Power supply devices, electrical appliances and filter circuits

Abstract

The present invention discloses a power supply device, an electrical appliance and a filter circuit, wherein the power supply device includes a rectifier circuit, a filter circuit and a switching power supply, wherein the rectifier circuit is connected to the power input and is used to rectify the input signal and output the rectified signal; the filter circuit is connected to the rectifier circuit and is used to filter the rectified signal and output the filtered signal, and the filter circuit includes a plurality of RC filter units, wherein the plurality of RC filter units are connected in series; the switching power supply is connected to the filter circuit and is used to process the filtered signal to output the load power. The power supply device, the electrical appliance and the filter circuit of the present invention can improve the pressure resistance of the filter circuit by setting a multi-stage RC filter unit, more effectively resist the impact caused by power supply fluctuation, and have a simple structure and are suitable for production.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical appliance manufacturing, and in particular relates to a power supply device, and an electrical appliance and a filter circuit comprising the power supply device. Background Art

[0002] Rectification and filtering circuits play a vital role in the reliability and life of electrical appliances, and the life of filter capacitors often depends on voltage, ripple current, and temperature rise. The quality of power grid voltage varies from country to country and region to region. In areas with poor power grid quality, there are countless cases of filter capacitors failing due to overvoltage caused by long-term power grid fluctuations and nonlinear voltage-stabilized power supply shocks. In addition, high-voltage capacitors are often large in size, not suitable for production, and have complex processes and are not popular. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, a first object of the present invention is to provide a power supply device, which can improve the withstand voltage performance of the filter circuit, has a simple structure and is easy to produce.

[0005] A second object of the present invention is to provide an electrical appliance comprising the power supply device.

[0006] The third objective of the present invention is to provide a filter circuit.

[0007] In order to achieve the above-mentioned purpose, the power supply device of the first aspect embodiment of the present invention includes: a rectifier circuit, which is connected to the power input, and is used to rectify the input signal and output the rectified signal; a filter circuit, which is connected to the rectifier circuit, and is used to filter the rectified signal and output the filtered signal, and the filter circuit includes multiple RC filter units, wherein the multiple RC filter units are connected in series; a switching power supply, which is connected to the filter circuit, and is used to process the filtered signal to output power for load consumption.

[0008] According to the power supply device of the embodiment of the present invention, filtering is achieved by setting a plurality of RC filter units in series in the filter circuit, which can improve the overall voltage resistance of the filter circuit and avoid filtering failure caused by overvoltage due to power supply fluctuations. The structure is simple, the volume is small and it is easy to produce.

[0009] In some embodiments, the RC filter unit includes a capacitor and at least one resistor, wherein the capacitor is connected in parallel with the resistor.

[0010] In some embodiments, the at least one resistor is multiple, and the multiple resistors are connected in series or in parallel or in a combination of series and parallel.

[0011] In some embodiments, one of the plurality of RC filter units is connected to the power ground, and the one RC filter unit includes a first capacitor, a first resistor, and a second resistor, wherein the first capacitor is connected in parallel with the first resistor and the second resistor, the first resistor is connected in series with the second resistor, and a voltage sampling output point is provided between the first resistor and the second resistor, and the voltage sampling output point is connected to the voltage sampling terminal of the switching power supply. By sharing the resistor of the RC filter unit connected to the power ground for voltage sampling, harmonics and surge voltage on the sampling signal can be reduced, which is beneficial to EMC improvement.

[0012] In some embodiments, one of the RC filter units further includes a second capacitor, and the second capacitor is connected in parallel with the second resistor.

[0013] In some embodiments, the ratio of the withstand voltage value of the capacitance of any one of the plurality of RC filter units to the capacitance of any other RC filter unit is equal to the ratio of the resistance of any one of the RC filter units to the resistance of any other RC filter unit. Thus, voltage equalization can be achieved within the filter circuit to ensure that the voltage value applied to each filter capacitor does not exceed its withstand voltage value.

[0014] In order to achieve the above object, an electrical appliance according to an embodiment of the second aspect of the present invention comprises a load and the power supply device described in the above embodiment, wherein the load is connected to the power supply device.

[0015] The electrical appliance according to the embodiment of the present invention can reduce the impact of power supply fluctuation on the filter withstand voltage of the power supply by adopting the power supply device of the above embodiment, thereby improving reliability.

[0016] In order to achieve the above-mentioned purpose, a filter circuit in an embodiment of the third aspect of the present invention comprises a plurality of RC filter units, wherein the plurality of RC filter units are connected in series.

[0017] According to the filter circuit of the embodiment of the present invention, by designing a multi-stage RC filter unit, the voltage resistance of the filter circuit can be improved to avoid filtering failure caused by overvoltage due to power supply fluctuation. The structure is simple, the volume is small and it is easy to produce.

[0018] In some embodiments, the RC filter unit includes a capacitor and at least one resistor, wherein the capacitor is connected in parallel with the resistor.

[0019] In some embodiments, when there are multiple resistors, the multiple resistors are connected in series or in parallel or in a combination of series and parallel.

[0020] In some embodiments, one of the plurality of RC filter units is connected to the power ground, and the one RC filter unit includes a first capacitor, a first resistor, and a second resistor, wherein the first capacitor is connected in parallel with the first resistor and the second resistor, the first resistor is connected in series with the second resistor, and a voltage sampling output point is provided between the first resistor and the second resistor, and the voltage sampling output point is connected to the voltage sampling terminal of the switching power supply. By sharing the resistor of the RC filter unit connected to the power ground for voltage sampling, harmonics and surge voltage on the sampling signal can be reduced, which is beneficial to EMC improvement.

[0021] In some embodiments, one of the RC filter units further includes a second capacitor, and the second capacitor is connected in parallel with the second resistor.

[0022] In some embodiments, the ratio of the withstand voltage value of the capacitance of any one of the plurality of RC filter units to the capacitance of any other RC filter unit is equal to the ratio of the resistance of any one of the RC filter units to the resistance of any other RC filter unit. Thus, voltage equalization can be achieved within the filter circuit to ensure that the voltage value applied to each filter capacitor does not exceed its withstand voltage value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a block diagram of a power supply device according to an embodiment of the present invention;

[0024] Figure 2 is a circuit diagram of a power supply device and its connection diagram according to an embodiment of the present invention;

[0025] Figure 3 is a block diagram of an electrical appliance according to an embodiment of the present invention;

[0026] Figure 4 is a block diagram of a filter circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] The power supply device according to the first embodiment of the present invention will be described below with reference to the accompanying drawings.

[0029] Figure 1 is a block diagram of a power supply device according to an embodiment of the present invention, Figure 1As shown, the power supply device 100 according to the embodiment of the present invention includes a rectifier circuit 10 , a filter circuit 20 and a switch power supply 30 .

[0030] Among them, the rectifier circuit 10 is connected to a power input, such as a mains input, for rectifying the input signal and outputting a rectified signal; the filter circuit 20 is connected to the rectifier circuit 10, for filtering the rectified signal and outputting a filtered signal. Usually, the filter circuit is implemented in the form of RC or LC. However, the voltage resistance of a single-stage RC or LC filter circuit is relatively poor. Long-term exposure to power grid fluctuations and nonlinear voltage-stabilized power supply shocks can easily cause capacitor failure, and high-voltage-resistant capacitors are large in size and difficult to produce. In order to improve the voltage resistance of the filter circuit, in an embodiment of the present invention, the filter circuit 20 includes a plurality of RC filter units 21, such as Figure 1 In the figure, N is two or more, wherein multiple RC filter units 21 are connected in series, that is, a multi-stage RC circuit is used to achieve filtering, and the withstand voltage ratio of the filter circuit 20 is equivalent to the sum of the withstand voltage values ​​of each RC filter unit 21. Compared with single-stage filtering, the withstand voltage capability of the filter circuit 20 can be improved, and the filtering failure caused by power grid fluctuations can be reduced, and the volume of the RC circuit is smaller than that of the LC circuit. The switching power supply 30 is connected to the filter circuit 20, and is used to process the filter signal to output the load power consumption, so as to ensure the stability of the load power consumption.

[0031] According to the power supply device 100 of the embodiment of the present invention, filtering is achieved by setting a plurality of RC filter units 21 in series in the filter circuit 20, which can improve the voltage resistance of the filter circuit 20 and avoid filtering failure caused by overvoltage due to power supply fluctuations. The structure is simple, the volume is small and it is easy to produce.

[0032] Furthermore, in the embodiment, the rectifier circuit 10 may adopt a bridge rectifier circuit or other rectifier circuits, such as Figure 2 As shown, it is a circuit diagram of a power supply device according to an embodiment of the present invention, wherein the rectifier circuit 10 includes a diode D1, a diode D2, a diode D3 and a diode D4, and the four diodes constitute a bridge rectifier circuit, the input end is connected to the AC power, and the output is connected to the filter circuit 20 to realize the rectification of the input signal.

[0033] In an embodiment of the present invention, the RC filter unit 21 may include a capacitor and at least one resistor, wherein the capacitor and the resistor are connected in parallel. Specifically, the filter withstand voltage value of each RC filter unit 21 may be different, and according to the different withstand voltages of the filter capacitors in each RC filter unit 21, the voltage is divided by the parallel resistors of the RC circuit. Figure 2 As shown, the RC filter unit 21 may be composed of a capacitor and a resistor connected in parallel, for example Figure 2 The capacitor E1 and the resistor R1 in the figure can also be composed of a capacitor and multiple resistors, for example Figure 2 The capacitor E2, resistor R2 and resistor R3 are included.

[0034] In some embodiments, when the RC filter unit 21 has multiple resistors, the multiple resistors may be connected in series, for example Figure 2 The resistors R2 and R3 may be connected in parallel or in a combination of series and parallel, i.e. resistors connected in parallel and in series, and the selection may be made based on the withstand voltage design requirements.

[0035] Specifically, Figure 2 Taking the circuit as an example, the positive electrode of capacitor E1 is connected to the cathode of diode D1 and diode D4 and one end of resistor R1, and the negative electrode of capacitor E1 is connected to the other end of resistor R1, and resistor R1 and capacitor E1 constitute a first RC filter unit. Capacitor E2, resistor R2, and resistor R3 constitute a second RC filter unit, which is connected in series with the first RC filter unit and finally connected to the power supply ground. Among them, the sum of the withstand voltage values ​​of capacitor E1 and capacitor E2 is greater than the fluctuating voltage of the power grid or the impulse voltage of the nonlinear regulated power supply. By connecting multiple low-voltage RC filter units 21 in series, the total withstand voltage value of the filter circuit 20 can be increased.

[0036] In an embodiment, the ratio of the withstand voltage value of the capacitance of any one RC filter unit 21 to the capacitance of any other RC filter unit 21 among the plurality of RC filter units 21 is equal to the ratio of the resistance value of the resistance of any one RC filter unit 21 to the resistance value of any other RC filter unit 21. Figure 2 As shown, the withstand voltage ratio of capacitor E1 to capacitor E2 is equal to the resistance ratio of resistor R1 to the sum of resistors R2 and R3. For example, if E1=500F, E2=100F, then E1 / E2=5 / 1, then R1 / (R2+R3)=5 / 1. For the case where the resistors of the RC filter unit 21 are connected in parallel or in series, the resistance value of the resistors of the RC filter unit 21 is equivalent to the resistance value after being connected in parallel or in series, so that voltage equalization can be achieved in the filter circuit 20, ensuring that the voltage value applied to capacitors E1 and E2 does not exceed their withstand voltage value.

[0037] In the embodiment of the present invention, one RC filter unit among the plurality of RC filter units 21 of the filter circuit 20 is connected to the power ground, such as Figure 2 The second RC filter unit 21 shown in the figure includes a first capacitor E2, a first resistor R2 and a second resistor R3, wherein the first capacitor E2 is connected in parallel with the first resistor R2 and the second resistor R3, the first resistor R2 is connected in series with the second resistor R3, and a voltage sampling output point is provided between the first resistor R2 and the second resistor R3, and the voltage sampling output point is connected to the voltage sampling terminal of the switching power supply 30, for example Figure 2The medium voltage sampling signal Vshunt is input to the voltage sampling terminal of the switching power supply 30 . The voltage sampling signal Vshunt can be used as an input signal of the overvoltage or undervoltage protection circuit of the switching power supply 30 to play a protective role.

[0038] Furthermore, if Figure 2 As shown, the RC filter unit 21 connected to the power ground also includes a second capacitor C2, which is connected in parallel with the second resistor R3 to play the role of sampling output filtering. Figure 2 As shown, the first resistor R2 and the second resistor R3 are connected in series for voltage division, the second resistor R3 and the second capacitor C2 are connected in parallel, and the first resistor R1, the second resistor R2 and the second capacitor C2 form a voltage sampling circuit. The sampling circuit shares the resistance of the RC filter unit 21 connected to the power ground. After filtering by other RC filter units 21, the harmonics and surge voltage division of the voltage sampling signal will be reduced, which is more conducive to the EMC improvement of the switching power supply 30.

[0039] In summary, the power supply device 100 of the embodiment of the present invention, the filter circuit 20 can improve the filter withstand voltage and resist the impact of grid fluctuations or nonlinear voltage-stabilized power supplies by setting a multi-stage RC filter unit 21, and has a simple structure and is suitable for production. In addition, the voltage acquisition circuit shares the resistance of the RC filter unit 21 connected to the power ground, which can reduce the harmonics and surge voltage on the sampling signal, which is beneficial to EMC improvement.

[0040] Based on the power supply device of the above embodiment, an electrical appliance according to an embodiment of the second aspect of the present invention will be described below with reference to the accompanying drawings.

[0041] Figure 3 is a block diagram of an electrical appliance according to an embodiment of the present invention, such as Figure 3 As shown, the electrical appliance 1000 of the embodiment of the present invention includes a load 200 and the power supply device 100 of the above embodiment. The load 200 is connected to the power supply device 100. The power supply device 100 processes input signals such as AC power and outputs load power to supply power to the load 200.

[0042] According to the electrical appliance 1000 of the embodiment of the present invention, by adopting the power supply device 100 of the above embodiment, the impact of power supply fluctuation on the filtering withstand voltage of the power supply can be reduced, and the reliability is improved.

[0043] The filter circuit according to the third embodiment of the present invention will be described below with reference to the accompanying drawings.

[0044] Figure 4 is a block diagram of a filter circuit according to an embodiment of the present invention, such as Figure 4As shown, the filter circuit 20 of the embodiment of the present invention includes a plurality of RC filter units 21, wherein the plurality of RC filter units 21 are connected in series, and N represents two or more RC filter units.

[0045] According to the filter circuit 20 of the embodiment of the present invention, by designing a multi-stage RC filter unit 21, the voltage resistance of the filter circuit 20 can be improved to avoid filtering failure caused by overvoltage due to power supply fluctuation. The structure is simple, the volume is small, and it is easy to produce.

[0046] Further, in the embodiment, the RC filter unit 21 includes a capacitor and at least one resistor, wherein the capacitor and the resistor are connected in parallel. Specifically, the filter withstand voltage value of each RC filter unit 21 may be different, and according to the different withstand voltages of the filter capacitors in each RC filter unit 21, the voltage is divided by the parallel resistors of the RC circuit. Figure 2 As shown, the RC filter unit 21 may be composed of a capacitor and a resistor connected in parallel, for example Figure 2 The capacitor E1 and the resistor R1 in the figure can also be composed of a capacitor and multiple resistors, for example Figure 2 The capacitor E2, resistor R2 and resistor R3 are included.

[0047] In some embodiments, when the RC filter unit 21 has multiple resistors, the multiple resistors may be connected in series, for example Figure 2 The resistors R2 and R3 may be connected in parallel or in a combination of series and parallel, i.e. resistors connected in parallel and in series, and the selection may be made based on the withstand voltage design requirements.

[0048] In an embodiment, the ratio of the withstand voltage value of the capacitance of any one RC filter unit 21 to the capacitance of any other RC filter unit 21 among the plurality of RC filter units 21 is equal to the ratio of the resistance value of the resistance of any one RC filter unit 21 to the resistance value of any other RC filter unit 21. Figure 2 As shown, the withstand voltage ratio of capacitor E1 to capacitor E2 is equal to the resistance ratio of resistor R1 to the sum of resistors R2 and R3. For example, if E1=500F, E2=100F, then E1 / E2=5 / 1, then R1 / (R2+R3)=5 / 1. For the case where the resistors of the RC filter unit 21 are connected in parallel or in series, the resistance value of the resistors of the RC filter unit 21 is equivalent to the resistance value after being connected in parallel or in series, thereby achieving uniformity within the filter circuit 20 and ensuring that the voltage value applied to the capacitors E1 and E2 does not exceed their withstand voltage values.

[0049] In the embodiment of the present invention, one RC filter unit among the plurality of RC filter units 21 of the filter circuit 20 is connected to the power ground, such as Figure 2The second RC filter unit 21 shown in the figure includes a first capacitor E2, a first resistor R2 and a second resistor R3, wherein the first capacitor E2 is connected in parallel with the first resistor R2 and the second resistor R3, the first resistor R2 is connected in series with the second resistor R3, and a voltage sampling output point is provided between the first resistor R2 and the second resistor R3, and the voltage sampling output point is connected to the voltage sampling end of the switching power supply 30, and the voltage sampling signal can be used as an input signal of the overvoltage or undervoltage protection circuit of the switching power supply 30 to play a protective role.

[0050] Furthermore, if Figure 2 As shown, the RC filter unit 21 connected to the power ground further includes a second capacitor C2, and the second capacitor C2 is connected in parallel with the second resistor R3 to play the role of sampling output filtering.

[0051] In summary, the filter circuit 20 of the embodiment of the present invention, by setting a multi-stage RC filter unit 21, can improve the filter withstand voltage compared to a single-stage filter, resist the impact of grid fluctuations or nonlinear voltage-stabilized power supplies, and has a simple structure, suitable for production, and the resistance of the RC filter unit 21 connected to the power ground can divide the voltage and output a voltage sampling signal to the switching power supply, thereby improving the EMC of the switching power supply and providing more accurate data.

[0052] It should be noted that, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0053] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0054] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A power supply device, characterized in that: The power supply device comprises: A rectifier circuit, the rectifier circuit is connected to the power input and is used to rectify the input signal and output a rectified signal; A filter circuit, the filter circuit is connected to the rectifier circuit, and is used to filter the rectified signal and output a filtered signal. The filter circuit includes a plurality of RC filter units, wherein the plurality of RC filter units are connected in series, the filter capacitor of each RC filter unit has a different withstand voltage, and the voltage is divided by a parallel resistor of the RC circuit; A switching power supply, the switching power supply is connected to the filtering circuit and is used to process the filtering signal to output power for a load; One of the plurality of RC filter units is connected to a power ground, and the one RC filter unit comprises a first capacitor, a first resistor, and a second resistor, wherein the first capacitor is connected in parallel with the first resistor and the second resistor, the first resistor is connected in series with the second resistor, a voltage sampling output point is provided between the first resistor and the second resistor, and the voltage sampling output point is connected to a voltage sampling terminal of the switching power supply; The one RC filter unit further includes a second capacitor, and the second capacitor is connected in parallel with the second resistor.

2. The power supply device according to claim 1, characterized in that: The RC filter unit includes a capacitor and at least one resistor, wherein the capacitor is connected in parallel with the resistor.

3. The power supply device according to claim 2, characterized in that: The at least one resistor is multiple, and the multiple resistors are connected in series or in parallel or in a combination of series and parallel.

4. The power supply device according to claim 2, characterized in that: The ratio of the withstand voltage value of the capacitance of any one of the multiple RC filter units to the capacitance of any other RC filter unit is equal to the ratio of the resistance of any one of the RC filter units to the resistance of any other RC filter unit.

5. An electrical appliance, characterized in that: The electrical appliance comprises a load and a power supply device as described in any one of claims 1 to 4, and the load is connected to the power supply device.

6. A filter circuit, characterized in that: The filter circuit includes a plurality of RC filter units, wherein the plurality of RC filter units are connected in series, the filter capacitors of each RC filter unit have different withstand voltages, and voltage division is performed through parallel resistors of the RC circuit; One of the plurality of RC filter units is connected to a power ground, and the one RC filter unit comprises a first capacitor, a first resistor, and a second resistor, wherein the first capacitor is connected in parallel with the first resistor and the second resistor, the first resistor is connected in series with the second resistor, a voltage sampling output point is provided between the first resistor and the second resistor, and the voltage sampling output point is connected to a voltage sampling terminal of a switching power supply; The one RC filter unit further includes a second capacitor, and the second capacitor is connected in parallel with the second resistor.

7. The filter circuit according to claim 6, characterized in that: The RC filter unit includes a capacitor and at least one resistor, wherein the capacitor is connected in parallel with the resistor.

8. The filter circuit according to claim 7, characterized in that: When there are multiple resistors, the multiple resistors are connected in series or in parallel or in a combination of series and parallel.

9. The filter circuit according to claim 7, characterized in that: The ratio of the withstand voltage value of the capacitance of any one of the multiple RC filter units to the capacitance of any other RC filter unit is equal to the ratio of the resistance of any one of the RC filter units to the resistance of any other RC filter unit.

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