresponding buck or boost circuits to convert the output voltage of the secondary circuit 12 through the buck or boost circuit to meet actual needs. This is suitable for fast charging applications with two or more ports that require a single independent step-down. During charging, the control module 14 can control the switch Q1 to adjust the output voltage of the primary circuit 11, thereby adjusting the charging voltage of the USB port connected to the output of the secondary circuit 12. For the other USB ports, the control module 14 can control the corresponding buck or boost circuit to meet the corresponding charging needs. This approach eliminates the need for a single step-up or step-down circuit and can improve the output efficiency of the power supply circuit.

[0072] In addition, when the power supply circuit includes multiple USB ports, a protocol conversion unit can be set in the control module 14 to realize charging protocol conversion for multiple USB ports and send it to the control logic unit 142 in the control module 14, so that the control logic unit 142 can obtain the charging protocol and control the switch tubes Q1 and Q2 and the corresponding boost or buck circuit of the USB port based on the obtained charging protocol so that the output voltage meets the charging requirements. Among them, the protocol conversion unit is used to detect the charging protocol type and the maximum charging power that can be supported by the electronic device after insertion. For example, the charging protocol includes but is not limited to PD2.0 / 3.0 / 3.1, BC1.2, QC / 2.0 / 3.0 / 4.0 / 5.0, Apple Fast Charge Protocol, MTK Fast Charge Protocol, Huawei FCP / SCP / SSCP, Fusion Fast Charge Protocol and Samsung Fast Charge Protocol. In this way, compared with the power supply circuit shown in Figure 10, a protocol conversion unit and a boost or buck circuit are set for each USB port, which effectively reduces the volume of the power supply circuit, improves the product yield, and reduces production costs.

[0073] To sum up, according to the power supply circuit of an embodiment of the present invention, the first switch control signal is transmitted to the switch tube of the primary circuit through the isolation module to control the switch tube of the primary circuit, thereby realizing direct control of the primary side by the secondary side, eliminating the PWM controller on the primary side, effectively reducing the volume of the power supply circuit, and at the same time eliminating the signal conversion process brought about by the optocoupler feedback, and having high timeliness.

[0074] In some embodiments, a charging device is also provided, comprising the aforementioned power supply circuit.

[0075] It should be noted that charging equipment includes but is not limited to adapters, socket strips, and energy storage systems.

[0076] According to the charging device of an embodiment of the present invention, through the aforementioned power supply circuit, the first switch control signal is transmitted to the switch tube of the primary circuit through the isolation module to control the switch tube of the primary circuit, thereby realizing direct control of the primary side by the secondary side, eliminating the PWM controller on the primary side, effectively reducing the volume of the power supply circuit, and at the same time eliminating the signal conversion process caused by the optocoupler feedback, with high timeliness.

[0077] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0078] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0080] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0081] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A power supply circuit, characterized in that: It includes: a transformer, a primary circuit connected to the primary winding of the transformer, a secondary circuit connected to the first secondary winding of the transformer, an isolation module and a control module, wherein the control module is connected to the secondary circuit and the transmitting end of the isolation module, and the receiving end of the isolation module is connected to the switch tube of the primary circuit, wherein the control module is used to generate a first switch control signal based on the output voltage of the secondary circuit, and transmit the signal to the switch tube of the primary circuit through the isolation module to perform switch control on the switch tube of the primary circuit.

2. The power supply circuit according to claim 1, characterized in that: The isolation module includes a wireless communication module or an optical communication module.

3. The power supply circuit according to claim 2, characterized in that: The optical communication module includes an infrared transceiver module or a millimeter wave transceiver module.

4. The power supply circuit according to claim 1, characterized in that: It also includes a self-excited soft start circuit, which is connected to the receiving end of the isolation module and the switch tube of the primary circuit, and is used to control the switch tube of the primary circuit to enable the power supply circuit to self-excite and soft start, and after the startup is completed, control the receiving end of the isolation module to be connected to the switch tube of the primary circuit.

5. The power supply circuit according to claim 4, characterized in that: The self-excited soft start circuit comprises: An oscillator circuit for generating a carrier signal; A comparison circuit, connected to the oscillation circuit, for comparing the carrier signal with the fundamental wave signal to generate a second switch control signal; A selection circuit is connected to the comparison circuit, the receiving end of the isolation module and the switch tube of the primary circuit, and is used to control the comparison circuit to be connected to the switch tube of the primary circuit when the power supply circuit is self-excited and soft-started, so as to control the switch tube of the primary circuit through a second switch control signal to soft-start the power supply circuit, and when the power supply circuit is started, control the receiving end of the isolation module to be connected to the switch tube of the primary circuit.

6. The power supply circuit according to claim 5, characterized in that: The self-excited soft start circuit also includes a first power supply circuit, which is connected to the primary circuit, the oscillation circuit, the comparison circuit and the selection circuit, and is used to supply power to the oscillation circuit, the comparison circuit and the selection circuit.

7. The power supply circuit according to claim 1, characterized in that: It also includes a second power supply circuit connected to the second secondary winding of the transformer, and the second power supply circuit is connected to the receiving end of the isolation module for supplying power to the receiving end of the isolation module; wherein the secondary circuit is also connected to the transmitting end of the isolation module for supplying power to the transmitting end of the isolation module.

8. The power supply circuit according to claim 1, characterized in that: The control module comprises: A sampling unit, the sampling unit is connected to the secondary circuit and is used to sample the output voltage of the secondary circuit; a control logic unit, the control logic unit being connected to the sampling unit and configured to generate the first switch control signal based on the output voltage of the secondary circuit; A feedback unit, wherein the feedback unit is connected to the control logic unit and the transmitting end of the isolation module and is used to provide a first switch control signal adapted to the isolation module.

9. The power supply circuit according to claim 8, characterized in that: The control module also includes: a control circuit, which is connected to the control logic unit and the switch tube of the secondary circuit, wherein the control logic unit is also used to generate a third switch control signal based on the output voltage of the secondary circuit, and the control circuit is used to control the switch tube of the secondary circuit based on the third switch control signal.

10. A charging device, characterized in that: The invention comprises a power supply circuit according to any one of claims 1 to 9.

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