CN217037146U - Filter circuit, filter and washing machine - Google Patents

Abstract

The utility model provides a filter circuit, a filter and a washing machine, wherein the filter circuit comprises a main lead, and a first magnetic ring and a second magnetic ring are connected on the main lead in series; the current input end of the first conducting wire is connected with the current output end of the main conducting wire, and the current output end of the first conducting wire is connected with a first load; a first capacitor is connected in series between the current input end of the first lead and the first load; the current input end of the second wire is connected with the main wire, and the current output end of the second wire is connected with a second load; an inductor is connected in series between the current input end of the second lead and the second load; a second capacitor is serially connected between the inductor and the second load; a third capacitor and a fourth capacitor are connected in parallel between the current input end of the second wire and the inductor, and a fifth capacitor and a sixth capacitor are connected in parallel between the second inductor and the second load. The filter circuit has low cost and high generalization.

Description

Filter circuit, filter and washing machine

Technical Field

The utility model belongs to the field of filter circuits, and particularly relates to a filter circuit, a filter and a washing machine.

Background

Along with the innovation of science and technology, washing machine products are more and more popular in the market, are convenient to use, have various functions and are distributed throughout each family. While enjoying convenience brought by the washing machine, the electromagnetic interference generated by the load to the outside is more and more serious due to the diversification of the functions of the washing machine. The electromagnetic interference sources of the washing machine mainly include a switching power supply, a load motor and the like in the washing machine. And because the washing machine has compact internal structure and narrow space, the load wiring mode is limited. In order to suppress the electromagnetic interference generated from the washing machine and to pass the electromagnetic compatibility related test, a large number of filtering measures are often required to be added to the product.

The filtering measure adopted by the washing machine at present is to use a multistage filtering lead combining an independent filter, a power line magnetizing ring, a main board filter and a driving board filter, but the method has high cost, complex process and poor universality.

The present invention has been made in view of this point.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provides a filter circuit, a filter and a washing machine which are low in cost and high in universality.

To solve the above technical problem, the present invention provides a filter circuit, which comprises

The magnetic circuit comprises a main lead, a first magnetic ring and a second magnetic ring, wherein the main lead is connected with the first magnetic ring and the second magnetic ring in series;

the current input end of the first conducting wire is connected with the current output end of the main conducting wire, and the current output end of the first conducting wire is connected with a first load; a first capacitor is connected in series between the current input end of the first lead and the first load;

the current input end of the second wire is connected with the main wire, and the current output end of the second wire is connected with a second load; an inductor is connected in series between the current input end of the second lead and the second load; a second capacitor is serially connected between the inductor and the second load; and a third capacitor and a fourth capacitor are connected in parallel between the current input end of the second wire and the inductor, and a fifth capacitor and a sixth capacitor are connected in parallel between the second capacitor and the second load.

Further optionally, the main conductor comprises a main neutral wire and a main live wire; the first lead comprises a first zero line and a first live line, the first zero line is connected with the main zero line,

the first live wire is connected with the main live wire; the first capacitor is connected between the first zero line and the first live line.

Further optionally, the second wire includes a second neutral wire and a second live wire, the second neutral wire is connected to the main neutral wire, and the second live wire is connected to the main live wire;

the second capacitor is connected between the second zero line and the second live line between the inductor and the second load;

the main lead further comprises a ground wire, and the third capacitor is connected between the second zero line and the ground wire between the current input end of the second lead and the inductor; the fourth capacitor is connected between the second live wire and the ground wire between the current input end of the second lead and the inductor; the fifth capacitor is connected between the second zero line and the ground wire between the inductor and the second load, and the sixth capacitor is connected between the second live wire and the ground wire between the inductor and the second load.

Further optionally, a first resistor is further connected in series between the parallel circuit of the third capacitor and the fourth capacitor and the ground line, and a circuit formed by the third capacitor, the fourth capacitor and the first resistor is located between the current input end of the second wire and the inductor.

Further optionally, a second resistor is further connected in series between the ground line and a parallel circuit of the fifth capacitor and the sixth capacitor, and a circuit formed by the fifth capacitor, the sixth capacitor, and the second resistor is located between the second capacitor and the second load.

Further optionally, the zero line, the live wire and the ground wire are wound around the first magnetic ring, the zero line and the live wire are wound around the second magnetic ring, the first magnetic ring is connected between a current output end of the main lead and the second magnetic ring, and the second magnetic ring is connected between the first magnetic ring and a current input end of the main lead.

Further optionally, the first magnetic ring is a magnetic ring with low-frequency impedance and high-frequency impedance, and the second magnetic ring is a magnetic ring with high low-frequency impedance and low high-frequency impedance.

The second object of the present invention is also to provide a filter device, which is characterized by using the above filter circuit.

The third object of the present invention is also to provide a washing machine, which adopts the above filter circuit, or has the above filter device.

Further optionally, the washing machine comprises an external power line, a main board, a driving board and a motor,

the current input end of main wire with external power source line links to each other, the current output end of first wire with the mainboard links to each other, the current output end of second wire with the drive plate links to each other, the drive plate with the motor electricity links to each other.

After adopting the technical scheme, compared with the prior art, the utility model has the following beneficial effects:

the high-efficiency filtering mode combining the filtering lead and the special winding method of the magnetic ring provided by the utility model achieves the purpose of efficiently inhibiting the wide-frequency-band electromagnetic interference generated by the washing machine by adjusting the device type selection, the filtering structure, the magnetic ring winding method and the load wiring method of the filtering lead, and has the advantages of wide interference frequency range inhibition, high universality and low cost.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the principles of the utility model and not to limit the utility model to the proper form disclosed herein. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1: is a schematic diagram of a conventional filter circuit.

FIG. 2 is a schematic diagram: is a schematic diagram of a filter circuit according to an embodiment of the present invention.

FIG. 3: the conventional magnetic winding method and wiring are schematically shown.

FIG. 4 is a schematic view of: the magnetic winding method and the wiring diagram of the embodiment of the utility model are shown.

FIG. 5: the utility model is a schematic diagram of the whole wiring of the washing machine.

FIG. 6: the terminal disturbance voltage test result of the filter circuit of the embodiment of the utility model is not added to the washing machine.

FIG. 7 is a schematic view of: the terminal disturbance voltage test result of the filter circuit of the embodiment of the utility model is added to the washing machine.

FIG. 8: the harassing power test result of the filter circuit of the embodiment of the utility model is not added to the washing machine.

FIG. 9: the harassing power test result of the filter circuit of the embodiment of the utility model is added to the washing machine.

Wherein: 1. a filter circuit; 2, a main board; 3-a drive plate; 4-a motor; 5-motor wire; 6-inlet of washing machine; 7-external power line.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In the description of the present invention, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "contacting," and "communicating" are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

Fig. 1 shows a conventional filter circuit for a washing machine, which employs a multi-stage filter circuit using a combination of an independent filter, a power line magnetizing ring, a main board filter and a driving board filter, but the above method has high cost, complex process and poor versatility. The present embodiment provides a filter circuit, as shown in fig. 2, the filter circuit mainly includes a first capacitor CX1CX1, a second capacitor CX2CX2, an inductor LL, a third capacitor CY1CY1, a fourth capacitor CY2CY2, a fifth capacitor CY3CY3, and a sixth capacitor CY4CY 4. The filter circuit of the present embodiment includes a main conductor, and a first conductor and a second conductor connected to the main conductor. A first magnetic ring and a second magnetic ring are connected in series on the main lead; the current input end of the first wire is connected with the current output end of the main wire, and the current output end of the first wire is connected with a first load; a first capacitor CX1 is connected in series between the current input end of the first lead and the first load; the current input end of the second wire is connected with the main wire, and the current output end of the second wire is connected with a second load; an inductor L is connected in series between the current input end of the second lead and the second load; a second capacitor CX2 is serially connected between the inductor L and the second load; a third capacitor CY1 and a fourth capacitor CY2 are connected in parallel between the current input end of the second wire and the inductor L, and a fifth capacitor CY3 and a sixth capacitor CY4 are connected in parallel between the second capacitor L and the second load.

This embodiment can restrain electromagnetic interference through one-level filter circuit, and the reducible independent wave filter and the mainboard filtering of using of current filtering measure relatively, this filter circuit all has fabulous filtering effect to full frequency channel interference, and simple structure, commonality are good, low cost, can greatly save product development time and cost. Further optionally, the main conductor comprises a main zero line N and a main live line L; the first lead comprises a first zero line and a first live wire, the first zero line is connected with the main zero line N, and the first live wire is connected with the main live wire L; the first capacitance CX1 is connected between the first neutral line and the first live line. The second lead comprises a second zero line and a second live line, the second zero line is connected with the main zero line N, and the second live line is connected with the main live line L; the second capacitor CX2 is connected between the second zero line and the second live line between the inductor L and the second load; the main lead further comprises a ground wire PE, and a third capacitor CY1 is connected between the second zero wire and the ground wire between the current input end of the second lead and the inductor L; the fourth capacitor CY2 is connected between the second live wire between the current input end of the second conductor and the inductor L and the ground wire; the fifth capacitor CY3 is connected between the second zero line and the ground line between the inductor L and the second load, and the sixth capacitor CY4 is connected between the second live line and the ground line between the inductor L and the second load. The inductance L may optionally be a common mode inductance. The X capacitor and the Y capacitor are both filter capacitors, and the X capacitor is mainly connected between the zero line N and the live line L and used for eliminating differential mode interference. The Y capacitor is mainly connected between the live line L/zero line N and the ground PE and used for eliminating common-mode interference.

Further optionally, in order to improve the effect of suppressing high-frequency interference and optimize an interference signal release path, a first resistor R1 is further connected in series between the parallel circuit of the third capacitor CY1 and the fourth capacitor CY2 and the ground, and a circuit formed by the third capacitor CY1, the fourth capacitor CY2 and the first resistor R1 is located between the current input end of the second wire and the inductor L.

Further optionally, in order to improve the effect of suppressing high-frequency interference and optimize an interference signal release path, a second resistor R2 is further connected in series between the parallel circuit of the fifth capacitor CY3 and the sixth capacitor CY4 and the ground, and a circuit formed by the fifth capacitor CY3, the sixth capacitor CY4 and the second resistor R2 is located between the second capacitor CX2 and the second load.

Further optionally, setting the inductance L value of the inductance L to be L, the capacitance value to be C, and the resonant frequency of the filter circuit to be f, satisfies

The value of common mode inductance L in the existing filter circuit is 450uH-25mH, and the common mode inductance L is composed of an inductance coil and a magnetic core or an air core coil. CX1, CX2, CY1, CY2, CY3 and CY4 take the value of 0.01nF-10uF, and generally an ampere-standard capacitor or a thin-film capacitor is selected. R1 and R2 are 10-300 omega, and color circle resistance or patch resistance is generally selected. In order to ensure the optimal filtering effect, the filter circuit of this embodiment may adjust the selection of L, CX1, CX2, CY1, CY2, CY3, CY4, R1, and R2 according to the interference frequency points, so that the resonant frequency of the filter circuit is mainly concentrated on the frequency point with higher interference intensity, which satisfies the formula

The capacitance is selected in an approximate numerical range according to the resonance frequency and a theoretical formula, and finally, the capacitance is accurately selected according to other parasitic parameters (parasitic capacitance and parasitic inductance) of the circuit, and the selected optimal value can be verified through experiments. Taking the interference with the frequency of 500KHz as an example, L selects 10mH, CX1 selects 10nF, CX2 selects 0.47uF, CY1, CY2, CY3 and CY4 selects 4.7nF, and R1 and R2 select 200 omega to have the optimal filtering effect;

further alternatively, the first magnetic ring and the second magnetic ring in the existing filter circuit are ferrite magnetic rings, the first magnetic ring and the second magnetic ring are both selected to be magnetic rings suitable for the high frequency band, and the existing magnetic ring winding method is as shown in fig. 3, in which the first magnetic ring is wound by the zero-live line, and the second magnetic ring is wound by the ground line; the winding method of the magnetic ring of the filter circuit in this embodiment is as shown in fig. 4, the zero line, the live line and the ground line are wound together on the first magnetic ring, the zero line and the live line are wound together on the second magnetic ring, the first magnetic ring is connected between the current output end of the main conductor and the second magnetic ring, and the second magnetic ring is connected between the first magnetic ring and the current input end of the main conductor.

Further alternatively, the first magnetic ring and the second magnetic ring of the existing filter circuit are ferrite magnetic rings, in order to avoid that the line impedance is too large at low frequency (150kHz-30MHz) to affect the filtering effect, the first magnetic ring of this embodiment is a magnetic ring with low impedance and high frequency impedance, and the second magnetic ring is a magnetic ring with high impedance at low frequency and low impedance at high frequency.

The filter circuit of this embodiment forms high-efficient filtering mode through combining together with first magnetic ring and the special method of winding of second magnetic ring, and device selection, filtering structure, magnetic ring winding and the load of adjusting filter circuit are walked the line mode, reach the purpose of high-efficient suppression electromagnetic interference, have that the frequency range of suppression interference is wide, the commonality is high and advantage with low costs.

In the embodiment, the filter circuit device model selection, the magnetic ring winding method and the internal load outgoing line mode are optimized, so that the scheme has extremely high universality.

The embodiment further provides a filter device, which is characterized by adopting the filter circuit.

The present embodiment also proposes a washing machine, as shown in fig. 5, which employs the above-described filter circuit 1, or has the above-described filter device. The washing machine comprises an external power supply line 7, a mainboard 2, a drive plate 3 and a motor 4, wherein the current input end of a main lead is connected with the external power supply line 7 through a washing machine wire inlet 6, the current output end of a first lead is connected with the mainboard 2, the current output end of a second lead is connected with the drive plate 3, and the drive plate 3 is electrically connected with the motor 4 through a motor wire 5. In order to avoid interference on the motor wire of the driving plate to be coupled to the driving plate power supply zero live wire through wires and reduce wire-to-wire crosstalk, the motor wire and the zero live wire of the driving plate need to be separately wired, as shown in the attached drawing 5.

The utility model also tests the disturbance voltage and disturbance power of the terminal of the washing machine without using the filter circuit of the embodiment, and the test results are shown in fig. 6 and 8; in addition, utility model people still tested disturbance voltage and disturbance power respectively to the washing machine terminal that adopts the filter circuit of this embodiment, and the test result is as shown in fig. 7 and fig. 9.

From the above test results, when the filter circuit of the embodiment is not added to the washing machine, the terminal disturbance voltage test exceeds 29.39dB, and the result is shown in fig. 6; the disturbance power test exceeds 9.84dB, and the result is shown in figure 8. All do not meet the requirements of national standards;

the washing machine adopts the filter circuit of the embodiment, the magnetic ring winding method shown in the figure 4 and the wiring mode shown in the figure 5, the allowance of 7.39dB is obtained in a terminal disturbance voltage test, and the result is shown in the figure 7; the disturbance power test has a margin of 6.2dB, and the result is shown in fig. 9. The requirements of national standards are met, the margin is high, and the interference suppression effect is obvious.

The embodiment designs a broadband high-efficiency electromagnetic interference suppression circuit for the washing machine, and has the advantages of wide interference suppression frequency range, high universality and low cost; by optimizing the magnetic ring type selection and the winding method thereof, a mode of combining two-wire co-winding and three-wire co-winding is designed, the interference suppression frequency band and the interference suppression capability of the magnetic ring are widened, and the problem of high-frequency crosstalk formed between the washing machine wiring lines is solved.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims (10)

1. A filter circuit, comprising

The main guide wire is connected with a first magnetic ring and a second magnetic ring in series;

the current input end of the first conducting wire is connected with the current output end of the main conducting wire, and the current output end of the first conducting wire is connected with a first load; a first capacitor is connected in series between the current input end of the first lead and the first load;

the current input end of the second wire is connected with the main wire, and the current output end of the second wire is connected with a second load; an inductor is connected in series between the current input end of the second lead and the second load; a second capacitor is serially connected between the inductor and the second load; and a third capacitor and a fourth capacitor are connected in parallel between the current input end of the second wire and the inductor, and a fifth capacitor and a sixth capacitor are connected in parallel between the second capacitor and the second load.

2. The filter circuit of claim 1, wherein said main conductor comprises a main neutral conductor, a main live conductor; the first lead comprises a first zero line and a first live line, the first zero line is connected with the main zero line,

the first live wire is connected with the main live wire; the first capacitor is connected between the first zero line and the first live line.

3. The filter circuit of claim 2, wherein said second conductor comprises a second neutral conductor and a second live conductor, said second neutral conductor being connected to said main neutral conductor and said second live conductor being connected to said main live conductor;

the second capacitor is connected between the second zero line and the second live line between the inductor and the second load;

the main lead further comprises a ground wire, and the third capacitor is connected between the second zero line and the ground wire between the current input end of the second lead and the inductor; the fourth capacitor is connected between the second live wire and the ground wire between the current input end of the second lead and the inductor; the fifth capacitor is connected between the second zero line and the ground wire between the inductor and the second load, and the sixth capacitor is connected between the second live wire and the ground wire between the inductor and the second load.

4. The filter circuit according to claim 3, wherein a first resistor is further connected in series between the parallel circuit of the third capacitor and the fourth capacitor and the ground line, and a circuit formed by the third capacitor, the fourth capacitor and the first resistor is located between the current input end of the second wire and the inductor.

5. The filter circuit according to claim 4, wherein a second resistor is further connected in series between the parallel circuit of the fifth capacitor and the sixth capacitor and the ground, and a circuit formed by the fifth capacitor, the sixth capacitor and the second resistor is located between the second capacitor and the second load.

6. A filter circuit as claimed in any one of claims 3 to 5, wherein said neutral conductor, said live conductor and said ground conductor are wound together around said first magnetic loop, said neutral conductor and said live conductor are wound together around said second magnetic loop, and said first magnetic loop is connected between a current output terminal of said main conductor and said second magnetic loop, and said second magnetic loop is connected between said first magnetic loop and a current input terminal of said main conductor.

7. The filter circuit as claimed in claim 6, wherein said first magnetic loop is a magnetic loop having low frequency impedance and high frequency impedance, and said second magnetic loop is a magnetic loop having high frequency impedance and low frequency impedance.

8. A filter arrangement, characterized in that it employs a filter circuit according to any one of claims 1-7.

9. A washing machine, characterized in that it employs a filter circuit according to any one of claims 1 to 7, or has a filter device according to claim 8.

10. The washing machine as claimed in claim 9, wherein the washing machine comprises an external power cord, a main board, a driving board and a motor,

the current input end of main wire with external power source line links to each other, the current output end of first wire with the mainboard links to each other, the current output end of second wire with the drive plate links to each other, the drive plate with the motor electricity links to each other.

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