Detection assembly, flyback transformer and power supply equipment

Abstract

The invention relates to a detection assembly, a flyback transformer and power supply equipment, the detection assembly is applied to the flyback transformer, the flyback transformer comprises a primary circuit, a secondary circuit and an auxiliary winding, and the detection assembly comprises a first protection circuit connected with the primary circuit; the detection module is provided with a detection pin, and the detection pin is connected with the first protection circuit and used for carrying out overcurrent protection on the primary circuit; the second protection circuit and the first protection circuit are arranged in parallel; the second protection circuit comprises a detection branch circuit which is connected with the auxiliary winding; the detection branch comprises a thermistor, a first voltage dividing element and a first switching diode which are connected in series; and the clamping branch circuit is connected with the thermistor and is used for carrying out voltage clamping on the thermistor within the reverse recovery time of the first switching diode.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power supply, and in particular to a detection component, a flyback transformer and a power supply device. Background Art

[0002] The flyback transformer is a key component in a switching power supply. The flyback transformer usually includes a primary winding and a secondary winding; the primary winding inputs alternating current and generates magnetic flux lines, and the secondary winding generates a corresponding induced voltage according to the turns ratio between the primary winding and the secondary winding.

[0003] In order to reduce the saturation of the flyback transformer core in the related art, a current detection circuit is usually set in the flyback transformer for overcurrent protection. Due to the mutual influence between the internal circuits of the current detection circuit, the detection accuracy of the current detection circuit is low, resulting in failure to achieve effective overcurrent protection. Summary of the invention

[0004] In order to overcome the problems existing in the related art, the present disclosure provides a detection component, a flyback transformer and a power supply device.

[0005] According to a first aspect of an embodiment of the present disclosure, a detection component is provided, which is applied to a flyback transformer. The flyback transformer includes a primary circuit, a secondary circuit and an auxiliary winding. The detection component includes:

[0006] A first protection circuit connected to the primary circuit;

[0007] A detection module having a detection pin, wherein the detection pin is connected to the first protection circuit and is used to perform overcurrent protection on the primary circuit;

[0008] A second protection circuit is connected to the detection pin, and the second protection circuit includes:

[0009] A detection branch connected to the auxiliary winding; the detection branch comprises: a thermistor, a first voltage dividing element and a first switch diode connected in series;

[0010] The clamping branch is connected to the thermistor and is used to clamp the voltage of the thermistor within the reverse recovery time of the first switching diode.

[0011] Optionally, an anode of the first switch diode is connected to the auxiliary winding, and a cathode of the first switch diode is connected to the first voltage divider element;

[0012] The first end of the thermistor is connected to the detection pin, and the second end of the thermistor is connected to the first voltage divider element;

[0013] The clamping branch comprises:

[0014] A second switch diode, wherein a cathode of the second switch diode is connected to the second end of the thermistor, and an anode of the second switch diode is grounded.

[0015] Optionally, the first protection circuit includes:

[0016] A second voltage-dividing element, wherein a first end of the second voltage-dividing element is connected to a primary switch tube of the primary circuit, and a second end of the second voltage-dividing element is grounded;

[0017] The detection pin of the detection module is connected to the first end of the second voltage-dividing element, and is used to detect the voltage of the second voltage-dividing element when the primary switch tube is turned on.

[0018] Optionally, the detection component includes:

[0019] Circuit board; the first protection circuit and the second protection circuit are both located on the circuit board;

[0020] The position of the second switch diode in the clamping branch on the circuit board is close to the position of the detection branch on the circuit board.

[0021] Optionally, the position of the thermistor on the circuit board is close to the position of the primary switch tube of the primary circuit on the circuit board.

[0022] Optionally, the detection component further includes:

[0023] A filter capacitor, wherein a first end of the filter capacitor is connected to a first end of the thermistor, and a second end of the filter capacitor is connected to a common ground with the second switch diode.

[0024] Optionally, the detection component further includes:

[0025] A voltage-stabilizing diode, wherein a first end of the voltage-stabilizing diode is connected to a first end of the thermistor, and a second end of the voltage-stabilizing diode is grounded;

[0026] The circuit board at least comprises:

[0027] A metal wiring is used to sequentially connect a detection pin of the detection module, a first end of the voltage-stabilizing diode, a first end of the filter capacitor, and a first end of the thermistor.

[0028] Optionally, the second switching diode is a first type diode; wherein a reverse recovery time of the first type diode is shorter than a reverse recovery time of the second type diode.

[0029] According to a second aspect of an embodiment of the present disclosure, there is provided a flyback transformer, comprising:

[0030] The detection component according to the first aspect of the embodiment of the present disclosure;

[0031] A primary circuit connected to a first protection circuit of the detection component;

[0032] Secondary circuit;

[0033] The auxiliary winding is located at one side of the primary winding, and the auxiliary winding is connected to the detection branch in the detection component.

[0034] According to a third aspect of an embodiment of the present disclosure, there is provided a power supply device, including:

[0035] The transformer structure described in the second aspect of the embodiment of the present disclosure.

[0036] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0037] The detection component of the embodiment of the present disclosure may include a first protection circuit, a second protection circuit and a detection module; the detection pin of the detection module is connected to the first protection circuit and the second protection circuit; since the first protection circuit is connected to the primary circuit of the flyback transformer, the detection module can detect the electrical parameters of the first protection circuit to achieve overcurrent protection for the primary circuit; by setting a clamping circuit in the second protection circuit, within the reverse recovery time of the first switching diode in the detection branch, the clamping circuit is used to clamp the voltage of the thermistor in the detection branch, thereby reducing the current value of the reverse current flowing through the thermistor, and then making the electrical parameters of the electrical signal flowing through the first protection circuit close to the electrical parameters of the electrical signal flowing through the primary circuit, thereby effectively improving the detection accuracy of the detection module and effectively achieving overcurrent protection for the flyback transformer.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0040] Figure 1 is a schematic diagram of a circuit structure of a detection component according to an exemplary embodiment;

[0041] Figure 2 is a schematic diagram of a circuit structure of a detection component without a clamping branch according to an exemplary embodiment;

[0042] Figure 3 is a schematic diagram of a (partial) circuit structure of a flyback transformer according to an exemplary embodiment;

[0043] Figure 4 A circuit board diagram of a flyback transformer according to an exemplary embodiment is shown Figure 1 ;

[0044] Figure 5 is a (partial) three-dimensional schematic diagram of a circuit board of a flyback transformer according to an exemplary embodiment;

[0045] Figure 6 A circuit board diagram of a flyback transformer according to an exemplary embodiment is shown Figure 2 ;

[0046] Figure 7 is a schematic diagram of current waveforms of three different flyback transformers in a stable state according to an exemplary embodiment;

[0047] Figure 8 1 is a schematic diagram of current waveforms of three different flyback transformers under a short-circuit condition according to an exemplary embodiment. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices consistent with some aspects of the present disclosure as detailed in the appended claims.

[0049] The present disclosure provides a detection component, such as Figure 1 As shown, Figure 1 1 is a schematic diagram of a circuit structure of a detection component according to an exemplary embodiment. The detection component can be applied to a flyback transformer, which includes a primary circuit, a secondary circuit and an auxiliary winding; it is worth noting that the detection component can at least be used to detect the current value in the primary circuit to perform overcurrent protection on the primary circuit.

[0050] The detection component 10 comprises:

[0051] A first protection circuit 11, connected to the primary circuit;

[0052] The detection module U2 has a detection pin CS, and the detection pin CS is connected to the first protection circuit 11, and is used to perform overcurrent protection on the primary circuit;

[0053] The second protection circuit 12 is connected to the detection pin CS, and the second protection circuit 12 includes:

[0054] A detection branch connected to the auxiliary winding L1; the detection branch comprises: a thermistor NTC2, a first voltage dividing element R22 and a first switch diode D7 connected in series;

[0055] The clamping branch 121 is connected to the thermistor NTC2 and is used to clamp the voltage of the thermistor NTC2 within the reverse recovery time of the first switch diode D7.

[0056] In the embodiment of the present disclosure, the detection component includes: a first protection circuit, a second protection circuit and a detection module.

[0057] The detection module may have a detection pin, and the detection pin is connected to the first protection circuit and the second protection circuit to detect electrical parameters of the electrical signal flowing through the first protection circuit and the second protection circuit respectively.

[0058] The first protection circuit is connected to the primary circuit in the flyback transformer.

[0059] It should be noted that the primary circuit at least includes: a primary winding and a primary switch tube. It is understandable that the primary circuit of the flyback transformer is connected to an external power supply, and when the primary switch tube is closed, the external power supply inputs an electrical signal to the primary winding.

[0060] It is worth noting that the detection module can determine the electrical parameters of the electrical signal input into the primary winding by detecting the electrical parameters of the electrical signal flowing through the first protection circuit, thereby controlling the on and off state of the primary switching tube to achieve overcurrent protection for the primary circuit and prevent core saturation caused by excessive current in the flyback transformer.

[0061] In some embodiments, a first end of the first protection circuit may be connected to the source of the primary switch tube, and a second end may be grounded; the detection pin may be connected to the first end of the first protection circuit.

[0062] The second protection circuit includes a detection branch; wherein the detection branch includes: a thermistor, a first voltage divider element and a first switching diode connected in series; and the first end of the detection branch is connected to the detection pin of the detection module, and the second end of the detection branch is connected to the auxiliary winding in the flyback transformer.

[0063] It is understandable that the detection module can determine the resistance value of the thermistor by detecting the electrical parameters of the electrical signal flowing through the detection branch, thereby realizing overheat protection for the flyback transformer.

[0064] It is worth noting that, in theory, when the primary switch tube in the primary circuit is in a closed state, the first switch diode in the detection branch is in a reverse cut-off state, that is, the detection branch is disconnected, and the detection module can detect the electrical parameters of the electrical signal flowing through the first protection circuit to achieve overcurrent protection for the primary circuit. When the primary switch terminal in the primary circuit is in an open state, the first switch diode in the detection branch is in a forward conduction state, that is, the detection branch is turned on, and the detection module can detect the electrical parameters of the electrical signal flowing through the detection branch to achieve overheating protection for the flyback transformer.

[0065] However, the switching diode has a certain reverse recovery time. It should be noted that during the reverse recovery time of the switching diode, the current flowing through the switching diode will not immediately become zero, that is, the switching diode is not turned off.

[0066] During the reverse recovery time of the first switching diode in the detection branch, the first switching diode is not turned off, so that the electrical parameters of the electrical signal flowing through the first protection circuit detected by the detection module will be smaller than the electrical parameters of the electrical signal flowing through the primary circuit, thereby reducing the detection accuracy of the detection module and failing to achieve effective overcurrent protection for the primary circuit. At this time, in order to ensure that the transformer is not saturated, the volume of the magnetic core needs to be increased, resulting in an increase in the cost of the transformer.

[0067] Based on this, in order to reduce the impact of the detection branch on the detection accuracy of the detection module, the embodiment of the present disclosure sets a clamping branch in the second protection circuit, and the clamping branch is connected to the thermistor; thereby, within the reverse recovery time of the first switching diode, the clamping branch is used to clamp the voltage of the thermistor.

[0068] Since the thermistor, the first voltage divider and the first switch diode are connected in series, the voltage of the thermistor is clamped by the clamping branch, which can also be understood as the voltage of the first switch diode is clamped by the clamping branch.

[0069] It should be noted that the voltage of the thermistor is clamped by the clamping branch, so that during the reverse recovery time of the first switching diode, even if the first switching diode is not turned off, the voltage drop of the thermistor is significantly reduced compared to the voltage drop of the thermistor that is not voltage clamped after the voltage of the thermistor is clamped, so that the electrical parameters of the electrical signal flowing through the detection branch are also reduced a lot accordingly, and then the electrical parameters of the electrical signal flowing through the first protection circuit are close to the electrical parameters of the electrical signal flowing through the primary circuit, thereby effectively improving the detection accuracy of the detection module and effectively realizing overcurrent protection of the flyback transformer.

[0070] The detection component of the embodiment of the present disclosure may include a first protection circuit, a second protection circuit and a detection module; the detection pin of the detection module is connected to the first protection circuit and the second protection circuit; since the first protection circuit is connected to the primary circuit of the flyback transformer, the detection module can detect the electrical parameters of the first protection circuit to achieve overcurrent protection for the primary circuit; by setting a clamping circuit in the second protection circuit, within the reverse recovery time of the first switching diode in the detection branch, the clamping circuit is used to clamp the voltage of the thermistor in the detection branch, thereby reducing the current value of the reverse current flowing through the thermistor, and then making the electrical parameters of the electrical signal flowing through the first protection circuit close to the electrical parameters of the electrical signal flowing through the primary circuit, thereby effectively improving the detection accuracy of the detection module and effectively achieving overcurrent protection for the flyback transformer.

[0071] Alternatively, if Figure 1 As shown, the anode of the first switch diode D7 is connected to the auxiliary winding L1, and the cathode of the first switch diode D7 is connected to the first voltage dividing element R22;

[0072] The first end of the thermistor NTC2 is connected to the detection pin CS, and the second end of the thermistor NTC2 is connected to the first voltage dividing element R22;

[0073] The clamping branch 121 comprises:

[0074] A second switch diode D9 , wherein a cathode of the second switch diode D9 is connected to the second end of the thermistor NTC2 , and an anode of the second switch diode D9 is grounded.

[0075] In an embodiment of the present disclosure, a thermistor, a first voltage divider element and a first switching diode are connected in series between an auxiliary winding and a detection pin of a detection module, wherein an anode of the first switching diode is connected to the auxiliary winding, and a cathode of the first switching diode is connected to the first voltage divider element; a first end of the thermistor is connected to the detection pin, and a second end of the thermistor is connected to the first voltage divider element.

[0076] Here, the thermistor may be a thermistor with a negative temperature coefficient, that is, the higher the temperature, the smaller the resistance of the thermistor. In some embodiments, the thermistor may be a thermistor in a 0402 package.

[0077] It can be understood that the auxiliary winding is coupled to the primary winding. When the primary switch tube is disconnected, the auxiliary winding outputs a forward voltage to the anode of the first switch diode, so that the first switch diode is in a forward conduction state; at this time, the detection module can detect the voltage value of the first end of the thermistor. If the voltage value of the first end of the thermistor is larger, it means that the resistance of the thermistor is smaller, and the temperature inside the flyback transformer module is higher.

[0078] When the primary switch is turned on, the auxiliary winding outputs a reverse voltage to the anode of the first switch diode. However, since the first switch diode has a certain reverse recovery time, a reverse current exists in the detection branch during the reverse recovery time of the first switch diode. The reverse current flows along the thermistor, the first voltage divider, the first switch diode and the auxiliary winding to the ground terminal. At this time, the current value of the electrical signal flowing through the primary circuit is determined by the current value of the electrical signal in the first protection circuit and the current value of the reverse current.

[0079] Since the reverse voltage output by the auxiliary winding to the anode of the first switching diode has a larger voltage value, the reverse current value is larger, resulting in a larger difference between the current value of the electrical signal in the first protection circuit detected by the detection module and the current value of the electrical signal flowing through the primary circuit.

[0080] In the embodiment of the present disclosure, a second switch diode is added in the detection component, the cathode of the second switch diode is connected to the second end of the thermistor, and the anode of the second switch diode is grounded, so that the voltage of the thermistor is clamped by the second switch diode.

[0081] It is worth noting that since the clamping voltage is much smaller than the reverse voltage output by the auxiliary winding, the voltage drop of the thermistor is effectively reduced during the reverse recovery time of the first switching diode, thereby greatly reducing the current value of the electrical signal flowing through the thermistor, thereby reducing the difference between the current value of the electrical signal in the first protection circuit detected by the detection module and the current value of the electrical signal flowing through the primary circuit.

[0082] In the disclosed embodiment, a second switching diode is provided, wherein the cathode of the second switching diode is connected to the second end of the thermistor and the anode of the second switching diode is grounded; thereby, the second switching diode is used to perform voltage clamping on the thermistor, thereby reducing the current value of the reverse current flowing through the thermistor within the reverse recovery time of the first switching diode, thereby making the electrical parameters of the electrical signal flowing through the first protection circuit close to the electrical parameters of the electrical signal flowing through the primary circuit, thereby effectively improving the detection accuracy of the detection module and effectively realizing overcurrent protection for the flyback transformer.

[0083] Alternatively, if Figure 1 As shown, the first protection circuit 11 includes:

[0084] A second voltage-dividing element R15, wherein a first end of the second voltage-dividing element R15 is connected to a primary switch tube Q2 of the primary circuit, and a second end of the second voltage-dividing element R15 is grounded;

[0085] The detection pin CS of the detection module U2 is connected to the first end of the second voltage-dividing element R15, and is used to detect the voltage of the second voltage-dividing element R15 when the primary switch tube Q2 is turned on.

[0086] In an embodiment of the present disclosure, the first protection circuit includes: a second voltage divider element; wherein a first end of the second voltage divider element is connected to a source of a primary switch tube of a primary circuit; and a second end of the second voltage divider element is grounded.

[0087] It can be understood that when the primary switch tube is turned on, the electrical signal in the primary circuit flows to the ground terminal via the second voltage divider element.

[0088] The detection pin of the detection module is connected to the first end of the second voltage divider element to detect the voltage of the first end of the second voltage divider element, thereby determining the current value of the electrical signal flowing through the second voltage divider element based on the voltage drop of the second voltage divider element and the resistance value of the second voltage divider element, thereby determining the current value of the electrical signal flowing through the primary circuit.

[0089] The detection module can be connected to the gate of the primary switch tube, and is used to control the on-off state of the primary switch tube according to the current value of the electrical signal flowing through the second voltage divider element.

[0090] It is worth noting that the detection module detects the current value of the electrical signal flowing through the first protection circuit when the primary switch tube is turned on. When the current value is greater than the preset current value, the detection module controls the primary switch tube to disconnect, thereby realizing overcurrent protection for the primary circuit and preventing the core saturation of the flyback transformer due to excessive current.

[0091] like Figure 1 and Figure 2 As shown, Figure 2 It is a circuit structure diagram of a detection component without a clamping branch according to an exemplary embodiment. Theoretically, when the primary switch tube Q2 is turned on, the first switch diode D7 is reversely cut off, and the current I2 on the detection branch is zero; at this time, the current I1 output by the primary switch tube Q2 is equal to the current I3 in the first protection circuit.

[0092] Since the current I3 flowing through the second voltage-dividing element R15 causes a voltage drop across the second voltage-dividing element R15 , the voltage Vcs detected by the detection pin CS of the detection module U2 changes.

[0093] For example, the voltage Vcs detected by the detection pin CS may be determined by the following formula:

[0094] V cs =I3*R 15 (1)

[0095] Among them, I1=I3.

[0096] The detection module U2 controls the current of the first protection branch 11 based on the voltage Vcs detected by the detection pin CS, that is, controls the current output by the primary switch tube Q2.

[0097] However, in actual practice, since there is a reverse recovery time when the first switch diode D7 switches from the forward conduction state to the reverse cutoff state, a reverse current exists in the detection branch during the reverse recovery time, that is, the current I2 is not zero.

[0098] Exemplarily, the current I2 of the detection branch within the reverse recovery time of the first switch diode D7 may be determined by the following formula:

[0099]

[0100] Among them, the V L1 is the reflected voltage of the auxiliary winding.

[0101] It should be noted that the reflected voltage V L1 Usually larger; for example, when the single output of the flyback transformer is 20V, the reflected voltage V L1 The closer it is to -60V; the voltage Vcs detected by the detection pin CS is generally very small, about 1V, so the reverse current of the detection branch is larger.

[0102] At this time, the current I1 output by the primary switch tube Q2 can be determined by the following formula:

[0103] I1=I3+|I2| (3)

[0104] In fact, the voltage Vcs detected by the detection pin CS can be determined by the following formula:

[0105] V cs =(I1-|I2|)*R 15 (4)

[0106] Therefore, in actual process, the voltage Vcs detected by the detection pin CS of the detection module U2 is smaller than the voltage corresponding to the current I1 output by the primary switch tube, thereby causing the detection accuracy of the detection module to decrease.

[0107] After the thermistor is voltage clamped by the second switch diode, the current I2' of the detection branch within the reverse recovery time of the first switch diode D7 is:

[0108]

[0109] At this time, the voltage Vcs detected by the detection pin CS can be determined by the following formula:

[0110] V cs =(I1-|I2′|)*R 15 (6)

[0111] It is worth noting that during the reverse recovery time of the first switch diode D7, the second switch diode D9 clamps the voltage at the A terminal. Since the voltage drop across the diode is about 0.7V, the voltage at the A terminal is about -0.7V at this time; from formula (5) and formula (2), it can be seen that I2' is much smaller than I2, and its influence on the circuit can be ignored, so that during the reverse recovery time of the first switch diode D7, the reverse current flowing through the thermistor has almost no influence on the current detection of the detection module, thereby greatly improving the detection accuracy of the detection module.

[0112] Alternatively, if Figure 3 , Figure 4 and Figure 5 As shown, Figure 3 is a schematic diagram of a (partial) circuit structure of a flyback transformer according to an exemplary embodiment; Figure 4 A circuit board diagram of a flyback transformer according to an exemplary embodiment is shown Figure 1 ; Figure 5 1 is a (partial) three-dimensional schematic diagram of a circuit board of a flyback transformer according to an exemplary embodiment. The detection component 10 includes:

[0113] Circuit board; the first protection circuit 11 and the second protection circuit 12 are both located on the circuit board;

[0114] The position of the second switch diode D9 in the clamping branch 121 on the circuit board is close to the position of the detection branch on the circuit board.

[0115] In the embodiment of the present disclosure, the detection component may include a circuit board; the first protection circuit and the second protection circuit are both located on the circuit board.

[0116] It should be noted that the circuit board can be used to assemble different electronic components. In the disclosed embodiment, the electronic components of the first protection circuit and the second protection circuit are both assembled on the circuit board, and the wiring on the circuit board is used to connect the first protection circuit and the second protection circuit.

[0117] In some embodiments, the circuit board may also be equipped with a primary switch tube.

[0118] It is worth noting that, in the embodiment of the present disclosure, a clamping branch is added to the second protection circuit, that is, a second switching diode is added. In order to make the loop area of ​​the circuit board as small as possible, the layout of the second protection circuit on the circuit board can be adjusted.

[0119] The position of the second switch diode in the clamping branch on the circuit board should be close to the position of the detection branch on the circuit board; Figure 4 As shown, the mounting position of the second switch diode D9 on the circuit board should be close to the mounting positions of the first switch diode D7, thermistor NTC2 and the first voltage divider element R22 on the circuit board.

[0120] It is worth noting that in the circuit board layout of the embodiment of the present disclosure, the length of the path in the circuit board from the auxiliary winding through the first switching diode, the first voltage divider element, the thermistor and the second switching diode is shortened by arranging the second switching diode close to the first switching diode, the thermistor and the first voltage divider element.

[0121] Alternatively, if Figure 4 As shown, the position of the thermistor NTC2 on the circuit board is close to the position of the primary switch tube Q2 of the primary circuit on the circuit board.

[0122] In the disclosed embodiment, the position of the thermistor on the circuit board should be close to the position of the primary switch tube in the primary circuit on the circuit board.

[0123] It is worth noting that the resistance of the thermistor will change with the temperature. By placing the thermistor close to the primary switch tube, the heat generated by the primary circuit can be better sensed, so that the detection branch can be used to implement overheat protection for the flyback transformer.

[0124] In some embodiments, the rated zero-power resistance of the thermistor may be 25 ohms.

[0125] It should be noted that zero-power resistance refers to the extremely low power consumption of thermistor when measuring thermistor value at a certain temperature, so low that the change in thermistor resistance caused by its power consumption can be ignored. Rated zero-power resistance refers to the zero-power resistance value detected at an ambient temperature of 25°C.

[0126] In the embodiment of the present disclosure, the thermistor is placed close to the primary switch tube during circuit board layout, so that the resistance change of the thermistor can more accurately reflect the temperature change in the primary circuit, making it easier to use the detection component to better implement overheat protection for the flyback transformer.

[0127] Alternatively, if Figure 3 As shown, the detection component 10 further includes:

[0128] A filter capacitor C5, wherein a first end of the filter capacitor C5 is connected to a first end of the thermistor NTC2, and a second end of the filter capacitor C5 is connected to a common ground with the second switch diode D9.

[0129] In the embodiment of the present disclosure, the detection component also includes: a filter capacitor; the first end of the filter capacitor is connected to the first end of the thermistor, and the second end of the filter capacitor is commonly connected to the anode of the second switch diode.

[0130] It can be understood that by introducing a filter capacitor in the detection component and connecting the filter capacitor and the second switch diode to a common ground, the high-frequency current in the circuit can be guided to the ground terminal, thereby reducing the radiation and propagation of electromagnetic interference.

[0131] In some embodiments, in order to reduce electromagnetic interference, a filter capacitor may be connected in parallel with the second switch diode.

[0132] Alternatively, if Figure 3 and Figure 6 As shown, Figure 6 A circuit board diagram of a flyback transformer according to an exemplary embodiment is shown Figure 2 The detection component 10 further includes:

[0133] A voltage stabilizing diode Dcs1, wherein a first end of the voltage stabilizing diode Dcs1 is connected to a first end of the thermistor NTC2, and a second end of the voltage stabilizing diode Dcs1 is grounded;

[0134] The circuit board at least comprises:

[0135] A metal wiring is used to sequentially connect the detection pin CS of the detection module U2, the first end of the voltage-stabilizing diode Dcs1, the first end of the filter capacitor C5, and the first end of the thermistor NTC2.

[0136] In the embodiment of the present disclosure, the detection component also includes: a voltage regulator diode; the first end of the voltage regulator diode is connected to the first end of the thermistor, and the second end of the voltage regulator diode is grounded.

[0137] It is worth noting that by providing a voltage regulator diode in the detection component, the influence of electrostatic discharge (ESD) or other transient pulses on the first protection circuit and the second protection circuit can be reduced.

[0138] In the embodiment of the present disclosure, the circuit board may include multiple metal traces; it should be noted that the circuit board may include a trace layer, which includes multiple metal traces, so as to utilize multiple metal traces to achieve electrical connection between multiple electronic components assembled on the circuit board.

[0139] The detection pin of the detection module can be connected to the first end of the voltage regulator diode, the first end of the filter capacitor and the first end of the thermistor in sequence through a metal wiring.

[0140] It can be understood that by connecting the detection pin of the detection module, the first end of the voltage-stabilizing diode, the first end of the filter capacitor and the first end of the thermistor in sequence through a metal trace, not only can the filter capacitor and the voltage-stabilizing diode be utilized to improve the electromagnetic compatibility (EMC) performance of the detection component, but also the loop area within the circuit board can be reduced.

[0141] Optionally, the second switching diode is a first type diode; wherein a reverse recovery time of the first type diode is shorter than a reverse recovery time of the second type diode.

[0142] In the embodiment of the present disclosure, the second switching diode in the clamping branch may be a first type diode.

[0143] It should be noted that, according to the length of the reverse recovery time of the diode, the diode can be divided into a first type diode and a second type diode; wherein the reverse recovery time of the first type diode is shorter than the reverse recovery time of the second type diode.

[0144] It will be appreciated that the first type diode may be a fast recovery diode.

[0145] When the first switching diode is in the forward conduction state, the second switching diode should be in the reverse cutoff state. However, since the diode has a certain reverse recovery time, in order to reduce the influence of the second switching diode on the electrical parameters of the electrical signal flowing through the detection branch detected by the detection module, the second switching diode should adopt a fast recovery diode.

[0146] The present disclosure provides a flyback transformer, the flyback transformer comprising:

[0147] The detection component shown in one or more of the above technical solutions;

[0148] A primary circuit connected to a first protection circuit of the detection component;

[0149] Secondary circuit;

[0150] The auxiliary winding is located at one side of the primary winding, and the auxiliary winding is connected to the detection branch in the detection component.

[0151] In the embodiment of the present disclosure, the flyback transformer may include: a primary circuit, a secondary circuit, an auxiliary winding and a detection component.

[0152] It should be noted that the flyback transformer can be used to convert the electrical signal output by an external power supply into the magnetic field energy of the flyback transformer, and then convert the magnetic field energy into electrical energy and input it into the load circuit, thereby providing the load circuit with a power supply signal with lower noise and higher quality.

[0153] The primary circuit is connected to an external power supply, and the primary circuit at least includes a primary winding and a primary switch tube, and the primary winding is connected to the drain of the primary switch tube.

[0154] The secondary circuit is connected to the load circuit, and the secondary circuit at least includes a secondary winding and a secondary rectifier tube, and the secondary winding is connected to the secondary rectifier tube.

[0155] It should be noted that the electrical signal output by the external power supply is input into the primary winding, and the electrical signal of the primary winding is coupled to the secondary winding through the high-frequency conduction and disconnection of the primary switching tube, and then output to the load circuit after rectification by the secondary rectifier tube to charge or power the load circuit.

[0156] The auxiliary winding is located at one side of the primary winding, and the auxiliary winding is coupled to the primary winding.

[0157] The detection component includes: a first protection circuit, a second protection circuit and a detection module; wherein the detection pin of the detection module is connected to the first protection circuit and the second protection circuit.

[0158] It is worth noting that the detection module can determine the electrical parameters of the electrical signal input into the primary winding by detecting the electrical parameters of the electrical signal flowing through the first protection circuit, thereby controlling the on and off state of the primary switching tube to achieve overcurrent protection for the primary circuit and prevent core saturation caused by excessive current in the flyback transformer.

[0159] The second protection circuit includes: a detection branch and a clamping branch. The detection branch includes: a thermistor, a first voltage divider element and a first switch diode connected in series; and the clamping branch is connected to the thermistor.

[0160] The detection module can determine the resistance value of the thermistor by detecting the electrical parameters of the electrical signal flowing through the detection branch, thereby realizing overheat protection for the flyback transformer.

[0161] Considering that the reverse current in the detection branch may affect the detection accuracy of the detection module during the reverse recovery time of the first switch diode, the embodiment of the present disclosure utilizes a clamping branch to perform voltage clamping on the thermistor during the reverse recovery time of the first switch diode, thereby reducing the current value of the reverse current in the detection branch, so that the electrical parameters of the electrical signal flowing through the first protection circuit are close to the electrical parameters of the electrical signal flowing through the primary circuit, thereby effectively improving the detection accuracy of the detection module and effectively realizing overcurrent protection of the flyback transformer.

[0162] Exemplarily, the flyback transformer shown in the embodiment of the present disclosure can be tested, and the test conditions are: the primary winding turns of the flyback transformer Np=40Ts, the primary inductance Lp=305uH; the oven temperature is 40°C, the input voltage of the flyback transformer is 264Vac, and the output electrical signal is 11V 6A.

[0163] like Figure 7 As shown, Figure 7 1 is a schematic diagram of current waveforms of three different flyback transformers in a stable state according to an exemplary embodiment, wherein the magnetic cores of the three different flyback transformers are different.

[0164] (A) is the current waveform of the flyback transformer including the first type of magnetic core, wherein the maximum magnetic induction intensity Bmax=0.323T and the current peak value Ipk=2.57A; (B) is the current waveform of the flyback transformer including the second type of magnetic core, wherein the maximum magnetic induction intensity Bmax=0.323T and the current peak value Ipk=2.59A; (C) is the current waveform of the flyback transformer including the third type of magnetic core, wherein the maximum magnetic induction intensity Bmax=0.323T and the current peak value Ipk=2.57A.

[0165] like Figure 8 As shown, Figure 8 1 is a schematic diagram of current waveforms of three different flyback transformers under a short circuit condition according to an exemplary embodiment, wherein the three different flyback transformers have different magnetic cores.

[0166] (D) is the current waveform of the flyback transformer including the first type of magnetic core, wherein the maximum magnetic induction intensity Bmax=0.353T and the current peak value Ipk=2.784A; (E) is the current waveform of the flyback transformer including the second type of magnetic core, wherein the maximum magnetic induction intensity Bmax=0.353T and the current peak value Ipk=2.784A; (F) is the current waveform of the flyback transformer including the third type of magnetic core, wherein the maximum magnetic induction intensity Bmax=0.349T and the current peak value Ipk=2.748A.

[0167] Depend on Figure 7and Figure 8 It can be seen that when the short-circuit current peak is optimized and reduced, the three flyback transformers with different 96B cores can meet the requirements under high temperature conditions.

[0168] An embodiment of the present disclosure provides a power supply device, the power supply device comprising:

[0169] A flyback transformer as shown in one or more of the above technical solutions.

[0170] In the embodiment of the present disclosure, the power supply device includes: a flyback transformer; using the flyback transformer to convert the electrical signal output by the external power supply into the magnetic field energy of the flyback transformer, and then converting the magnetic field energy into electrical energy, which is input into the load circuit, thereby providing the load circuit with a power supply signal with lower noise and higher quality.

[0171] Here, the power supply device may be a flyback switching power supply device.

[0172] The flyback transformer of the embodiment of the present disclosure includes: a primary circuit, a secondary circuit, an auxiliary winding and a detection component.

[0173] The detection component includes: a first protection circuit, a second protection circuit and a detection module; wherein the detection pin of the detection module is connected to the first protection circuit and the second protection circuit; the second protection circuit includes: a detection branch and a clamping branch. The detection branch includes: a thermistor, a first voltage divider element and a first switch diode connected in series; the clamping branch is connected to the thermistor.

[0174] The disclosed embodiment utilizes a clamping branch to perform voltage clamping on the thermistor within the reverse recovery time of the first switching diode, thereby reducing the current value of the reverse current in the detection branch, so that the electrical parameters of the electrical signal flowing through the first protection circuit are close to the electrical parameters of the electrical signal flowing through the primary circuit, thereby effectively improving the detection accuracy of the detection module and effectively realizing overcurrent protection for the flyback transformer.

[0175] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0176] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A detection component, characterized in that: Applied in a flyback transformer, the flyback transformer includes a primary circuit, a secondary circuit and an auxiliary winding, and the detection component includes: A first protection circuit connected to the primary circuit; A detection module having a detection pin, wherein the detection pin is connected to the first protection circuit and is used to perform overcurrent protection on the primary circuit; A second protection circuit is connected to the detection pin, and the second protection circuit includes: A detection branch connected to the auxiliary winding; the detection branch comprises: a thermistor, a first voltage dividing element and a first switch diode connected in series; The clamping branch is connected to the thermistor and is used to clamp the voltage of the thermistor within the reverse recovery time of the first switching diode.

2. The detection component according to claim 1, characterized in that: An anode of the first switch diode is connected to the auxiliary winding, and a cathode of the first switch diode is connected to the first voltage dividing element; The first end of the thermistor is connected to the detection pin, and the second end of the thermistor is connected to the first voltage divider element; The clamping branch comprises: A second switch diode, wherein a cathode of the second switch diode is connected to the second end of the thermistor, and an anode of the second switch diode is grounded.

3. The detection component according to claim 1 or 2, characterized in that: The first protection circuit comprises: A second voltage-dividing element, wherein a first end of the second voltage-dividing element is connected to a primary switch tube of the primary circuit, and a second end of the second voltage-dividing element is grounded; The detection pin of the detection module is connected to the first end of the second voltage-dividing element, and is used to detect the voltage of the second voltage-dividing element when the primary switch tube is turned on.

4. The detection component according to claim 3, characterized in that: The detection component comprises: Circuit board; the first protection circuit and the second protection circuit are both located on the circuit board; The position of the second switch diode in the clamping branch on the circuit board is close to the position of the detection branch on the circuit board.

5. The detection component according to claim 4, characterized in that: The position of the thermistor on the circuit board is close to the position of the primary switch tube of the primary circuit on the circuit board.

6. The detection component according to claim 4 or 5, characterized in that: The detection component further includes: A filter capacitor, wherein a first end of the filter capacitor is connected to a first end of the thermistor, and a second end of the filter capacitor is connected to a common ground with the second switch diode.

7. The detection component according to claim 6, characterized in that: The detection component further includes: A voltage-stabilizing diode, wherein a first end of the voltage-stabilizing diode is connected to a first end of the thermistor, and a second end of the voltage-stabilizing diode is grounded; The circuit board at least comprises: A metal wiring is used to sequentially connect a detection pin of the detection module, a first end of the voltage-stabilizing diode, a first end of the filter capacitor, and a first end of the thermistor.

8. The detection component according to claim 2, characterized in that: The second switching diode is a first type diode; wherein a reverse recovery time of the first type diode is shorter than a reverse recovery time of the second type diode.

9. A flyback transformer, characterized in that: include: The detection component according to any one of claims 1 to 8; A primary circuit connected to a first protection circuit of the detection component; Secondary circuit; The auxiliary winding is located at one side of the primary winding, and the auxiliary winding is connected to the detection branch in the detection component.

10. A power supply device, characterized in that: include: A flyback transformer as claimed in claim 9.

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