Power supply circuit and power supply device
By introducing a forward winding to assist the power supply winding in the power supply circuit, the compatibility problem of traditional power supply structures under large voltage variation range is solved, and higher power supply reliability and stable power supply to the controller are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2026-03-24
Smart Images
Figure CN224037266U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of power supply, in particular to a power supply circuit and a power supply device. BACKGROUND
[0002] With the development of science and technology, various electrical equipment emerge in an endless stream. In order to use the electrical equipment to work normally, the electrical equipment needs to be charged. With the continuous updating of charging standards and technology, the fast charging power is getting larger and larger, and the voltage variation range of the fast charging output voltage is large.
[0003] The large voltage variation range output brings great challenges to the power supply of the controller. When the controller is powered by using a traditional power supply structure such as a flyback converter, the power supply voltage variation range is as wide as the output voltage variation range, and the controller is difficult to be compatible, resulting in low working reliability of the traditional power supply structure. CONTENT OF THE INVENTION
[0004] Therefore, it is necessary to provide a power supply circuit and a power supply device with high working reliability in view of the low working reliability of the traditional power supply structure.
[0005] In a first aspect, the present application provides a power supply circuit, comprising: a primary main winding, a secondary output winding, an auxiliary power supply winding, a first energy storage element, a second energy storage element, a third energy storage element and a switch tube.
[0006] A first end of the primary main winding is connected to a first end of the switch tube, a second end of the switch tube is connected to a second end of the first energy storage element and the ground, a control end of the switch tube is connected to a controller, a second end of the primary main winding is connected to a first end of the first energy storage element and a voltage input end, and the voltage input end is connected to an input voltage.
[0007] A first end of the secondary output winding is connected to a first end of the second energy storage element and a first output end, and a second end of the secondary output winding is connected to a second end of the second energy storage element and the ground.
[0008] A first end of the auxiliary power supply winding is connected to a second end of the third energy storage element and the ground, a second end of the auxiliary power supply winding is connected to a first end of the third energy storage element and a second output end, and the second output end is connected to the controller.
[0009] The auxiliary power supply winding is a forward winding, and the first end of the primary main winding, the first end of the secondary output winding and the first end of the auxiliary power supply winding are the same-named ends.
[0010] In one of the embodiments, the power supply circuit further comprises a first rectifying element and a second rectifying element.
[0011] The first end of the secondary side output winding is connected to the first end of the second energy storage element through the first rectifying element, and the second end of the auxiliary power supply winding is connected to the first end of the third energy storage element through the second rectifying element.
[0012] In one of the embodiments, the first rectifying element and the second rectifying element are both diodes.
[0013] In one of the embodiments, the first rectifying element is a first diode, and the second rectifying element is a second diode, the anode of the first diode is connected to the same end of the secondary side output winding, and the cathode of the first diode is connected to the first end of the second energy storage element and the first output end; the anode of the second diode is connected to the different end of the auxiliary power supply winding, and the cathode of the second diode is connected to the first end of the third energy storage element.
[0014] In one of the embodiments, the power supply circuit further comprises a power factor correction circuit, and the power factor correction circuit is connected to the voltage input end.
[0015] In one of the embodiments, the power supply circuit further comprises a voltage conversion circuit, and the voltage conversion circuit is connected to the second output end and the controller.
[0016] In one of the embodiments, the number of the auxiliary power supply windings is more than two, each auxiliary power supply winding is connected in series, and the number of the third energy storage elements is the same as the number of the auxiliary power supply windings.
[0017] The first end of one of the auxiliary power supply windings is connected to the second end of one of the third energy storage elements and grounded, and the second end of one of the auxiliary power supply windings is connected to the first end of the second energy storage element and the second output end.
[0018] In one of the embodiments, the primary side main winding, the secondary side output winding and the auxiliary power supply winding are wound on the same core.
[0019] In one of the embodiments, the first energy storage element, the second energy storage element and the third energy storage element are all capacitors.
[0020] In the second aspect, the application further provides a power supply device, comprising a controller and the power supply circuit of any one of the above embodiments.
[0021] The power supply circuit and the power supply device, comprising a primary main winding, a secondary output winding, an auxiliary power supply winding, a first energy storage component, a second energy storage component, a third energy storage component and a switch tube, the first end of the primary main winding is connected to the first end of the switch tube, the second end of the switch tube is connected to the second end of the first energy storage component and the ground; the control end of the switch tube is used for connecting the controller, the second end of the primary main winding is connected to the first end of the first energy storage component and the voltage input end, the voltage input end is connected to the input voltage; the first end of the secondary output winding is connected to the first end of the second energy storage component and the first output end; the second end of the secondary output winding is connected to the second end of the second energy storage component and the ground; the first end of the auxiliary power supply winding is connected to the second end of the third energy storage component and the ground; the second end of the auxiliary power supply winding is connected to the first end of the third energy storage component and the second output end, the second output end is connected to the controller; the auxiliary power supply winding is a forward winding, the first end of the primary main winding, the first end of the secondary output winding and the first end of the auxiliary power supply winding are the same end. Since the auxiliary power supply winding adopts the forward winding for power supply, the output voltage of the auxiliary power supply winding is irrelevant to the output voltage of the first output end and is relevant to the input voltage. When the output voltage of the first output end changes in a large range, the auxiliary power supply winding is only affected by the input voltage, the change range of the input voltage is small, therefore, the change range of the voltage of the second output end is also small, the voltage output by the second output end can directly supply power to the controller, the controller can be compatible, thereby improving the working reliability of the power supply circuit. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.
[0023] Figure 1 It is a structural schematic diagram of the power supply circuit in an embodiment;
[0024] Figure 2 It is a structural schematic diagram of the power supply circuit in another embodiment;
[0025] Figure 3 It is a structural schematic diagram of the power supply circuit in another embodiment;
[0026] Figure 4 It is a structural schematic diagram of the power supply circuit in another embodiment. DETAILED DESCRIPTION
[0027] For the purpose of understanding the present application, the present application will be described in more detail below with reference to the attached drawings. The embodiments of the present application are shown in the drawings. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.
[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0029] It should be understood that the terms "first", "second" and so on used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, a first resistor can be referred to as a second resistor, and similarly, a second resistor can be referred to as a first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.
[0030] It should be understood that "connection" in the following embodiments, if the circuits, modules, units and the like connected to each other have the transmission of electrical signals or data, should be understood as "electrically connected", "communicatively connected" and the like.
[0031] It should be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of the element" means part or all of the element.
[0032] As used herein, the singular forms "a", "an" and "the" can include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "comprise / comprising" or "have / having" specifies the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in the specification includes any and all combinations of the related listed items.
[0033] In one embodiment, a power supply circuit is provided, as Figure 1As shown, it comprises: a primary main winding Lp, a secondary output winding Ls, an auxiliary power winding Lf, a first energy storage element 102, a second energy storage element 104, a third energy storage element 106, and a switch tube Q1. The first end of the primary main winding Lp is connected to the first end of the switch tube Q1, the second end of the switch tube Q1 is connected to the second end of the first energy storage element 102 and grounded; the control end of the switch tube Q1 is used to connect the controller, the second end of the primary main winding Lp is connected to the first end of the first energy storage element 102 and the voltage input end, and the voltage input end is used to input the input voltage Vin; the first end of the secondary output winding Ls is connected to the first end of the second energy storage element 104 and the first output end; the second end of the secondary output winding Ls is connected to the second end of the second energy storage element 104 and grounded; the first end of the auxiliary power winding Lf is connected to the second end of the third energy storage element 106 and grounded; the second end of the auxiliary power winding Lf is connected to the first end of the third energy storage element 106 and the second output end, and the second output end is used to connect the controller; the auxiliary power winding Lf is a forward winding, and the first ends of the primary main winding Lp, the secondary output winding Ls and the auxiliary power winding Lf are the same name ends.
[0034] Wherein, the first end of the primary main winding Lp refers to Figure 1 the end of the primary main winding Lp marked with "*" in the figure, and the second end of the primary main winding Lp refers to Figure 1 the end of the primary main winding Lp not marked with "*" in the figure. The first end of the secondary output winding Ls refers to Figure 1 the end of the secondary output winding Ls marked with "*" in the figure, and the second end of the secondary output winding Ls refers to Figure 1 the end of the secondary output winding Ls not marked with "*" in the figure. The first end of the auxiliary power winding Lf refers to Figure 1 the end of the auxiliary power winding Lf marked with "*" in the figure, and the second end of the auxiliary power winding Lf refers to Figure 1 the end of the auxiliary power winding Lf not marked with "*" in the figure. The first ends of the primary main winding Lp, the secondary output winding Ls and the auxiliary power winding Lf are the same name ends, that is Figure 1 the ends marked with "*" in the primary main winding Lp, the secondary output winding Ls and the auxiliary power winding Lf are the same name ends. It can be understood that the second ends of the primary main winding Lp, the secondary output winding Ls and the auxiliary power winding Lf are also the same name ends, that is Figure 1 the ends not marked with "*" in the primary main winding Lp, the secondary output winding Ls and the auxiliary power winding Lf are the same name ends.
[0035] The first end of the primary main winding Lp is connected to the second end of the first energy storage device 102 through the switch tube Q1, the second end of the primary main winding Lp is connected to the first end of the first energy storage device 102, and the voltage input end is used to connect the input voltage Vin. The primary main winding Lp can be connected to the input voltage Vin through the voltage input end. The first energy storage device 102 can be connected to the input voltage to charge itself, and the charging circuit is voltage input end-first energy storage device 102-GND. The first energy storage device 102 can also release the stored electrical energy and discharge, and the discharging circuit is first energy storage device 102-voltage input end-primary main winding Lp-switch tube Q1-GND.
[0036] The first end of the switch tube Q1 is connected to the first end of the primary main winding Lp, the second end of the switch tube Q1 is connected to the second end of the first energy storage device 102, and the control end of the switch tube Q1 is connected to the controller. The controller can control the on-off state between the first end and the second end of the switch tube Q1 by sending different level signals to the control end of the switch tube Q1, thereby controlling the on-off state between the first end of the primary main winding Lp and the first energy storage device 102, to control the working state of the primary main winding Lp.
[0037] The first end of the secondary output winding Ls is connected to the first end of the second energy storage device 104 and the first output end, and the second end of the secondary output winding Ls is connected to the second end of the second energy storage device 104 and grounded. The current direction and magnetic flux direction of the secondary output winding Ls are opposite to those of the primary main winding Lp. When the current direction of the primary main winding Lp is from the voltage input end to the switch tube Q1, that is, from top to bottom, the upper end of the primary main winding Lp is positive and the lower end is negative, and the induced voltage of the secondary output winding Ls is positive at the lower end and negative at the upper end, and the current of the secondary output winding Ls flows out from the positive end and flows into the negative end, that is, the current direction of the secondary output winding Ls is from the second end of the secondary output winding Ls to the first end of the secondary output winding Ls, that is, from top to bottom. At this time, the second energy storage device 104 is in a discharging state, which is generally not allowed, so a related device can be arranged between the first end of the secondary output winding Ls and the first end of the second energy storage device 104 to block the current.
[0038] When the switch tube Q1 is turned off, the lower end of the primary main winding Lp will induce a voltage higher than the input voltage, which is coupled to the upper end of the secondary output winding Ls, and the energy stored in the second energy storage device 104 is output from the upper end of the secondary output winding Ls, and at the same time, the load is powered.
[0039] The primary main winding Lp, the secondary output winding Ls and the auxiliary power supply winding Lf are used to realize the function of the transformer. The auxiliary power supply winding Lf is a forward winding, the winding direction, the current direction and the magnetic flux direction of the auxiliary power supply winding Lf are the same as those of the primary main winding Lp, and the voltage Vf output by the second output end connected to the auxiliary power supply winding Lf is affected by the input voltage Vin input by the voltage input end connected to the primary main winding Lp. The voltage Vf output by the second output end connected to the auxiliary power supply winding Lf is used to supply power to the controller.
[0040] For example, taking the controller as an ACDC controller, as shown in the schematic diagram, the "*" on the transformer winding represents the winding homonymic end. As shown in the schematic diagram, the auxiliary power supply winding Lf is a forward winding. Since the auxiliary power supply winding Lf is a forward winding, the output voltage of the auxiliary power supply winding Lf is independent of the output voltage of the secondary output winding Ls and is related to the input voltage Vin. Figure 1
[0041] Suppose that the number of turns of the primary main winding Lp is Np, the input voltage is Vin, the number of turns of the auxiliary power supply winding Lf is Nf, and the output voltage of the auxiliary power supply winding Lf is Vf. Then the output voltage of the auxiliary power supply winding Lf is:
[0042] After the structure of the transformer is determined, The auxiliary power supply winding Lf voltage Vf is only related to the input voltage Vin. Generally, the input voltage Vin is an alternating rectified voltage. For full voltage input, the input alternating voltage ranges from 90VAC to 264VAC, and the voltage variation range is 2.93 times. The voltage fluctuation range after rectification is also 2.93 times, that is, the variation range of the input voltage Vin is 2.93 times. The variation range of the input voltage Vin is 2.93 times, so the variation range of the output voltage Vf of the auxiliary power supply winding Lf is also 2.93 times.
[0043] In the fast charging application scenario of 5V-48V, the output voltage Vout of the first output end changes by 9.6 times. In the embodiment, since the forward winding is used for power supply, when the output voltage Vout of the first output end changes in a large range, the variation range of the output voltage Vf of the forward auxiliary power supply winding Lf is only 2.93 times, which reduces the variation range and improves the efficiency.
[0044] The power supply circuit comprises a primary main winding Lp, a secondary output winding Ls, an auxiliary power supply winding Lf, a first energy storage element 102, a second energy storage element 104, a third energy storage element 106, and a switch tube Q1. A first end of the primary main winding Lp is connected to a first end of the switch tube Q1, a second end of the switch tube Q1 is connected to a second end of the first energy storage element 102 and grounded; a control end of the switch tube Q1 is used for connecting a controller; a second end of the primary main winding Lp is connected to a first end of the first energy storage element 102 and a voltage input end for inputting a voltage Vin; a first end of the secondary output winding Ls is connected to a first end of the second energy storage element 104 and a first output end; a second end of the secondary output winding Ls is connected to a second end of the second energy storage element 104 and grounded; a first end of the auxiliary power supply winding Lf is connected to a second end of the third energy storage element 106 and grounded; a second end of the auxiliary power supply winding Lf is connected to a first end of the third energy storage element 106 and a second output end for connecting the controller; the auxiliary power supply winding Lf is a forward winding, and the first end of the primary main winding Lp, the first end of the secondary output winding Ls and the first end of the auxiliary power supply winding Lf are homonymous ends. Since the auxiliary power supply winding Lf adopts the forward winding for power supply, the output voltage of the auxiliary power supply winding Lf is irrelevant to the output voltage of the first output end and is relevant to the input voltage Vin. When the output voltage of the first output end changes in a large range, the auxiliary power supply winding Lf is only affected by the input voltage Vin, the change range of the input voltage Vin is small, and thus the change range of the voltage of the second output end is also small. The voltage output by the second output end can directly supply power to the controller, and the controller is compatible, thereby improving the working reliability of the power supply circuit.
[0045] In an exemplary embodiment, the power supply circuit further comprises a first rectifier element and a second rectifier element; the first end of the secondary output winding Ls is connected to the first end of the second energy storage element 104 through the first rectifier element, and the second end of the auxiliary power supply winding Lf is connected to the first end of the third energy storage element 106 through the second rectifier element.
[0046] The first rectifier element can comprise a structure for limiting the current flow direction. The first end of the secondary output winding Ls is connected to the first end of the second energy storage element 104 through the first rectifier element. Correspondingly, the first rectifier element can limit the current flow direction to be from the first end of the secondary output winding Ls to the first end of the second energy storage element 104, but not from the first end of the second energy storage element 104 to the first end of the secondary output winding Ls. Thus, the second energy storage element 104 can be charged or the electrical energy stored in the second energy storage element 104 can be transmitted to the first output end through the first end of the second energy storage element 104 to output the voltage through the first output end when the current flow direction of the secondary input winding is different.
[0047] The second rectifying element can include a structure for limiting the current flow direction. The second end of the auxiliary power winding Lf is connected to the first end of the third energy storage element 106 through the second rectifying element. Correspondingly, the second rectifying element can limit the current flow direction to be from the second end of the auxiliary power winding Lf to the first end of the third energy storage element 106, but not from the first end of the third energy storage element 106 to the second end of the auxiliary power winding Lf. Thus, the third energy storage element 106 can be charged when the current flow direction of the auxiliary power winding Lf is different, and the electrical energy stored in the third energy storage element 106 can be transmitted to the second output end through the first end of the third energy storage element 106, and the voltage output through the second output end can be output to the controller to supply power to the controller. It can be understood that in other embodiments, the second rectifying element can also include a structure for limiting the current size, which is not limited herein.
[0048] In the embodiment, the power supply circuit further includes a first rectifying element and a second rectifying element. The first end of the secondary output winding Ls is connected to the first end of the second energy storage element 104 through the first rectifying element, and the second end of the auxiliary power winding Lf is connected to the first end of the third energy storage element 106 through the second rectifying element. The first rectifying element and the second rectifying element can limit the current, which is beneficial to improve the working performance of the power supply circuit.
[0049] The types of the first rectifying element and the second rectifying element are not unique. In an exemplary embodiment, the first rectifying element and the second rectifying element are both diodes. Through the unidirectional conductivity of the diodes, the current flow direction can be limited, which is beneficial to the normal working of the power supply circuit. Moreover, the diodes have low cost and high working reliability.
[0050] In an exemplary embodiment, as shown in Figure 2 the first rectifying element is a first diode D1, and the second rectifying element is a second diode D2. The first end of the secondary output winding Ls is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the first end of the second energy storage element 104 and the first output end. The first diode D1 can limit the current flow direction to be from the first end of the secondary output winding Ls to the first end of the second energy storage element 104, but not from the first end of the second energy storage element 104 to the first end of the secondary output winding Ls. Thus, the second energy storage element 104 can be charged when the current flow direction of the secondary input winding is different, or the electrical energy stored in the second energy storage element 104 can be transmitted to the first output end through the first end of the second energy storage element 104, and the voltage output through the first output end can be output.
[0051] The second end of the auxiliary power winding Lf is connected to the anode of the second diode D2, and the cathode of the second diode D2 is connected to the first end of the third energy storage component 106. The second diode D2 can limit the current flow to be from the second end of the auxiliary power winding Lf to the first end of the third energy storage component 106, but not from the first end of the third energy storage component 106 to the second end of the auxiliary power winding Lf. Thus, the third energy storage component 106 can be charged when the current flow of the auxiliary power winding Lf is different, and the electric energy stored in the third energy storage component 106 can be transmitted to the second output end through the first end of the third energy storage component 106, and the voltage output through the second output end can be output to the controller to supply power to the controller.
[0052] It can be understood that in other embodiments, the first rectifying element and the second rectifying element can also be MOS tubes or other devices with controllable unidirectional conduction. Generally, the rectifying device connected to the secondary side output winding Ls uses MOS tube synchronous rectification control, which can improve the efficiency; the rectifying device connected to the auxiliary power winding Lf uses diode, which is simple in structure and saves cost.
[0053] In the embodiment, the first rectifying element and the second rectifying element are both diodes. Through the unidirectional conduction of the diodes, the current flow can be limited, which is beneficial to the normal operation of the power supply circuit. Moreover, the diodes are low in cost and high in working reliability.
[0054] In an exemplary embodiment, the power supply circuit further comprises a power factor correction circuit connected to the voltage input end. Alternatively, the power factor correction circuit is connected between the voltage input end and the first end of the first energy storage component.
[0055] When the power factor correction circuit is connected to the voltage input end, the input voltage Vin input by the voltage input end can be stabilized within a certain voltage range. The structure of the power factor correction circuit is not limited, for example, it can comprise a rectifier bridge, a Boost converter (or other DC-DC switching converter) and a corresponding control circuit. The rectifier bridge is used to convert the input alternating current into direct current. The Boost converter is used to convert the direct current output by the rectifier bridge into a pulse quantity smaller and stable bus direct current voltage under the control of a certain duty cycle, and at the same time, the input inductance current presents a sinusoidal current consistent with the input voltage Vin waveform. The control circuit is used to control the operation of the Boost converter, so that it can realize the function of power factor correction. The power factor correction circuit can improve the input current harmonics, improve the power factor, and also stabilize the voltage to a certain extent. It should be understood that in some embodiments, the power supply circuit can not include a power factor correction circuit, for example, when the power supply circuit is used for low-power applications, the power factor correction circuit can not be included.
[0056] In the embodiment, the power supply circuit further comprises a power factor correction circuit connected to the voltage input end, and the input voltage Vin inputted by the voltage input end can be stabilized within a certain voltage range. Since the voltage outputted by the second output end connected to the auxiliary power supply winding Lf is affected by the input voltage Vin, the voltage outputted by the second output end can be more stable and the variation range can be smaller after the input voltage Vin is stabilized by the power factor correction circuit, and the controller can be better powered.
[0057] In an exemplary embodiment, as shown in Figure 3 the power supply circuit further comprises a voltage conversion circuit 202 connected to the second output end and the controller. The voltage conversion circuit 202 can convert the voltage outputted by the second output end and then power the controller, so as to better meet the power supply requirements of the controller. It should be understood that in some embodiments, the power supply circuit can not comprise the voltage conversion circuit 202.
[0058] The structure of the voltage conversion circuit 202 is not unique, for example, it can be a boost circuit, a buck circuit or a buck-boost circuit, etc., which can be determined according to actual requirements.
[0059] In the embodiment, the power supply circuit further comprises a voltage conversion circuit 202 connected to the second output end and the controller. The voltage conversion circuit 202 can convert the voltage outputted by the second output end and then power the controller, so as to better meet the power supply requirements of the controller. It should be understood that in some embodiments, the power supply circuit can not comprise the voltage conversion circuit 202.
[0060] In addition, the number of auxiliary power supply windings Lf and third energy storage elements 106 is not unique. In an exemplary embodiment, as shown in Figure 4 the number of auxiliary power supply windings Lf is more than two (the number in the figure is two, which are Lf1 and Lf2), each auxiliary power supply winding Lf is connected in series, and the number of third energy storage elements 106 is the same as the number of auxiliary power supply windings Lf (the third energy storage elements 106 in Figure 4 comprise a capacitor C2 and a capacitor C4). The first end of an auxiliary power supply winding Lf is connected to the second end of a third energy storage element 106 and grounded, and the second end of an auxiliary power supply winding Lf is connected to the first end of a second energy storage element 104 and the second output end.
[0061] The number of the third energy storage elements 106 is the same as the number of the auxiliary power supply windings Lf, one third energy storage element 106 corresponds to one auxiliary power supply winding Lf, and one auxiliary power supply structure is formed. The power supply circuit can include one or more auxiliary power supply structures. In one auxiliary power supply structure, the first end of the auxiliary power supply winding Lf is connected to the second end of one third energy storage element 106 and grounded, and the second end of the auxiliary power supply winding Lf is connected to the first end of one second energy storage element 104 and one second output terminal.
[0062] The auxiliary power supply windings Lf are connected in series, and each auxiliary power supply winding Lf is a forward winding. The auxiliary power supply windings Lf have the same winding direction and connection mode. In addition, the second end of each auxiliary power supply winding Lf and the first end of each second energy storage element 104 are connected to one second output terminal, or the number of the second output terminals is more than one, and the second end of each auxiliary power supply winding Lf and the first end of each second energy storage element 104 are connected to one second output terminal respectively.
[0063] When the number of the auxiliary power supply windings Lf is more than two and each auxiliary power supply winding Lf is connected to one third energy storage element 106, the number of the auxiliary power supply windings Lf put into work can be adjusted to adjust the output voltage of the second output terminal, so as to adjust the voltage supplied to the controller, and the controller receives the voltage meeting the demand.
[0064] In an optional embodiment, when the power supply circuit includes a second rectifying element and the number of the auxiliary power supply windings Lf is two, the number of the second rectifying elements is the same as the number of the auxiliary power supply windings Lf, one second rectifying element corresponds to one auxiliary power supply winding Lf and one third energy storage element, and one standby power supply structure is formed. The power supply circuit can include one or more standby power supply structures. Figure 4 In the embodiment, the second rectifying element includes a second diode D2 and a third diode D3. In one standby power supply structure, the anode of the second rectifying element is connected to the second end of the auxiliary power supply winding Lf, and the cathode of the second rectifying element is connected to the first end of the third energy storage element 104 and one second output terminal.
[0065] In the embodiment, the number of the auxiliary power supply windings Lf is more than two, the auxiliary power supply windings Lf are connected in series, and the number of the third energy storage elements 106 is the same as the number of the auxiliary power supply windings Lf. The first end of one auxiliary power supply winding Lf is connected to the second end of one third energy storage element 106 and grounded, and the second end of one auxiliary power supply winding Lf is connected to the first end of one second energy storage element 104 and one second output terminal. Thus, the voltage output to the controller can be adjusted more finely, which is beneficial to improve the working performance of the controller.
[0066] Further, in an exemplary embodiment, as shown inFigure 4 As shown, the power supply circuit further comprises a voltage switching circuit 204 connected to the second output terminals and the controller. The voltage switching circuit 204 can be directly connected to the controller or connected to the controller through a voltage conversion circuit.
[0067] When the number of the second output terminals is plural, one voltage output terminal is connected to the first end of one third energy storage component 106 and the second end of one auxiliary power supply winding Lf, and each second output terminal is connected to the voltage switching circuit 204. The voltage switching circuit 204 can control the number of the second output terminals in conduction to adjust the number of the auxiliary power supply windings Lf in operation. When the number of the second output terminals is plural, the second output terminals are connected to the voltage switching circuit 204, and the voltage switching circuit 204 can control the number of the third energy storage components 106 and the auxiliary power supply windings Lf in conduction with the second output terminals, so as to adjust the number of the auxiliary power supply windings Lf in operation. The structure of the voltage switching circuit 204 is not limited, and exemplarily, the voltage switching circuit 204 can comprise a plurality of switches, one switch corresponding to one second output terminal, or the voltage switching circuit 204 can comprise one switch, the contact of the switch being connected to the second output terminals, etc., which can be determined according to actual requirements.
[0068] In the embodiment, the power supply circuit further comprises a voltage switching circuit 204 connected to the second output terminals and the controller. The voltage switching circuit 204 can switch the second output terminals in conduction with the controller, so as to adjust the number of the auxiliary power supply windings Lf in operation and realize the rapid adjustment of the supply voltage of the controller.
[0069] In an exemplary embodiment, the primary main winding Lp, the secondary output winding Ls and the auxiliary power supply winding Lf are wound on the same core. In the case that the primary main winding Lp, the secondary output winding Ls and the auxiliary power supply winding Lf are wound on the same core, the electromagnetic interference can be reduced, the energy transmission efficiency can be improved, the space can be saved, and the performance of the power supply circuit can be improved.
[0070] In addition, the types of the first energy storage component 102, the second energy storage component 104 and the third energy storage component 106 are not unique, and in an exemplary embodiment, the first energy storage component 102, the second energy storage component 104 and the third energy storage component 106 are all capacitors. Specifically, as shown in the embodiment, Figure 2 In the embodiment, the first energy storage component 102 is a capacitor C1, the second energy storage component 104 is a capacitor C3, and the third energy storage component 106 is a capacitor C2. The advantages of the capacitor as an energy storage element mainly include fast charging and discharging speed, long service life, low maintenance cost, environmental protection and applicability to various application occasions. It can be understood that in other embodiments, the types of the first energy storage component 102, the second energy storage component 104 and the third energy storage component 106 can also be other types, for example, including inductors or other elements, etc., which can be determined according to actual requirements.
[0071] The embodiment of the present application also provides a power supply device, comprising a controller and the power supply circuit of any of the above embodiments. Specifically, the controller is connected to the second output end of the power supply circuit and the control end of the switch tube Q1, and is used for working according to the voltage output by the second output end, and is also used for controlling the on-off state of the switch tube Q1. The type of the controller is not limited, for example, it can be an ACDC (alternating current to direct current) controller.
[0072] In order to better understand the above embodiments, the following will be explained in detail in combination with specific embodiments. In one embodiment, as shown in Figures 1-4 The power supply circuit comprises a primary main winding Lp, a secondary output winding Ls, an auxiliary power supply winding Lf, a first energy storage element 102, a second energy storage element 104, a third energy storage element 106, a switch tube Q1, a first rectifier element and a second rectifier element. The first rectifier element is a first diode D1, and the second rectifier element is a second diode D2. The first energy storage element 102, the second energy storage element 104 and the third energy storage element 106 are all capacitors. The first energy storage element 102 is a capacitor C1, the second energy storage element 104 is a capacitor C3, and the third energy storage element 106 is a capacitor C2 and C4.
[0073] As shown in Figures 2-4 The "*" on the transformer winding indicates the same name end of the winding, and the auxiliary power supply winding Lf is a forward winding, which is used for supplying power to the controller. The controller is an ACDC controller.
[0074] In the PD (Power Delivery, power delivery) fast charging application scenario of 5V-48V, the charging power is greater than 75W, and the power supply circuit can further comprise a power factor correction circuit. The power factor correction circuit can stabilize the input voltage Vin at about 390V. Since the auxiliary power supply winding Lf is a forward winding, the output voltage of the auxiliary power supply winding Lf is irrelevant to the secondary output voltage, and is relevant to the input voltage Vin.
[0075] Suppose that the number of turns of the Lp winding is Np, and the input voltage is Vin; the number of turns of the auxiliary power supply winding Lf is Nf, and the output voltage of the auxiliary power supply winding Lf is Vf. Then the output voltage of the auxiliary power supply winding Lf is:
[0076] After the transformer is determined, The input voltage Vin is stabilized by the power factor correction circuit, so the voltage Vf of the auxiliary power supply winding Lf basically does not change.
[0077] As can be seen from the above, in the PD fast charging application scenario of 5V-48V, the Vout output voltage changes by 9.6 times. Since the forward winding is used for power supply, when the output voltage Vout changes in a large range, the forward winding auxiliary power supply Vf does not change, which can directly power the ACDC controller. The auxiliary power supply winding Lf can save the voltage conversion link, save cost, reduce size, and increase efficiency.
[0078] Even if the input does not have a power factor correction circuit, the input voltage Vin is not fixed, such as an application scenario of direct rectification of alternating current, the auxiliary power supply winding Lf uses the forward winding of the embodiment, which still has advantages:
[0079] Assuming that the input does not have a power factor correction circuit, the input voltage Vin is an alternating current rectified voltage, for full voltage input, the input alternating voltage range is 90VAC-264VAC, and the voltage change range is 2.93 times. The voltage fluctuation range after rectification is also 2.93 times, that is, the change range of the input voltage Vin is 2.93 times.
[0080] The auxiliary power supply mode using the forward winding is as follows:
[0081] Assuming that the Lp winding has Np turns, the input voltage Vin is Vin; the auxiliary power supply winding Lf has Nf turns, and the output voltage of the auxiliary power supply winding Lf is Vf, then the output voltage of the auxiliary power supply winding Lf is:
[0082] After the transformer is determined, The output voltage Vf of the auxiliary power supply winding Lf is fixed and only related to the input voltage Vin, and the change range of the input voltage Vin is 2.93 times, so the change range of the output voltage Vf of the auxiliary power supply winding Lf is also 2.93 times.
[0083] As can be seen from the above, in the PD fast charging application scenario of 5V-48V, the Vout output voltage changes by 9.6 times. Since the forward winding is used for power supply, when the output voltage Vout changes in a large range, the change range of the output voltage Vf of the auxiliary power supply winding Lf is only 2.93 times, which can reduce the voltage change range without double winding power supply and voltage conversion circuit, thereby reducing the complexity of the transformer and circuit, saving cost, and improving efficiency. It can be understood that in other embodiments, the power supply circuit can also set a voltage conversion circuit or multiple auxiliary power supply windings Lf according to actual needs to meet different working scene requirements. The flyback converter of the embodiment uses the forward winding auxiliary power supply scheme, which greatly reduces the auxiliary power supply voltage change range. In addition, the flyback converter of the embodiment is not limited to the PD fast charging application, nor is it limited to 5V-48V output. It is applicable to all wide voltage output application scenarios.
[0084] The power supply circuit provided by the embodiment can directly supply power to the ACDC controller without voltage conversion, without double winding, and without special treatment of the auxiliary power winding Lf, thereby saving the number of components, reducing the size, saving the cost, and improving the overall efficiency.
[0085] In addition, in the wide voltage output application scenario, when the input does not have a power factor correction circuit, the auxiliary power winding Lf can be directly supplied with power without voltage conversion circuit, thereby achieving the effect of double flyback winding power supply, greatly reducing the variation range of the auxiliary power supply voltage, saving the components of the voltage conversion part, being conducive to reducing the size, saving the cost, and improving the overall efficiency.
[0086] In the description of the specification, the description of the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.
[0087] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description simple, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.
[0088] The above-described embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.
Claims
1. A power supply circuit, characterized in that, include: Primary winding, secondary output winding, auxiliary power supply winding, first energy storage device, second energy storage device, third energy storage device, and switching transistor; The first end of the primary winding is connected to the first end of the switching transistor, and the second end of the switching transistor is connected to the second end of the first energy storage device and ground; the control end of the switching transistor is connected to the controller, and the second end of the primary winding is connected to the first end of the first energy storage device and the voltage input end, and the voltage input end is connected to the input voltage; The first end of the secondary output winding is connected to the first end and the first output end of the second energy storage device; the second end of the secondary output winding is connected to the second end of the second energy storage device and ground. The first end of the auxiliary power supply winding is connected to the second end of the third energy storage device and ground; the second end of the auxiliary power supply winding is connected to the first end and the second output end of the third energy storage device, and the second output end is connected to the controller; The auxiliary power supply winding is a forward winding, and the first end of the primary winding, the first end of the secondary output winding, and the first end of the auxiliary power supply winding are the same name ends.
2. The power supply circuit according to claim 1, characterized in that, It also includes a first rectifier element and a second rectifier element; The first end of the secondary output winding is connected to the first end of the second energy storage device through the first rectifier element, and the second end of the auxiliary power supply winding is connected to the first end of the third energy storage device through the second rectifier element.
3. The power supply circuit according to claim 2, characterized in that, Both the first rectifier element and the second rectifier element are diodes.
4. The power supply circuit according to claim 3, characterized in that, The first rectifier element is a first diode, and the second rectifier element is a second diode. The anode of the first diode is connected to the same-name terminal of the secondary output winding, and the cathode of the first diode is connected to the first terminal and the first output terminal of the second energy storage device. The anode of the second diode is connected to the opposite-name terminal of the auxiliary power supply winding, and the cathode of the second diode is connected to the first terminal of the third energy storage device.
5. The power supply circuit according to claim 1, characterized in that, It also includes a power factor correction circuit, which is connected to the voltage input terminal.
6. The power supply circuit according to claim 1, characterized in that, It also includes a voltage conversion circuit, which is connected to the second output terminal and the controller.
7. The power supply circuit according to claim 1, characterized in that, The number of auxiliary power supply windings is two or more, and the auxiliary power supply windings are connected in series. The number of third energy storage devices is the same as the number of auxiliary power supply windings.
8. The power supply circuit according to any one of claims 1-7, characterized in that, The primary winding, the secondary output winding, and the auxiliary power supply winding are wound on the same iron core.
9. The power supply circuit according to any one of claims 1-7, characterized in that, The first energy storage device, the second energy storage device, and the third energy storage device are all capacitors.
10. A power supply device, characterized in that, Includes a controller and a power supply circuit as described in any one of claims 1-9.