Power supply circuit of control chip and main control circuit

Abstract

The utility model discloses a power supply circuit of a control chip and a main control circuit, and in the power supply circuit, an input circuit is connected with a first winding of a transformer and the control chip. The charging circuit is connected with the second winding of the transformer and is connected with the control chip. Wherein the first capacitor and the second capacitor of the charging circuit are respectively connected with the second winding in parallel, the input circuit charges the first capacitor and the second capacitor through the first winding and the second winding, and then the first capacitor or the second capacitor supplies power to the control chip. The first capacitor and the second capacitor are connected with the second winding in parallel, the first capacitor or the second capacitor is charged based on different output signals of the control chip, the number of windings of the transformer does not need to be additionally increased, and the component cost consumed by the power supply circuit is saved under the condition that it is guaranteed that the power supply circuit normally supplies power to the control chip; the size of the power supply circuit is reduced, reliability of the power supply circuit is improved, and user experience of the power supply circuit is improved.

Description

Technical Field

[0001] The present application relates to the field of power charging technology, and in particular to a power supply circuit and a main control circuit of a control chip. Background Art

[0002] In the constant current charging application condition of the flyback topology power supply, once the output charging voltage is clamped very low by the charging device, the self-supply winding cannot provide normal operating voltage to the main control PWM (Pulse Width Modulation) chip, causing the power supply to malfunction.

[0003] At present, the commonly used solution in the industry is to add other unit circuits in the circuit to power the main control PWM chip, or to add an additional forward winding in the transformer to ensure the normal power supply of the self-powered winding. However, this method uses more and more complex components, has a high cost, a large circuit size, low reliability, and is easily affected by the external environment. Utility Model Content

[0004] The present application provides a power supply circuit for a control chip to solve the above technical problems. The power supply circuit includes:

[0005] A transformer, comprising a first winding and a second winding arranged on the same side;

[0006] An input circuit connected to the first winding, wherein the control chip is connected to the input circuit and is used to control the input circuit;

[0007] a charging circuit connected to the second winding, and the charging circuit is connected to the control chip, and is used to supply power to the control chip;

[0008] The charging circuit includes a first capacitor, a second capacitor, a first diode and a second diode. The first capacitor and the second capacitor are respectively connected in parallel with the second winding, and the first capacitor is connected to the second winding through the first diode, and the second capacitor is connected to the second winding through the second diode. The input circuit charges the first capacitor or the second capacitor through the cooperation of the first winding and the second winding to power the control chip.

[0009] The polarity of one end where the first diode is connected to the second winding is the same as the polarity of one end where the second diode is connected to the second winding.

[0010] The output end of the first diode is connected to the first end of the first capacitor, the input end of the first diode is connected to the first end of the second winding, and the second end of the first capacitor is connected to the second end of the second winding;

[0011] The output end of the second diode is connected to the input end of the first diode, the input end of the second diode is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the second end of the first capacitor;

[0012] The first end of the first capacitor is connected to the input end of the control chip, and the first capacitor and the second capacitor provide power for the control chip.

[0013] The input circuit includes a first switch tube, a third capacitor and a first power supply, wherein:

[0014] The first input end of the first switch tube is connected to the output end of the control chip, the second input end of the first switch tube is connected to the first end of the first winding, and the output end of the first switch tube is grounded;

[0015] The first power source is connected to the second end of the first winding;

[0016] A first end of the third capacitor is connected to the first power supply, and a second end of the third capacitor is grounded.

[0017] Wherein, the power supply circuit further includes a rectifier circuit, the transformer further includes a third winding, the third winding is arranged on the opposite side of the first winding, the rectifier circuit is connected to the third winding, wherein,

[0018] The rectifier circuit includes a third diode, a second power supply and a fourth capacitor, the output end of the third diode is connected to the second power supply, the input end of the third diode is connected to the first end of the third winding, the first end of the fourth capacitor is connected to the second power supply, the second end of the fourth capacitor is connected to the second end of the third winding, and the second end of the fourth capacitor is grounded.

[0019] The amount of electricity after the first capacitor is charged is proportional to the output voltage of the second power supply and the number of coils of the second winding, and inversely proportional to the number of coils of the third winding;

[0020] The amount of electricity of the second capacitor after being charged is directly proportional to the output voltage of the first power supply and the number of coils of the second winding, and inversely proportional to the number of coils of the first winding.

[0021] Wherein, the charging circuit also includes a voltage stabilizing circuit, the first end of the first capacitor is connected to the first end of the voltage stabilizing circuit, the second end of the voltage stabilizing circuit is connected to the input end of the control chip, and the voltage stabilizing circuit is used to stabilize the voltage output by the first capacitor and the second capacitor.

[0022] Wherein, the voltage stabilizing circuit includes a first resistor, a second resistor, a voltage stabilizing diode, a second switch tube and a fifth capacitor; Wherein,

[0023] The first end of the first resistor is connected to the first end of the first capacitor, and the second end of the first resistor is connected to the first input end of the second switch tube;

[0024] The first end of the second resistor is connected to the first input end of the second switch tube, and the second end of the second resistor is connected to the second input end of the second switch tube;

[0025] The input end of the voltage stabilizing diode is connected to the first end of the second capacitor, and the output end of the voltage stabilizing diode is connected to the second input end of the second switch tube;

[0026] The output end of the second switch tube is connected to the input end of the control chip;

[0027] A first end of the fifth capacitor is connected to the output end of the second switch tube, a second end of the fifth capacitor is connected to the input end of the voltage stabilizing diode, and a second end of the fifth capacitor is grounded.

[0028] Wherein, the input circuit includes a third switch tube, a fourth switch tube, a first power supply, a first inductor and a sixth capacitor; wherein,

[0029] The first input end of the third switch tube is connected to the output end of the control chip, the second input end of the third switch tube is connected to the first power supply, the output end of the third switch tube is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the first winding, the first end of the sixth capacitor is connected to the second end of the first winding, and the second end of the sixth capacitor is grounded;

[0030] The first input end of the fourth switch tube is connected to the output end of the control chip, the second input end of the fourth switch tube is connected to the first end of the first inductor, and the output end of the fourth switch tube is connected to the second end of the sixth capacitor.

[0031] Wherein, the power supply circuit further includes a rectifier circuit, the transformer further includes a third winding and a fourth winding arranged on the same side, the third winding and the fourth winding are arranged on the opposite side of the first winding, and the rectifier circuit is connected to the third winding and the fourth winding, wherein,

[0032] The rectifier circuit includes a fourth diode, a fifth diode, a second power supply and a fourth capacitor.

[0033] The input end of the fourth diode is connected to the first end of the third winding, the output end of the fourth diode is connected to the first end of the fourth capacitor, the second end of the third winding is connected to the second end of the fourth capacitor, the first end of the fourth capacitor is connected to the second power supply, and the second end of the fourth capacitor is grounded;

[0034] An input end of the fifth diode is connected to a first end of the fourth winding, an output end of the fifth diode is connected to a first end of the fourth capacitor, and a second end of the fourth winding is connected to a second end of the third winding.

[0035] In order to solve the above-mentioned technical problems, the present application also provides a main control circuit, comprising a power supply circuit and a control chip as described above, wherein the power supply circuit is connected to the output end and the input end of the control chip, and the power supply circuit receives a signal from the output end of the control chip to charge a first capacitor and a second capacitor in the power supply circuit, and the first capacitor and the second capacitor power the control chip through the input end of the control chip.

[0036] Beneficial effects of the present application: Different from the prior art, the power supply circuit of the present application includes a transformer, an input circuit and a charging circuit. The transformer includes a first winding and a second winding arranged on the same side, the input circuit is connected to the first winding, and the control chip is connected to the input circuit for controlling the input circuit. The charging circuit is connected to the second winding, and the charging circuit is connected to the control chip for powering the control chip. Among them, the charging circuit includes a first capacitor, a second capacitor, a first diode and a second diode, the first capacitor and the second capacitor are respectively connected in parallel with the second winding, the first capacitor is connected to the second winding through the first diode, and the second capacitor is connected to the second winding through the second diode, and the polarity of one end connected to the first diode and the second winding is the same as the polarity of one end connected to the second diode and the second winding, the input circuit charges the first capacitor or the second capacitor through the cooperation of the first winding and the second winding, and then the first capacitor and the second capacitor power the control chip. By connecting the first capacitor and the second capacitor in parallel with the second winding, the first capacitor or the second capacitor is charged without increasing the number of windings of the transformer. While ensuring that the power supply circuit normally supplies power to the control chip, the cost of components consumed by the power supply circuit is saved, the size of the power supply circuit is reduced, the reliability of the power supply circuit is improved, and the user experience of the power supply circuit is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] in:

[0039] Figure 1 It is a structural schematic diagram of the first embodiment of the power supply circuit of the present application;

[0040] Figure 2 is a structural schematic diagram of a second embodiment of the power supply circuit of the present application;

[0041] Figure 3 yes Figure 2 A partial structural diagram of a first embodiment of a power supply circuit;

[0042] Figure 4 yes Figure 2 A partial structural diagram of a second embodiment of a power supply circuit;

[0043] Figure 5 yes Figure 2 A partial structural diagram of a third embodiment of a power supply circuit.

[0044] Figure symbols: power supply circuit 1; transformer T1; first winding S1; second winding S2; third winding S3; fourth winding S4; input circuit 11; first switch tube Q1; third switch tube Q3; fourth switch tube Q4; third capacitor C3; sixth capacitor C6; first power supply Vbus; first inductor L1; charging circuit 12; first capacitor C1; second capacitor C2; first diode D1; second diode D2; voltage regulator circuit 121; first resistor R1; second resistor R2; voltage regulator diode ZD; second switch tube Q2; fifth capacitor C5; rectifier circuit 13; third diode D3; fourth diode D4; fifth diode D5; second power supply Vout; fourth capacitor C4. DETAILED DESCRIPTION

[0045] The scheme of the embodiment of the present application is described in detail below in conjunction with the drawings of the specification.

[0046] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0047] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the objects associated before and after are in an "or" relationship. In addition, "many" in this article means two or more than two. In addition, the term "at least one" in this article means any combination of at least two of any one or more of a plurality of, for example, including at least one of A, B, and C, and can mean including any one or more elements selected from the set consisting of A, B, and C. In addition, the terms "first", "second", and "third" in this application are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0049] See also Figure 1 , Figure 1 The power supply circuit provided in the embodiment of the present application is used to supply power to a control chip, and includes a transformer T1 , an input circuit 11 and a charging circuit 12 .

[0050] Among them, the transformer T1 includes a first winding S1 and a second winding S2 arranged on the same side; the input circuit 11 is connected to the first winding S1, and the control chip is connected to the input circuit 11 for controlling the input circuit 11; the charging circuit 12 is connected to the second winding S2, and the charging circuit 12 is connected to the control chip for powering the control chip.

[0051] The charging circuit 12 includes a first capacitor C1, a second capacitor C2, a first diode D1 and a second diode D2. The first capacitor C1 and the second capacitor C2 are respectively connected in parallel with the second winding S2, and the first capacitor C1 is connected to the second winding S2 through the first diode D1, and the second capacitor C2 is connected to the second winding S2 through the second diode D2. The input circuit 11 charges the first capacitor C1 or the second capacitor C2 through the cooperation of the first winding S1 and the second winding S2 to power the control chip.

[0052] The polarity of one end of the first diode D1 connected to the second winding S2 is the same as the polarity of one end of the second diode D2 connected to the second winding S2. For example, the input end of the first diode D1 is connected to the second winding S2, and the input end of the second diode D2 is connected to the second winding S2; or the output end of the first diode D1 is connected to the second winding S2, and the output end of the second diode D2 is connected to the second winding S2.

[0053] Specifically, the control chip controls the current flow direction of the input circuit 11, controls the current flow direction of the first winding S1, and the current flow in the first winding S1 generates a magnetic flux, so that a current is generated on the second winding S2. Since the first capacitor C1 is connected to the second winding S2 through the first diode D1, and the second capacitor C2 is connected to the second winding S2 through the second diode D2, and the polarity of one end where the first diode D1 and the second winding S2 are connected is the same as the polarity of one end where the second diode D2 and the second winding S2 are connected, according to the current flow direction on the second winding S2, the current flows through the branch where the first capacitor C1 exists or the branch where the second capacitor C2 exists, and the first capacitor C1 or the second capacitor C2 is charged, so that the first capacitor C1 and the second capacitor C2 have enough electricity to power the control chip. When the current flow direction of the first winding S1 changes, the charging circuit 12 can still charge the first capacitor C1 or the second capacitor C2, thereby improving the charging efficiency of the charging circuit 12, ensuring that the first capacitor C1 and the second capacitor C2 have enough electricity to power the control chip, and providing the reliability of the power supply circuit.

[0054] In one embodiment, the output end of the first diode D1 is connected to the first end of the first capacitor C1, the input end of the first diode D1 is connected to the first end of the second winding S2, and the second end of the first capacitor C1 is connected to the second end of the second winding S2. The output end of the second diode D2 is connected to the input end of the first diode D1, the input end of the second diode D2 is connected to the first end of the second capacitor C2, and the second end of the second capacitor C2 is connected to the second end of the first capacitor C1. In addition, the first end of the first capacitor C1 is connected to the input end of the control chip, and then the first capacitor C1 and the second capacitor C2 provide power for the control chip.

[0055] Optionally, the input circuit 11 includes a first switch tube Q1 , a third capacitor C3 and a first power supply Vbus.

[0056] The first input end of the first switch tube Q1 is connected to the output end of the control chip, the second input end of the first switch tube Q1 is connected to the first end of the first winding S1, and the output end of the first switch tube is grounded. The first power supply Vbus is connected to the second end of the first winding S1. The first end of the third capacitor C3 is connected to the first power supply Vbus, and the second end of the third capacitor C3 is grounded.

[0057] Furthermore, the power supply circuit 1 further includes a rectifier circuit 13, and the transformer T1 further includes a third winding S3, the third winding S3 and the first winding S1 are arranged on opposite sides, and the rectifier circuit 13 is connected to the third winding S3.

[0058] Among them, the rectifier circuit 13 includes a third diode D3, a second power supply Vout and a fourth capacitor C4, the output end of the third diode D3 is connected to the second power supply Vout, the input end of the third diode D3 is connected to the first end of the third winding S3, the first end of the fourth capacitor C4 is connected to the second power supply Vout, the second end of the fourth capacitor C4 is connected to the second end of the third winding S3, and the second end of the fourth capacitor C4 is grounded.

[0059] The following briefly describes the process of the input circuit 11, the charging circuit 12 and the rectifier circuit 13 cooperating to charge the first capacitor C1 and the second capacitor C2:

[0060] like Figure 1 As shown, one end of the first winding S1, the second winding S2 and the third winding S3 is marked with a black dot, indicating that the end is the same-name end of the first winding S1, the second winding S2 and the third winding S3. When current is passed through the two mutually inductive windings and the directions of the generated magnetic flux are the same, the current inflow ends of the two windings are called the same-name ends (also called the same-polarity ends).

[0061] The output end of the control chip outputs a pulse signal to the first switch tube Q1. When the pulse signal is at a high level, the first switch tube Q1 is turned on. At this time, the first power supply Vbus outputs current, and a current loop of "first power supply Vbus-first end of the first winding S1-second end of the first winding S1-first switch tube Q1-ground GND" is formed in the input circuit 11. Among them, the third capacitor C3 plays a filtering role to ensure the stability of the current loop in the input circuit 11 and improve the reliability of the power supply circuit 1.

[0062] In the charging circuit 12, the first end of the second winding S2 and the second end of the first winding S1 are the same end, so a current loop of "the second end of the second winding S2-the second capacitor C2-the second diode D2-the first end of the second winding S2" is formed in the charging circuit 12 to charge the second capacitor C2.

[0063] At the same time, in the rectifier circuit 13, since the first end of the third winding S3 and the second end of the first winding S1 are the same-named ends, the first end of the third winding S3 is the current outflow end, and due to the existence of the third diode D3, the current loop of "second power supply Vout-third winding S3-third diode D3-ground SGND" is limited, and the current generated by the third winding S3 is blocked by the third diode D3. At this time, it can be considered that the third winding S3 has no current.

[0064] When the pulse signal output by the control chip is at a low level, the first switch tube Q1 is cut off. At this time, the loop of the output current of the first power supply Vbus is cut off, but the current on the first winding S1 does not disappear immediately, but slowly decreases. At this time, it can be considered that the current direction on the first winding S1 is from the second section of the first winding S1 to the first end of the first winding S1. Then in the rectifier circuit 13, the third winding S3 forms a current of "the second end of the third winding S3-the first end of the third winding S3", and at this time the current direction is the same as the current direction allowed to flow through the third diode D3, and the third winding S3 supplies power to the second power supply Vout. And part of the current of the third winding S3 will enter the fourth capacitor C4 to charge the fourth capacitor C4. Since the second end of the second winding S2 and the first end of the first winding S1 are the same end, at this time, the charging circuit 12 forms a current loop of "the first end of the second winding S2-the first diode D1-the first capacitor C1-the second end of the second winding S2" to charge the first capacitor C1.

[0065] In one embodiment, since the third winding S3 charges the fourth capacitor C4 at this time, during the period when the third winding S3 does not generate current, the fourth capacitor C4 can be discharged to charge the second power source Vout.

[0066] Among them, in the transformer, the voltage ratio corresponding to the two windings will be equal to the ratio of the winding coils of the two windings. When the first capacitor C1 is charged, there is also current in the third winding S3, and the current loop of the first power supply Vbus is interrupted, and the voltage corresponding to the first winding S1 cannot be determined. Therefore, the relevant parameters of the second winding S2 and the relevant parameters of the third winding S3 are used to represent the amount of electricity after the first capacitor C1 is charged. Then the amount of electricity after the first capacitor C1 is charged is proportional to the second power supply Vout and the number of coils of the second winding S2, and inversely proportional to the number of coils of the third winding S3.

[0067] When the second capacitor C2 is charged, the current in the second winding S2 is caused by the first winding S1, and there is no current in the third winding S3 at this time, that is, the voltage corresponding to the third winding S3 cannot be determined, so the relevant parameters of the second winding S2 and the relevant parameters of the first winding S1 are used to represent the amount of electricity after the first capacitor C1 is charged. Then, the amount of electricity after the second capacitor C2 is charged is proportional to the output voltage of the first power supply Vbus and the number of coils of the second winding S2, and inversely proportional to the number of coils of the first winding S1.

[0068] That is, the amount of electricity V after the first capacitor C1 is charged C1 Available formulas:

[0069]

[0070] Indicates, where Vout is the output voltage of the second power supply Vout, N S2is the number of coils of the second winding S2, N S3 is the number of coils of the third winding S3.

[0071] The amount of electricity after the second capacitor C2 is charged is V C2 Available formulas:

[0072]

[0073] Indicates, where Vbus is the output voltage of the first power supply Vbus, N S2 is the number of coils of the second winding S2, N S1 is the number of coils of the first winding S1.

[0074] In the embodiment of the present application, the amount of electricity after charging the first capacitor C1 or the second capacitor C2 can be changed by setting the output voltage of the first power supply Vbus, the output voltage of the second power supply Vout, or the ratio of the number of coils of the second winding S2 to the first winding S1, and the ratio of the number of coils of the second winding S2 to the third winding S3, so as to provide the control chip with an appropriate voltage for power supply, thereby improving the reliability of the power supply circuit 1.

[0075] The control chip outputs a pulse signal to the input circuit 11. When the pulse signal is at a high level, the power supply circuit 1 charges the second capacitor C2; when the pulse signal is at a low level, the power supply circuit 1 charges the first capacitor C1. That is, in one cycle of the control chip outputting the pulse signal, the power supply circuit 1 charges the first capacitor C1 and the second capacitor C2 respectively, thereby improving the charging efficiency of the charging circuit 12 for the first capacitor C1 and the second capacitor C2.

[0076] Furthermore, the charged first capacitor C1 and the charged second capacitor C2 supply power to the control chip to ensure the normal operation of the control chip. Wherein, the voltage of the first capacitor C1 and the second capacitor C2 supplying power to the control chip is Vcc, then Vcc=V C1 +V C2 .

[0077] Optionally, the charging circuit 12 also includes a voltage stabilizing circuit 121, the first end of the first capacitor C1 is connected to the first end of the voltage stabilizing circuit 121, the second end of the voltage stabilizing circuit 121 is connected to the input end of the control chip, and the voltage stabilizing circuit 121 is used to stabilize the voltage output by the first capacitor C1 and the second capacitor C2.

[0078] Specifically, the voltage stabilizing circuit 121 includes a first resistor R1, a second resistor R2, a voltage stabilizing diode ZD, a second switch tube Q2 and a fifth capacitor C5. Among them, the first end of the first resistor R1 is connected to the first end of the first capacitor C1, and the second end of the first resistor R1 is connected to the first input end of the second switch tube Q2. The first end of the second resistor R2 is connected to the first input end of the second switch tube Q2, and the second end of the second resistor R2 is connected to the second input end of the second switch tube Q2. The input end of the voltage stabilizing diode ZD is connected to the first end of the second capacitor C2, and the output end of the voltage stabilizing diode ZD is connected to the second input end of the second switch tube Q2. The output end of the second switch Q2 is connected to the input end of the control chip. The first end of the fifth capacitor C5 is connected to the output end of the second switch tube Q2, the second end of the fifth capacitor C5 is connected to the input end of the voltage stabilizing diode ZD, and the second end of the fifth capacitor C5 is grounded.

[0079] Among them, when the voltage output by the first capacitor C1 and the second capacitor C2 fluctuates, the voltage stabilizing circuit 121 stabilizes the voltage so that the first capacitor C1 and the second capacitor C2 output a stable voltage to the control chip. For example, when the output voltage of the first capacitor C1 and the second capacitor C2 increases, the voltage difference between the second input end of the second switch tube Q2 and the output end of the second switch tube Q2 becomes smaller, that is, the conduction of the second switch tube Q2 decreases. Due to the reduction of the conduction of the second switch tube Q2, the second switch tube Q2 will reduce the output voltage of the output end of the second switch tube Q2, thereby keeping the output voltage to the control chip constant. When the output voltage of the first capacitor C1 and the second capacitor C2 decreases, the voltage difference between the second input end of the second switch tube Q2 and the output end of the second switch tube Q2 increases, that is, the conduction of the second switch tube Q2 increases. Due to the increase of the conduction of the second switch tube Q2, the second switch tube Q2 will increase the output voltage of the output end of the second switch tube Q2, thereby keeping the output voltage to the control chip constant. The fifth capacitor C5 plays a filtering role, further maintains the stability of the output voltage, and improves the reliability of the power supply circuit 1.

[0080] In another embodiment, if Figure 2 As shown, Figure 2 The input circuit 11 includes a third switch tube Q3, a fourth switch tube Q4, a first power source Vbus, a first inductor L1 and a sixth capacitor C6.

[0081] Specifically, the first input end of the third switch tube Q3 is connected to the output end of the control chip, the second input end of the third switch tube Q3 is connected to the first power supply Vbus, the output end of the third switch tube Q3 is connected to the first end of the first inductor L1, the second end of the first inductor L1 is connected to the first end of the first winding S1, the first end of the sixth capacitor C6 is connected to the second end of the first winding S1, and the second end of the sixth capacitor C6 is grounded. The first input end of the fourth switch tube Q4 is connected to the output end of the control chip, the second input end of the fourth switch tube Q4 is connected to the first end of the first inductor L1, and the output end of the fourth switch tube Q4 is connected to the second end of the sixth capacitor C6.

[0082] Optionally, the power supply circuit 1 further includes a rectifier circuit 13, and the transformer T1 further includes a third winding S3 and a fourth winding S4 arranged on the same side, and the third winding S3 and the fourth winding S4 are arranged on the opposite side of the first winding S1, and the rectifier circuit 13 is connected to the third winding S3 and the fourth winding S4.

[0083] Specifically, the rectifier circuit 13 includes a fourth diode D4, a fifth diode D5, a second power supply Vout, and a fourth capacitor C4. The input end of the fourth diode D4 is connected to the first end of the third winding S3, the output end of the fourth diode D4 is connected to the first end of the fourth capacitor C4, the second end of the third winding S3 is connected to the second end of the fourth capacitor C4, the first end of the fourth capacitor C4 is connected to the second power supply Vout, and the second end of the fourth capacitor C4 is grounded. The input end of the fifth diode D5 is connected to the first end of the fourth winding S4, the output end of the fifth diode D5 is connected to the first end of the fourth capacitor C4, and the second end of the fourth winding S4 is connected to the second end of the third winding S3.

[0084] For details, please refer to Figure 3-Figure 5 , Figure 3 yes Figure 2 A partial structural diagram of a first embodiment of a power supply circuit; Figure 4 yes Figure 2 A partial structural diagram of a second embodiment of a power supply circuit; Figure 5 yes Figure 2 Schematic diagram of the partial structure of the third embodiment of the power supply circuit. In this embodiment, the connecting branch between the first input end of the fourth switch tube Q4 and the output end of the control chip has no intersection with the connecting branch between the third capacitor C3 and the ground terminal GND; the connecting branch between the output end of the second diode D2 and the input end of the first diode D1 has no intersection with the connecting branch between the second end of the first capacitor C1 and the second end of the second winding S2; and the connecting branch between the output end of the fourth diode D4 and the output end of the fifth diode D5 has no intersection with the connecting branch between the second end of the fourth winding S4 (the second end of the third winding S3) and the ground terminal SGND.

[0085] Among them, the first end of the first winding S1, the first end of the second winding S2, the first end of the third winding S3 and the second end of the fourth winding S4 are ends of the same name.

[0086] The following briefly describes the process of charging the first capacitor C1 and the second capacitor C2 by the power supply circuit 1 in this embodiment:

[0087] When the pulse signal output by the control chip to the third switch tube Q3 and the fourth switch tube Q4 is at a high level, the third switch tube Q3 is turned on and the fourth switch tube Q4 is cut off. At this time, the input circuit 11 forms a current loop of "first power supply Vbus-third switch tube Q3-first inductor L1-sixth capacitor C6-ground GND", so that the second winding S2 and the fourth winding S4 generate current and charge the sixth capacitor C6 at the same time. Among them, the sixth capacitor C6 and the first inductor L1 form an LC circuit to store the current output by the first power supply Vbus.

[0088] In the rectifier circuit 13, since the first end of the third winding S3 and the second end of the fourth winding S4 are current input ends, and due to the existence of the fourth diode D4, the current loops of "the second end of the fourth winding S4-the first end of the fourth winding S4-the fifth diode D5-the second power supply Vout" and "the second end of the fourth winding S4-the first end of the fourth winding S4-the fifth diode D5-the fourth capacitor C4-the second end of the fourth winding S4" exist in the rectifier circuit 13 to charge the second power supply Vout and the fourth capacitor C4. In the charging circuit 12, a current loop of "the first end of the second winding S2-the first diode D1-the first capacitor C1-the first end of the second winding S2" is formed to charge the first capacitor C1.

[0089] When the pulse signal output by the control chip to the third switch tube Q3 and the fourth switch tube Q4 is at a low level, the third switch tube Q3 is turned off, the fourth switch tube Q4 is turned on, and the sixth capacitor C6 is discharged, forming a current loop of "the first end of the sixth capacitor C6-the first inductor L1-the fourth switch tube Q4-the second end of the sixth capacitor C6". Then, a current loop of "the first end of the third winding S3-the fourth diode D4-the fourth capacitor C4-the second end of the third winding S3" is formed in the rectifier circuit 13 to charge the second power supply Vout and the fourth capacitor C4. A current loop of "the second end of the second winding S2-the second capacitor C2-the second diode D2-the first end of the second winding S2" is formed in the charging circuit 12 to charge the second capacitor C2.

[0090] Through the above circuit structure, the first capacitor C1 and the second capacitor C2 are charged respectively within a pulse signal cycle output by the control chip, and the charging efficiency of the first capacitor C1 and the second capacitor C2 is improved to ensure the power supply performance of the power supply circuit 1 for the control chip and improve the reliability of the power supply circuit 1.

[0091] In one embodiment, the second power supply Vout can be connected to an electrical device, and then the second power supply Vout supplies power to the electrical device, and the electrical device is operated. Wherein, since the third winding S3 and the fourth winding S4 charge the second power supply Vout while the third winding S3 and the fourth winding S4 also charge the fourth capacitor C4, when there is no current in the third winding S3 and the fourth winding S4, the fourth capacitor C4 can charge the second power supply Vout to ensure the stability of the second power supply Vout supplying power to the electrical device.

[0092] In summary, the power supply circuit 1 provided in the embodiment of the present application includes an input circuit 11, a charging circuit 12 and a rectifier circuit 13, each circuit being connected to the winding of the transformer T1. Among them, the charging circuit 12 includes a first capacitor C1 and a second capacitor C2, and the first capacitor C1 and the second capacitor C2 are respectively connected in parallel with the second winding S2, and then when the current flow direction in the first winding S1 connected to the input circuit 11 changes, the first capacitor C1 or the second capacitor C2 is charged, so as to realize that within a pulse signal cycle output by the control chip, the first capacitor C1 and the second capacitor C2 are charged, and the charging efficiency of the first capacitor C1 and the second capacitor C2 is improved, so as to ensure the stability of the first capacitor C1 and the second capacitor C2 supplying power to the control chip, and improve the reliability of the power supply circuit 1. The first capacitor C1 and the second capacitor C2 are connected in parallel to the same winding, and the setting cost of the winding in the power supply circuit 1 is reduced while ensuring the normal power supply to the control chip, the circuit is simple, and the setting volume of the power supply circuit 1 is reduced.

[0093] The present application also provides a main control circuit, including a power supply circuit 1 and a control chip. The power supply circuit 1 is connected to the output end and the input end of the control chip. The power supply circuit 1 receives a signal from the output end of the control chip to charge the first capacitor C1 and the second capacitor C2 in the power supply circuit 1. Then the first capacitor C1 and the second capacitor C2 power the control chip through the input end of the control chip to ensure the normal operation of the control chip.

[0094] When the output charging voltage is clamped very low by the electrical device, that is, when the control chip outputs a low level, the charging circuit 12 charges the first capacitor C1 to ensure that the charging circuit 12 supplies power to the control chip. The third winding S3 charges the second power supply Vout to ensure that the second power supply Vout supplies power to the electrical device. When the output charging voltage is normal, that is, when the control chip outputs a high level, the charging circuit 12 charges the second capacitor C2.

[0095] In the main control circuit provided in this embodiment book, when the control chip outputs high or low levels, the charging circuit 12 can charge the corresponding capacitor, thereby ensuring that the charging circuit 12 supplies power to the control chip, ensuring the normal working voltage of the control chip, avoiding abnormal power supply operation, and improving the practicality and reliability of the main control circuit.

[0096] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A power supply circuit for a control chip, characterized in that: include: A transformer, comprising a first winding and a second winding arranged on the same side; An input circuit connected to the first winding, wherein the control chip is connected to the input circuit and is used to control the input circuit; a charging circuit connected to the second winding, and the charging circuit is connected to the control chip, and is used to supply power to the control chip; The charging circuit includes a first capacitor, a second capacitor, a first diode and a second diode. The first capacitor and the second capacitor are respectively connected in parallel with the second winding, and the first capacitor is connected to the second winding through the first diode, and the second capacitor is connected to the second winding through the second diode. The input circuit charges the first capacitor or the second capacitor through the cooperation of the first winding and the second winding to power the control chip. The polarity of one end where the first diode is connected to the second winding is the same as the polarity of one end where the second diode is connected to the second winding.

2. The power supply circuit according to claim 1, characterized in that: The output end of the first diode is connected to the first end of the first capacitor, the input end of the first diode is connected to the first end of the second winding, and the second end of the first capacitor is connected to the second end of the second winding; The output end of the second diode is connected to the input end of the first diode, the input end of the second diode is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the second end of the first capacitor; The first end of the first capacitor is connected to the input end of the control chip, and the first capacitor and the second capacitor provide power for the control chip.

3. The power supply circuit according to claim 1, characterized in that: The input circuit includes a first switch tube, a third capacitor and a first power supply, wherein: The first input end of the first switch tube is connected to the output end of the control chip, the second input end of the first switch tube is connected to the first end of the first winding, and the output end of the first switch tube is grounded; The first power source is connected to the second end of the first winding; A first end of the third capacitor is connected to the first power supply, and a second end of the third capacitor is grounded.

4. The power supply circuit according to claim 3, characterized in that: The power supply circuit further includes a rectifier circuit, and the transformer further includes a third winding, the third winding is arranged on the opposite side of the first winding, and the rectifier circuit is connected to the third winding, wherein: The rectifier circuit includes a third diode, a second power supply and a fourth capacitor, the output end of the third diode is connected to the second power supply, the input end of the third diode is connected to the first end of the third winding, the first end of the fourth capacitor is connected to the second power supply, the second end of the fourth capacitor is connected to the second end of the third winding, and the second end of the fourth capacitor is grounded.

5. The power supply circuit according to claim 4, characterized in that: The amount of electricity after the first capacitor is charged is proportional to the output voltage of the second power supply and the number of coils of the second winding, and inversely proportional to the number of coils of the third winding; The amount of electricity of the second capacitor after being charged is directly proportional to the output voltage of the first power supply and the number of coils of the second winding, and inversely proportional to the number of coils of the first winding.

6. The power supply circuit according to claim 1, characterized in that: The charging circuit also includes a voltage stabilizing circuit, the first end of the first capacitor is connected to the first end of the voltage stabilizing circuit, the second end of the voltage stabilizing circuit is connected to the input end of the control chip, and the voltage stabilizing circuit is used to stabilize the voltage output by the first capacitor and the second capacitor.

7. The power supply circuit according to claim 6, characterized in that: The voltage stabilizing circuit includes a first resistor, a second resistor, a voltage stabilizing diode, a second switch tube and a fifth capacitor; wherein, The first end of the first resistor is connected to the first end of the first capacitor, and the second end of the first resistor is connected to the first input end of the second switch tube; The first end of the second resistor is connected to the first input end of the second switch tube, and the second end of the second resistor is connected to the second input end of the second switch tube; The input end of the voltage stabilizing diode is connected to the first end of the second capacitor, and the output end of the voltage stabilizing diode is connected to the second input end of the second switch tube; The output end of the second switch tube is connected to the input end of the control chip; A first end of the fifth capacitor is connected to the output end of the second switch tube, a second end of the fifth capacitor is connected to the input end of the voltage stabilizing diode, and a second end of the fifth capacitor is grounded.

8. The power supply circuit according to claim 1, characterized in that: The input circuit includes a third switch tube, a fourth switch tube, a first power supply, a first inductor and a sixth capacitor; wherein, The first input end of the third switch tube is connected to the output end of the control chip, the second input end of the third switch tube is connected to the first power supply, the output end of the third switch tube is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the first winding, the first end of the sixth capacitor is connected to the second end of the first winding, and the second end of the sixth capacitor is grounded; The first input end of the fourth switch tube is connected to the output end of the control chip, the second input end of the fourth switch tube is connected to the first end of the first inductor, and the output end of the fourth switch tube is connected to the second end of the sixth capacitor.

9. The power supply circuit according to claim 8, characterized in that: The power supply circuit further includes a rectifier circuit, and the transformer further includes a third winding and a fourth winding arranged on the same side, the third winding and the fourth winding are arranged on the opposite side of the first winding, and the rectifier circuit is connected to the third winding and the fourth winding, wherein: The rectifier circuit includes a fourth diode, a fifth diode, a second power supply and a fourth capacitor. The input end of the fourth diode is connected to the first end of the third winding, the output end of the fourth diode is connected to the first end of the fourth capacitor, the second end of the third winding is connected to the second end of the fourth capacitor, the first end of the fourth capacitor is connected to the second power supply, and the second end of the fourth capacitor is grounded; An input end of the fifth diode is connected to a first end of the fourth winding, an output end of the fifth diode is connected to a first end of the fourth capacitor, and a second end of the fourth winding is connected to a second end of the third winding.

10. A main control circuit, characterized in that: It includes a power supply circuit and a control chip as described in any one of claims 1 to 9, the power supply circuit is connected to the output end and the input end of the control chip, the power supply circuit receives a signal from the output end of the control chip, charges a first capacitor and a second capacitor in the power supply circuit, and the first capacitor and the second capacitor power the control chip through the input end of the control chip.

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