High-power switching power supply circuit

Abstract

The utility model relates to the technical field of switching power supplies, in particular to a high-power switching power supply circuit, which is characterized in that a driving unit comprises a driving chip IC1, an inductor L1, a high-precision current sampling circuit, a low-power-consumption RCD absorption circuit and an external power semiconductor circuit; one end of the RCD absorption circuit is used as a first output end of the driving unit, and one end of the inductor L1 is used as a second output end of the driving unit; the output end of the driving chip IC1 is electrically connected with the input end of the external power semiconductor circuit, the ground end of the external power semiconductor circuit is electrically connected with the first end of the current sampling circuit, the second end of the current sampling circuit is electrically connected with the current sampling end of the driving chip IC1, and the third end of the current sampling circuit is grounded. The output end of the external power semiconductor circuit and the other end of the inductor L1 are electrically connected with the other end of the RCD absorption circuit. The problem that reliability and stability are reduced due to the fact that a high-power switching power supply is difficult in heat dissipation and serious in heating is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of switching power supply, especially a kind of high-power switching power supply circuit. BACKGROUND

[0002] As the key equipment of energy conversion and distribution, switching power supply is widely used in industrial control, communication equipment, server room and electric vehicle charging station and many other occasions. With the continuous improvement of the power density of switching power supply, the heat dissipation problem increasingly becomes the key factor restricting the performance and reliability of high-power switching power supply.

[0003] At present, in the working process of high-power switching power supply, its internal electronic components, especially power semiconductor devices (such as MOSFET, IGBT, etc.), will generate a large amount of heat due to the high integration in the chip, and the power semiconductor devices are packaged layer by layer inside the chip. If these heat cannot be dissipated in time and effectively, it will lead to a sharp rise in the temperature of the drive unit, accelerate the aging process of the internal and external electronic components of the drive unit, shorten its service life, and also reduce the performance parameters of the components, such as the increase of on-resistance and the decrease of switching speed, thereby affecting the overall conversion efficiency and stability of the high-power switching power supply. SUMMARY

[0004] In view of the above defects, the purpose of the utility model is to provide a kind of high-power switching power supply circuit, solve the problem of reliability and stability reduction caused by the difficulty of high-power switching power supply heat dissipation and serious heating.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] A kind of high-power switching power supply circuit, including drive unit, the drive unit includes drive chip IC1, inductance L1, high-precision current sampling circuit, low-power RCD absorption circuit and external power semiconductor circuit;One end of the RCD absorption circuit is used as the first output end of the drive unit, one end of the inductance L1 is used as the second output end of the drive unit;

[0007] The output end of the drive chip IC1 and the input end of the external power semiconductor circuit are electrically connected, the ground end of the external power semiconductor circuit and the first end of the current sampling circuit are electrically connected, the second end of the current sampling circuit and the current sampling end of the drive chip IC1 are electrically connected, the third end of the current sampling circuit is grounded, the output end of the external power semiconductor circuit and the other end of the inductance L1 are electrically connected with the other end of the RCD absorption circuit.

[0008] Furthermore, the external power semiconductor circuit includes a resistor R25, a resistor R27, a resistor R28, a capacitor C1, a diode D7 and a MOS transistor Q2; one end of the resistor R25 is used as an input end of the external power semiconductor circuit, one end of the resistor R28 is used as a ground end of the external power semiconductor circuit, and the drain of the MOS transistor Q2 is used as an output end of the external power semiconductor circuit;

[0009] One end of the capacitor C1 is electrically connected to the drain of the MOS transistor Q2, the other end of the capacitor C1 and the source of the MOS transistor Q2 are electrically connected to one end of the resistor R28, the other end of the resistor R25, the anode of the diode D7, and the gate of the MOS transistor Q2 are electrically connected to the other end of the resistor R28, the cathode of the diode D7 is electrically connected to one end of the resistor R27, and the other end of the resistor R27 is electrically connected to one end of the resistor R25.

[0010] Furthermore, the resistance of the resistor R25 is greater than the resistance of the resistor R27.

[0011] Furthermore, the RCD absorption circuit includes a capacitor C3, a resistor R13, a resistor R14, a resistor R15, a resistor R30 and a diode D1; one end of the resistor R14 serves as one end of the RCD absorption circuit, and the anode of the diode D1 serves as the other end of the RCD absorption circuit;

[0012] One end of the capacitor C3 and one end of the resistor R13 are electrically connected to one end of the resistor R14, the other end of the capacitor C3, the other end of the resistor R13, the other end of the resistor R14, and one end of the resistor R30 are electrically connected to one end of the resistor R15, and the other end of the resistor R30 and the other end of the resistor R15 are electrically connected to the cathode of the diode D1.

[0013] Furthermore, the current sampling circuit includes multiple resistors R3, one end of one of the resistors R3 is used as one end of the current sampling circuit, and the other end of the resistor R3 is used as the other end of the current sampling circuit; one end of all the resistors R3 are electrically connected together, and the other ends of all the resistors R3 are electrically connected together.

[0014] Furthermore, the driving unit further includes a resistor R6, a resistor R8, a resistor R10, a resistor R16, a capacitor C6, a capacitor EC1, a diode D2, a diode D3 and a low-power power receiving circuit; the input end of the power receiving circuit serves as the input end of the driving unit, and the anode of the diode D3 serves as the third output end of the driving unit;

[0015] The input end of the power receiving circuit is electrically connected to one end of the RCD absorption circuit, the cathode of the diode D3 is electrically connected to one end of the resistor R16, the other end of the resistor R16, the anode of the diode D2, and one end of the resistor R10 are all electrically connected to the positive electrode of the capacitor EC1, the startup power supply end of the driver chip IC1, the output end of the power receiving circuit, and one end of the capacitor C6 are all electrically connected to the cathode of the diode D2, the GND end of the driver chip IC1 and the other end of the capacitor C6 are grounded, the overvoltage protection end of the driver chip IC1 and the other end of the resistor R10 are all electrically connected to one end of the resistor R8, the other end of the resistor R8, the negative electrode of the capacitor EC1, the current detection end of the driver chip IC1, and one end of the resistor R6 are all grounded, and the other end of the resistor R6 is electrically connected to the maximum on-time end of the driver chip IC1.

[0016] Furthermore, the power receiving circuit includes multiple resistors R11, one end of the first resistor R11 is used as the input end of the power receiving circuit, the other end of the previous resistor R11 is electrically connected to one end of the next resistor R11, and the other end of the last resistor R11 is used as the output end of the power receiving circuit.

[0017] Furthermore, it also includes a rectifier and filter unit, a transformer unit, a de-stroboscopic unit and a high-precision dummy load unit; the output end of the rectifier and filter unit is electrically connected to the input end of the drive unit, the first output end, the second output end and the third output end of the drive unit are electrically connected to the first input end, the second input end and the third input end of the transformer unit respectively, the output end of the transformer unit is electrically connected to the input end of the dummy load unit, and the output end of the dummy load unit is electrically connected to the input end of the de-stroboscopic unit.

[0018] Furthermore, the dummy load unit includes multiple resistors R18; one end and the other end of one of the resistors R18 are used as the input end or output end of the dummy load unit; one end of all the resistors R18 are electrically connected together, and the other ends of all the resistors R18 are electrically connected together.

[0019] Furthermore, the transformer unit includes a resistor R7, a resistor R17, a capacitor C2, a capacitor EC2, a capacitor EC3, a capacitor CY1, a diode D4, a diode D6, and a transformer T1; the primary winding like-name end, the opposite-name end, and the auxiliary winding like-name end of the transformer T1 are respectively used as the first input end, the second input end, and the third input end of the transformer unit, and the positive and negative electrodes of the capacitor EC3 are both used as the output ends of the transformer unit;

[0020] The opposite-name end of the auxiliary winding of the transformer T1 is grounded, the same-name end of the primary winding of the transformer T1 is electrically connected to one end of the capacitor CY1, the other end of the capacitor CY1, one end of the capacitor C2, the cathode of the diode D6, the cathode of the diode D4, and the positive electrode of the capacitor EC3 are all electrically connected to the positive electrode of the capacitor EC2, the other end of the capacitor C2 and one end of the resistor R7 are all electrically connected to one end of the resistor R17, the other end of the resistor R7, the other end of the resistor R17, the anode of the diode D6, and the anode of the diode D4 are all electrically connected to the same-name end of the secondary winding of the transformer T1, and the opposite-name end of the secondary winding of the transformer T1 and the negative electrode of the capacitor EC3 are all electrically connected to the negative electrode of the capacitor EC2.

[0021] The technical solution provided by the utility model may have the following beneficial effects: based on the fact that the high-power switching power supply has difficulty in heat dissipation and has serious heat generation, it is because the driving unit has a high degree of integration, slow heat dissipation, and heat accumulation; therefore, the power semiconductor circuit with the most serious heat generation in the driving unit is externalized to achieve rapid heat dissipation. When the driving unit is started, the external power semiconductor circuit is turned on or off to realize the cycle; and through a high-precision current sampling circuit, the signal fluctuation during the cycle is reduced to avoid heat generation due to unstable operation; and through a low-power RCD absorption circuit, when facing a high-power transformer (the signal of the driving unit is transmitted to the transformer unit), the filtering and protection process is avoided to avoid serious heat generation due to excessive power consumption; so that the high-power switching power supply has good heat dissipation and less heat generation, which greatly improves the reliability and stability of the high-power switching power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a physical diagram of a circuit board of a high-power switching power supply circuit in one embodiment of the present utility model.

[0023] Figure 2 This is a circuit of a high-power switching power supply circuit in one embodiment of the utility model Figure 1 .

[0024] Figure 3 Yes Figure 1 A circuit of a high-power switching power supply circuit shown Figure 2 .

[0025] Wherein: drive unit 2, drive chip IC1, inductance L1, current sampling circuit 22, RCD absorption circuit 23, external power semiconductor circuit 24, resistance R25, resistance R27, resistance R28, capacitor C1, diode D7, MOS tube Q2, capacitor C3, resistance R13, resistance R14, resistance R15, resistance R30, diode D1, resistance R3, resistance R6, resistance R8, resistance R10, resistance R16, capacitor C6, capacitor EC1, diode D2, diode D3, power supply receiving circuit 21, resistance R11, rectifier filter unit 1, transformer unit 3, anti-flicker unit 5, dummy load unit 4, fuse F1, voltage-dependent resistor VR1, capacitor CX1, common mode inductor LF1, common mode inductor LF2, rectifier bridge DB1, resistance R1, resistance R2, inductance L2, capacitor CB1, capacitor CB2, capacitor CB3, voltage-dependent resistor VR2, anti-flicker chip IC2, resistance R19, resistance R19, resistance R20, resistance R21, resistance R22, resistance R23, resistance R24, capacitor C4, capacitor C5, diode D5, MOS tube Q1, resistance R18, resistance R7, resistance R17, capacitor C2, capacitor EC2, capacitor EC3, capacitor CY1, diode D4, diode D6, transformer T1. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are merely for the purpose of explaining the present application, and should not be construed as limiting the present application.

[0027] In the description of the embodiments of the present application, the terms "first", "second" are only for descriptive purpose, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0028] In the description of the embodiments of the present application, it should be noted that, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0029] The following combination Figures 1 to 3 , describing a high-power switching power supply circuit of an embodiment of the present utility model.

[0030] A high-power switching power supply circuit includes a drive unit 2, which includes a drive chip IC1, an inductor L1, a high-precision current sampling circuit 22, a low-power RCD absorption circuit 23, and an external power semiconductor circuit 24; one end of the RCD absorption circuit 23 serves as a first output end of the drive unit 2, and one end of the inductor L1 serves as a second output end of the drive unit 2;

[0031] The output end of the driver chip IC1 is electrically connected to the input end of the external power semiconductor circuit 24, the ground end of the external power semiconductor circuit 24 is electrically connected to the first end of the current sampling circuit 22, the second end of the current sampling circuit 22 is electrically connected to the current sampling end of the driver chip IC1, the third end of the current sampling circuit 22 is grounded, and the output end of the external power semiconductor circuit 24 and the other end of the inductor L1 are both electrically connected to the other end of the RCD absorption circuit 23.

[0032] The utility model proposes a high-power switching power supply circuit preferably implemented as follows Figures 2 to 3 As shown, the circuit board is as follows Figure 1 As shown. The reason why high-power switching power supplies have difficulty in dissipating heat and generate severe heat is that the drive unit is highly integrated, dissipates heat slowly, and accumulates heat. Therefore, the power semiconductor circuit (i.e., the external power semiconductor circuit 24) that generates the most heat in the drive unit is externalized to achieve rapid heat dissipation. When the drive unit is started, the external power semiconductor circuit 24 is turned on or off to achieve a cycle. A high-precision current sampling circuit 22 is used to reduce signal fluctuations during the cycle to avoid heat generation due to unstable operation. A low-power RCD absorption circuit 23 is also used to avoid severe heat generation due to excessive power consumption during the filtering and protection process when facing a high-power transformer (signal transmission from the drive unit 2 to the transformer unit 3). This ensures that the high-power switching power supply has good heat dissipation and generates less heat, greatly improving the reliability and stability of the high-power switching power supply.

[0033] It should be noted that the driver chip IC1 may be, for example, a BP3286HL chip, and the output terminal is a GATE terminal.

[0034] Furthermore, the external power semiconductor circuit 24 includes a resistor R25, a resistor R27, a resistor R28, a capacitor C1, a diode D7, and a MOS transistor Q2; one end of the resistor R25 serves as an input end of the external power semiconductor circuit 24, one end of the resistor R28 serves as a ground end of the external power semiconductor circuit 24, and the drain of the MOS transistor Q2 serves as an output end of the external power semiconductor circuit 24;

[0035] One end of the capacitor C1 is electrically connected to the drain of the MOS transistor Q2. The other end of the capacitor C1 and the source of the MOS transistor Q2 are electrically connected to one end of the resistor R28. The other end of the resistor R25, the anode of the diode D7, and the gate of the MOS transistor Q2 are electrically connected to the other end of the resistor R28. The cathode of the diode D7 is electrically connected to one end of the resistor R27. The other end of the resistor R27 is electrically connected to one end of the resistor R25.

[0036] In this embodiment, the external power semiconductor circuit 24 is composed of a resistor R25, a resistor R27, a resistor R28, a capacitor C1, a diode D7, and a MOS transistor Q2. The driver chip IC1 can drive the MOS transistor Q2 to be turned on or off via the resistor R25 to achieve a cycle, and the residual voltage on the gate of the MOS transistor Q2 can be discharged to the resistor R27 via the diode D6.

[0037] Furthermore, the resistance of the resistor R25 is greater than the resistance of the resistor R27.

[0038] In this embodiment, since the resistor R25 and the resistor R27 are respectively the driving resistor and the discharge resistor of the MOS transistor Q2, the resistance of the resistor R25 is preferably greater than the resistance of the resistor R27, so that the MOS transistor Q2 can be started slowly and turned off quickly, thereby reducing power consumption and heat.

[0039] Furthermore, the RCD absorption circuit 23 includes a capacitor C3, a resistor R13, a resistor R14, a resistor R15, a resistor R30 and a diode D1; one end of the resistor R14 serves as one end of the RCD absorption circuit 23, and the anode of the diode D1 serves as the other end of the RCD absorption circuit 23;

[0040] One end of the capacitor C3 and one end of the resistor R13 are electrically connected to one end of the resistor R14, the other end of the capacitor C3, the other end of the resistor R13, the other end of the resistor R14, and one end of the resistor R30 are electrically connected to one end of the resistor R15, and the other end of the resistor R30 and the other end of the resistor R15 are electrically connected to the cathode of the diode D1.

[0041] In this embodiment, the RCD absorption circuit 23 is composed of a capacitor C3, a resistor R13, a resistor R14, a resistor R15, a resistor R30 and a diode D1. When facing a high-power transformer (from the transformer unit 3), the absorption capacity can be increased by increasing the capacitor C3 or reducing the resistance values ​​of the resistors R13 and R14 to match the high-power transformer; more importantly, the cathode side of the diode D1 is composed of two resistors, namely the resistor R15 and the resistor R30, which can reduce the loss of a single resistor. Compared with using a single resistor on the cathode side of the diode D1, the loss is smaller and the heat generation is less.

[0042] Furthermore, the current sampling circuit 22 includes multiple resistors R3, one end of one resistor R3 is used as one end of the current sampling circuit 22, and the other end of the resistor R3 is used as the other end of the current sampling circuit 22; one end of all resistors R3 are electrically connected together, and the other ends of all resistors R3 are electrically connected together.

[0043] In this embodiment, the current sampling circuit 22 comprises a plurality of resistors R3 connected in parallel to form a sampling resistor, which can finely adjust the output current of the driver chip IC1 and reduce the error in the output current of the driver chip IC1. To further finely adjust the output current of the driver chip IC1, the resistor R3 preferably uses a resistor with an accuracy of 1% or less, such as a 0.5% accuracy resistor or a 1% accuracy resistor, to further reduce the error in the output current of the driver chip IC1.

[0044] Furthermore, the driving unit 2 further includes a resistor R6, a resistor R8, a resistor R10, a resistor R16, a capacitor C6, a capacitor EC1, a diode D2, a diode D3, and a low-power power receiving circuit 21; an input end of the power receiving circuit 21 serves as an input end of the driving unit 2, and an anode of the diode D3 serves as a third output end of the driving unit 2;

[0045] The input end of the power receiving circuit 21 is electrically connected to one end of the RCD absorption circuit 23, the cathode of the diode D3 is electrically connected to one end of the resistor R16, the other end of the resistor R16, the anode of the diode D2, and one end of the resistor R10 are all electrically connected to the positive electrode of the capacitor EC1, the startup power supply end of the driver chip IC1, the output end of the power receiving circuit 21, and one end of the capacitor C6 are all electrically connected to the cathode of the diode D2, the GND end of the driver chip IC1 and the other end of the capacitor C6 are grounded, the overvoltage protection end of the driver chip IC1 and the other end of the resistor R10 are all electrically connected to one end of the resistor R8, the other end of the resistor R8, the negative electrode of the capacitor EC1, the current detection end of the driver chip IC1, and one end of the resistor R6 are all grounded, and the other end of the resistor R6 is electrically connected to the maximum conduction time end of the driver chip IC1.

[0046] In this embodiment, the driving unit 2 further includes a peripheral circuit consisting of a resistor R6, a resistor R8, a resistor R10, a resistor R16, a capacitor C6, a capacitor EC1, a diode D2, a diode D3 and a low-power power receiving circuit 21, as shown in FIG. Figure 2 As shown, the driving function is realized, and at the same time, power consumption and heat generation are reduced when a low-power power receiving circuit 21 is used to receive the startup voltage. Among them, the driver chip IC1 can be a BP3286HL chip, the current detection terminal is the VS terminal, the maximum on-time terminal is the Tonmax terminal, the drain terminal is the DRAIN terminal, and the overvoltage protection terminal is the OVP terminal.

[0047] Further, the power receiving circuit 21 comprises a plurality of resistors R11, one end of a first resistor R11 serving as an input end of the power receiving circuit 21, the other end of the previous resistor R11 and one end of the next resistor R11 being electrically connected, and the other end of the last resistor R11 serving as an output end of the power receiving circuit 21.

[0048] In this embodiment, the power receiving circuit 21 is formed by a plurality of resistors R11 connected in series, serving as a high-voltage starting voltage dividing current limiting resistor of the driving chip IC1, which can well play a current limiting role, avoiding damage to the starting power supply end of the driving chip IC1; at the same time, being composed of a plurality of resistors R11, the total resistance value precision can be improved, ensuring that the resistance value matches the power supply voltage, avoiding that the voltage supplied to the starting power supply end of the driving chip IC1 is too large or too small, causing the driving chip IC1 to work unstably at the voltage trough, thereby causing heat due to unstable voltage.

[0049] It should be noted that the number of resistors R11 is preferably 2-4, and the number of resistors is less than 2, which is easy to cause the total resistance value to be too small and the current limiting capacity to be insufficient; and the number of resistors is more than 4, which is easy to cause the total resistance value to be too large, increase energy consumption, and cause the voltage of the starting power supply end of the driving chip IC1 to be insufficient, resulting in unstable work.

[0050] Further, it further comprises a rectifier filtering unit 1, a transformer unit 3, a frequency flash removal unit 5 and a high-precision dummy load unit 4; the output end of the rectifier filtering unit 1 is electrically connected with the input end of the driving unit 2, the first output end, the second output end and the third output end of the driving unit 2 are respectively electrically connected with the first input end, the second input end and the third input end of the transformer unit 3, the output end of the transformer unit 3 is electrically connected with the input end of the dummy load unit 4, and the output end of the dummy load unit 4 is electrically connected with the input end of the frequency flash removal unit 5.

[0051] In this embodiment, based on the driving unit 2 with low heat generation and good heat dissipation, the rectifier filtering unit 1 is electrically connected with the input end of the driving unit 2 for rectifier filtering; then the transformer unit 3 is electrically connected with the output end of the driving unit 2 for stable transformation; then the high-precision dummy load unit 4 is electrically connected with the output end of the transformer unit 3, so that the dummy load unit 4 can just bear the voltage output by the transformer unit 3, without causing additional loss, reducing heat generation, and at the same time, having the ability to stabilize the voltage when the switching power supply circuit is in an idle state; finally, the frequency flash removal unit 5 is electrically connected with the output end of the dummy load unit 4 to output after reducing the ripple of the output current, achieving the frequency flash removal effect; thereby forming a high-power switching power supply with good heat dissipation and low heat generation, improving the reliability and stability of the high-power switching power supply.

[0052] It should be noted that one of the preferred circuit structures of the rectifier filtering unit 1 is as shown in Figure 2As shown, the rectifier and filter unit 1 includes a fuse F1, a varistor VR1, a capacitor CX1, a common-mode inductor LF1, a common-mode inductor LF2, a rectifier bridge DB1, a resistor R1, a resistor R2, an inductor L2, a capacitor CB1, a capacitor CB2, a capacitor CB3 and a varistor VR2; one end of the varistor VR1 and one end of the fuse F1 are used as the input end of the rectifier and filter unit 1, and one end of the varistor VR2 is used as the output end of the rectifier and filter unit 1; one end of the varistor VR1 and one end of the capacitor CX1 are electrically connected to the first winding input end of the common-mode inductor LF1, and the other end of the fuse F1, the other end of the varistor VR1 and the other end of the capacitor CX1 are electrically connected to the second winding input end of the common-mode inductor LF1, and the first winding output end of the common-mode inductor LF1 is electrically connected to the output end of the common-mode inductor LF1. The output end and the second winding output end are electrically connected to the first winding input end and the second winding input end of the common-mode inductor LF2 respectively, the first winding output end and the second winding output end of the common-mode inductor LF2 are electrically connected to the first input end and the second input end of the rectifier bridge DB1 respectively, the second output end of the rectifier bridge DB1 is grounded, the first output end of the rectifier bridge DB1, one end of the capacitor CB1, and one end of the inductor L2 are all electrically connected to one end of the resistor R1, one end of the capacitor CB2, the other end of the inductor L2, one end of the resistor R2, and the other end of the resistor R1 are all electrically connected to one end of the varistor VR2, the other end of the resistor R2 is electrically connected to one end of the capacitor CB3, the other end of the capacitor CB1, the other end of the capacitor CB2, the other end of the capacitor CB3, and the other end of the varistor VR2 are grounded.

[0053] The rectifier and filter unit 1 is composed of a fuse F1, a varistor VR1, a capacitor CX1, a common-mode inductor LF1, a common-mode inductor LF2, a rectifier bridge DB1, a resistor R1, a resistor R2, an inductor L2, a capacitor CB1, a capacitor CB2, a capacitor CB3 and a varistor VR2. The signal is filtered out of differential and common-mode interference before the rectifier bridge DB1, and filtered after the rectifier bridge DB1, thereby realizing the rectification and filtering function.

[0054] It should also be noted that one of the preferred circuit structures of the destroboscopic unit 5 is as follows: Figure 3As shown, the destrobe unit 5 includes a destrobe chip IC2, a resistor R19, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a capacitor C4, a capacitor C5, a diode D5 and a MOS tube Q1; one end of the resistor R19 and one end of the capacitor C4 are used as the input end of the destrobe unit 5, and one end and the other end of the resistor R24 ​​are used as the output end of the destrobe unit 5; the other end of the resistor R19 and one end of the capacitor C5 are electrically connected to the voltage end of the destrobe chip IC2, the other end of the capacitor C5 and the GND end of the destrobe chip IC2 are grounded, and one end of the resistor R19 and the cathode of the diode D5 are connected to the cathode of the resistor R24 One end is electrically connected, the anode of the diode D5, the other end of the resistor R24, and one end of the resistor R21 are all electrically connected to the drain of the MOS tube Q1, the other end of the resistor R21 and one end of the resistor R20 are all electrically connected to the protection end of the destrober chip IC2, the other end of the resistor R20 is grounded, the gate of the MOS tube Q1 is electrically connected to the gate end of the destrober chip IC2, one end of the resistor R22, one end of the resistor R23, and the source of the MOS tube Q1 are all electrically connected to the current detection end of the destrober chip IC2, the other end of the resistor R22, the other end of the resistor R23, and one end of the capacitor C4 are all grounded, and the other end of the capacitor C4 is electrically connected to the current ripple end of the destrober chip IC2.

[0055] The de-strobe unit 5 is composed of a de-strobe chip IC2, resistors R19, R20, R21, R22, R23, R24, capacitors C4, C5, diode D5, and MOS transistor Q1, which reduces current ripple and achieves de-strobe. The de-strobe chip IC2 can be a JW1251O, with a voltage terminal at VIN, a current ripple terminal at VC, a gate terminal at VG, a current detection terminal at VS, and a protection terminal at VLMT.

[0056] Furthermore, the dummy load unit 4 includes multiple resistors R18; one end and the other end of one resistor R18 are both used as the input end or the output end of the dummy load unit 4; one end of all resistors R18 are electrically connected together, and the other ends of all resistors R18 are electrically connected together.

[0057] In this embodiment, the dummy load unit 4 is composed of multiple resistors R18 connected in parallel, and is connected in parallel between the transformer unit 3 and the de-strobe unit 5. It acts as a load when the de-strobe unit 5 is not connected to a load, maintaining the voltage stability of the switching power supply circuit when no-load, and also serves as a discharge resistor when the power is off to ensure the stability of the switching power supply circuit; more importantly, the parallel connection of multiple resistors R18 can accurately adjust the carrying capacity of the dummy load unit 4, so as to achieve no-load voltage stabilization capability without increasing additional losses.

[0058] It should be noted that, because the carrying capacity of the dummy load unit 4 is precisely adjusted by connecting multiple resistors R18 in parallel, if the total resistance of the dummy load unit 4 is too small, additional losses may be increased, and if the total resistance is too large, it will not be able to play the role of no-load voltage stabilization; therefore, the number of resistors R18 is preferably 2-4, which meets the precise adjustment requirements and avoids the total resistance being too large or too small.

[0059] Furthermore, the transformer unit 3 includes a resistor R7, a resistor R17, a capacitor C2, a capacitor EC2, a capacitor EC3, a capacitor CY1, a diode D4, a diode D6, and a transformer T1; the primary winding like-name terminal, the opposite-name terminal, and the auxiliary winding like-name terminal of the transformer T1 serve as the first input terminal, the second input terminal, and the third input terminal of the transformer unit 3, respectively; and the positive and negative electrodes of the capacitor EC3 serve as the output terminals of the transformer unit 3;

[0060] The opposite-name end of the auxiliary winding of the transformer T1 is grounded, the same-name end of the primary winding of the transformer T1 is electrically connected to one end of the capacitor CY1, the other end of the capacitor CY1, one end of the capacitor C2, the cathode of the diode D6, the cathode of the diode D4, and the positive electrode of the capacitor EC3 are all electrically connected to the positive electrode of the capacitor EC2, the other end of the capacitor C2 and one end of the resistor R7 are all electrically connected to one end of the resistor R17, the other end of the resistor R7, the other end of the resistor R17, the anode of the diode D6, and the anode of the diode D4 are all electrically connected to the same-name end of the secondary winding of the transformer T1, and the opposite-name end of the secondary winding of the transformer T1 and the negative electrode of the capacitor EC3 are all electrically connected to the negative electrode of the capacitor EC2.

[0061] In this embodiment, the transformer unit 3 cooperates with the drive unit 2 to achieve voltage transformation, wherein a preferred circuit structure is as follows: Figure 3 As shown, it is composed of resistor R7, resistor R17, capacitor C2, capacitor EC2, capacitor EC3, capacitor CY1, diode D4, diode D6 and transformer T1.

[0062] Other structures and operations of a high-power switching power supply circuit according to an embodiment of the present invention are known to ordinary technicians in this field and will not be described in detail here.

[0063] Throughout this specification, references to terms such as "embodiment" and "example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0064] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A high-power switching power supply circuit, characterized in that: The device comprises a driving unit, wherein the driving unit includes a driving chip IC1, an inductor L1, a high-precision current sampling circuit, a low-power RCD absorption circuit, and an external power semiconductor circuit; one end of the RCD absorption circuit serves as a first output end of the driving unit, and one end of the inductor L1 serves as a second output end of the driving unit; The output end of the driver chip IC1 is electrically connected to the input end of the external power semiconductor circuit, the ground end of the external power semiconductor circuit is electrically connected to the first end of the current sampling circuit, the second end of the current sampling circuit is electrically connected to the current sampling end of the driver chip IC1, the third end of the current sampling circuit is grounded, and the output end of the external power semiconductor circuit and the other end of the inductor L1 are both electrically connected to the other end of the RCD absorption circuit.

2. A high-power switching power supply circuit according to claim 1, characterized in that: The external power semiconductor circuit includes a resistor R25, a resistor R27, a resistor R28, a capacitor C1, a diode D7 and a MOS transistor Q2; one end of the resistor R25 serves as an input end of the external power semiconductor circuit, one end of the resistor R28 serves as a ground end of the external power semiconductor circuit, and the drain of the MOS transistor Q2 serves as an output end of the external power semiconductor circuit; One end of the capacitor C1 is electrically connected to the drain of the MOS transistor Q2, the other end of the capacitor C1 and the source of the MOS transistor Q2 are electrically connected to one end of the resistor R28, the other end of the resistor R25, the anode of the diode D7, and the gate of the MOS transistor Q2 are electrically connected to the other end of the resistor R28, the cathode of the diode D7 is electrically connected to one end of the resistor R27, and the other end of the resistor R27 is electrically connected to one end of the resistor R25.

3. A high-power switching power supply circuit according to claim 2, characterized in that: The resistance of the resistor R25 is greater than the resistance of the resistor R27.

4. A high-power switching power supply circuit according to claim 1, characterized in that: The RCD absorption circuit includes a capacitor C3, a resistor R13, a resistor R14, a resistor R15, a resistor R30 and a diode D1; one end of the resistor R14 serves as one end of the RCD absorption circuit, and the anode of the diode D1 serves as the other end of the RCD absorption circuit; One end of the capacitor C3 and one end of the resistor R13 are electrically connected to one end of the resistor R14, the other end of the capacitor C3, the other end of the resistor R13, the other end of the resistor R14, and one end of the resistor R30 are electrically connected to one end of the resistor R15, and the other end of the resistor R30 and the other end of the resistor R15 are electrically connected to the cathode of the diode D1.

5. The high-power switching power supply circuit according to claim 1, characterized in that: The current sampling circuit includes multiple resistors R3, one end of one of the resistors R3 is used as one end of the current sampling circuit, and the other end of the resistor R3 is used as the other end of the current sampling circuit; one end of all the resistors R3 is electrically connected together, and the other ends of all the resistors R3 are electrically connected together.

6. A high-power switching power supply circuit according to claim 1, characterized in that: The driving unit further includes a resistor R6, a resistor R8, a resistor R10, a resistor R16, a capacitor C6, a capacitor EC1, a diode D2, a diode D3 and a low-power power receiving circuit; The input terminal of the power receiving circuit is used as the input terminal of the driving unit, and the anode of the diode D3 is used as the third output terminal of the driving unit; The input end of the power receiving circuit is electrically connected to one end of the RCD absorption circuit, the cathode of the diode D3 is electrically connected to one end of the resistor R16, the other end of the resistor R16, the anode of the diode D2, and one end of the resistor R10 are all electrically connected to the positive electrode of the capacitor EC1, the startup power supply end of the driver chip IC1, the output end of the power receiving circuit, and one end of the capacitor C6 are all electrically connected to the cathode of the diode D2, the GND end of the driver chip IC1 and the other end of the capacitor C6 are grounded, the overvoltage protection end of the driver chip IC1 and the other end of the resistor R10 are all electrically connected to one end of the resistor R8, the other end of the resistor R8, the negative electrode of the capacitor EC1, the current detection end of the driver chip IC1, and one end of the resistor R6 are all grounded, and the other end of the resistor R6 is electrically connected to the maximum on-time end of the driver chip IC1.

7. A high-power switching power supply circuit according to claim 6, characterized in that: The power receiving circuit includes multiple resistors R11, one end of the first resistor R11 is used as the input end of the power receiving circuit, the other end of the previous resistor R11 is electrically connected to one end of the next resistor R11, and the other end of the last resistor R11 is used as the output end of the power receiving circuit.

8. The high-power switching power supply circuit according to claim 1, characterized in that: It also includes a rectifier and filter unit, a transformer unit, a de-stroboscopic unit and a high-precision dummy load unit; the output end of the rectifier and filter unit is electrically connected to the input end of the drive unit, the first output end, the second output end and the third output end of the drive unit are electrically connected to the first input end, the second input end and the third input end of the transformer unit respectively, the output end of the transformer unit is electrically connected to the input end of the dummy load unit, and the output end of the dummy load unit is electrically connected to the input end of the de-stroboscopic unit.

9. The high-power switching power supply circuit according to claim 8, characterized in that: The dummy load unit includes multiple resistors R18; one end and the other end of one of the resistors R18 are used as the input end or the output end of the dummy load unit; one end of all the resistors R18 are electrically connected together, and the other ends of all the resistors R18 are electrically connected together.

10. The high-power switching power supply circuit according to claim 8, characterized in that: The transformer unit includes a resistor R7, a resistor R17, a capacitor C2, a capacitor EC2, a capacitor EC3, a capacitor CY1, a diode D4, a diode D6, and a transformer T1; the primary winding like-name end, the opposite-name end, and the auxiliary winding like-name end of the transformer T1 are respectively used as the first input end, the second input end, and the third input end of the transformer unit, and the positive electrode and negative electrode of the capacitor EC3 are both used as the output end of the transformer unit; The opposite-name end of the auxiliary winding of the transformer T1 is grounded, the same-name end of the primary winding of the transformer T1 is electrically connected to one end of the capacitor CY1, the other end of the capacitor CY1, one end of the capacitor C2, the cathode of the diode D6, the cathode of the diode D4, and the positive electrode of the capacitor EC3 are all electrically connected to the positive electrode of the capacitor EC2, the other end of the capacitor C2 and one end of the resistor R7 are all electrically connected to one end of the resistor R17, the other end of the resistor R7, the other end of the resistor R17, the anode of the diode D6, and the anode of the diode D4 are all electrically connected to the same-name end of the secondary winding of the transformer T1, and the opposite-name end of the secondary winding of the transformer T1 and the negative electrode of the capacitor EC3 are all electrically connected to the negative electrode of the capacitor EC2.

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