Switching power supplies and household appliances

Abstract

The present application discloses a switching power supply and a household appliance, wherein the switching power supply includes a charging circuit, including an input capacitor and an energy storage element, and the two ends of the input capacitor are configured to be an input power supply voltage; a main discharge circuit, including a main output capacitor, the main output capacitor is connected to the energy storage element, and the two ends of the main output capacitor are configured to be connected to a load; at least one branch discharge circuit, each branch power supply circuit includes a sub-switch and a branch output capacitor, the first end of the sub-switch is connected to the energy storage element, and the two ends of the branch output capacitor are configured to be connected to the load. The present application can reduce the cost of a multi-way switching power supply.

Description

Technical Field

[0001] The present application relates to the technical field of switching power supplies, and in particular to switching power supplies and household appliances. Background Art

[0002] A switching power supply, also known as an exchange power supply or a switching converter, is a high-frequency power conversion device and a type of power supply. Its function is to convert a voltage level into the voltage or current required by the user through different forms of architecture.

[0003] The output voltage of a switching power supply often requires multiple different stable DC voltages, and the traditional implementation method requires several sets of output voltages, which requires the installation of several energy storage inductors. However, the cost of energy storage inductors is relatively high, so the cost of a multi-output switching power supply is relatively high. Summary of the invention

[0004] The present application provides a switching power supply and a household appliance to solve the problem of high manufacturing cost of multi-output switching power supplies in the prior art.

[0005] In order to solve the above technical problems, the present application proposes a switching power supply, including a charging circuit, including an input capacitor and an energy storage element, and the two ends of the input capacitor are configured to be an input power supply voltage; a main discharge circuit, including a main output capacitor, the main output capacitor is connected to the energy storage element, and the two ends of the main output capacitor are configured to be connected to the load; at least one branch discharge circuit, each branch power supply circuit includes a sub-switch and a branch output capacitor, the first end of the sub-switch is connected to the energy storage element, and the two ends of the branch output capacitor are configured to be connected to the load.

[0006] In order to solve the above technical problems, the present application proposes a household appliance, comprising the above switching power supply.

[0007] The present application discloses a switching power supply, wherein the switching power supply includes a charging circuit, including an input capacitor and an energy storage element, and the two ends of the input capacitor are configured to be an input power supply voltage; a main discharge circuit, including a main output capacitor, the main output capacitor is connected to the energy storage element, and the two ends of the main output capacitor are configured to be connected to a load; at least one branch discharge circuit, each branch power supply circuit includes a sub-switch and a branch output capacitor, the first end of the sub-switch is connected to the energy storage element, and the two ends of the branch output capacitor are configured to be connected to the load. Compared with the switching power supply of the prior art, the multi-way switching power supply in the present application only needs to set up one energy storage element, and multiple voltage outputs can share one energy storage element, there is no problem of commutation, and the circuit structure is simple, which can significantly reduce the cost of the multi-way switching power supply solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 This is a schematic diagram of the circuit structure of an embodiment of the switching power supply of the present application;

[0010] Figure 2 It is a circuit structure diagram of another embodiment of the switching power supply of the present application;

[0011] Figure 3 It is a circuit structure diagram of another embodiment of the switching power supply of the present application;

[0012] Figure 4 It is a structural schematic diagram of an embodiment of the household appliance of the present application. DETAILED DESCRIPTION

[0013] In order to enable those skilled in the art to better understand the technical solution of the present application, the switching power supply and household appliances provided by the invention are further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0014] This application discloses a switching power supply, see Figure 1 , Figure 1 1 is a schematic diagram of a circuit structure of an embodiment of a switching power supply of the present application. In this embodiment, the switching power supply 100 may include a charging circuit 110 , a main discharging circuit 120 and at least one branch discharging circuit 130 .

[0015] The charging circuit 110 may include an input capacitor Cin, an energy storage element, and a main switch IC1. The two ends of the input capacitor Cin may be configured as an input power supply voltage Vin1, and the power supply voltage Vin1 may be a DC voltage after the AC power passes through a rectifier circuit, or a DC voltage generated by other power conversion. In some cases, the input capacitor Cin may also be considered as several capacitors connected in parallel.

[0016] The energy storage element is used to store the electric energy input by the input capacitor Cin when the charging circuit 110 is turned on, and discharge when the main discharge circuit 120 or the branch discharge circuit 130 is turned on to supply power to the load. In the present application, the energy storage element can be an energy storage inductor L1 or an energy storage transformer T1, such as Figure 1 As shown, the energy storage unit is an energy storage inductor L1.

[0017] The main switch IC1 may be connected between the input capacitor Cin and the energy storage element. The main switch IC1 may be a switching power supply chip encapsulated with a power switch tube, or a power switch tube controlled by a switching power supply controller.

[0018] The main discharge loop 120 may include a main output capacitor C1 , which may be connected to an energy storage inductor L1 , and both ends of the main output capacitor C1 may be configured to be connected to a load, that is, the load is connected in parallel to both ends of the main output capacitor C1 .

[0019] Each discharge loop 130 may include a sub-switch IC2 and a branch output capacitor C2. The first end of the sub-switch IC2 may be connected to the second end of the energy storage inductor L1, and the two ends of the branch output capacitor C2 may be configured to connect to a load, that is, the load is connected in parallel to the two ends of the branch output capacitor C2. The sub-switch IC2 may be the same as the main switch IC1, and may be a switching power supply chip encapsulated with a power switch tube, or a power switch tube controlled by a switching power supply controller.

[0020] The main switch IC1 can be configured to control the energy storage inductor L1 to store energy or discharge energy: when the main switch IC1 is turned on, the charging circuit 110 is turned on, and the energy storage inductor L1 stores energy; when the main switch IC1 is turned off, the charging circuit 110 is not turned on, and the energy storage inductor L1 discharges.

[0021] The secondary switch IC2 can be configured to control the conduction or disconnection of the branch discharge loop 130 where it is located: when the secondary switch IC2 is turned on, the branch discharge loop 130 where the secondary switch IC2 is located is turned on; when the secondary switch IC2 is turned off, the branch discharge loop 130 where the secondary switch IC2 is located is not turned on.

[0022] Furthermore, the main switch IC1 and the sub-switch IC2 can be controlled by a controller of the switching power supply 100 , thereby realizing multi-channel voltage output of the switching power supply 100 .

[0023] The output voltage of each discharge circuit 130 is different, and the output voltage of the main discharge circuit 120 is greater than the output voltage of any discharge circuit 130 .

[0024] In the switching power supply 100 of the present embodiment, in response to the main switch IC1 being turned on, the charging circuit 110 is turned on, and the power supply voltage Vin1 generates an input current in the charging circuit 110 to charge the energy storage element; in response to the main switch IC1 being turned off, the main discharge circuit 120 is turned on, and the energy stored in the energy storage unit will output a load current in the main discharge circuit 120 or a branch discharge circuit 130, and generate an output voltage on the main output capacitor C1 or the branch output capacitor C2 to supply power to the load.

[0025] In this embodiment, the discharge circuit with the highest output voltage is used as the main discharge circuit 120. According to the voltage characteristics, when the main switch IC1 is disconnected, the load current output by the energy storage unit 120 only flows to the discharge circuit with the lowest output voltage that is turned on for power supply, that is, the main switch IC1 and the secondary switch IC2 can be turned on at the same time, and there will be no problem of circuit short circuit or voltage reverse flow.

[0026] In detail, in response to the main switch IC1 being turned off and all branch discharge loops 130 being turned off, the energy stored in the energy storage unit can output a load current in the main discharge loop 120 and output a voltage in the main output capacitor C1 .

[0027] In response to the main switch IC1 being turned off and only one branch discharge loop 130 being turned on, the energy stored in the energy storage unit can output a load current in the turned-on branch discharge loop 130 and output a voltage at the branch output capacitor C2 of the turned-on branch discharge loop 130 .

[0028] In response to the main switch IC1 being turned off and the plurality of branch discharge loops 130 being turned on, the energy stored in the energy storage unit can output a load current in the branch discharge loop 130 with the lowest output voltage and output a voltage at the branch output capacitor C2 of the branch discharge loop 130 with the lowest output voltage.

[0029] Through the above-mentioned manner, the main switch IC1 and the sub-switch IC2 can work independently of each other, the working frequencies can be the same or different, and the duty cycle timings can be partially overlapped or completely non-overlapped.

[0030] This embodiment discloses a switching power supply, wherein the switching power supply includes a charging circuit, including an input capacitor and an energy storage element, and the two ends of the input capacitor are configured to be an input power supply voltage; a main discharge circuit, including a main output capacitor, the main output capacitor is connected to the energy storage element, and the two ends of the main output capacitor are configured to be connected to a load; at least one branch discharge circuit, each branch power supply circuit includes a secondary switch and a branch output capacitor, the first end of the secondary switch is connected to the energy storage element, and the two ends of the branch output capacitor are configured to be connected to the load. Compared with the switching power supply of the prior art, the multi-way switching power supply in the present application only needs to set up one energy storage element, and multiple voltage outputs can share one energy storage element, there is no problem of commutation, and the circuit structure is simple, which can significantly reduce the cost of the multi-way switching power supply solution.

[0031] Optionally, the main discharge loop 120 may further include a main isolation diode D1 , the input end of the main isolation diode D1 may be connected to the second end of the energy storage inductor L1 , and the output end of the main isolation diode D1 may be connected to the first end of the main output capacitor C1 .

[0032] Each discharge loop 130 may further include a secondary isolation diode D2, the input end of the secondary isolation diode D2 may be connected to the second end of the energy storage inductor L1, the output end of the secondary isolation diode D2 may be connected to the first end of the branch output capacitor C2 via the secondary switch IC2, and the second end of the branch output capacitor C2 may be grounded.

[0033] In some embodiments, the positions of the secondary isolation diode D2 and the secondary switch IC2 can be swapped, that is, the second end of the energy storage inductor L1 can be connected to the input end of the secondary isolation diode D2 through the secondary switch IC2, and the output end of the secondary isolation diode D2 can be connected to the first end of the branch output capacitor C2.

[0034] The main isolation diode D1 and the secondary isolation diode D2 can prevent voltage reverse flow. In some other embodiments, each branch discharge circuit 130 can be configured to connect loads of different voltages. In at least one branch discharge circuit 130, except for the branch discharge circuit 130 connected to the minimum voltage load, the remaining branch discharge circuits 130 can also include a secondary isolation diode D2, the input end of the secondary isolation diode D2 is connected to the energy storage inductor L1, and the output end of the secondary isolation diode D2 can be connected to the first end of the branch output capacitor C2. That is, in these embodiments, the branch discharge circuit 130 with the lowest output voltage may not be provided with a secondary isolation diode D2.

[0035] Continue reading Figure 1 The main discharge circuit 120 may further include a freewheeling diode D1a. The first end of the input capacitor Cin may be connected to the first end of the main switch IC1, the first end of the energy storage inductor L1 may be connected to the second end of the main switch IC1, and the second end of the energy storage inductor L1 may be connected to the first end of the main output capacitor C1 through the main isolation diode D1.

[0036] The output end of the freewheeling diode D1a can be connected between the second end of the main switch IC1 and the first end of the energy storage inductor L1, and the input end of the freewheeling diode D1a, the second end of the input capacitor Cin, and the second end of the main output capacitor C1 can be connected and grounded.

[0037] At least one branch discharge loop 130 can be connected in parallel and connected to the node Vbus between the second end of the energy storage inductor L1 and the main isolation diode D1, so as to achieve the purpose of sharing one energy storage inductor L1 for each output in time sharing. Assuming that the load currents of the main discharge loop 120 and the branch discharge loop 130 are Io1, Io2, Io3, ..., Ion respectively, and the output voltages of the main discharge loop 120 and the branch discharge loop 130 are Vo1, Vo2, Vo3, ..., Von respectively, it can be obtained from the switching power supply 100 in this embodiment:

[0038] The average load current IL of the energy storage unit is the sum of the load currents of the main discharge circuit 120 and the branch discharge circuit 130, that is:

[0039] IL=I1+I2+…+In

[0040] The effective duty cycle Dk of the load current of the energy storage unit occupied by the main discharge circuit 120 or the branch discharge circuit 130 is the quotient of the load current of the main discharge circuit 120 or the branch discharge circuit 130 divided by the average load current IL of the energy storage unit, that is:

[0041]

[0042] The total output power Po of the switching power supply 100 is the sum of the output powers of the main discharge circuit 120 and the branch discharge circuit 130, wherein the output power of the main discharge circuit 120 or the branch discharge circuit 130 is equal to the product of the output voltage of the main discharge circuit 120 or the branch discharge circuit 130 and the load current, that is:

[0043] Po=Vo1·Io1+Vo2·Io2+…+Von·Ion

[0044] The equivalent output voltage Veq of the switching power supply 100 is the quotient of the total output power Po of the switching power supply 100 and the average load current IL of the energy storage unit, that is:

[0045]

[0046] The duty cycle of the main switch IC1 is the quotient of the equivalent output voltage Veq of the switching power supply 100 divided by the power supply voltage Vin1, that is:

[0047]

[0048] For example, if Vin1=100Vdc, the switching power supply has three outputs, of which Vol=18Vdc, Vo2=12Vdc, and Vo3=5Vdc; the required load currents are Io1=0.2A, Io2=0.3A, and Io3=0.5A respectively; then the average current of the energy storage inductor in this embodiment will be IL=1.0A; the effective duty ratios of the current of the energy storage inductor occupied by Vo1, Vo2, and Vo3 in time-sharing are 20%, 30%, and 50% respectively; the total power of the multiple outputs Po=9.7W; the equivalent output voltage Veq=9.7V; the duty ratio of the switch tube regulated by the main path is D=9.7%.

[0049] It can be seen that in this embodiment, each output of the switching power supply reuses the energy storage inductor in time-sharing according to the current proportion, thereby saving the energy storage inductor in each branch discharge circuit to achieve the purpose of saving costs. In addition, when the secondary switch of each branch discharge circuit is switched, there is no current switching with the freewheeling diode, so the radiation interference of the branch discharge circuit is greatly reduced.

[0050] See also Figure 2 , Figure 2 FIG. 2 is a schematic diagram of a circuit structure of another embodiment of the switching power supply of the present application. In this embodiment, the switching power supply 100 may include a charging circuit 110 , a main discharging circuit 120 and at least one branch discharging circuit 130 .

[0051] The charging circuit 110 may include an input capacitor Cin, a main switch IC1 and an energy storage unit. In this embodiment, the energy storage unit is an energy storage inductor L1. The main discharge circuit 120 may include a freewheeling diode D1a, a main isolation diode D1 and a main output capacitor C1. The branch discharge circuit 130 may include a secondary isolation diode D2, a secondary switch IC2 and a branch output capacitor C2.

[0052] The input end of the secondary isolation diode D2 can be used as the input end of the branch discharge loop 130, the output end of the secondary isolation diode D2 can be connected to the first end of the branch output capacitor C2 through the secondary switch IC2, the second end of the branch output capacitor C2 can be grounded, and the load of the branch discharge loop 130 can be connected to both ends of the branch output capacitor C2.

[0053] In other embodiments, the secondary isolation diode D2 and the secondary switch IC2 can be swapped, that is, the first end of the secondary switch IC2 can be used as the input end of the branch discharge loop 130, the second end of the secondary switch IC2 can be connected to the input end of the secondary isolation diode D2, and the output end of the secondary isolation diode D2 can be connected to the first end of the branch output capacitor C2.

[0054] The first end of the input capacitor Cin can be connected to the first end of the main switch IC1, the input end of the freewheeling diode D1a can be connected to the second end of the main switch IC1, and the output end of the freewheeling diode D1a can be connected to the input end of the main isolation diode D1. At least one branch discharge loop 130 can be connected in parallel and connected to the node Vbus between the output end of the freewheeling diode D1a and the input end of the main isolation diode D1.

[0055] The first end of the energy storage inductor L1 can be connected between the main switch IC1 and the input end of the freewheeling diode D1a, and the second end of the energy storage inductor L1, the second end of the input capacitor Cin, and the second end of the main output capacitor C1 can be connected and grounded.

[0056] See also Figure 3 , Figure 3FIG. 2 is a schematic diagram of a circuit structure of another embodiment of the switching power supply of the present application. In this embodiment, the switching power supply 100 may include a charging circuit 110 , a main discharging circuit 120 and at least one branch discharging circuit 130 .

[0057] The charging circuit 110 may include an input capacitor Cin, a main switch IC1 and an energy storage unit. In this embodiment, the energy storage unit is an energy storage transformer T1. The main discharge circuit 120 may include a freewheeling diode D1a, a main isolation diode D1 and a main output capacitor C1. The branch discharge circuit 130 may include a secondary isolation diode D2, a secondary switch IC2 and a branch output capacitor C2.

[0058] The input end of the secondary isolation diode D2 can be used as the input end of the branch discharge loop 130, the output end of the secondary isolation diode D2 can be connected to the first end of the branch output capacitor C2 through the secondary switch IC2, the second end of the branch output capacitor C2 can be grounded, and the load of the branch discharge loop 130 can be connected to both ends of the branch output capacitor C2.

[0059] In other embodiments, the secondary isolation diode D2 and the secondary switch IC2 can be swapped, that is, the first end of the secondary switch IC2 can be used as the input end of the branch discharge loop 130, the second end of the secondary switch IC2 can be connected to the input end of the secondary isolation diode D2, and the output end of the secondary isolation diode D2 can be connected to the first end of the branch output capacitor C2.

[0060] The energy storage transformer T1 may include a first coil L2 and a second coil L3. A first end of the first coil L2 may be connected to a first end of an input capacitor Cin, and a second end of the first coil L2 may be connected to a second end of the input capacitor Cin through a main switch IC1.

[0061] The second end of the second coil L3 can be connected to the second end of the main output capacitor C1 and grounded, the input end of the freewheeling diode D1a can be connected to the first end of the second coil L3, and the output end of the freewheeling diode D1a can be connected to the input end of the main isolation diode D1.

[0062] The second end of the first coil L2 and the first end of the second coil L3 are the same end, and the first end of the first coil L2 and the second end of the second coil L3 are the same end. At least one branch discharge loop 130 is connected in parallel and connected to the node Vbus between the output end of the freewheeling diode D1a and the input end of the main isolation diode D1.

[0063] See also Figure 4 , Figure 4 2 is a schematic diagram of a household appliance of the present application. The household appliance 200 may include the switching power supply 100 in the above embodiment. In this embodiment, the household appliance 200 may be a small household appliance such as an induction cooker, a soybean milk machine, a water dispenser, a microwave oven, etc.

[0064] It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. In addition, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0065] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0066] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0067] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A switching power supply, characterized in that: The switching power supply comprises: A charging circuit, comprising an input capacitor, an energy storage element and a main switch, wherein both ends of the input capacitor are configured as an input power supply voltage; the main switch is connected between the input capacitor and the energy storage element; A main discharge circuit, comprising a main output capacitor, a main isolation diode and a freewheeling diode, wherein the main output capacitor is connected to the energy storage element, and both ends of the main output capacitor are configured to be connected to a load; an input end of the freewheeling diode is connected to the main switch, an output end of the freewheeling diode is connected to an input end of the main isolation diode, and an output end of the main isolation diode is connected to a first end of the main output capacitor; at least one branch discharge loop, each branch discharge loop comprising a sub-switch and a branch output capacitor, a first end of the sub-switch being connected to the energy storage element, and two ends of the branch output capacitor being configured to be connected to a load; The energy storage element is an energy storage inductor, a first end of the energy storage inductor is connected between the main switch and the input end of the freewheeling diode, and a second end of the energy storage inductor, a second end of the input capacitor, and a second end of the main output capacitor are connected and grounded.

2. The switching power supply according to claim 1, characterized in that: Each branch discharge loop further includes a secondary isolation diode, an input end of the secondary isolation diode is connected to the output end of the freewheeling diode, and an output end of the secondary isolation diode is connected to the first end of the branch output capacitor.

3. The switching power supply according to claim 1, characterized in that: The main switch and the secondary switch are switching power supply chips encapsulating power switch tubes or power switch tubes controlled by a switching power supply controller.

4. The switching power supply according to claim 1, characterized in that: The average load current of the energy storage element is the sum of the load currents of the main discharge circuit and the branch discharge circuit.

5. The switching power supply according to claim 4, characterized in that: The effective duty ratio of the load current of the energy storage element occupied by the main discharge circuit or the branch discharge circuit is the quotient of the load current of the main discharge circuit or the branch discharge circuit divided by the average load current of the energy storage element.

6. The switching power supply according to claim 5, characterized in that: The total output power of the switching power supply is the sum of the output powers of the main discharge circuit and the branch discharge circuit, wherein the output power of the main discharge circuit or the branch discharge circuit is equal to the product of the output voltage of the main discharge circuit or the branch discharge circuit and the load current.

7. The switching power supply according to claim 6, characterized in that: The equivalent output voltage of the switching power supply is the quotient of the total output power of the switching power supply and the average load current of the energy storage element.

8. The switching power supply according to claim 7, characterized in that: The duty cycle of the main switch is the quotient of the equivalent output voltage of the switching power supply divided by the power supply voltage.

9. A household appliance, characterized in that: Comprising a switching power supply as described in any one of claims 1-8.

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