Switching power supply filter circuit of electric cooking appliance

Abstract

The utility model discloses a switching power supply filter circuit of an electric cooking appliance, which is characterized in that the positive electrode of an electrolytic capacitor C1 of the filter circuit is connected with the negative electrode of a diode D1, the negative electrode of the electrolytic capacitor C1 is connected with the positive electrode of a diode D2 and the negative electrode of a diode D3, and the positive electrode of an electrolytic capacitor C2 is connected with the positive electrode of the diode D1 and the negative electrode of the diode D2; and the negative electrode of the electrolytic capacitor C2 is connected with the positive electrode of the diode D3. According to the utility model, the problem of high voltage resistance of the switching power supply is effectively solved, the problem of non-uniform voltage division when the two electrolytic capacitors are connected in series is prevented, the problem that the temperature of one electrolytic capacitor is too high and the temperature of the other electrolytic capacitor is not changed when the two electrolytic capacitors are connected in series is also prevented, and the reliability of the whole circuit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric cooker circuits, and specifically, to a filter circuit for the switching power supply of an electric cooker. Background Art

[0002] Currently, the commonly used electrolytic capacitors usually have a withstand voltage of 500V. When the mains voltage is higher than 350VAC, the electrolytic capacitors are prone to damage. Take the induction cooker as an example. As Figure 1 shown, the switching power supply of the induction cooker uses a filter capacitor. When the product is used in high-voltage areas such as Yunnan, Guizhou, and Sichuan or some high-voltage countries, the capacitor is prone to damage. Therefore, someone proposed a solution of connecting two capacitors in series, as Figure 2 shown. However, when two capacitors are connected in series, it is easy to cause uneven voltage division, forming a vicious cycle. Therefore, this solution is not the best choice. If electrolytic capacitors with a withstand voltage higher than 500V are selected, not only is it difficult to purchase, but also the price is expensive, the cost performance is low, and there are quality risks. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a filter circuit for the switching power supply of an electric cooker, which can give full play to the filtering function of the capacitor, solve the problems existing in the above background art, and overcome the deficiencies of the prior art.

[0004] A filter circuit for the switching power supply of an electric cooker includes a filter circuit, and is characterized in that: the positive pole of the electrolytic capacitor C1 of the filter circuit is connected to the negative pole of the diode D1, the negative pole of the electrolytic capacitor C1 is connected to the positive pole of the diode D2 and the negative pole of the diode D3, the positive pole of the electrolytic capacitor C2 is connected to the positive pole of the diode D1 and the negative pole of the diode D2, the negative pole of the electrolytic capacitor C2 is connected to the positive pole of the diode D3, and the filter circuit is applied to the front-stage circuit of the switching power supply circuit of the electric cooker.

[0005] Further, the VCC terminal of the filter circuit is connected to the positive pole of the switching power supply circuit, and the GND terminal of the filter circuit is connected to the negative pole of the switching power supply circuit.

[0006] Further, when the input voltage U is greater than the sum of the voltages Uc1 across the electrolytic capacitor C1 and the voltage Uc2 across the electrolytic capacitor C2, D2 conducts, and the mains power supplies series charging to the electrolytic capacitor C1 and the electrolytic capacitor C2; when U < Uc1 = Uc2, the diodes D1 and D3 conduct, and the electrolytic capacitors C1 and C2 discharge in parallel to provide working current to the filter circuit of the switching power supply of the electric cooker.

[0007] The beneficial effects of the utility model are as follows:

[0008] This invention effectively solves the problem of high voltage resistance in switching power supplies, resolves the issue of uneven voltage distribution when two electrolytic capacitors are connected in series, and avoids the situation where one electrolytic capacitor has an excessively high temperature while the other remains at a constant temperature, thus improving the overall reliability of the circuit.

[0009] This invention improves the pre-stage filtering circuit of the power supply, increasing the cost only slightly, but significantly improving the withstand voltage of the subsequent switching power supply. While achieving the goals of improved withstand voltage and circuit reliability, the components are readily available and inexpensive. Attached Figure Description

[0010] Figure 1 For existing switching power supply filter capacitors Figure 1 .

[0011] Figure 2 For existing switching power supply filter capacitors Figure 2 .

[0012] Figure 3 This is the circuit diagram of the switching power supply filter for the electric cooking appliance of this utility model.

[0013] Figure 4 for Figure 3 A mirror image.

[0014] Figure 5 This is a schematic diagram of the switching power supply filtering circuit for the electric cooking appliance of this utility model. Detailed Implementation

[0015] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0016] In the description of this utility model, it should be understood that the terms "center," "horizontal," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise stated, "a plurality of" means two or more.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can be a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0018] This invention connects two electrolytic capacitors and three diodes, effectively solving the high-voltage withstand problem of the switching power supply. It prevents uneven voltage distribution when two electrolytic capacitors are connected in series, and also addresses the issue of one electrolytic capacitor overheating while the other remains at a constant temperature due to uneven voltage distribution. This improves the overall circuit reliability and cost-effectiveness. Specifically, the filter circuit has a power supply VCC and a ground terminal GND. One electrolytic capacitor is connected to the power supply VCC on one side, and the other is connected to the ground terminal on the other side. Both electrolytic capacitors are commercially available 500V capacitors. Directing the current from one power supply terminal to the other ground terminal stabilizes the voltage, increases the voltage withstand and reliability of the electrolytic capacitors, and allows them to fully utilize the charging and discharging capabilities of the two series-connected capacitors. During charging, the capacitors only charge to half their capacity, and during discharging, they release twice their capacity, providing sufficient starting conditions for the switching power supply and protecting it.

[0019] See Figure 3-5 This utility model discloses a switching power supply filter circuit for electric cookers, which can be applied to induction cookers to improve their high voltage resistance, enabling them to operate normally in areas with high mains voltage. It includes a resistor R1 connected in series, a diode D4, a filter circuit 1, and a switching power supply circuit 2. The filter circuit 1 consists of three diodes and two electrolytic capacitors, forming two branches. Each branch is connected to the power supply VCC and ground GND, respectively. The two branches are connected by a diode. Specifically, the positive terminal of electrolytic capacitor C1 in filter circuit 1 is connected to the negative terminal of diode D1; the negative terminal of electrolytic capacitor C1 is connected to the positive terminals of diodes D2 and D3; the positive terminal of electrolytic capacitor C2 is connected to the positive terminals of diodes D1 and D2; and the negative terminal of electrolytic capacitor C2 is connected to the positive terminal of diode D3 and grounded. In this embodiment, three diodes are added to the two series-connected filter capacitors of the induction cooker switching power supply. This allows the two series-connected electrolytic capacitors to fully utilize their charging and discharging capabilities, enabling them to charge slowly and discharge twice the amount of electricity. This provides sufficient valley voltage for the switching power supply while also protecting it.

[0020] like Figure 5As shown, the VCC terminal of the filter circuit 1 is connected to the negative electrode of the diode D4 and the positive electrode of the switching power supply circuit 2, and the GND terminal of the filter circuit is connected to the negative electrode of the switching power supply circuit 2.

[0021] When the input voltage U is greater than the voltage Uc1 across C1 plus the voltage Uc2 across C2, D2 conducts, and the mains power charges C1 and C2 in series; when U < Uc1 and Uc1 = Uc2, D1 and D3 conduct, and C1 and C2 discharge in parallel, providing working current to the filter circuit of the electric cooker switching power supply. When the withstand voltage values of the capacitors C1 and C2 are 450V, their series withstand voltage can reach 700V, and the static charges of the capacitors will not accumulate. The resulting filter circuit can provide effective withstand voltage capacity when the switching power supply of the induction cooker is working.

[0022] As described above, it is only the preferred embodiment of the present invention, and does not impose any limitation on the technical scope of the present invention. Therefore, other filter circuits of electric cooker switching power supplies obtained by adopting technical features identical or similar to those of the above embodiments of the present invention are all within the protection scope of the present invention.

Claims

1. An electric cooking appliance switching power supply filter circuit comprising a filter circuit, characterized by: The positive pole of the electrolytic capacitor C1 of the filter circuit is connected with the negative pole of the diode D1, the negative pole of the electrolytic capacitor C1 is connected with the positive pole of the diode D2 and the negative pole of the diode D3, the positive pole of the electrolytic capacitor C2 is connected with the positive pole of the diode D1 and the negative pole of the diode D2, the negative pole of the electrolytic capacitor C2 is connected with the positive pole of the diode D3, and the filter circuit is applied to the front-stage circuit of the switching power supply circuit of the electric cooker.

2. The switching power supply filter circuit of an electric cooking utensil according to claim 1, characterized in that: The VCC end of the filter circuit is connected with the positive pole of the switching power supply circuit of the electric cooker, and the GND end of the filter circuit is connected with the negative pole of the switching power supply circuit.

3. The switching power supply filter circuit of an electric cooking utensil according to claim 2, characterized in that: When the input voltage U is greater than the sum of the voltage Uc1 between the electrolytic capacitor C1 and the voltage Uc2 between the electrolytic capacitor C2, the diode D2 is turned on, and the mains charges the electrolytic capacitor C1 and the electrolytic capacitor C2 in series; when U

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