CN113300610A - Switching power supply circuit and household appliance - Google Patents
Switching power supply circuit and household appliance Download PDFInfo
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- CN113300610A CN113300610A CN202110741995.7A CN202110741995A CN113300610A CN 113300610 A CN113300610 A CN 113300610A CN 202110741995 A CN202110741995 A CN 202110741995A CN 113300610 A CN113300610 A CN 113300610A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
Abstract
The invention discloses a switching power supply circuit and a household appliance, which comprise a rectification module, a booster circuit, a transformer, an input control circuit and a feedback circuit, wherein the booster circuit is connected with the output end of the rectification module; the transformer comprises a primary winding, a first secondary winding and a second secondary winding, and the primary winding is connected with the output end of the booster circuit; the input control circuit comprises a first switching tube connected with the primary winding and a drive control chip connected with the first switching tube; the input end of the feedback circuit is respectively connected with the first secondary winding and the second secondary winding to detect output voltage, and the output end of the feedback circuit is connected to the driving control chip; by simultaneously collecting the output voltages of the first secondary winding and the second secondary winding, namely the feedback voltage is acted by the output voltages of the multi-path input windings together, the cross regulation rate is relatively wide, and the stability of the output voltages of the multi-path windings can be improved.
Description
Technical Field
The invention relates to the technical field of electronic circuits, in particular to a switching power supply circuit and a household appliance.
Background
The flyback transformer switching power supply is characterized in that when a primary coil of a transformer is just excited by direct-current pulse voltage, a secondary coil of the transformer does not provide power output for a load, and the power output is provided for the load only after the excitation voltage of the primary coil of the transformer is turned off.
The flyback switching power supply with the multi-path output windings has the problems of narrow cross regulation rate and unstable output voltage. The cross regulation rate refers to the degree of influence on adjacent windings when the load of the secondary output winding changes. The situation of high voltage drift easily occurs in a non-feedback winding of the traditional flyback switching power supply scheme, so that device loss is caused, the output of multiple paths of windings is difficult to realize, and the voltage of multiple paths of output is unstable.
Disclosure of Invention
The present invention is directed to solve at least one of the problems of the prior art, and provides a switching power supply circuit and a household appliance, which can improve the stability of the output voltage of multiple windings.
In a first aspect, an embodiment of the present invention provides a switching power supply circuit, including a rectification module, a boost circuit, a transformer, an input control circuit, and a feedback circuit, where:
the booster circuit is connected with the output end of the rectifying module;
the transformer comprises a primary winding, a first secondary winding and a second secondary winding, and the primary winding is connected with the output end of the booster circuit;
the input control circuit comprises a first switching tube connected with the primary winding and a drive control chip connected with the first switching tube;
the input end of the feedback circuit is respectively connected with the first secondary winding and the second secondary winding to detect output voltage, and the output end of the feedback circuit is connected to the driving control chip.
The switching power supply circuit provided by the embodiment of the invention at least has the following beneficial effects: through setting up feedback circuit, wherein the voltage of arbitrary output winding of the same way is on the high side, can both feed back to drive control chip through feedback circuit, reduce output energy, thereby reduce all output winding's voltage simultaneously, the voltage of arbitrary output winding of the same way can both rise all output winding's voltage on the low side simultaneously, through the output voltage of gathering first secondary winding and second secondary winding simultaneously, feedback voltage is by the output voltage combined action of multichannel input winding promptly, the cross regulation rate that has the broad, can improve multichannel winding output voltage's stability.
In the above switching power supply circuit, the output terminals of the first secondary winding and the second secondary winding are commonly grounded.
In the above switching power supply circuit, the transformer further includes a third secondary winding connected to the input terminal of the feedback circuit, and an output terminal of the third secondary winding is grounded in common with an output terminal of the first winding.
It can be understood that, the transformer may be provided with a third secondary winding, even a fourth secondary winding and a fifth secondary winding, in addition to the first secondary winding and the second secondary winding, all the secondary windings are connected to the input end of the feedback circuit to feed back the output voltage of the secondary windings of the path to the feedback circuit, and the feedback single path may combine and match the output voltages of the secondary windings of the paths and then feed back the combined and matched output voltages to the driving control chip, so as to have a wider cross regulation rate.
In the switching power supply circuit, the feedback circuit further comprises an isolation sampling chip, and the second secondary winding is connected to the input end of the feedback circuit through the isolation sampling chip.
The isolation sampling chip is arranged between the second secondary winding and the input end of the feedback circuit, so that the interference between the second secondary winding and the feedback circuit can be reduced, the first secondary winding and the second secondary winding do not need to be arranged in a common ground mode, the second secondary winding can be independently grounded to realize ground protection, and the grounding reliability and safety are improved.
In the above switching power supply circuit, the transformer further includes a third secondary winding connected to the output terminal of the feedback circuit through the isolation sampling chip.
Similarly, the transformer can be provided with a first secondary winding, a second secondary winding, a third secondary winding, and even a fourth secondary winding and a fifth secondary winding, all the secondary windings are connected with the input end of the feedback circuit to feed back the output voltage of the secondary windings to the feedback circuit, and the feedback single path can combine and match the output voltage of each secondary winding and then feed back the combined voltage to the driving control chip, so that the transformer has a wider cross regulation rate.
In the switching power supply circuit, the feedback circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a three-terminal adjustable shunt reference source and an optical coupler, the output end of the first secondary winding is connected with one end of the first resistor, the output end of the second secondary winding is connected with one end of the second resistor, the other end of the first resistor and the other end of the second resistor are connected to one end of the third resistor and connected to the reference electrode of the three-terminal adjustable shunt reference source, the other end of the third resistor is grounded, the cathode of the three-terminal adjustable shunt reference source is connected to the direct current power supply end through the fourth resistor, the anode of the three-terminal adjustable shunt reference source is grounded through the input end of the optical coupler, and the output end of the optical coupler is connected to the drive control chip.
The output voltage of the first secondary winding is divided by a first resistor and a third resistor to realize sampling, the output voltage of the second secondary winding is divided by a second resistor and a third resistor to realize sampling, the voltage sampling of the first secondary winding and the voltage sampling of the second secondary winding are superposed and then are connected to a reference pole of a three-terminal adjustable shunt reference source to be compared with the reference voltage of the three-terminal adjustable shunt reference source, wherein, by adjusting the resistance values of the first resistor and the second resistor, the voltage sampling ratio of the first secondary winding and the second secondary winding can be adjusted, for example, the rated output voltage of the first secondary winding is U1, the rated output voltage of the second secondary winding is U2, the ratio of the first resistor and the third resistor is A1, the ratio of the second resistor and the third resistor is A2, and reasonable first resistance value and second resistance value can be set according to the load requirement and the working voltage range of the first secondary winding and the second secondary winding, so that a 1U 1+ a 2U 2 satisfies the reference voltage of the three-terminal adjustable shunt reference source, which is typically 2.5V. When the voltage of any secondary winding is higher, a duty ratio adjusting signal can be fed back to the driving control chip through the optical coupler, and the voltage of all secondary windings is reduced; on the contrary, when the voltage of any secondary winding is low, the duty ratio adjusting signal can be fed back to the driving control chip through the optical coupler, and the voltages of all secondary windings are increased. The occupation ratio of A1 and A2 is determined according to the load power of U1 and U2, and the larger the load power is, the larger the proportion coefficient is selected.
In the above switching power supply circuit, the feedback circuit further includes an isolation sampling chip disposed between the second resistor and the third resistor.
The isolation sampling chip is arranged between the second resistor and the third resistor, so that the interference between the second secondary winding and the feedback circuit can be reduced, the first secondary winding and the second secondary winding do not need to be arranged in a common ground mode, the second secondary winding can be independently grounded to realize ground protection, and the grounding reliability and safety are improved.
In the above switching power supply circuit, the transformer further includes a fourth winding, and an output end of the fourth winding is connected to a power supply end of the driving control chip.
The fourth winding of the transformer is used for supplying power to the driving control chip, the structure of the switching power supply circuit can be simplified, a direct-current high-voltage pressing conversion module is not needed for supplying power to the driving control chip, and cost is reduced.
In the switching power supply circuit, the input control circuit further comprises a fifth resistor, a sixth resistor and a seventh resistor, the positive electrode of the output end of the booster circuit, the fifth resistor, the sixth resistor and the negative electrode of the output end of the booster circuit are sequentially connected, the connection point of the fifth resistor and the sixth resistor is connected to the drive control chip, and the drive control chip is further connected to the control pin of the first switching tube through the seventh resistor.
The voltage of the output end of the booster circuit is subjected to partial pressure sampling by the fifth resistor and the sixth resistor and then is sent to the driving control chip, so that the driving control chip can adjust the frequency and the duty ratio of the control signal of the first switching tube according to the input voltage of the transformer.
In the above switching power supply circuit, the boost circuit is a boost circuit.
The boost circuit is one of six basic chopper circuits, and is a switching direct current boost circuit which can make the output voltage higher than the input voltage.
In the switching power supply circuit, the rectifier module is a rectifier bridge stack.
The rectifier bridge stack product is formed by bridge connection of four rectifier silicon chips and external insulation plastic packaging, and a zinc metal shell is added outside an insulation layer of the high-power rectifier bridge for encapsulation, so that heat dissipation is enhanced.
In a second aspect, an embodiment of the present invention provides a household appliance, including the switching power supply circuit as described in the embodiment of the first aspect.
The household appliance provided by the invention at least has the following beneficial effects: through setting up feedback circuit at switching power supply circuit, wherein the voltage of arbitrary output winding of the same kind is on the high side, can both feed back to drive control chip through feedback circuit, reduce output energy, thereby reduce all output winding's voltage simultaneously, the voltage of arbitrary output winding of the same reason is on the low side can both rise all output winding's voltage simultaneously, through the output voltage of gathering first secondary winding and second secondary winding simultaneously, feedback voltage is by the output voltage combined action of multichannel input winding promptly, the cross regulation rate that has the broad, can improve multichannel winding output voltage's stability.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.
Fig. 1 is a schematic circuit diagram of a switching power supply circuit according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a switching power supply circuit according to a second embodiment of the present invention;
fig. 3 is a circuit schematic diagram of a switching power supply circuit according to a third embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a switching power supply circuit according to a fourth embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a switching power supply circuit according to a fifth embodiment of the present invention;
fig. 6 is a schematic circuit diagram of a switching power supply circuit according to a sixth embodiment of the present invention;
fig. 7 is a circuit schematic diagram of a switching power supply circuit according to a seventh embodiment of the present invention;
fig. 8 is a schematic circuit diagram of a switching power supply circuit according to an eighth embodiment of the present invention.
Detailed Description
Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
In the description of the present invention, if there are first and second described only for the purpose of distinguishing technical features, it is not understood that relative importance is indicated or implied or that the number of indicated technical features or the precedence of the indicated technical features is implicitly indicated or implied.
In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.
The flyback transformer switching power supply is characterized in that when a primary coil of a transformer is just excited by direct-current pulse voltage, a secondary coil of the transformer does not provide power output for a load, and the power output is provided for the load only after the excitation voltage of the primary coil of the transformer is turned off.
The flyback switching power supply with the multi-path output windings has the problems of narrow cross regulation rate and unstable output voltage. The cross regulation rate refers to the degree of influence on adjacent windings when the load of the secondary output winding changes. The situation of high voltage drift easily occurs in a non-feedback winding of the traditional flyback switching power supply scheme, so that device loss is caused, the output of multiple paths of windings is difficult to realize, and the voltage of multiple paths of output is unstable.
The embodiment of the invention provides a switching power supply circuit and a household appliance, which can improve the stability of the output voltage of a multi-path winding.
The embodiments of the present invention will be further explained with reference to the drawings.
Referring to fig. 1, fig. 1 is a schematic circuit diagram of a switching power supply circuit according to an embodiment of the present invention.
The embodiment of the first aspect of the present invention provides a switching power supply circuit, including a rectification module 100, a boost circuit 200, a transformer 300, an input control circuit 400, and a feedback circuit 500, where:
the output end of the rectifying module 100 is connected to the input end of the boost circuit 200;
the transformer 300 comprises a primary winding 301 and two secondary windings, wherein the output end of the booster circuit 200 is connected to the primary winding 301, and the two secondary windings are a first secondary winding 310 and a second secondary winding 320 respectively;
the input control circuit 400 comprises a first switching tube Q1 and a driving control chip IC1, wherein the first switching tube Q1 is connected with the primary winding 301, and the driving control chip IC1 is connected with the first switching tube Q1;
the voltage sampling end of the feedback circuit 500 is connected with the first secondary winding 310 and the second secondary winding 320; the output terminal of the feedback circuit 500 is connected to the feedback terminal of the drive control chip IC 1.
According to the switching power supply circuit provided by the embodiment of the invention, by arranging the feedback circuit 500, the voltage of any one path of output winding is higher and can be fed back to the driving control chip IC1 through the feedback circuit 500, so that the output energy is reduced, the voltage of all the output windings can be reduced at the same time, similarly, the voltage of any one path of output winding is lower and can be increased at the same time, and by collecting the output voltage of the first secondary winding 310 and the output voltage of the second secondary winding 320 at the same time, namely the feedback voltage is acted by the output voltages of the multiple paths of input windings together, the switching power supply circuit has a wider cross regulation rate and can improve the stability of the output voltages of the multiple paths of windings.
In the above-described switching power supply circuit of fig. 1, the second secondary winding 320 is commonly grounded to the output terminal of the first secondary winding 310. Since no isolation is provided between the first secondary winding 310 and the second secondary winding 320, the outputs thereof are generally commonly provided.
Referring to fig. 2, fig. 2 is a schematic circuit diagram of a switching power supply circuit according to a second embodiment of the present invention. The switching power supply circuit comprises a rectifying module 100, a booster circuit 200, a transformer 300, an input control circuit 400 and a feedback circuit 500, wherein:
the commercial power alternating current power supply is connected to the input end of the rectification module 100;
the output end of the rectifying module 100 is connected with the input end of the booster circuit 200;
the transformer 300 comprises a primary winding 301, a first secondary winding 310, a second secondary winding 320 and a third secondary winding 330, wherein the primary winding 301 is connected with the output end of the booster circuit 200;
the input control circuit 400 comprises a first switching tube Q1 and a driving control chip IC1, wherein the first switching tube Q1 is connected with the primary winding 301, and the driving control chip IC1 is connected with the first switching tube Q1;
the input terminal, i.e. the voltage sampling terminal, of the feedback circuit 500 is simultaneously connected to the output terminals of the three secondary windings of the third secondary winding 330, the second secondary winding 320 and the first secondary winding 310, so that the feedback circuit 500 can simultaneously detect the output voltages of the three secondary windings;
the feedback end of the driving control chip IC1 is connected with the output end of the feedback circuit 500;
the output terminal of the first secondary winding 310, the output terminal of the second secondary winding 320, and the output terminal of the third secondary winding 330 are connected in common.
It is understood that, instead of providing the first secondary winding 310 and the second secondary winding 320 as shown in fig. 1, the transformer 300 may also be provided with a third secondary winding 330 as shown in fig. 2, and may even be provided with a fourth secondary winding and a fifth secondary winding, all of the secondary windings are connected to the input terminal of the feedback circuit 500 to feed back the output voltage of the secondary windings to the feedback circuit 500, and a single feedback circuit may combine and match the output voltages of the secondary windings and feed back the combined and matched output voltages to the driving control chip IC1, so as to have a wider cross regulation ratio.
Referring to fig. 3, fig. 3 is a schematic circuit diagram of a switching power supply circuit according to a third embodiment of the present invention. The switching power supply circuit comprises a rectifying module 100, a boosting circuit 200, a transformer 300, an input control circuit 400 and a feedback circuit 500, and is different from the switching power supply circuit shown in fig. 1 in that the feedback circuit 500 comprises an isolation sampling chip IC2, the input end of the isolation sampling chip IC2 is connected with the second secondary winding 320, and the output end of the isolation sampling chip IC2 is connected with the output end of the first secondary winding 310 and is connected with the input end of the feedback circuit 500.
The isolation sampling chip IC2 is disposed between the second secondary winding 320 and the input terminal of the feedback circuit 500, so that interference between the second secondary winding 320 and the feedback circuit 500 can be reduced, the second secondary winding 320 and the first secondary winding 310 do not need to be disposed in common, the second secondary winding 320 can be grounded separately to realize ground protection, and reliability and safety of grounding are improved.
Referring to fig. 4, fig. 4 is a schematic circuit diagram of a switching power supply circuit according to a fourth embodiment of the present invention. The switching power supply circuit includes a rectifying module 100, a boost circuit 200, a transformer 300, an input control circuit 400, and a feedback circuit 500, wherein:
the output end of the rectifying module 100 is connected to the input end of the boost circuit 200;
the transformer 300 comprises three secondary windings, namely a first secondary winding 310, a second secondary winding 320 and a third secondary winding 330, and a primary winding 301, and the output end of the booster circuit 200 is connected to the primary winding 301;
the input control circuit 400 comprises a first switching tube Q1 and a driving control chip IC1, wherein the first switching tube Q1 is connected with the primary winding 301, and the driving control chip IC1 is connected with the first switching tube Q1; the output ends of the first secondary winding 310, the second secondary winding 320 and the third secondary winding 330 are all connected to the input end of the feedback circuit 500;
the output end of the feedback circuit 500 outputs a voltage feedback signal to the feedback end of the drive control chip IC 1;
the feedback circuit 500 includes an isolation sampling chip IC2, the output end of the first secondary winding 310 is directly connected to the input end of the feedback circuit 500, the second secondary winding 320 and the third secondary winding 330 are both connected to the isolation sampling chip IC2, and the voltage sampling signal is transmitted to the input end of the feedback circuit 500 after passing through the isolation sampling chip IC 2.
It is understood that, in addition to the transformer 300 having only the first secondary winding 310 and the second secondary winding 320 as shown in fig. 3, a third secondary winding 330 as shown in fig. 4 may be provided, and even a fourth secondary winding and a fifth secondary winding may be provided, all of the secondary windings are connected to the input terminal of the feedback circuit 500 to feed back the output voltage of the secondary windings to the feedback circuit 500, and a single feedback circuit may combine and match the output voltages of the secondary windings and feed back the combined and matched output voltages to the driving control chip IC1, so as to have a wider cross regulation rate.
In addition, if the transformer 300 is further provided with a fourth secondary winding and a fifth secondary winding, the fourth secondary winding and the fifth secondary winding may be connected to the output terminal of the feedback circuit 500 through the isolation sampling chip IC2 as in the case of the second secondary winding 320 and the third secondary winding 330, or may be directly connected to the input terminal of the feedback circuit 500 as in the case of the first secondary winding 310, and those skilled in the art can flexibly set the configuration according to the load condition of the switching power supply circuit.
Referring to fig. 5 and 6, fig. 5 and 6 are schematic circuit diagrams of switching power supply circuits according to fifth and sixth embodiments of the present invention. The switching power supply circuit includes a rectifying module 100, a boost circuit 200, a transformer 300, an input control circuit 400, and a feedback circuit 500, wherein:
the output end of the rectifying module 100 is connected to the input end of the boost circuit 200;
the transformer 300 comprises a primary winding 301 connected to the output of the booster circuit 200, the transformer 300 further comprising at least two secondary windings, for example a first secondary winding 310 and a second secondary winding 320;
the input control circuit 400 comprises a first switching tube Q1 and a driving control chip IC1, wherein the first switching tube Q1 is connected with the primary winding 301, and the driving control chip IC1 is connected with the first switching tube Q1;
the feedback circuit 500 comprises a first resistor R1 connected with the output end of the first secondary winding 310, a second resistor R2 connected with the output end of the second secondary winding 320, and a fourth resistor R4, a third resistor R3, an optical coupler 510 and a three-terminal adjustable shunt reference source TL431, specifically, the first resistor R1 and the third resistor R3 are connected in series between the output end of the first secondary winding 310 and the ground terminal, the second resistor R2 and the third resistor R3 are connected in series between the output end of the second secondary winding 320 and the ground terminal, the connection point of the first resistor R1, the second resistor R2 and the third resistor R3 is connected to the reference electrode of the three-terminal adjustable shunt reference source TL431, the cathode of the three-terminal adjustable shunt reference source TL431 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to the dc 0, the anode of the adjustable shunt reference source TL431 is connected to one optical coupler at the input end of the three-terminal of the adjustable shunt reference source TL 510, the other pin of the input end of the optical coupler 510 is grounded, and the two pins of the output end of the optical coupler 510 are connected to the driving control chip IC 1.
The first resistor R1 and the third resistor R3 divide the output voltage of the first secondary winding 310 and then input the three-terminal adjustable shunt reference source TL431 to realize sampling, and similarly, the output voltage of the second secondary winding 320 is divided by the second resistor R2 and the third resistor R3 to realize sampling, the voltage sample of the first secondary winding 310 and the voltage sample of the second secondary winding 320 are superimposed and then connected to the reference electrode of the three-terminal adjustable shunt reference source TL431 to be compared with the reference voltage of the three-terminal adjustable shunt reference source TL431, wherein by adjusting the resistances of the first resistor R1 and the second resistor R2, the voltage sampling ratio of the first secondary winding 310 and the second secondary winding 320 can be adjusted, for example, the rated output voltage of the first secondary winding 310 is U1, the rated output voltage of the second secondary winding 320 is U2, the ratio of the first resistor R1 and the third resistor R3 is a1, and the ratio of the second resistor R2 and the third resistor R3 is a2, reasonable resistance values of the first resistor R1 and the second resistor R2 can be set according to the load requirements and the working voltage range of the first secondary winding 310 and the second secondary winding 320, so that a1 × U1+ a2 × U2 meets the reference voltage of the three-terminal adjustable shunt reference source TL431, and the reference voltage is generally 2.5V. When the voltage of any secondary winding is higher, a duty ratio adjusting signal can be fed back to the driving control chip IC1 through the optocoupler 510, and the voltages of all secondary windings are reduced; on the contrary, when the voltage of any secondary winding is lower, the duty ratio adjusting signal can be fed back to the driving control chip IC1 through the optical coupler 510, and the voltages of all secondary windings are increased. The occupation ratio of A1 and A2 is determined according to the load power of U1 and U2, and the larger the load power is, the larger the proportion coefficient is selected.
In the switching power supply circuits of fig. 5 and 6, the transformer 300 may further include a third secondary winding 330, and the feedback circuit 500 further includes an eighth resistor R8 connected to an output terminal of the third secondary winding 330, and another terminal of the eighth resistor R8 is connected to a reference pole of the three-terminal adjustable shunt reference source TL 431. The output voltage of the third secondary winding 330 is divided by an eighth resistor R8 and a third resistor R3 to realize sampling, and the sampling of the third secondary winding 330, the voltage sampling of the first secondary winding 310 and the voltage sampling of the second secondary winding 320 are superposed and then connected to a reference pole of a three-terminal adjustable shunt reference source TL 431. Correspondingly, the rated output voltage of the third secondary winding 330 is U3, the ratio of the eighth resistor R8 to the third resistor R3 is A3, and the reasonable resistance value of the first resistor R1, the resistance value of the second resistor R2 and the resistance value of the eighth resistor R8 are set according to the load requirements and the working voltage ranges of the first secondary winding 310, the second secondary winding 320 and the third secondary winding 330, so that the a 1U 1+ a 2U 2+ A3U 3 meets the reference voltage of the three-terminal adjustable shunt reference source 431.
Referring to fig. 7 and 8, fig. 7 and 8 are schematic circuit diagrams of switching power supply circuits according to a seventh embodiment and an eighth embodiment of the present invention, respectively. Compared with the switching power supply circuit shown in fig. 6, the switching power supply circuit shown in fig. 8 is mainly different in that the feedback circuit 500 further includes an isolation sampling chip IC2, the isolation sampling chip IC2 is disposed between the second resistor R2 and the third resistor R3, and when the third secondary winding 330 is present in the switching power supply circuit, the isolation sampling chip IC2 is also disposed between the eighth resistor R8 and the third resistor R3.
The isolation sampling chip IC2 is disposed between the third resistor R3 and the second resistor R2, so that interference between the second secondary winding 320 and the feedback circuit 500 can be reduced, the second secondary winding 320 and the first secondary winding 310 do not need to be disposed in common, the second secondary winding 320 can be grounded separately to realize ground protection, and reliability and safety of grounding are improved.
In the switching power supply circuit shown in fig. 5 to 8, the transformer 300 is further provided with a fourth winding 340, and an output end of the fourth winding 340 is connected to a power supply end of the driving control chip IC1, so as to supply power to the driving control chip IC 1.
The fourth winding 340 of the transformer 300 is used for supplying power to the drive control chip IC1, so that the structure of the switch power supply circuit can be simplified, a direct-current high-voltage conversion and pressing module is not needed for supplying power to the drive control chip IC1, and the cost is reduced.
In the switching power supply circuits shown in fig. 5 to 8, the input control circuit 400 further includes a seventh resistor R7, a sixth resistor R6, and a fifth resistor R5, the positive electrode of the output end of the voltage boost circuit 200 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6 and to the driving control chip IC1, the other end of the sixth resistor R6 is connected to the negative electrode of the output end of the voltage boost circuit 200, and the driving control chip IC1 is further connected to the control pin of the first switching transistor Q1 through the seventh resistor R7.
The voltage at the output end of the voltage boost circuit 200 is divided and sampled by the sixth resistor R6 and the fifth resistor R5, and then sent to the driving control chip IC1, so that the driving control chip IC1 adjusts the frequency and duty ratio of the control signal of the first switching tube Q1 according to the input voltage of the transformer 300.
In the switching power supply circuits shown in fig. 5 to 8 described above, the boost circuit 200 employs a boost voltage boost circuit.
The Boost circuit is one of six basic chopper circuits, namely a Boost converter, and is a switching direct current Boost circuit which can enable the output voltage to be higher than the input voltage. The method is mainly applied to the transmission of a direct current motor, a single-phase Power Factor Correction (PFC) circuit and other alternating current and direct current power supplies.
In the above-described switching power supply circuits shown in fig. 5 to 8, the rectifier module 100 employs a bridge stack.
The rectifier bridge stack product is formed by bridge connection of four rectifier silicon chips and external insulation plastic packaging, and a zinc metal shell is added outside an insulation layer of the high-power rectifier bridge for encapsulation, so that heat dissipation is enhanced.
In addition, a second aspect embodiment of the present invention provides a household appliance, including the switching power supply circuit as described in the first aspect embodiment, for example, including any one of the switching power supply circuits described above in fig. 1 to 8.
According to the household appliance provided by the embodiment of the invention, the feedback circuit 500 is arranged in the switching power supply circuit, wherein the voltage of any one path of output winding is higher and can be fed back to the driving control chip IC1 through the feedback circuit 500, so that the output energy is reduced, the voltage of all the output windings can be reduced at the same time, the voltage of all the output windings can be increased at the same time by similarly acquiring the output voltage of the first secondary winding 310 and the output voltage of the second secondary winding 320, namely the feedback voltage is acted by the output voltages of the multiple paths of input windings together, the cross regulation rate is wider, and the stability of the output voltages of the multiple paths of windings can be improved.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.
Claims (12)
1. A switching power supply circuit, comprising:
a rectification module;
the booster circuit is connected with the output end of the rectifying module;
the transformer comprises a primary winding, a first secondary winding and a second secondary winding, and the primary winding is connected with the output end of the booster circuit;
the input control circuit comprises a first switching tube connected with the primary winding and a drive control chip connected with the first switching tube;
and the input end of the feedback circuit is respectively connected with the first secondary winding and the second secondary winding to detect output voltage, and the output end of the feedback circuit is connected to the drive control chip.
2. The switching power supply circuit according to claim 1, wherein output terminals of the first secondary winding and the second secondary winding are common to ground.
3. The switching power supply circuit according to claim 2, wherein the transformer further comprises a third secondary winding connected to the input of the feedback circuit, an output of the third secondary winding being common to the output of the first winding.
4. The switching power supply circuit according to claim 1, wherein the feedback circuit further comprises an isolation sampling chip, and the second secondary winding is connected to an input terminal of the feedback circuit through the isolation sampling chip.
5. The switching power supply circuit according to claim 4, wherein the transformer further comprises a third secondary winding connected to the output of the feedback circuit through the isolated sampling chip.
6. The switching power supply circuit according to claim 1, wherein the feedback circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a three-terminal adjustable shunt reference source and an optocoupler, the output end of the first secondary winding is connected with one end of the first resistor, the output end of the second secondary winding is connected with one end of the second resistor, the other end of the first resistor and the other end of the second resistor are connected to one end of the third resistor and connected to a reference pole of the three-terminal adjustable shunt reference source, the other end of the third resistor is grounded, the cathode of the three-end adjustable shunt reference source is connected to a direct current power supply end through the fourth resistor, the anode of the three-end adjustable shunt reference source is grounded through the input end of the optical coupler, and the output end of the optical coupler is connected to the driving control chip.
7. The switching power supply circuit according to claim 6, wherein the feedback circuit further comprises an isolation sampling chip disposed between the second resistor and the third resistor.
8. The switching power supply circuit according to claim 1, wherein the transformer further comprises a fourth winding, an output terminal of the fourth winding being connected to a power supply terminal of the drive control chip.
9. The switching power supply circuit according to claim 1, wherein the input control circuit further includes a fifth resistor, a sixth resistor, and a seventh resistor, an output positive terminal of the voltage boost circuit, the fifth resistor, the sixth resistor, and an output negative terminal of the voltage boost circuit are connected in sequence, a connection point of the fifth resistor and the sixth resistor is connected to the driving control chip, and the driving control chip is further connected to the control pin of the first switching tube through the seventh resistor.
10. The switching power supply circuit according to claim 1, wherein the voltage boosting circuit is a boost voltage boosting circuit.
11. The switching power supply circuit according to claim 1, wherein the rectifying module is a bridge rectifier.
12. A household appliance, characterized by comprising a switching power supply circuit according to any one of claims 1 to 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110741995.7A CN113300610A (en) | 2021-06-30 | 2021-06-30 | Switching power supply circuit and household appliance |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110741995.7A CN113300610A (en) | 2021-06-30 | 2021-06-30 | Switching power supply circuit and household appliance |
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| CN113300610A true CN113300610A (en) | 2021-08-24 |
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| CN202110741995.7A Pending CN113300610A (en) | 2021-06-30 | 2021-06-30 | Switching power supply circuit and household appliance |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117134605A (en) * | 2023-04-28 | 2023-11-28 | 荣耀终端有限公司 | Power supply circuit, power supply control method, and power supply device |
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2021
- 2021-06-30 CN CN202110741995.7A patent/CN113300610A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117134605A (en) * | 2023-04-28 | 2023-11-28 | 荣耀终端有限公司 | Power supply circuit, power supply control method, and power supply device |
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