阅读说明：本技术 一种无高压大电解电容的开关电源电路及电视机 (Switch power supply circuit without high-voltage large electrolytic capacitor and television ) 是由 陈建忠 杨寄桃 鲍晓杰 于 2019-11-26 设计创作，主要内容包括：本发明公开了一种无高压大电解电容的开关电源电路及电视机,所述开关电源与所述用电设备连接,包括第一滤波模块、整流模块、第二滤波模块、第三滤波模块和开关电源模块；交流电源输出的交流电经所述第一滤波模块进行滤波处理后通过整流模块进行整流后变为直流电,所述开关电源模块将经第二滤波模块进行滤波处理后的直流电转换成预设电压后分别输出至所述用电设备；所述第一滤波模块用于抑制开关电源模块工作时产生的共模干扰信号,所述第二滤波模块用于抑制所述开关电源模块工作时产生电磁辐射干扰信号和差模干扰信号,所述第三滤波模块用于抑制所述开关电源模块的输入端和输出端之间的干扰信号,有效降低了电磁辐射,提高了电源工作的安全性。(The invention discloses a switching power supply circuit without a high-voltage large electrolytic capacitor and a television, wherein the switching power supply is connected with electric equipment and comprises a first filtering module, a rectifying module, a second filtering module, a third filtering module and a switching power supply module; the alternating current output by the alternating current power supply is subjected to filtering processing by the first filtering module and then rectified by the rectifying module to be converted into direct current, and the direct current subjected to filtering processing by the second filtering module is converted into preset voltage by the switching power supply module and then respectively output to the electric equipment; the first filtering module is used for inhibiting common-mode interference signals generated when the switching power supply module works, the second filtering module is used for inhibiting electromagnetic radiation interference signals and differential-mode interference signals generated when the switching power supply module works, and the third filtering module is used for inhibiting interference signals between the input end and the output end of the switching power supply module, so that electromagnetic radiation is effectively reduced, and the safety of power supply work is improved.)

1. A switch power supply circuit without a high-voltage large electrolytic capacitor is connected with electric equipment and is characterized by comprising a first filtering module, a rectifying module, a second filtering module, a third filtering module and a switch power supply module; the alternating current output by the alternating current power supply is filtered by the first filtering module and then output to the rectifying module, the rectifying module rectifies the filtered alternating current and then outputs direct current to the second filtering module, the second filtering module filters the direct current and then outputs the direct current to the switching power supply module, and the switching power supply module converts the direct current into preset voltage and then outputs the preset voltage to the electric equipment to supply power to the television equipment;

the first filtering module is used for inhibiting a common-mode interference signal generated when the switching power supply module works, the second filtering module is used for inhibiting an electromagnetic radiation interference signal and a differential-mode interference signal generated when the switching power supply module works, and the third filtering module is used for inhibiting an interference signal between the input end of the switching power supply module and the output end of the switching power supply module.

2. The switching power supply circuit without the high voltage large electrolytic capacitor as claimed in claim 1, wherein the first filtering module comprises a first filtering unit and a second filtering unit, the first filtering unit is configured to suppress a common mode interference signal generated when the switching power supply module operates, and the second filtering unit is configured to suppress a common mode interference signal between a zero line or a live line and an input end of the switching power supply input module.

3. The switching power supply circuit without the high-voltage large electrolytic capacitor as claimed in claim 1, wherein the second filtering module comprises a third filtering unit and a fourth filtering unit, the third filtering unit is configured to suppress a differential mode interference signal conducted when the switching power supply module operates, and the fourth filtering unit is configured to suppress an electromagnetic radiation interference signal generated when the switching power supply module operates.

4. The switching power supply circuit without the high-voltage large electrolytic capacitor according to claim 2, wherein the first filtering unit comprises a first Y capacitor, a second Y capacitor, a first X capacitor and a first common-mode inductor, one end of the first Y capacitor is connected to the 4 th pin and the zero line of the first common-mode inductor, one end of the second Y capacitor is connected to the 1 st pin and the fire line of the first common-mode inductor, and the other end of the first Y capacitor and the other end of the second Y capacitor are both connected to a screw ground; one end of the first X capacitor is connected with the 3 rd pin of the first common-mode inductor and the second filtering unit, and the other end of the first X capacitor is connected with the 2 nd pin of the first common-mode inductor and the second filtering unit.

5. The switching power supply circuit without the high-voltage large electrolytic capacitor as claimed in claim 4, wherein the second filter unit comprises a third Y capacitor, a fourth Y capacitor, a second X capacitor and a second common-mode inductor; one end of the third Y capacitor is connected with one end of the first X capacitor and the 4 th pin of the second common-mode inductor, one end of the fourth Y capacitor is connected with the other end of the first X capacitor and the 1 st pin of the second common-mode inductor, and the other end of the third Y capacitor and the other end of the fourth Y capacitor are both connected with a screw ground; one end of the second X capacitor is connected with the 3 rd pin of the second common mode inductor and the rectifying module, and the other end of the second X capacitor is connected with the 2 nd pin of the second common mode inductor and the rectifying module.

6. The switching power supply circuit without the high-voltage large electrolytic capacitor as claimed in claim 3, wherein the third filtering unit comprises a first capacitor and a third common-mode inductor, one end of the first capacitor is connected to the rectifying module, a pin 3 of the third common-mode inductor and the third filtering module, the other end of the first capacitor is connected to the rectifying module and a pin 2 of the third common-mode inductor, and a pin 1 and a pin 4 of the third common-mode inductor are both connected to the fourth filtering unit.

7. The switching power supply circuit without the large high-voltage electrolytic capacitor as claimed in claim 6, wherein the fourth filtering unit comprises a second capacitor, one end of the second capacitor is connected to the input terminal of the switching power supply module and the 1 st pin of the third common-mode inductor, and the other end of the second capacitor is connected to the 4 th pin of the third common-mode inductor and the power ground.

8. The switching power supply circuit without the high-voltage large electrolytic capacitor as recited in claim 6, wherein the third filtering module comprises a fifth Y capacitor, one end of the fifth Y capacitor is connected to one end of the first capacitor, and the other end of the fifth Y capacitor is connected to the output end of the switching power supply module and the secondary ground to which the switching power supply module is connected.

9. The switching power supply circuit without the high-voltage large electrolytic capacitor as claimed in claim 1, wherein the switching power supply module comprises a switching tube, a transformer, a first buffer absorption unit and a second buffer absorption unit, the first buffer absorption unit is used for suppressing a spike voltage generated by the transformer, and the second buffer absorption unit is used for suppressing an interference signal generated by the switching tube in a turn-on or turn-off process.

10. A television set comprising a switching power supply circuit without a high voltage large electrolytic capacitor according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of power supplies, in particular to a switching power supply circuit without a high-voltage large electrolytic capacitor and a television.

Background

Along with the development of the society, the requirements of people on the size, the weight and the cost of various machine equipment are higher and higher, and the corresponding requirements on the switching power supply are also higher, so that the design difficulty of an EMI filter circuit in the switching power supply is increased, the traditional EMI filter circuit is only suitable for the switching power supply with a high-voltage large electrolytic capacitor, the noise of the switching power supply without the high-voltage large electrolytic capacitor is higher, conducted and radiated interference signals generated by the switching power supply in the working process are difficult to inhibit, and the working safety of the switching power supply is further reduced.

Thus, the prior art has yet to be improved and enhanced.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a switching power supply circuit without a high-voltage large electrolytic capacitor and a television, which optimizes the mechanism of the circuit, effectively inhibits common-mode interference signals and differential-mode interference signals generated by the power supply during operation, reduces electromagnetic radiation and improves the safety of the power supply during operation.

In order to achieve the purpose, the invention adopts the following technical scheme:

a switch power supply circuit without a high-voltage large electrolytic capacitor is connected with electric equipment and comprises a first filtering module, a rectifying module, a second filtering module, a third filtering module and a switch power supply module; the alternating current output by the alternating current power supply is filtered by the first filtering module and then output to the rectifying module, the rectifying module rectifies the filtered alternating current and then outputs direct current to the second filtering module, the second filtering module filters the direct current and then outputs the direct current to the switching power supply module, and the switching power supply module converts the direct current into preset voltage and then respectively outputs the preset voltage to the electric equipment to supply power to the television equipment;

the first filtering module is used for inhibiting a common-mode interference signal generated when the switching power supply module works, the second filtering module is used for inhibiting an electromagnetic radiation interference signal and a differential-mode interference signal generated when the switching power supply module works, and the third filtering module is used for inhibiting an interference signal between the input end of the switching power supply module and the output end of the switching power supply module.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the first filtering module comprises a first filtering unit and a second filtering unit, the first filtering unit is used for inhibiting a common-mode interference signal generated when the switching power supply module works, and the second filtering unit is used for inhibiting the common-mode interference signal between a zero line or a live line and the input end of the switching power supply module.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the second filtering module comprises a third filtering unit and a fourth filtering unit, the third filtering unit is used for inhibiting a differential mode interference signal conducted when the switching power supply module works, and the fourth filtering unit is used for inhibiting an electromagnetic radiation interference signal generated when the switching power supply module works.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the first filtering unit comprises a first Y capacitor, a second Y capacitor, a first X capacitor and a first common-mode inductor, wherein one end of the first Y capacitor is connected with a 4 th pin and a zero line of the first common-mode inductor, one end of the second Y capacitor is connected with a 1 st pin and a live wire of the first common-mode inductor, and the other end of the first Y capacitor and the other end of the second Y capacitor are connected with a screw ground; one end of the first X capacitor is connected with the 3 rd pin of the first common-mode inductor and the second filtering unit, and the other end of the first X capacitor is connected with the 2 nd pin of the first common-mode inductor and the second filtering unit.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the second filtering unit comprises a second filtering unit which comprises a third Y capacitor, a fourth Y capacitor, a second X capacitor and a second common-mode inductor; one end of the third Y capacitor is connected with one end of the first X capacitor and the 4 th pin of the second common-mode inductor, one end of the fourth Y capacitor is connected with the other end of the first X capacitor and the 1 st pin of the second common-mode inductor, and the other end of the third Y capacitor and the other end of the fourth Y capacitor are both connected with a screw ground; one end of the second X capacitor is connected with the 3 rd pin of the second common mode inductor and the rectifying module, and the other end of the second X capacitor is connected with the 2 nd pin of the second common mode inductor and the rectifying module.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the third filtering unit comprises a first capacitor and a third common-mode inductor, one end of the first capacitor is connected with the rectifying module, a pin 3 of the third common-mode inductor and the third filtering module, the other end of the first capacitor is connected with the rectifying module and a pin 2 of the third common-mode inductor, and a pin 1 and a pin 4 of the third common-mode inductor are both connected with the fourth filtering unit.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the fourth filtering unit comprises a second capacitor, one end of the second capacitor is connected with the input end of the switching power supply module and the 1 st pin of the third common-mode inductor, and the other end of the second capacitor is connected with the 4 th pin of the third common-mode inductor and the power ground.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the third filtering module comprises a fifth Y capacitor, one end of the fifth Y capacitor is connected with one end of the first capacitor, and the other end of the fifth Y capacitor is connected with the output end of the switching power supply module and a secondary ground connected with the switching power supply module.

In the switching power supply circuit without the high-voltage large electrolytic capacitor, the switching power supply module comprises a switching tube, a transformer, a first buffering absorption unit and a second buffering absorption unit, wherein the first buffering absorption unit is used for inhibiting peak voltage generated by the transformer, and the second buffering absorption unit is used for inhibiting an interference signal generated in the switching tube in the on or off process.

A television set comprises a switching power supply circuit as described above.

Compared with the prior art, the switching power supply circuit without the high-voltage large electrolytic capacitor and the television are characterized in that the switching power supply is connected with the electric equipment and comprises a first filtering module, a rectifying module, a second filtering module, a third filtering module and a switching power supply module; the alternating current output by the alternating current power supply is subjected to filtering processing by the first filtering module and then rectified by the rectifying module to be converted into direct current, and the direct current subjected to filtering processing by the second filtering module is converted into preset voltage by the switching power supply module and then respectively output to the electric equipment; the first filtering module is used for inhibiting common-mode interference signals generated when the switching power supply module works, the second filtering module is used for inhibiting electromagnetic radiation interference signals and differential-mode interference signals generated when the switching power supply module works, and the third filtering module is used for inhibiting interference signals between the input end and the output end of the switching power supply module, so that electromagnetic radiation is effectively reduced, and the safety of power supply work is improved.

Drawings

FIG. 1 is a block diagram of a switching power supply circuit without a high-voltage large electrolytic capacitor according to the present invention;

FIG. 2 is a schematic diagram of the connection of the switching power supply circuit without the high-voltage large electrolytic capacitor provided by the present invention with the screw ground, the primary ground, the power ground and the screen back plate;

fig. 3 is a schematic circuit diagram of a switching power supply circuit without a high-voltage large electrolytic capacitor according to the present invention.

Detailed Description

The invention provides a switching power supply circuit without a high-voltage large electrolytic capacitor and a television, which optimize the mechanism of the circuit, effectively inhibit common-mode interference signals and differential-mode interference signals generated by the power supply during working, reduce electromagnetic radiation and improve the working safety of the power supply.

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The switching power supply circuit 10 provided by the invention can be used in other fields such as liquid crystal displays, notebook computers, adapters and the like besides the television field, and can effectively reduce the cost, reduce the power supply volume, reduce interference signals and improve the electromagnetic compatibility of products.

Referring to fig. 1 and fig. 2, the switching power supply circuit 10 without a high voltage and a large electrolytic capacitor according to the present invention is connected to an electric device, and includes a first filtering module 100, a rectifying module 200, a second filtering module 300, a third filtering module 400 and a switching power supply module 500, where the first filtering module 100 is connected to an ac power supply 20 through a zero line N and a live line L, the first filtering unit 110 is further connected to a screw ground a, and is connected to the second filtering module 300 through the rectifying module 200, the second filtering module 300 is connected to the switching power supply module 500 and a power ground B, the switching power supply module 500 is connected to the electric device, and the third filtering module 400 is connected to a secondary ground C connected to the second filtering module 300 and the switching power supply module 500; it should be noted that in this embodiment, the electric devices are a screen backboard 30 and a light bar 40, there are two corresponding switching power supply modules 500, one of the switching power supply modules 500 is used for supplying power to the screen backboard 30, the other switching power supply is used for supplying power to the light bar 40, and the two switching power supply modules 500 have the same functional structure.

The alternating current output by the alternating current power supply 20 is filtered by the first filtering module 100 and then output to the rectifying module 200, the rectifying module 200 rectifies the filtered alternating current and outputs direct current to the second filtering module 300, the second filtering module 300 filters the direct current and outputs the filtered direct current to the switching power supply module 500, and the switching power supply module 500 converts the direct current into preset voltage and then outputs the preset voltage to the screen back plate 30 and the light bar 40 respectively to supply power to the screen back plate 30 and the light bar 40, so that stable operation of the screen back plate 30 and the light bar 40 is ensured.

The first filtering module 100 is configured to suppress a common-mode interference signal generated when the switching power supply module 500 works, the second filtering module 300 is configured to suppress an electromagnetic radiation interference signal and a differential-mode interference signal generated when the switching power supply module 500 works, and the third filtering module 400 is configured to suppress an interference signal between an input end of the switching power supply module 500 and an output end of the switching power supply module 500, so that safety of power supply work is improved.

When the switching power supply circuit 10 enters an operating state to supply power to the electric device, the switching power supply module 500 generates a common mode interference signal and a differential mode interference signal during the operating process, wherein the common mode interference signal is an interference signal between the live line L or the zero line N and the ground, the differential mode interference signal is an interference signal between the zero line N and the live line L in the ac power supply 20, the common mode interference signal finally output by the electric equipment to the live line L and the zero line N is filtered by the first filtering module 100 and then is connected to the ac power supply socket, common-mode interference signals generated by the electric equipment and the switching power supply module 500 during operation are filtered by the first filtering module 100 at the ac power outlet, further, the common mode interference signal is prevented from being output to a power grid and other electric equipment to interfere with the other electric equipment; meanwhile, the common-mode interference signal generated by the power grid is filtered by the first filtering module 100, so that the common-mode interference signal of the power grid is prevented from interfering with the work of the electric equipment, and the power supply of the electric equipment is stable.

The second filtering module 300 is connected between the switching power supply module 500 and the rectifying module 200, so that conducted common mode interference signals and differential mode interference signals are greatly suppressed, signal interference between a power grid and other electric equipment and the switching power supply module 500 is avoided, and normal operation of the electric equipment is ensured; and the third filtering module 400 connected between the second filtering module 300 and the secondary ground C connected to the switching power supply module 500 can filter out the common mode noise output by the switching power supply module 500, so as to balance the interference signal between the second filtering module 300 and the output terminal of the switching power supply module 500, and avoid the interference signal between the second filtering module 300 and the output terminal of the switching power supply module 500 from being large and interfering with the operation of the electric equipment.

Further, referring to fig. 3, the first filtering module 100 includes a first filtering unit 110 and a second filtering unit 120, the first filtering unit 110 is connected to the ac power supply 20, the second filtering unit 120 and a screw ground a, wherein the screw ground a is connected to the screen back plate 30, and the second filtering unit 120 is also connected to the screw ground a and the rectifying module 200; the first filtering unit 110 is configured to suppress a common mode interference signal generated when the switching power supply module 500 operates, that is, to suppress a common mode interference signal output by an electrical device and transmitted to the live line L and the zero line N, or a common mode interference signal generated by the power grid and other electrical devices, so as to avoid affecting the normal operation of the electrical device, the power grid, and other electrical devices; the second filtering unit 120 is configured to suppress a common mode interference signal between the zero line N or the live line L and the input end of the switching power supply module 500, that is, the second filtering unit 120 is configured to balance the interference signal between the live line L or the zero line N and the output end of the switching power supply module 500, so that the common mode interference signal is sequentially filtered in the process of inputting the alternating current, the influence of the common mode interference signal on the switching power supply circuit 10 is greatly suppressed, and the safety of the power supply operation is improved.

Further, the second filtering module 300 includes a third filtering unit 310 and a fourth filtering unit 320, the second filtering unit 120 is connected to the rectifying module 200, the third filtering module 400 and the fourth filtering unit 320, and the fourth filtering unit 320 is further connected to the input terminal of the switching power supply module 500 and a power ground B; the third filtering unit 310 is configured to suppress a differential mode interference signal conducted by the switching power supply module 500 during operation, the fourth filtering unit 320 is configured to suppress an electromagnetic radiation interference signal generated by the switching power supply module 500 during operation, and the presence of the first filtering unit suppresses a differential mode interference signal generated by the switching power supply module 500 during operation, so as to prevent the differential mode interference signal from being output to a power grid and other electric devices through an ac power outlet, or prevent the differential mode interference signal generated by the power grid from being output to the switching power supply module 500, so as to affect normal operation of the switching power supply circuit 10; the fourth filtering unit 320 is connected between the input terminal of the switching power supply module 500 and the power ground B, so that a main loop in the switching power supply circuit 10 is minimized, and electromagnetic radiation generated by the switching power supply module 500 through the loop when the switching power supply circuit 10 works is reduced.

Further, please refer to fig. 3, the first filtering unit 110 includes a first Y capacitor CY1, a second Y capacitor CY2, a first X capacitor CX1, and a first common mode inductor L1, wherein one end of the first Y capacitor CY1 is connected to the 4 th pin of the first common mode inductor L1 and the zero line N, one end of the second Y capacitor CY2 is connected to the 1 st pin of the first common mode inductor L1 and the live line L, and the other end of the first Y capacitor CY1 and the other end of the second Y capacitor CY2 are both connected to the screw ground a; the first Y capacitor CY1 and the second Y capacitor CY2 form a capacitor Y1 in pairs, one end of the first X capacitor CX1 is connected to the 3 rd pin of the first common-mode inductor L1 and the second filter unit 120, the other end of the first X capacitor CX1 is connected to the 2 nd pin of the first common-mode inductor L1 and the second filter unit 120, the first Y capacitor CY1 and the second Y capacitor CY2 are connected in pairs between the live line L and the neutral line N and the ground line, are close to an alternating current power supply socket, suppress a common-mode interference signal generated by the power grid at the input end of the alternating current power supply 20, and avoid the common-mode interference signal generated by the power grid from influencing the electric equipment and the switching power supply module 500; also can with the consumer with the module is produced to switching power supply module 500 is unified the filtering at alternating current supply socket's port department, when having reduced common mode interference return circuit, avoids the common mode interference signal that this consumer and switching power supply module 500 produced to cause the interference to electric wire netting and other consumers, and then influences switching power supply circuit 10's security.

Further, the second filtering unit 120 includes a second filtering unit 120 including a third Y capacitor CY3, a fourth Y capacitor CY4, a second X capacitor CX2, and a second common mode inductor L2; one end of the third Y capacitor CY3 is connected to one end of the first X capacitor CX1 and the 4 th pin of the second common mode inductor L2, one end of the fourth Y capacitor CY4 is connected to the other end of the first X capacitor CX1 and the 1 st pin of the second common mode inductor L2, and the other end of the third Y capacitor CY3 and the other end of the fourth Y capacitor CY4 are both connected to a screw ground a; second X electric capacity CX 2's one end is connected second common mode inductance L2 the 3 rd foot with rectifier module 200, second X electric capacity CX 2's the other end is connected second common mode inductance L2 the 2 nd foot with rectifier module 200, third Y electric capacity CY3 and fourth Y electric capacity CY4 appear in pairs and constitute electric capacity Y2, the common mode interference signal of the input of filtering switching power supply module 500 through second filtering unit 120, also promptly the common mode interference signal of switching power supply module 500 conduction in the course of the work, the realization is right common mode interference signal filters one by one, has balanced live wire L or zero line N and elementary interference signal.

Further, the third filtering unit 310 includes a first capacitor C1 and a third common mode inductor L3, one end of the first capacitor C1 is connected to the rectifying module 200, the 3 rd pin of the third common mode inductor L3 and the third filtering module 400, the other end of the first capacitor C1 is connected to the rectifying module 200 and the 2 nd pin of the third common mode inductor L3, the 1 st pin and the 4 th pin of the third common mode inductor L3 are both connected to the fourth filtering unit 320, and the first capacitor C1 suppresses the differential mode interference signal generated by the switching power supply module 500, so as to avoid the interference of the differential mode interference signal in the switching power supply circuit 10, where the first capacitor C1 is a PFC capacitor in this embodiment.

Further, the fourth filtering unit 320 includes a second capacitor C2, one end of the second capacitor C2 is connected to the input terminal of the switching power supply module 500 and the 1 st pin of the third common mode inductor L3, the other end of the second capacitor C2 is connected to the 4 th pin of the third common mode inductor L3 and the power ground B, wherein the second capacitor C2 is a PFC capacitor, the first capacitor C1, the third common mode inductor L3 and the second capacitor C2 form a pi-type filter, the first capacitor C1 and the third common mode inductor L3 are used for filtering the differential mode interference signal, the second capacitor C2 is connected between the input terminal of the switching power supply module 500 and the power ground B, the main loop in the switching power supply circuit 10 is minimized, and the electromagnetic radiation generated by the switching power supply module 500 through the loop when the switching power supply circuit 10 works is reduced; and through the pi-type filter, the capacity of the X capacitor in the first filtering module 100 is reduced, the bleed-off voltage after the ac power supply 20 is disconnected is reduced, the safety of the switching power supply circuit 10 is improved, and the loss of the bleed-off resistor of the X capacitor is reduced, thereby reducing the standby power consumption.

Further, the third filtering module 400 includes a fifth Y capacitor CY5, one end of the fifth Y capacitor CY5 is connected to one end of the first capacitor C1, the other end of the fifth Y capacitor CY5 is connected to the output end of the switching power supply module 500 and a secondary ground C to which the switching power supply module 500 is connected, and the fifth Y capacitor CY5 is disposed between the first capacitor C1 and the secondary ground C, so that an interference signal between the primary ground and the secondary ground C is balanced, the interference signal between the input end and the output end of the switching power supply module 500 is suppressed, and the safety of the switching power supply circuit 10 is further improved.

Further, referring to fig. 3, in the switching power module 500 connected to the light bar 40, the fourth filtering unit 320 includes a third capacitor C3, the third filtering module 400 includes a sixth Y capacitor CY6, one end of the third capacitor C3 is connected to the 1 st pin of the third common-mode inductor L3 and the input end of the switching power module 500, the other end of the third capacitor C3 is connected to the 4 th pin of the common-mode inductor, the power ground B and one end of the sixth Y capacitor CY6, the other end of the sixth Y capacitor CY6 is connected to the secondary ground C, the third capacitor C3 is a PFC capacitor, the suppression by the third capacitor C3 minimizes the main loop in the switching power circuit 10, reduces the electromagnetic radiation generated by the switching power module 500 through the loop when the switching power circuit 10 operates, and the presence of the sixth Y capacitor CY6 is capable of effectively balancing the interference signal between the primary ground and the secondary ground C, the interference signal between the input end and the output end of the switching power supply module 500 is suppressed, and the safety of the switching power supply circuit 10 is further improved.

Further, the switching power supply module 500 includes a switching tube Q1, a transformer T1, a magnetic bead L1, a first buffer absorption unit 510, and a second buffer absorption unit 520, a control end of the switching tube Q1 is connected to the switching control circuit, a first connection end of the switching tube Q1 is connected to the first buffer absorption unit 510, the second buffer absorption unit 520, and the pin 3 of the transformer T1 through a magnetic bead L1, a second connection end of the switching tube Q1 is connected to the power ground B, the second buffer absorption unit 520 is further connected to the transformer T1 and the power ground B, the first buffer absorption unit 510 is further connected to one end of the second capacitor C2, the switching control circuit is the prior art, and a specific connection structure thereof is not described herein; the first buffer absorption unit 510 is configured to suppress a spike voltage generated by the transformer T1, and the second buffer absorption unit 520 is configured to suppress an interference signal generated by the switching transistor Q1 during a turn-on or turn-off process, and by connecting the magnetic bead L1 between the switching transistor Q1 and the transformer T1, electromagnetic radiation caused by a high di/dt generated by a varying current of the switching transistor Q1 can be effectively filtered.

Further, the first buffer absorption unit 510 includes a fourth capacitor C4, a first diode D1 and a first resistor R1, the second buffer absorption unit 520 includes a fifth capacitor C5 and a second resistor R2, one end of the fourth capacitor C4 and one end of the first resistor R1 are both connected to the 1 st pin of the transformer T1 and one end of the second capacitor C2, the other end of the fourth capacitor C4 and the other end of the first resistor R1 are both connected to the cathode of the first diode D1, the anode of the first diode D1 and one end of the fifth capacitor C5 are both connected to the 3 rd pin of the transformer T1, and the other end of the fifth capacitor C5 is connected to the power ground B through the second resistor R2; when the switching tube Q1 is turned off, the transformer T1 instantaneously generates a high spike voltage due to lenz's law, the spike voltage is transferred to the fourth capacitor C4 for storage, and then the electric energy stored in the fourth capacitor C4 is consumed by the first resistor R1 or returned to the power supply, thereby achieving the effect of buffering the spike voltage; the fifth capacitor C5 and the second capacitor C2 form an RC circuit, the RC circuit is additionally arranged between the switching tube Q1 and the power ground B, interference signals generated in the switching-off or switching-off process of the switching tube Q1 can be filtered, heat generated in the working process of the switching tube Q1 is absorbed, and therefore the working temperature rise of the switching circuit is reduced.

Further, the switching power supply module 500 further includes a second diode D2 and a sixth capacitor C6, the second diode D2 is a freewheeling diode, the anode of the second diode D2 is connected to the 11 th pin and the 12 th pin of the transformer T1, the cathode of the second diode D2 is connected to one end of the sixth capacitor C6 and the panel back plate 30, and the other end of the sixth capacitor C6 is connected to the secondary ground C.

The preset voltage output by the transformer T1 is filtered by the sixth capacitor C6 and then output to the electric equipment to supply power to the electric equipment, and in order to balance an interference signal between the first capacitor C1 and the fifth capacitor C5, a fifth Y capacitor CY5 is disposed between the first capacitor C1 and the fifth capacitor C5, the fifth Y capacitor CY5 can filter common mode noise at the output ends of the fifth capacitor C5 and the first capacitor C1, the value of the fifth Y capacitor CY5 can be different according to the difference in the strength of the output common mode noise, and under the condition that the safety requirement is met, the value of the fifth Y capacitor CY5 in this embodiment is 100pF to 4700pF, and other values can be selected in other embodiments, which is not limited by the present invention. The principle of the switching power supply module 500 connected to the light bar 40 is the same as that of the switching power supply module 500 connected to the screen backboard 30, and the description thereof is omitted.

Based on the above switching power supply circuit without the high-voltage large electrolytic capacitor, the invention also correspondingly provides a television, which comprises the above switching power supply circuit without the high-voltage large electrolytic capacitor, and the switching power supply circuit is not described in detail herein because the switching power supply circuit is described in detail above.

In summary, the switching power supply circuit and the television set provided by the invention without the high-voltage large electrolytic capacitor, the switching power supply is connected with the electric equipment, and comprises a first filtering module, a rectifying module, a second filtering module, a third filtering module and a switching power supply module; the alternating current output by the alternating current power supply is subjected to filtering processing by the first filtering module and then rectified by the rectifying module to be converted into direct current, and the direct current subjected to filtering processing by the second filtering module is converted into preset voltage by the switching power supply module and then respectively output to the electric equipment; the first filtering module is used for inhibiting common-mode interference signals generated when the switching power supply module works, the second filtering module is used for inhibiting electromagnetic radiation interference signals and differential-mode interference signals generated when the switching power supply module works, and the third filtering module is used for inhibiting interference signals between the input end and the output end of the switching power supply module, so that electromagnetic radiation is effectively reduced, and the safety of power supply work is improved.

It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.