A ripple reduction circuit and an electrical appliance

Abstract

The application discloses a kind of ripple reduction circuit and electrical appliance, the ripple reduction circuit includes: power module, for outputting preset voltage signal, and receiving feedback voltage signal, the preset voltage signal has ripple;Sampling module is connected at the output of the power module, for collecting the preset voltage signal;Amplification module is connected at the output of the sampling module, for the preset voltage signal amplification, and the preset voltage signal after amplification is as the feedback voltage signal output to the power module.Compared with prior art, the application can amplify the originally tiny feedback voltage, so that the measurement of feedback voltage is more accurate, and the power module has better measurement effect, so as to suppress ripple interference.

Description

Technical Field

[0001] This invention relates to the field of home appliances, and in particular to a ripple reduction circuit and appliance. Background Technology

[0002] Ripple is a phenomenon caused by voltage fluctuations in a DC power supply. Since a DC power supply is generally formed by rectifying and regulating an AC power supply, it inevitably contains some AC components in the DC power supply. This AC component superimposed on the DC power supply is called ripple.

[0003] Ripple can affect the reliability and operating condition of electrical components. In circuit design for home appliances, ripple is generally reduced through capacitor filtering; however, due to the different circuits that need to be adapted, existing filtering solutions are often unsuitable for different operating conditions, have poor versatility, and limited ability to suppress ripple.

[0004] Therefore, how to design a ripple reduction circuit and electrical appliance that can improve the ability to suppress ripple is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] In view of the problem that existing ripple reduction circuits cannot be adapted to most circuits and have limited ripple suppression capabilities, this invention proposes a ripple reduction circuit and electrical appliance.

[0006] The technical solution of this invention is to propose a ripple reduction circuit, 1. comprising:

[0007] A power module for outputting a preset voltage signal and receiving a feedback voltage signal, wherein the preset voltage signal has ripple;

[0008] A sampling module, which is connected to the output terminal of the power supply module, is used to acquire the preset voltage signal;

[0009] An amplification module, connected to the output of the sampling module, is used to amplify the preset voltage signal and output the amplified preset voltage signal as the feedback voltage signal to the power supply module.

[0010] Furthermore, it also includes:

[0011] An isolation module is connected between the amplification module and the power supply module to reduce interference from the amplification module to the power supply module.

[0012] Furthermore, the power module employs a DC-DC power conversion circuit or an LDO voltage regulator circuit.

[0013] Furthermore, the sampling module employs an amplitude meter or a sampling circuit.

[0014] Furthermore, the amplification module employs a voltage amplification circuit.

[0015] Furthermore, the isolation module employs an isolation capacitor or an isolation circuit.

[0016] Furthermore, the sampling module includes resistors R1 and R2;

[0017] One end of resistor R1 is connected to the output terminal of the power module, and the other end is connected in series with resistor R2.

[0018] The circuit is grounded, and the resistor R1 and resistor R2 are connected to the amplification module as the output terminal of the sampling module.

[0019] Furthermore, the amplification module includes: resistors R3, R4, R5, R6, and R7; capacitors C1 and C2; and transistor Q1.

[0020] In this configuration, the collector of transistor Q1 is connected to the power input via resistor R5, the emitter is connected to the ground via resistor R6, and the base is connected to the ground via resistor R4.

[0021] One end of the capacitor C1 is connected between the emitter of the transistor Q1 and the resistor R6, and the other end is connected between the resistor R1 and the resistor R2;

[0022] The capacitor C5 is connected in parallel across the resistor R4;

[0023] One end of resistor R3 is connected between the base of transistor Q1 and resistor R4, and the other end is connected between resistor R5 and the power input.

[0024] One end of the capacitor C2 is connected between the collector of the transistor Q1 and the resistor R5, and the other end is connected in series with the resistor R7 and then grounded.

[0025] The capacitor C2 and the resistor R7 serve as the output terminal of the amplification module.

[0026] Furthermore, the isolation module includes:

[0027] Resistors R8, R9, R10, R11, R12, capacitor C3, capacitor C4, transistor Q2;

[0028] Wherein, one end of resistor R8 is connected to the power input, and the other end is connected in series with resistor R9 and then grounded;

[0029] The collector of transistor Q2 is connected in series with resistor R10 and then connected to the power input; the emitter is connected in series with resistor R11 and then grounded; and the base is connected between resistors R8 and R9.

[0030] One end of capacitor C3 is connected between resistor C2 and resistor R7, and the other end is connected between resistor R8 and resistor R9;

[0031] One end of the capacitor C4 is connected between the emitter of the transistor Q2 and the resistor R11, and the other end is connected in series with the resistor R12 and then grounded;

[0032] The capacitor C4 and the resistor R12 are connected to the power module as the output terminal of the isolation module.

[0033] The present invention also proposes an electrical appliance having the above-described ripple reduction circuit.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] This invention employs an automatic gain control circuit, which amplifies the originally minute feedback voltage, thereby making the measurement of the feedback voltage more accurate and providing better measurement results for the power supply chip, thus achieving the purpose of ripple suppression. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the module connection of the ripple reduction circuit in the first embodiment of the present invention;

[0038] Figure 2 This is a detailed circuit topology diagram of the ripple reduction circuit in the first embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the module connection of the ripple reduction circuit in the second embodiment of the present invention;

[0040] Figure 4 This is a detailed circuit topology diagram of the ripple reduction circuit in the second embodiment of the present invention;

[0041] Figure 5 This is a specific circuit topology diagram of the sampling module in this invention;

[0042] Figure 6This is a specific circuit topology diagram of the amplification module in this invention;

[0043] Figure 7 This is a specific circuit topology diagram of the isolation module in this invention. Detailed Implementation

[0044] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0045] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0046] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0047] Ripple is a phenomenon caused by voltage fluctuations in a DC power supply. Since a DC power supply is generally formed by rectifying and regulating an AC power supply, it inevitably contains some AC components in the DC power supply. This AC component superimposed on the DC power supply is called ripple.

[0048] In circuit design for home appliances, ripple is generally reduced by capacitor filtering. However, due to the different circuits that need to be adapted, existing filtering solutions cannot be adapted to different operating conditions, have poor versatility, and have limited ability to suppress ripple.

[0049] To address the aforementioned problems, this invention proposes a ripple reduction circuit. Its main design concept involves an amplification module to amplify the originally minute feedback voltage, thereby making the measurement of the feedback voltage more accurate. Since ripple mainly manifests as voltage interference, this invention improves the measurement accuracy of the feedback voltage through this scheme, indirectly suppressing ripple interference.

[0050] Please see Figure 1 This is a schematic diagram of the module connection of the ripple reduction circuit in the first embodiment of the present invention. Figure 1 As can be clearly seen, the ripple reduction circuit in this invention consists of a power supply module, a sampling module, and an amplification module;

[0051] The power module is used to output a preset voltage signal and receive a feedback voltage signal, which has ripple.

[0052] The sampling module is connected to the output terminal of the power supply module and is used to collect the aforementioned preset voltage signal;

[0053] The amplification module is connected to the output of the sampling module. It is used to amplify the preset voltage signal and output the amplified preset voltage signal as a feedback voltage signal to the power supply module.

[0054] Based on the above design, the control concept of this invention is that when the power module sends a preset voltage signal, the preset voltage signal is sampled by the sampling module, and then the preset voltage signal is amplified by the amplification module and re-output as a feedback voltage signal to the power module. The power module can obtain a more accurate feedback voltage signal, thereby adjusting the output preset voltage signal and achieving the purpose of suppressing ripple interference.

[0055] Therefore, compared with the prior art, the present invention improves the measurement effect of feedback voltage and enhances the ability to suppress ripple through this design.

[0056] Furthermore, the aforementioned power module employs a DC-DC power conversion circuit or an LDO voltage regulator circuit.

[0057] The design of the DC-DC power conversion circuit can be a scheme of AC power supply + transformer + rectifier circuit. The input voltage and output voltage of the transformer are related to its own turns ratio, which satisfies the following relationship:

[0058] V1*N2=V2*N1;

[0059] Here, V1 is the input voltage of the transformer, V2 is the output voltage of the transformer, N1 is the number of turns in the primary winding of the transformer, and N2 is the number of turns in the secondary winding of the transformer.

[0060] Therefore, the output voltage can be adjusted by changing the ratio between the number of turns in the primary winding and the number of turns in the secondary winding of the transformer. Then, the output voltage of the transformer is converted into DC by the rectifier circuit to achieve the required voltage. Here, the rectifier circuit can adopt the traditional rectifier bridge design.

[0061] An LDO (Limited-Displacement) voltage regulator is a DC-DC step-down linear regulator that maintains a stable output voltage even when the input voltage or load changes. LDO voltage regulators are characterized by their small size, low noise, low power consumption, and ease of application.

[0062] Furthermore, the above sampling module can employ an amplitude meter or a sampling circuit.

[0063] Here, the amplitude meter can obtain the amplitude of voltage change and then calculate the actual voltage magnitude, which is calculated based on the relationship between the amplitude and the effective value of the voltage.

[0064] The sampling circuit can be implemented using a sampling resistor, and its circuit structure is simple. Alternatively, the output voltage of the power module can be sampled using the principle of resistor voltage division.

[0065] Furthermore, the aforementioned amplification module employs a voltage amplification circuit.

[0066] Its specific design can be achieved by using a transistor and a voltage resistor, or by using an amplifier to form an amplification circuit; the specific design is not limited.

[0067] Please see Figure 2 This is a detailed circuit topology diagram of the ripple reduction circuit in the first embodiment. Please refer to [link / reference]. Figure 5 In this first embodiment, the sampling module includes resistors R1 and R2;

[0068] Among them, one end of resistor R1 is connected to the output terminal of the power supply module, and the other end is connected to ground after being connected in series with resistor R2. The area between resistor R1 and resistor R2 serves as the output terminal of the sampling module and is connected to the amplification module.

[0069] This scheme uses resistor voltage division for voltage sampling. VOUT is the output voltage of the power module, which is grounded after passing through resistors R1 and R2. According to the principle of resistor series voltage division, the voltage across the resistor is proportional to its resistance value. Therefore, the output voltage of the sampling module can be determined as R2*VOUT / (R1+R2).

[0070] This invention samples the output voltage of the power module through this scheme, which can achieve a more accurate measurement effect. At the same time, resistors R1 and R2 can also play a voltage division role, avoiding the impact of excessive voltage on subsequent circuits.

[0071] Please see Figure 2 and Figure 6 In this first embodiment, the amplification module includes: resistors R3, R4, R5, R6, and R7; capacitors C1 and C2; and transistor Q1.

[0072] Among them, the collector series resistor R5 of transistor Q1 is connected to the power input, the emitter series resistor R6 is connected to ground, and the base series resistor R4 is connected to ground.

[0073] One end of capacitor C1 is connected between the emitter of transistor Q1 and resistor R6, and the other end is connected between resistor R1 and resistor R2;

[0074] Capacitor C5 is connected in parallel across resistor R4;

[0075] One end of resistor R3 is connected between the base of transistor Q1 and resistor R4, and the other end is connected between resistor R5 and the power input.

[0076] One end of capacitor C2 is connected between the collector of transistor Q1 and resistor R5, and the other end is connected in series with resistor R7 and then grounded.

[0077] The capacitor C2 and resistor R7 serve as the output terminal of the amplifier module.

[0078] In this scheme, capacitors C1 and C2 are used for coupling, capacitor C2 is used for energy storage and filtering, resistors R3 and R4 are used for voltage division, resistor R5 is used for current limiting, resistor R6 is used for feedback, resistor R7 is used as the load resistor, and switch Q1 is used to amplify the voltage signal.

[0079] like Figure 2 As shown, it is a schematic diagram of the connection between the sampling circuit and the amplification circuit. VOUT is the output voltage of the power supply module, and FB is the output of the amplification circuit. In this first embodiment, the output terminal of the amplification module is directly connected to the power supply module. The power supply module can receive the amplified feedback voltage signal, thereby improving the accuracy of the measurement and achieving the effect of suppressing ripple interference.

[0080] Please see Figure 3 This is a schematic diagram of the module connection of the ripple reduction circuit in the second embodiment of the present invention. Figure 3 As can be clearly seen, the ripple reduction circuit in this invention consists of a power supply module, a sampling module, an amplification module, and an isolation module;

[0081] The power module is used to output a preset voltage signal and receive a feedback voltage signal, which has ripple.

[0082] The sampling module is connected to the output terminal of the power supply module and is used to collect the aforementioned preset voltage signal;

[0083] The amplification module is connected to the output of the sampling module. It is used to amplify the preset voltage signal and output the amplified preset voltage signal as a feedback voltage signal to the power supply module.

[0084] An isolation module, connected between the amplifier module and the power supply module, can reduce the interference caused by the amplifier module to the power supply module.

[0085] Based on the above design, the control concept of this invention is that when the power module sends a preset voltage signal, the preset voltage signal is sampled by the sampling module, then amplified by the amplification module, and then isolated by the isolation module as a feedback voltage signal before being re-output to the power module. The power module can obtain a more accurate feedback voltage signal, thereby adjusting the output preset voltage signal and achieving the purpose of suppressing ripple interference.

[0086] Therefore, compared with the prior art, the present invention improves the measurement effect of feedback voltage and enhances the ability to suppress ripple through this design.

[0087] Furthermore, the aforementioned power module employs a DC-DC power conversion circuit or an LDO voltage regulator circuit.

[0088] The design of the DC-DC power conversion circuit can be a scheme of AC power supply + transformer + rectifier circuit. The input voltage and output voltage of the transformer are related to its own turns ratio, which satisfies the following relationship:

[0089] V1*N2=V2*N1;

[0090] Here, V1 is the input voltage of the transformer, V2 is the output voltage of the transformer, N1 is the number of turns in the primary winding of the transformer, and N2 is the number of turns in the secondary winding of the transformer.

[0091] Therefore, the output voltage can be adjusted by changing the ratio between the number of turns in the primary winding and the number of turns in the secondary winding of the transformer. Then, the output voltage of the transformer is converted into DC by the rectifier circuit to achieve the required voltage. Here, the rectifier circuit can adopt the traditional rectifier bridge design.

[0092] An LDO (Limited-Displacement) voltage regulator is a DC-DC step-down linear regulator that maintains a stable output voltage even when the input voltage or load changes. LDO voltage regulators are characterized by their small size, low noise, low power consumption, and ease of application.

[0093] Furthermore, the above sampling module can employ an amplitude meter or a sampling circuit.

[0094] Here, the amplitude meter can obtain the amplitude of voltage change and then calculate the actual voltage magnitude, which is calculated based on the relationship between the amplitude and the effective value of the voltage.

[0095] The sampling circuit can be implemented using a sampling resistor, and its circuit structure is simple. Alternatively, the output voltage of the power module can be sampled using the principle of resistor voltage division.

[0096] Furthermore, the aforementioned amplification module employs a voltage amplification circuit.

[0097] Its specific design can be achieved by using a transistor and a voltage resistor, or by using an amplifier to form an amplification circuit; the specific design is not limited.

[0098] Furthermore, the aforementioned isolation module employs isolation capacitors or isolation circuits.

[0099] There are three main types of isolation schemes: optocoupler isolation, magnetic isolation, and capacitive isolation. In this invention, capacitive isolation is preferred.

[0100] Isolation capacitors utilize the property of capacitors to "pass AC and block DC" and are used where DC needs to be blocked, such as coupling between amplifier stages. This is the commonly used RC coupling, which connects the collector (signal output terminal) of the previous stage to the base (signal input terminal) of the next stage with a capacitor. AC signals can pass through smoothly, but there is no DC connection between the stages.

[0101] Isolation circuits can be constructed using capacitors, transistors, and resistors, offering higher reliability compared to single-capacitor isolation.

[0102] Please see Figure 4 This is a detailed circuit topology diagram of the ripple reduction circuit in the fourth embodiment. Please refer to [link / reference]. Figure 5 In this first embodiment, the sampling module includes resistors R1 and R2;

[0103] Among them, one end of resistor R1 is connected to the output terminal of the power supply module, and the other end is connected to ground after being connected in series with resistor R2. The area between resistor R1 and resistor R2 serves as the output terminal of the sampling module and is connected to the amplification module.

[0104] This scheme uses resistor voltage division for voltage sampling. VOUT is the output voltage of the power module, which is grounded after passing through resistors R1 and R2. According to the principle of resistor series voltage division, the voltage across the resistor is proportional to its resistance value. Therefore, the output voltage of the sampling module can be determined as R2*VOUT / (R1+R2).

[0105] This invention samples the output voltage of the power module through this scheme, which can achieve a more accurate measurement effect. At the same time, resistors R1 and R2 can also play a voltage division role, avoiding the impact of excessive voltage on subsequent circuits.

[0106] Please see Figure 4 and Figure 6 In this second embodiment, the amplification module includes: resistors R3, R4, R5, R6, and R7; capacitors C1 and C2; and transistor Q1.

[0107] Among them, the collector series resistor R5 of transistor Q1 is connected to the power input, the emitter series resistor R6 is connected to ground, and the base series resistor R4 is connected to ground.

[0108] One end of capacitor C1 is connected between the emitter of transistor Q1 and resistor R6, and the other end is connected between resistor R1 and resistor R2;

[0109] Capacitor C5 is connected in parallel across resistor R4;

[0110] One end of resistor R3 is connected between the base of transistor Q1 and resistor R4, and the other end is connected between resistor R5 and the power input.

[0111] One end of capacitor C2 is connected between the collector of transistor Q1 and resistor R5, and the other end is connected in series with resistor R7 and then grounded.

[0112] The capacitor C2 and resistor R7 serve as the output terminal of the amplifier module.

[0113] In this scheme, capacitors C1 and C2 are used for coupling, capacitor C2 is used for energy storage and filtering, resistors R3 and R4 are used for voltage division, resistor R5 is used for current limiting, resistor R6 is used for feedback, resistor R7 is used as the load resistor, and switch Q1 is used to amplify the voltage signal.

[0114] Please see Figure 4 and Figure 7 In this second embodiment, the isolation module includes:

[0115] Resistors R8, R9, R10, R11, R12, capacitor C3, capacitor C4, transistor Q2;

[0116] Among them, one end of resistor R8 is connected to the power input, and the other end is connected to ground in series with resistor R9.

[0117] The collector of transistor Q2 is connected to the power input via series resistor R10, the emitter is connected to ground via series resistor R11, and the base is connected between resistors R8 and R9.

[0118] One end of capacitor C3 is connected between resistors C2 and R7, and the other end is connected between resistors R8 and R9;

[0119] One end of capacitor C4 is connected between the emitter of transistor Q2 and resistor R11, and the other end is connected in series with resistor R12 and then grounded;

[0120] The capacitor C4 and resistor R12 are connected to the power module as the output terminal of the isolation module.

[0121] In this scheme, R8 and R9 are used for sampling; R10 is used for current limiting; R11 is used for feedback; R12 is used as a load resistor; and Q2 is used for isolation.

[0122] like Figure 4 As shown, it is a connection diagram of the sampling circuit, the amplification circuit, and the isolation circuit. VOUT is the output voltage of the power supply module, and FB is the output of the isolation circuit. In this second embodiment, the output terminal of the amplification module is connected to the power supply module through the isolation circuit. The power supply module can receive the amplified feedback voltage signal, thereby improving the accuracy of the measurement and achieving the effect of suppressing ripple interference.

[0123] In summary, as Figure 1 and Figure 2 As shown, the present invention proposes a ripple reduction circuit, comprising the following modules: a power supply module, a sampling module, an amplification module, and an isolation module;

[0124] The power module is used to output a preset voltage signal and receive a feedback voltage signal FB;

[0125] The sampling module is used to acquire a preset voltage signal, thereby obtaining the voltage that originally changed very little;

[0126] The amplification module is used to amplify the current ripple and output the amplified feedback voltage signal FB, so that the power supply module can more accurately identify the small level changes under the original small ripple.

[0127] The isolation module can reduce the interference that the amplification module causes to the power supply module.

[0128] The amplified voltage can be directly output as a feedback voltage, thereby enabling the detection and control of minute ripples. In different embodiments, it can also be converted into a feedback voltage through an isolation module.

[0129] This invention can effectively suppress the impact of excessive voltage ripple on circuit stability.

[0130] Furthermore, the present invention also proposes an electrical appliance having the above-mentioned ripple reduction circuit.

[0131] Compared with the prior art, the present invention has at least the following beneficial effects:

[0132] This invention employs an automatic gain control circuit, which amplifies the originally minute feedback voltage, thereby making the measurement of the feedback voltage more accurate and providing better measurement results for the power supply chip, thus achieving the purpose of ripple suppression.

[0133] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ripple reduction circuit, characterized in that, include: A power module for outputting a preset voltage signal and receiving a feedback voltage signal, wherein the preset voltage signal has ripple; A sampling module, which is connected to the output terminal of the power supply module, is used to acquire the preset voltage signal; An amplification module, connected to the output of the sampling module, is used to amplify the preset voltage signal and output the amplified preset voltage signal as the feedback voltage signal to the power supply module. The sampling module includes resistors R1 and R2; One end of resistor R1 is connected to the output terminal of the power module, and the other end is connected in series with resistor R2 and then grounded. The area between resistor R1 and resistor R2 serves as the output terminal of the sampling module and is connected to the amplification module. The amplification module includes: resistors R3, R4, R5, R6, and R7; capacitors C1 and C2; and transistor Q1. In this configuration, the collector of transistor Q1 is connected to the power input via resistor R5, the emitter is connected to the ground via resistor R6, and the base is connected to the ground via resistor R4. One end of the capacitor C1 is connected between the emitter of the transistor Q1 and the resistor R6, and the other end is connected between the resistor R1 and the resistor R2; The capacitor C5 is connected in parallel across the resistor R4; One end of resistor R3 is connected between the base of transistor Q1 and resistor R4, and the other end is connected between resistor R5 and the power input. One end of the capacitor C2 is connected between the collector of the transistor Q1 and the resistor R5, and the other end is connected in series with the resistor R7 and then grounded. The capacitor C2 and the resistor R7 serve as the output terminal of the amplification module.

2. The ripple reduction circuit according to claim 1, characterized in that, Also includes: An isolation module is connected between the amplification module and the power supply module to reduce interference from the amplification module to the power supply module.

3. The ripple reduction circuit according to claim 1, characterized in that, The power module uses a DC-DC power conversion circuit or an LDO voltage regulator circuit.

4. The ripple reduction circuit according to claim 1, characterized in that, The sampling module employs an amplitude meter or a sampling circuit.

5. The ripple reduction circuit according to claim 1, characterized in that, The amplification module uses a voltage amplification circuit.

6. The ripple reduction circuit according to claim 2, characterized in that, The isolation module employs an isolation capacitor or an isolation circuit.

7. The ripple reduction circuit according to claim 2, characterized in that, The isolation module includes: Resistors R8, R9, R10, R11, R12, capacitor C3, capacitor C4, transistor Q2; Wherein, one end of resistor R8 is connected to the power input, and the other end is connected in series with resistor R9 and then grounded; The collector of transistor Q2 is connected in series with resistor R10 and then connected to the power input; the emitter is connected in series with resistor R11 and then grounded; and the base is connected between resistors R8 and R9. One end of capacitor C3 is connected between resistor C2 and resistor R7, and the other end is connected between resistor R8 and resistor R9; One end of the capacitor C4 is connected between the emitter of the transistor Q2 and the resistor R11, and the other end is connected in series with the resistor R12 and then grounded; The capacitor C4 and the resistor R12 are connected to the power module as the output terminal of the isolation module.

8. An electrical appliance, characterized in that, The electrical appliance has a ripple reduction circuit as described in any one of claims 1 to 7.

Images