Switching power supply and computing device

Abstract

The embodiment of the invention provides a switching power supply and computing equipment. The switching power supply comprises a transformer, a main power switching device and a shielding piece. The transformer comprises a primary winding and a secondary winding. The first end of the primary winding is used for receiving input voltage, and the second end of the primary winding is electrically connected with the first end of the main power switch device. The secondary winding is used for being electrically connected with a load to supply power to the load. The second end of the main power switch device is used for receiving input voltage. The shielding piece is arranged between the primary winding and the secondary winding, the shielding piece is electrically connected with the first end of the primary winding, and the shielding piece is used for shielding common-mode current from the primary winding to the secondary winding. Therefore, radiation interference of the switching power supply caused by common-mode current can be reduced, and reliability and stability of power supply of the switching power supply are improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of computing devices, and in particular to a switching power supply and a computing device. Background Art

[0002] The power supply in the computing device may use a switching power supply. For some switching power supplies, such as open-type on-board switching power supplies, the radiation emission test of the switching power supply may exceed the standard, affecting the power supply reliability and stability of the switching power supply, and then affecting the working performance of the computing device. Summary of the invention

[0003] The embodiments of the present application provide a switching power supply and a computing device, which can effectively suppress the radiation interference of the common mode current in the switching power supply, prevent the radiation emission test of the switching power supply from exceeding the standard, and improve the reliability and stability of the power supply of the switching power supply.

[0004] In a first aspect, an embodiment of the present application provides a switching power supply, including a transformer, a main power switch device and a shielding member. The transformer includes a primary winding and a secondary winding, wherein the first end of the primary winding is used to receive an input voltage, and the second end of the primary winding is electrically connected to the first end of the main power switch device; the secondary winding is used to electrically connect to a load to supply power to the load. The second end of the main power switch device is used to receive an input voltage. The shielding member is disposed between the primary winding and the secondary winding, and the shielding member is electrically connected to the first end of the primary winding, and the shielding member is used to shield the common mode current from the primary winding to the secondary winding.

[0005] In the embodiment of the present application, by arranging the shielding member between the primary winding and the secondary winding of the transformer, the common mode current can be shielded from being transmitted from the primary winding to the secondary winding, thereby reducing the interference of the common mode current transmitted from the primary winding to the secondary winding on the switching power supply. In addition, the shielding member is electrically connected to the first end of the primary winding, and the common mode current generated by the switching of the main power switch device can be transmitted to the shielding member via the parasitic capacitance between the primary winding and the shielding member, and then transmitted from the shielding member to the first end of the primary winding, and then returned to the main power switch device through the first end of the primary winding and the second end of the main power switch device, forming a primary path for the common mode current. Thus, the common mode current transmission path in the switching power supply is changed, the range of the common mode current transmission path is reduced, that is, the loop area of ​​the common mode current is reduced, and then the spatial range of the common mode current radiation is reduced, the radiation interference generated by the common mode current of the switching power supply is reduced, and the reliability and stability of the switching power supply are improved.

[0006] Furthermore, the shielding member is used to provide a primary path for the common mode current, so that the common mode current flows to the second end of the main power switch device via the first end of the main power switch device, the parasitic capacitance between the primary winding and the shielding member, the shielding member, and the first end of the primary winding. In this way, the loop area of ​​the common mode current can be reduced, thereby reducing the spatial range of the common mode current radiation.

[0007] In some implementations, the switching power supply further includes a common mode capacitor, a first end of which is electrically connected to a second end of the main power switch device, and a second end of which is electrically connected to the secondary winding.

[0008] Furthermore, the common-mode capacitor is used to provide a secondary path for the common-mode current, so that the common-mode current flows to the second end of the main power switch device via the first end of the main power switch device, the parasitic capacitance between the primary winding and the secondary winding, and the common-mode capacitor.

[0009] By setting a common-mode capacitor, the common-mode current generated by the on-and-off of the main power switch device can also be transmitted to the secondary winding through the parasitic capacitance of the primary winding and the secondary winding, and then return to the main power switch device through the common-mode capacitor to form a secondary path, thereby further reducing the radiation interference caused by the common-mode current flowing into the ground through the parasitic capacitance between the secondary winding and the ground.

[0010] In some implementations, the common mode capacitor is a Y capacitor. Using a Y capacitor as a common mode capacitor can prevent radiation interference generated by a common mode current.

[0011] In some implementations, the shielding element is one or more of copper foil, aluminum foil, and iron sheet.

[0012] In some implementations, a thickness of the shield is less than a width of a separation between the primary winding and the secondary winding.

[0013] In some implementations, the switching power supply further includes a rectifier tube and an output capacitor. The first end of the rectifier tube is electrically connected to the first end of the secondary winding, the second end of the rectifier tube is used to electrically connect to the first end of the load, and the second end of the secondary winding is used to electrically connect to the second end of the load. The output capacitor is electrically connected between the second end of the rectifier tube and the second end of the secondary winding.

[0014] In this way, when the main power switch is turned on, the rectifier is turned off, and the output capacitor instead of the secondary winding provides power output to the load. When the main power switch is turned off, the rectifier is turned on, and the secondary winding provides power output to the load and can charge the output capacitor.

[0015] In some implementations, the switching power supply further includes a rectifier, an output capacitor, and an output inductor. The first end of the rectifier is electrically connected to the first end of the secondary winding, the second end of the rectifier is electrically connected to the first end of the output inductor, the second end of the output inductor is used to electrically connect to the first end of the load, and the second end of the secondary winding is used to electrically connect to the second end of the load. The output capacitor is electrically connected between the second end of the output inductor and the second end of the load.

[0016] In this configuration, when the main power switch is turned on, the rectifier is turned on, and the secondary winding provides power output to the load and can charge the output inductor and output capacitor. When the main power switch is turned off, the rectifier is turned off, and the output inductor and output capacitor provide power output to the load.

[0017] Furthermore, the switching power supply further comprises a flyback diode, the anode of the flyback diode is electrically connected to the second end of the rectifier tube, and the cathode of the flyback diode is electrically connected to the second end of the secondary winding. Thus, when the main power switch device is disconnected, the output inductor and the output capacitor form a path through the flyback diode to provide power output to the load, preventing the output inductor and the output capacitor from forming a path through the rectifier tube and the secondary winding.

[0018] In some implementations, the switching power supply further includes a rectifier circuit. The input end of the rectifier circuit is used to electrically connect to the input power supply, the first output end of the rectifier circuit is electrically connected to the first end of the primary winding, and the second output end of the rectifier circuit is electrically connected to the second end of the main power switch device. Based on this, the rectifier circuit can convert the AC input of the input power supply into DC and then provide it to the transformer.

[0019] In some implementations, the switching power supply further includes a circuit board, the transformer and the main power switch device are integrated on the circuit board, and the shielding member further includes a connecting portion, and the shielding member is electrically connected to the first end of the primary winding through the connecting portion. In this way, the switching power supply can be a board-mounted switching power supply. The switching power supply is used to power other components on the circuit board.

[0020] Furthermore, the switching power supply may further include a supporting member, and the shielding member is supported on the circuit board by the supporting member.

[0021] The support member contacts the shielding member at an end away from the end electrically connected to the primary winding to support the shielding member.

[0022] In some implementations, the switching power supply further includes a housing for housing the transformer, the main power switch device, and the shielding member. Thus, the switching power supply can be used to power a motherboard of a computing device, etc.

[0023] A second aspect of an embodiment of the present application provides a computing device, including a load and a switching power supply as described above, wherein the switching power supply is electrically connected to the load, and the switching power supply is used to supply power to the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic block diagram of a computing device provided in an embodiment of the present application.

[0025] Figure 2 It is a schematic diagram of the circuit structure of the switching power supply provided in the embodiment of the present application.

[0026] Figure 3 It is a circuit structure diagram of a switching power supply provided in another embodiment of the present application.

[0027] Figure 4 It is a schematic diagram of the circuit structure when the switching power supply of the embodiment of the present application performs a radiation emission test.

[0028] Figure 5 It is a schematic diagram of the structural decomposition of the switching power supply provided in an embodiment of the present application.

[0029] Figure 6 It is a schematic diagram of the structure of a transformer and a shielding member provided in another specific example of the present application. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application. In the absence of conflict, the following different embodiments and features in the embodiments can be combined with each other.

[0031] It should be noted that when a device is said to be "connected to" another device, it may be directly connected to the other device or it may be indirectly connected (with an intervening device).

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0033] For switching power supplies, the main power switching devices in the switching power supply will generate interference signals when switching, especially common-mode interference signals will radiate in all directions, causing the switching power supply to exceed the standard in the radiation emission test. Common-mode interference signals refer to noise signals that exist simultaneously on the wire and have the same phase. Common-mode interference signals (common-mode current signals) refer to those that flow in the same direction on the wire and return through the ground wire.

[0034] In order to enable those skilled in the art to better understand the technical solution provided by the embodiments of the present application, a detailed description is given below in conjunction with the accompanying drawings.

[0035] See also Figure 1 , Figure 1 A schematic diagram of a computing device provided in an embodiment of the present application is shown.

[0036] like Figure 1 As shown, the embodiment of the present application further provides a computing device 10, including a switching power supply 100 and a load 200. The switching power supply 100 is electrically connected to the load 200 and is used to supply power to the load 200.

[0037] For example, the load 200 may include a processing chip, such as a central processing unit (CPU) or a graphics processing unit (GPU). The load 200 may also include electronic components in other computing devices such as memory and hard disk.

[0038] It can be understood that the switching power supply 100 can be used to power any electronic device in the computing device 10. For example, the switching power supply 100 can power a motherboard in the computing device 10. The motherboard is an important circuit board in a server, and components such as a CPU, a controller, a memory, and a connector can be arranged on the motherboard. The switching power supply 100 can power electronic devices on the motherboard.

[0039] The computing device 10 provided in the embodiment of the present application does not specifically limit the application scenario. It can be understood that the computing device 10 can be an electronic device with functions such as processing, computing, and communication. For example, the computing device 10 can be a server, a switch, a computer, or a repeater. For example, the computing device 10 is introduced using a server as an example, and the type of server is not specifically limited. For example, the computing device 10 can be a rack server or an edge server. The server can be located in a data center or in other areas, and the embodiment of the present application does not make specific limitations.

[0040] In the embodiment of the present application, the switching power supply 100 provided in the server can be provided on the mainboard. The switching power supply 100 can realize AC to DC conversion, and can also realize DC to AC conversion. The switching power supply 100 can directly power the components on the mainboard, and the output voltage of the switching power supply 100 is not specifically limited, for example, the output DC is 12V. Of course, the switching power supply 100 is not limited to powering the mainboard on the server, and can be used to power various electronic components in the server that require DC power supply.

[0041] It can be understood that the input end of the switching power supply 100 can be electrically connected to the input power supply, and can also be electrically connected to the input power supply through a voltage conversion circuit to receive the voltage of the input power supply after voltage conversion.

[0042] See also Figure 2 and Figure 3 , an embodiment of the present application provides a switching power supply 100a / 100b.

[0043] The switching power supply 100a / 100b provided in the embodiment of the present application can be applied to a computing device 10, such as a server. The switching power supply 100a / 100b provided in the embodiment of the present application can also be applied to other devices, such as terminal devices, which can be cellular phones (Cellular Phone), smart phones (Smart Phone), personal digital assistants (Personal Digital Assistant, PDA), tablet computers (Tablet Personal Computer, Tablet PC), Bluetooth headset charging compartments, etc.

[0044] like Figure 2 As shown, the switching power supply 100 a provided in the embodiment of the present application includes a flyback circuit 110 a and a rectifier circuit 120 .

[0045] The flyback circuit 110 a includes a transformer T, a main power switch device Q1 and a shielding member 111 .

[0046] The transformer T includes a primary winding and a secondary winding. The first end of the primary winding of the transformer T is used to receive the input voltage, and the second end of the primary winding is electrically connected to the first end of the main power switch device Q1. The secondary winding of the transformer T is used to electrically connect the load R load , assuming that the load R load The second terminal of the main power switch device Q1 is used to receive the input voltage.

[0047] An input capacitor Ci may be electrically connected between the first end of the primary winding of the transformer T and the second end of the main power switch device Q1 , and the input capacitor Ci is used to perform voltage stabilization and filtering on the input voltage.

[0048] The shielding member 111 is disposed between the primary winding and the secondary winding, and is electrically connected to the first end of the primary winding. The shielding member 111 is used to shield the common mode current from the primary winding to the secondary winding.

[0049] Thus, by arranging the shielding member 111 between the primary winding and the secondary winding of the transformer T, the interference of the common mode current from the primary winding to the secondary winding on the switching power supply 100a can be reduced. When the shielding member 111 is electrically connected to the first end of the primary winding, the common mode current generated by the switching of the main power switch device Q1 can be transmitted through the parasitic capacitance C between the primary winding and the shielding member 111. ts The shielding element 111 is then transmitted from the shielding element 111 to the first end of the primary winding, and then returns to the main power switch device Q1 through the device electrically connected between the first end of the primary winding and the second end of the main power switch device Q1, forming a primary path (such as Figure 2 As shown by arrow ①).

[0050] As a result, the common-mode current will not be conducted to the secondary winding through the parasitic capacitance between the primary winding and the secondary winding of the transformer, and then to the ground through the parasitic capacitance between the second end of the secondary winding and the ground. The design of the switching power supply of the embodiment of the present application changes the common-mode current transmission path in the switching power supply 100a, reduces the range of the common-mode current transmission path, that is, reduces the loop area of ​​the common-mode current, and further reduces the spatial range of the common-mode current radiation, reduces the radiation interference generated by the common-mode current in the switching power supply 100a, and improves the reliability and stability of the power supply of the switching power supply 100a.

[0051] Furthermore, when the switching power supply 100a of the embodiment of the present application is applied to the computing device 10, a shielding member is added between the primary winding and the secondary winding of the transformer, and the shielding member is electrically connected to the positive terminal of the primary winding, thereby shielding the common-mode current from being transmitted from the primary winding to the secondary winding, and changing the common-mode current transmission path in the switching power supply, reducing the range of the common-mode current transmission path, and further reducing the spatial range of the common-mode current radiation, thereby reducing the tested common-mode current, and ultimately making the radiated emission (RE) test result of the switching power supply qualified.

[0052] It can be understood that when an input capacitor Ci is electrically connected between the first end of the primary winding and the second end of the main power switch device Q1, the common mode current returns to the main power switch device Q1 via the input capacitor Ci (eg Figure 2 As shown by arrow ①).

[0053] The embodiment of the present application does not limit the specific implementation form of the main power switch device Q1, for example, it can be any of the following switch devices: Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Insulate Gate Bipolar Transistor (IGBT) or Bipolar Junction Transistors (BJT). The embodiment of the present application does not specifically limit the type of the main power switch device Q1, for example, it can be P-type or N-type.

[0054] When the main power switch device Q1 is an NMOS tube, the first end of the main power switch device Q1 is the drain of the NMOS tube, and the second end of the main power switch device Q1 is the source of the NMOS tube.

[0055] In the embodiment of the present application, the shielding member 111 may be configured as a sheet-like structure.

[0056] Furthermore, in some implementations, the flyback circuit 110a may further include a common-mode capacitor C1, a first end of the common-mode capacitor C1 being electrically connected to a second end of the main power switch device Q1, and a second end of the common-mode capacitor C1 being electrically connected to the secondary winding. The common-mode capacitor may be used to provide a secondary path for the common-mode current.

[0057] It can be understood that the shielding member 111 can shield the common-mode current from the primary winding to the secondary winding, and this shielding effect can reduce the magnitude of the common-mode current from the primary winding to the secondary winding. Part of the common-mode current will be transmitted to the secondary winding through the parasitic capacitance between the primary winding and the secondary winding.

[0058] The common-mode current generated by the on-off of the main power switch device Q1 can also be transmitted to the secondary winding through the parasitic capacitance between the primary winding and the secondary winding, and then return to the main power switch device Q1 through the common-mode capacitor C1, forming a secondary path (such as Figure 2 Arrow ②), which can further reduce the parasitic capacitance C between the secondary winding and the ground. d The common-mode current flowing into the ground, that is, further reducing the loop area of ​​the common-mode current, and further reducing the radiation interference generated by the common-mode current, can further improve the power supply reliability and stability of the switching power supply 100a and reduce the impact on the computing device 10.

[0059] Therefore, through the primary path formed by the shielding member 111 and the secondary path formed by the common-mode capacitor C1, the transmission path of the common-mode current generated by the main power switching device Q1 is limited to the primary path and the secondary path, so that the loop area of ​​the common-mode current in the switching power supply 100a is greatly reduced, and the radiation space range of the common-mode current is effectively reduced, thereby effectively suppressing the radiation interference generated by the common-mode current, which can effectively improve the power supply reliability and stability of the switching power supply 100a and reduce the impact on the computing device 10.

[0060] In the embodiment of the present application, the second end of the common-mode capacitor C1 can be electrically connected to the first end of the secondary winding, or can be electrically connected to the second end of the secondary winding. Of course, in an example, the second end of the common-mode capacitor C1 is electrically connected to the second end of the secondary winding, which can avoid affecting the switching power supply 100a for the load R load powered by.

[0061] The common mode capacitor C1 can be set as a Y capacitor. A Y capacitor refers to a capacitor connected across the power line and the ground line (usually the live line and the ground line or the neutral line and the ground line). The capacitance of the common mode capacitor C1 can be set to approximately 1000pF~4700pF.

[0062] Please refer to Figure 2 The flyback circuit 110a further includes a rectifier tube D0 and an output capacitor Co. The first end of the rectifier tube D0 is electrically connected to the first end of the secondary winding, and the second end of the rectifier tube D0 is electrically connected to the load R load The first end of the secondary winding is used to electrically connect the load R load The output capacitor Co is electrically connected between the second end of the rectifier tube D0 and the second end of the secondary winding. When the main power switch device Q1 is turned on, the rectifier tube D0 is turned off, and the secondary winding does not supply power to the load R. load Provides power output, but from the output capacitor Co to the load R load Provide power output. When the main power switch Q1 is turned off, the rectifier D0 is turned on, and the secondary winding supplies power to the load R load Provides power output and charges the output capacitor Co.

[0063] It can be understood that the rectifier tube D0 can be set as a diode or a controllable switch, such as a triode, a MOS tube, a relay, etc. When the rectifier tube D0 is set as a diode, the first end of the rectifier tube D0 is the anode of the diode, and the second end is the cathode of the diode. load The first end is the positive input end, the load R load The second end is the negative input terminal.

[0064] Please refer again Figure 2The input end of the rectifier circuit 120 is used to electrically connect the input power supply Vac, the first output end of the rectifier circuit 120 is electrically connected to the first end of the primary winding, and the second output end of the rectifier circuit 120 is electrically connected to the second end of the main power switch device Q1. The input power supply Vac is an AC power supply. Of course, the input power supply Vac can also be a voltage conversion circuit, which is used to convert the voltage of the power provided by the outside and then provide it to the rectifier circuit 120.

[0065] In the embodiment of the present application, the rectifier circuit 120 includes four diodes, namely a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. Among them, the first diode D1 and the third diode D3 are connected in series as a first bridge arm, and the second diode D2 and the fourth diode D4 are connected in series as a second bridge arm. The first bridge arm and the second bridge arm are connected in parallel. The first input end of the rectifier circuit 120 is the common end of the second diode D2 and the fourth diode D4, that is, the anode of the second diode D2. The second input end of the rectifier circuit 120 is the common end of the first diode D1 and the third diode D3, that is, the anode of the first diode D1.

[0066] The positive output end of the rectifier circuit 120 is the first end after the two bridge arms are connected in parallel, that is, the cathode of the first diode D1 and the second diode D2, and the negative output end of the rectifier circuit 120 is the second end after the two bridge arms are connected in parallel, that is, the anode of the third diode D3 and the fourth diode D4.

[0067] The rectifier circuit 120 is used to convert the alternating current provided by the input power source Vac into direct current and then provide the direct current as an input voltage to the flyback circuit 110a.

[0068] Of course, in the embodiment of the present application, the input voltage received by the first end of the primary winding of the transformer T and the second end of the main power switching device Q1 is not limited to being provided by the rectifier circuit 120, but can also be directly provided by a DC power supply or provided by other DC conversion circuits. The embodiment of the present application does not impose any restrictions on this.

[0069] Figure 2 The switching power supply 100 a shown is a flyback switching power supply, and the first end of the primary winding of the transformer T and the second end of the secondary winding are like-named ends.

[0070] Of course, the switching power supply of the embodiment of the present application is not limited thereto. For example Figure 3 The switching power supply 100b shown can also be a forward switching power supply. The difference between the circuit structures of the forward switching power supply and the flyback switching power supply is that: The switching power supply 100b includes a forward circuit 110b. The forward circuit 110b of the switching power supply 100b includes Figure 2The flyback circuit 110a also includes an output inductor L0 in addition to the transformer T, the main power switch device Q1, the shielding member 111, the common mode capacitor C1, the rectifier tube D0 and the output capacitor Co.

[0071] In the forward circuit 110b, the second end of the rectifier tube D0 is electrically connected to the first end of the output inductor L0, and the second end of the output inductor L0 is electrically connected to the load R load The first end of the output capacitor Co is electrically connected to the second end of the output inductor L0 and the load R load And the first end of the primary winding of the transformer T and the first end of the secondary winding are the same-named terminals.

[0072] The working principle of the forward switching power supply is also different from that of the flyback switching power supply. In the switching power supply 100b, when the main power switch Q1 is turned on, the rectifier D0 is turned on, and the secondary winding supplies current to the load R load Provide power output and charge the output inductor L0 and the output capacitor Co. When the main power switch device Q1 is turned off, the energy stored in the output inductor L0 and the output capacitor Co is used to charge the load R load Provides power.

[0073] A freewheeling diode D5 may be connected in parallel between the second end of the rectifier tube D0 and the second end of the secondary winding, the anode of the freewheeling diode D5 is electrically connected to the second end of the secondary winding, and the cathode of the freewheeling diode D5 is electrically connected to the second end of the rectifier tube D0 and the first end of the output inductor L0. Thus, when the main power switch device Q1 is turned off, the output inductor L0 and the output capacitor Co form a path through the freewheeling diode D5 to provide a current to the load R1. load Power output is provided without forming a path through the rectifier tube D0 and the secondary winding.

[0074] In this embodiment, the switching power supply 100b forms two common-mode loops with smaller common-mode current transmission paths by disposing a shielding member 111 between the primary winding and the secondary winding of the transformer T, and electrically connecting the shielding member 111 to the first end of the primary winding, and disposing a common-mode capacitor C1 electrically connected between the second end of the secondary winding and the second end of the main power switching device Q1, thereby reducing the spatial range of the common-mode current radiating outward, reducing the radiation interference of the switching power supply 100b caused by the common-mode current, and improving the reliability and stability of the power supply of the switching power supply 100b.

[0075] Moreover, when the switching power supply 100b of the embodiment of the present application is applied to the computing device 10, the influence of the radiation interference of the switching power supply 100b on the computing device 10 can be reduced. Since the present embodiment can reduce the radiation interference generated by the switching power supply 100b, the radiation emission test of the switching power supply 100b can make the radiation emission test result of the switching power supply 100b qualified.

[0076] In summary, the switching power supplies 100a / 100b provided in the present application can reduce the spatial range of the common-mode current radiating outward, reduce the radiation interference caused by the common-mode current of the switching power supplies 100a / 100b, and improve the reliability and stability of the power supply of the switching power supplies 100a / 100b.

[0077] See also Figure 4 , Figure 4 A schematic diagram of the circuit structure of the switching power supply 100a provided in an embodiment of the present application when performing a radiation emission test is shown.

[0078] like Figure 4 As shown, when the switching power supply 100a is subjected to a radiation emission test, the input end of the switching power supply 100a is electrically connected to a Line Impedance Stabilization Network (LISN), and the LISN provides input power to the switching power supply 100a. In other words, the input end of the rectifier circuit 120 is electrically connected to the LISN, and the AC power supply supplies power to the switching power supply 100a through the LISN. The LISN is an important auxiliary device in the electromagnetic compatibility test of the power system, which can isolate radio wave interference, provide stable test impedance, and play a filtering role.

[0079] Since the switch power supply 100a is provided with a shielding member 111 electrically connected to the primary winding of the transformer T to form a primary path for the common mode current, and the common mode capacitor C1 to form a secondary path for the common mode current, the parasitic capacitance C1 from the main power switch device Q1 through the primary and secondary windings of the transformer T and then through the secondary winding and the ground can be effectively reduced. d The common-mode current flowing into the ground and the common-mode current flowing from the ground to the LISN and then into the rectifier circuit 120 are reduced, thereby effectively reducing the range of the common-mode current transmission path, reducing the loop area of ​​the common-mode current, and reducing the spatial range of the common-mode current radiation, so that the radiation emission test of the switching power supply 100a is qualified.

[0080] It can be understood that when the switching power supply 100b is subjected to the radiation emission test, its input terminal is also electrically connected to the LISN, and the effect obtained is the same as that of the switching power supply 100a, which will not be further described here.

[0081] In the embodiment of the present application, the shielding member 111 can be set as copper foil. Copper foil has a low cost and has a good shielding effect. Of course, the specific material of the shielding member 111 can be set according to actual application requirements, and the present application does not limit this. For example, it can also be set as aluminum foil, iron sheet, etc.

[0082] It is understandable that the material of the shielding member 111 in the embodiment of the present application is not limited to the above-mentioned metal, and may also be set to other electromagnetic shielding materials.

[0083] The thickness of the shielding member 111 can be set according to the spacing width between the primary winding and the secondary winding in the transformer T. The thickness of the shielding member 111 is less than the spacing width between the primary winding and the secondary winding in the transformer T. For example, the thickness range of the shielding member 111 is approximately 0.01mm~0.1mm. It can be understood that when the capacity specification requirement of the transformer T is large, the volume of the transformer T is also large, the spacing width between the primary winding and the secondary winding is also wide, and the thickness of the shielding member 111 can be selected to be a larger value, such as 0.1mm. When the capacity specification requirement of the transformer T is small, the volume of the transformer T is also small, the spacing width between the primary winding and the secondary winding is also narrow, and the space for placing the shielding member 111 is limited, then the thickness of the shielding member 111 can be selected to be a larger value, such as 0.01mm.

[0084] See also Figure 5 , Figure 5 FIG. 1 shows a schematic diagram of the structure of a switching power supply 100a / 100b provided in an embodiment of the present application. Figure 5 As shown, the switching power supply 100 a / 100 b further includes a circuit board 130 , on which components such as a transformer T and a main power switch component Q1 are integrated.

[0085] In the embodiment of the present application, the switching power supply 100a / 100b may be a board-mounted switching power supply. The switching power supply 100a / 100b is used to power other components on the circuit board 130. For example, when the switching power supply 100a / 100b is applied to the computing device 10, the circuit board 130 may be the main board of the computing device 10, and the switching power supply 100a / 100b is used to power other components on the main board. It can be understood that the circuit board 130 may also be a management board or other single board of the computing device 10.

[0086] It can be understood that the circuit board 130 can also integrate the input capacitor Ci, the main power switch device Q1, the common mode capacitor C1, the various diodes in the rectifier circuit 120, the rectifier tube D0, the output capacitor Co and other devices ( Figure 5 not shown).

[0087] In this example, the shielding member 111 is provided to shield the common mode current from being transmitted from the primary winding to the secondary winding, and the shielding member 111 can also provide a primary path for the common mode current, reduce the interference caused by the common mode current transmitted from the primary winding to the secondary winding, and reduce the range of the common mode current transmission path, thereby reducing the spatial range of the common mode current radiation. Therefore, even an open-type, housing-free onboard switching power supply can effectively suppress the radiation interference of the common mode current, prevent the radiation emission test from exceeding the standard, and provide the reliability and stability of the power supply of the switching power supply 100a / 100b.

[0088] The circuit board 130 may also be provided with a support member (not shown) for supporting the shielding member 111, so as to fix the shielding member 111 on the circuit board 130. Specifically, the support member may contact the end of the shielding member 111 away from the end electrically connected to the primary winding, so as to support the shielding member 111. Figure 5 In the embodiment of the present application, the diagonally opposite corner of the connecting portion 114 of the shielding member 111 may be in contact with the supporting member. Of course, the embodiment of the present application does not limit the specific contact position between the supporting member and the shielding member 111, and it can be set according to the specific structure of the shielding member 111.

[0089] It can be understood that the support member is made of insulating material, or the outer layer of the shielding member 111 is wrapped with insulating material to prevent the current on the shielding member 111 from being transmitted to the circuit board 130 .

[0090] In some other specific examples, the transformer T has a frame or a supporting space inside, which can support and fix the shielding member 111. In this case, there is no need to provide an additional supporting member to support the shielding member 111 on the circuit board 130.

[0091] In some implementations, the switching power supply 100 a / 100 b further includes a housing 140 , and the housing 140 is used to accommodate components such as a transformer T, a main power switch device Q1 , and a shielding member 111 .

[0092] The switching power supply 100a / 100b may also be an off-board power supply, in which case the circuit board 130 of the switching power supply 100a / 100b is independently provided from the mainboard of the computing device 10. The circuit board 130 may be accommodated in the housing 140 to isolate and protect the components inside the switching power supply 100a / 100b.

[0093] It is understandable that the housing 140 may be a plastic housing or a metal housing, and the present application does not impose any limitation on this.

[0094] When the housing 140 is a plastic housing, the switching power supply 100a / 100b suppresses the radiation interference of the common mode current through the shielding member 111 and the common mode capacitor C1, thereby ensuring the reliability and stability of the power supply of the switching power supply 100a / 100b.

[0095] When the shell 140 is a metal shell, the switching power supply 100a / 100b not only suppresses the radiation interference of the common mode current through the provided shielding member 111 and the common mode capacitor C1, but the shell 140 can also perform electromagnetic shielding on the switching power supply 100a / 100b, thereby further suppressing the radiation interference of the common mode current and further improving the power supply reliability and stability of the switching power supply 100a / 100b.

[0096] like Figure 5, shows the magnetic core structure of the transformer T in the embodiment of the present application, the magnetic core includes a first component MC1 and a second component MC2 arranged opposite to each other along the Z direction, and the first component MC1 and the second component MC2 form a spacing space along the Z direction. The primary winding and the secondary winding can be wound on the first component MC1 and the second component MC2 respectively. Correspondingly, the shielding member 111 is a sheet-like structure as a whole, and the shielding member 111 can be arranged in the spacing space formed by the first component MC1 and the second component MC2, so as to be arranged between the primary winding and the secondary winding.

[0097] The shielding member 111 may be configured as an annular structure having an opening 112, and the opening 112 may be connected to a central hole 113 of the annular structure. Figure 4 In the example, the shielding member 111 is configured as a rectangular ring structure.

[0098] A connecting portion 114 may be provided next to the opening 112 of the shielding member 111 . The connecting portion 114 extends toward the first component MC1 . The connecting portion 114 is connected to a first end of a primary winding wound on the first component MC1 .

[0099] Of course, the present application does not limit the structure of the magnetic core of the transformer T and the structure of the shielding member 111. For example, the magnetic core as a whole may also be a ring-shaped structure (such as a rectangular ring-shaped structure, a circular ring-shaped structure, etc.), the primary winding and the secondary winding may be respectively wound on two opposite sides of the magnetic core, and the shielding member 111 may be a circular ring-shaped structure or a rectangular sheet-shaped structure.

[0100] See also Figure 6 , Figure 6 FIG. 1 shows a schematic diagram of the structure of a transformer T and a shielding member 111 in another specific example of the present application. Figure 6 As shown, the magnetic core of the transformer T is a cylindrical structure, and the shielding member 111 is formed by bending a rectangular sheet structure to form a cylindrical structure that is not completely closed (that is, a gap is formed at both ends of the rectangular sheet structure). The secondary winding is wound on the magnetic core, and the shielding member 111 is arranged around the secondary winding, that is, the shielding member 111 surrounds the secondary winding. The primary winding is wound along the cylindrical structure formed by the shielding member 111. Thus, the shielding member 111 is arranged between the primary winding and the secondary winding. Among them, a connecting portion 114 is led out from the shielding member 111 to be electrically connected to the first end of the primary winding. The connecting portion 114 can be a lead wire.

[0101] It can be understood that the shielding member 111 in the embodiment of the present application can be set in shape and position according to the magnetic core structure in the transformer T and the winding method of the primary winding and the secondary winding, and the embodiment of the present application is not limited to this.

[0102] In the embodiment of the present application, an input interface electrically connected to the input end of the rectifier circuit 120 and an output interface electrically connected to the output capacitor Co can be provided on the housing 140 of the switching power supply 100a / 100b, so as to electrically connect the switching power supply 100a / 100b to the input power supply and the load R load .

[0103] The input power can be connected to the input interface through the input cable, and the load R load The output interface can be connected through an output cable. By providing a shielding member 111 between the primary winding and the secondary winding of the transformer T and electrically connecting the shielding member 111 to the first end of the primary winding, a primary path for the common-mode current can be provided, thereby reducing the magnitude of the common-mode current radiated from the connected input cable to the space by the input interface of the switching power supply 100a / 100b. By providing a common-mode capacitor C1 electrically connected between the second end of the secondary winding and the second end of the main power switch device Q1, a secondary path for the common-mode current can be provided, thereby reducing the magnitude of the common-mode current radiated from the connected output cable to the space by the output interface of the switching power supply 100a / 100b.

[0104] It can be seen that the embodiment of the present application can effectively reduce the overall space for the common-mode current in the switching power supply 100a / 100b to radiate outward, and can improve the reliability and stability of the power supply of the switching power supply 100a / 100b.

[0105] When the switching power supply 100a / 100b of the embodiment of the present application is provided in the computing device 10, the shielding member 111 and the common-mode capacitor C1 are provided to reduce the loop area of ​​the common-mode current in the switching power supply 100a / 100b, thereby reducing the spatial range of the common-mode current in the switching power supply 100a / 100b radiating outward, thereby reducing the radiation interference generated by the radiation emission, improving the power supply performance of the switching power supply 100a / 100b for the computing device 10, and reducing the interference effect of the switching power supply 100a / 100b on other components in the computing device 10.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A switching power supply, characterized in that: Including transformer, main power switch device and shielding parts; The transformer comprises a primary winding and a secondary winding; the first end of the primary winding is used to receive an input voltage, and the second end of the primary winding is electrically connected to the first end of the main power switch device; the secondary winding is used to electrically connect to a load to supply power to the load; The second end of the main power switch device is used to receive an input voltage; The shielding member is disposed between the primary winding and the secondary winding, and the shielding member is electrically connected to the first end of the primary winding, and the shielding member is used to shield the common mode current from the primary winding to the secondary winding.

2. The switching power supply according to claim 1, characterized in that: It also includes common-mode capacitance; The first end of the common-mode capacitor is electrically connected to the second end of the main power switch device, and the second end of the common-mode capacitor is electrically connected to the secondary winding.

3. The switching power supply according to claim 2, characterized in that: The common mode capacitor is a Y capacitor.

4. The switching power supply according to claim 1, characterized in that: The shielding element is one or more of copper foil, aluminum foil and iron sheet.

5. The switching power supply according to claim 1, characterized in that: The thickness of the shielding member is smaller than the spacing width between the primary winding and the secondary winding.

6. The switching power supply according to claim 1, characterized in that: It also includes rectifier tubes and output capacitors; The first end of the rectifier tube is electrically connected to the first end of the secondary winding, the second end of the rectifier tube is used to electrically connect to the first end of the load, and the second end of the secondary winding is used to electrically connect to the second end of the load; The output capacitor is electrically connected between the second end of the rectifier tube and the second end of the secondary winding.

7. The switching power supply according to claim 1, characterized in that: It also includes a rectifier circuit, wherein the input end of the rectifier circuit is used to electrically connect to an input power supply, the first output end of the rectifier circuit is electrically connected to the first end of the primary winding, and the second output end of the rectifier circuit is electrically connected to the second end of the main power switch device.

8. The switching power supply according to any one of claims 1 to 7, characterized in that: It also includes a circuit board, on which the transformer and the main power switch device are integrated; the shielding member also includes a connecting portion, through which the shielding member is electrically connected to the first end of the primary winding.

9. The switching power supply according to any one of claims 1 to 7, characterized in that: It also includes a shell, which is used to accommodate the transformer, the main power switch device and the shielding member.

10. A computing device, characterized in that It comprises a load and a switching power supply as claimed in any one of claims 1 to 9; the switching power supply is electrically connected to the load, and the switching power supply is used to supply power to the load.

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