CN216357404U

CN216357404U - Power supply circuit based on low PF universal adapter power IC

Info

Publication number: CN216357404U
Application number: CN202120744276.6U
Authority: CN
Inventors: 王瑜斐; 张祥东; 李学新; 余德辉
Original assignee: Huizhou Jinhu Industrial Development Co ltd; Huizhou Tianbao Chuang Neng Technology Co ltd; Ten Pao Electronics Huizhou Co Ltd
Current assignee: Huizhou Jinhu Industrial Development Co ltd; Huizhou Tianbao Chuang Neng Technology Co ltd; Ten Pao Electronics Huizhou Co Ltd
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2022-04-19
Anticipated expiration: 2031-04-12

Abstract

The utility model relates to a power supply circuit based on a low PF universal adapter power supply IC, which comprises an alternating current input circuit, a rectifying circuit and a filter circuit, wherein the output of the filter circuit is electrically connected with an A end, the A end is respectively and electrically connected with a transformer, an absorption circuit and a main control circuit, and the control end of the main control circuit is electrically connected with a grid electrode of a switch MOS tube. The output end of the first feedback circuit is electrically connected with the feedback end of the main control circuit. The input end of the second feedback circuit is electrically connected with the end A or the end B between the alternating current input circuit and the rectifying circuit, the output end of the second feedback circuit is electrically connected with the feedback end of the main control circuit, and the power supply end of the second feedback circuit is electrically connected with the first power supply circuit or the second power supply circuit. The scheme performs input current modulation in the process of ensuring constant voltage output feedback, thereby improving PF/THD, reducing the cost of LED driving power supplies, reducing the complexity of power supply circuits and reducing the volume of finished products.

Description

Power supply circuit based on low PF universal adapter power IC

Technical Field

The utility model relates to the technical field of power supply circuits, in particular to a power supply circuit based on a low PF universal adapter power supply IC.

Background

The existing adapter power supply IC (i.e. integrated circuit, abbreviated in chinese) has the following defects in use:

(1) most LED Power supply single-stage PFC (Power Factor Correction abbreviation, Chinese for Power Factor Correction) high PF (Power Factor comprehensive, Chinese for Power Factor) schemes are PSR (primary side feedback type) structures, and the topological structures cannot meet the requirements of dynamic response of customers, so that only two-stage (PFC + Flyback and the like) schemes can be selected when the schemes are used in a mode selection mode; this solution is not only costly but also bulky.

(2) Few parts of the single-stage PFC scheme adopt SSR (also called secondary feedback) topological structures, so that the structure has few manufacturers and high IC cost; and the conditions required to be met by each product are different, so that the product which cannot be designed by one IC can meet various performance requirements.

In order to overcome the above-mentioned shortcomings, we invented a power supply circuit based on a low PF universal adapter power IC.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems that most of single-stage PFC high-PF schemes of LED power supplies cannot meet dynamic response requirements, so that only a two-stage scheme can be selected, the cost is high, the size is large, SSR structures are rarely adopted in the single-stage PFC schemes, the product manufacturers are few, the IC cost is high, and products which cannot be designed by one IC can meet various performance requirements in the use of the conventional adapter power supply IC. The concrete solution is as follows:

the power supply circuit based on the low PF universal adapter power supply IC comprises an alternating current input circuit, a rectifying circuit and a filter circuit, wherein the rectifying circuit is electrically connected with the alternating current input circuit, the filter circuit is electrically connected with the rectifying circuit, the output end of the filter circuit is electrically connected with the end A, the end A is electrically connected with one end of a primary main winding of a transformer, one end of an absorption circuit and the input end of a main control circuit respectively, the control end of the main control circuit is electrically connected with a grid electrode of a switch MOS (metal oxide semiconductor) tube, a drain electrode of the switch MOS tube is electrically connected with the other end of the absorption circuit and the other end of the primary main winding of the transformer respectively, a primary feedback winding of the transformer is electrically connected with the input end of a first power supply circuit, the output end of the first power supply circuit is electrically connected with the power supply end of the main control circuit, a secondary winding of the transformer is electrically connected with the output circuit, and the output circuit is electrically connected with a bleeder circuit. The output end of the first feedback circuit is electrically connected with the feedback end of the main control circuit. The input end of the second feedback circuit is electrically connected with the end A or the end B between the alternating current input circuit and the rectifying circuit, the output end of the second feedback circuit is electrically connected with the feedback end of the main control circuit, the power supply end of the second feedback circuit is electrically connected with the output end of the first power supply circuit or the output end of the second power supply circuit, and the input end of the second power supply circuit is electrically connected with the end A.

Furthermore, the absorption circuit comprises one ends of resistors R20 and R22 and a capacitor C8 which are simultaneously and electrically connected with one end of the primary main winding of the transformer, the other ends of the resistors R20 and R22 and the capacitor C8 are simultaneously and electrically connected with one ends of resistors R19 and R24, the other ends of the resistors R19 and R24 are simultaneously and electrically connected with the cathode of a diode D2, and the anode of a diode D2 is electrically connected with the other end of the primary main winding of the transformer.

Further, the first power supply circuit comprises an anode of a diode D3 electrically connected with one end of a primary feedback winding of the transformer, a cathode of a diode D3 is electrically connected with one end of a resistor R21, the other end of the resistor R21 is simultaneously electrically connected with an anode of an electrolytic C7 and one end of a capacitor C6, and a cathode of an electrolytic C7 and the other end of a capacitor C6 are simultaneously electrically connected with the other end of the primary feedback winding of the transformer and are simultaneously grounded.

Furthermore, the main control circuit includes a pin 8 of the control chip U1 electrically connected to one end of a resistor R9, the other end of a resistor R9 electrically connected to one end of a resistor R10, the other end of the resistor R10 electrically connected to the end a, a pin 5 of the control chip U10 electrically connected to one end of the resistor R10, the other end of the resistor R10 electrically connected to one end of the resistor R10 and the cathode of a diode D10, the other end of the resistor R10 and the anode of the diode D10 electrically connected to one end of the resistor R10 and the gate of a switching MOS Q10, the source of the switching MOS Q10 electrically connected to one end of the resistor R10, the drain of the switching MOS Q10 electrically connected to the anode of the diode D10, a pin 3 of the control chip U10 electrically connected to one end of the resistor R10 and the capacitor C10, the other end of the resistor R10 electrically connected to one end of the resistors R10, the capacitor R10 and the capacitor R10, the resistor R10, the capacitor R10, and the capacitor R10, The other end of the R18 and the pin 4 of the control chip U1 are grounded simultaneously, and the pin 2 of the control chip U1 is a feedback end.

Furthermore, the output circuit comprises an anode of a diode D4 and one end of a capacitor C10 which are simultaneously electrically connected with one end of a secondary winding of the transformer, the other end of the capacitor C10 is simultaneously electrically connected with one ends of resistors R27 and R30, the other ends of resistors R27 and R30 and a cathode of the diode D4 are simultaneously electrically connected with anodes of the electrolytic capacitors C12 and C13 and one input end of a filter LF3, and the other end of the secondary winding of the transformer is simultaneously electrically connected with cathodes of the electrolytic capacitors C12 and C13 and the other input end of the filter LF 3.

Furthermore, the absorption circuit comprises an anode of a diode D5 electrically connected with one end of a secondary winding of the transformer, a cathode of a diode D5 is simultaneously electrically connected with one end of a capacitor C9 and one end of a resistor R34, the other end of the resistor R34 is simultaneously electrically connected with one end of a resistor R33 and a base of a triode Q2, a collector of the triode Q2 is simultaneously electrically connected with one end of the resistor R35 and a base of a triode Q3, a collector of the triode Q3 is electrically connected with one end of a resistor R36, the other ends of the resistors R35 and R36 are simultaneously electrically connected with one input end of a filter LF3, and the other ends of the capacitor C9, the resistor R33 and emitters of the triodes Q2 and Q3 are simultaneously electrically connected with the other input end of a filter LF 3.

Further, the first feedback circuit comprises two resistors R29 and R26, one end of each resistor R29 is electrically connected with one input end of the filter LF3, the other end of each resistor R29 is electrically connected with a reference electrode of the voltage stabilizing chip U2, one ends of the resistors R31, R32 and R28, the other ends of the resistors R31 and R32 are electrically connected with an anode of the voltage stabilizing chip U2 and the other input end of the filter LF3, the other end of the resistor R28 is electrically connected with one end of the capacitor C11, the other end of the resistor R26 is electrically connected with a pin 1 of the optocoupler U4 and one end of the resistor R25, the other ends of the resistor R25 and the capacitor C11, and a cathode of the voltage stabilizing chip U2 are electrically connected with a pin 2 of the optocoupler U4, a pin 3 of the optocoupler U4 is grounded, a pin 4 of the U4 is electrically connected with one end of the resistor R23, and the other end of the resistor R23 is electrically connected with a pin 2 of the control chip U1.

Alternative 1: the second feedback circuit comprises a capacitor C3 with one end electrically connected with the end A, the other end of the capacitor C3 is electrically connected with one end of a resistor R6, the other end of the resistor R6 is simultaneously electrically connected with one end of a resistor R7, one end of a resistor R4 and the base of a triode Q4, the emitter of a triode Q4 is electrically connected with one end of a resistor R8, the other end of a resistor R8 is simultaneously electrically connected with the feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4, the resistor R4 and the collector of a triode Q4 are simultaneously grounded, and the other end of the resistor R7 is electrically connected with the output end of the first power supply circuit.

Alternative 2: the second feedback circuit comprises a diode D6 with the anode connected to the AC input circuit and the live wire L between the rectification circuits, a diode D7 with the anode connected to the AC input circuit and the zero line N between the rectification circuits, the cathodes of the diodes D6 and D7 are electrically connected with one end of a capacitor C3, the other end of a capacitor C3 is electrically connected with one end of a resistor R6, the other end of the resistor R6 is electrically connected with one end of resistors R7 and R4 and the base of a triode Q4, the emitter of the triode Q4 is electrically connected with one end of the resistor R8, the other end of the R8 is electrically connected with the feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitors C4 and R4 and the collector of the triode Q4 are grounded, and the other end of the resistor R7 is electrically connected with the output end of the first power supply circuit.

Alternative 3: the second feedback circuit comprises a diode D6 with the anode connected to the AC input circuit and the live wire L between the rectification circuits, a diode D7 with the anode connected to the AC input circuit and the zero line N between the rectification circuits, the cathodes of the diodes D6 and D7 are electrically connected with one end of a capacitor C3, the other end of a capacitor C3 is electrically connected with one end of a resistor R6, the other end of the resistor R6 is electrically connected with one ends of a resistor R7 and a resistor R4 and the base of a triode Q4, the emitter of the triode Q4 is electrically connected with one end of the resistor R8, the other end of the R8 is electrically connected with the feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4, the resistor R4 and the collector of the triode Q4 are grounded, and the other end of the resistor R7 is electrically connected with the output end of the second power supply circuit.

In summary, the technical scheme of the utility model has the following beneficial effects:

the utility model solves the problems that most single-stage PFC high PF schemes of LED power supplies cannot meet dynamic response requirements, so that only a two-stage scheme can be selected, the cost is high, the size is large, SSR structures are rarely adopted in the single-stage PFC schemes, product manufacturers are few, the IC cost is high, and products which cannot be designed by one IC can meet various performance requirements in the use of the conventional adapter power supply IC. The scheme has the following advantages:

(1) the circuit can be suitable for PWM (Pulse Width Modulation, Chinese is Pulse Width Modulation) isolation power supply ICs with all SSR structures; a common PWM power supply is modified into a constant voltage LED power supply with high PF and PF/THD (Total Harmonic Distortion) improvement which accords with the current Harmonic standard (EN 61000-3-2).

(2) The design can be suitable for most of adapter ICs with pull-up characteristics and feedback pins (large pull-out current, low feedback voltage, small modulation Ton, and Ton is the conduction time of a switching tube), and is flexible and wide to apply; and the cost of the common PWM isolation power supply IC is lower, and the material cost of the single-stage PFC power supply can be reduced.

(3) The scheme provides a single-stage circuit with a combination of PF correction feedforward (namely a second feedback circuit) and constant voltage feedback (namely a first feedback circuit), the two modes can work in a coordinated mode, and input current modulation is also carried out in the process of ensuring constant voltage output feedback, so that PF/THD is improved.

(4) The cost of the LED driving power supply is reduced, the complexity of a power circuit is reduced, and the volume of a finished product is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the utility model, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a block diagram of an embodiment 1 of a power supply circuit based on a low PF universal adapter power IC according to the present invention;

FIG. 2 is a circuit diagram of a power circuit embodiment 1 of the present invention based on a low PF universal adapter power IC;

FIG. 3 is a block diagram of embodiment 2 of the present invention;

FIG. 4 is a circuit diagram according to embodiment 2 of the present invention;

FIG. 5 is a block diagram of embodiment 3 of the present invention;

fig. 6 is a circuit diagram of embodiment 3 of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the utility model, and not restrictive of the full scope of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

as shown in fig. 1 to 2, the power circuit based on the low PF universal adapter power IC includes an ac input circuit, a rectifier circuit electrically connected to the ac input circuit, a filter circuit electrically connected to the rectifier circuit, an output of the filter circuit being electrically connected to an a terminal, the a terminal being electrically connected to one terminal of a primary main winding of a transformer, one terminal of an absorption circuit, and an input terminal of a main control circuit, a control terminal of the main control circuit being electrically connected to a gate of a switching MOS transistor, a drain of the switching MOS transistor being electrically connected to the other terminal of the absorption circuit and the other terminal of the primary main winding of the transformer, a primary feedback winding of the transformer being electrically connected to an input terminal of a first power supply circuit, an output terminal of the first power supply circuit being electrically connected to a power supply terminal of the main control circuit, a secondary winding of the transformer being electrically connected to an output circuit, and the output circuit being electrically connected to a bleeder circuit. The output end of the first feedback circuit is electrically connected with the feedback end of the main control circuit. The power supply circuit also comprises a second feedback circuit, wherein the input end of the second feedback circuit is electrically connected with the end A (as in embodiment 1) or the end B between the alternating current input circuit and the rectifying circuit (as in embodiments 2 and 3), the output end of the second feedback circuit is electrically connected with the feedback end of the main control circuit, the power supply end of the second feedback circuit is electrically connected with the output end of the first power supply circuit (as in embodiments 1 and 2) or the output end of the second power supply circuit (as in embodiment 3), and the input end of the second power supply circuit (only used in embodiment 3) is electrically connected with the end A. Description of the drawings: the input end of the second feedback circuit refers to one end of a capacitor C3 in the following description, the output end of the second feedback circuit refers to one end of a capacitor C4 in the following description, and the power supply end of the second feedback circuit refers to the other end of a resistor R7 in the following description.

Furthermore, the absorption circuit comprises one ends of resistors R20 and R22 and a capacitor C8 which are simultaneously electrically connected with one end of the primary main winding of the transformer, the other ends of the resistors R20 and R22 and the capacitor C8 are simultaneously electrically connected with one ends of resistors R19 and R24, the other ends of the resistors R19 and R24 are simultaneously electrically connected with the cathode of a diode D2, and the anode of a diode D2 is electrically connected with the other end of the primary main winding of the transformer.

Furthermore, the main control circuit comprises a control chip U with 8 pins electrically connected with one end of a resistor R, the other end of the resistor R is electrically connected with one end of the resistor R, the other end of the resistor R is electrically connected with the end A, 5 pins of the control chip U are electrically connected with one end of the resistor R, the other end of the resistor R is electrically connected with one end of the resistor R and the cathode of a diode D, the other end of the resistor R and the anode of the diode D are electrically connected with one end of the resistor R and the grid of a switch MOS tube Q, the source of the switch MOS tube Q is electrically connected with one end of the resistor R, the drain of the switch MOS tube Q is electrically connected with the anode of the diode D, 3 pins of the control chip U are electrically connected with one ends of a resistor R and a capacitor C, the other end of the resistor R, one end of the R, the other ends of the resistor R and the R, the other end of the capacitor C, the other ends of the resistor R, R and R, and the other end of the 4 pins of the control chip U are grounded simultaneously, pin 2 of the control chip U1 is the feedback terminal.

Furthermore, the absorption circuit comprises an anode of a diode D5 electrically connected with one end of a secondary winding of the transformer, a cathode of a diode D5 is simultaneously electrically connected with one end of a capacitor C9 and one end of a resistor R34, the other end of the resistor R34 is simultaneously electrically connected with one end of a resistor R33 and a base of a triode Q2, a collector of a triode Q2 is simultaneously electrically connected with one end of a resistor R35 and a base of a triode Q3, a collector of the triode Q3 is electrically connected with one end of a resistor R36, the other ends of the resistors R35 and R36 are simultaneously electrically connected with one input end of a filter LF3, and an emitter of the capacitor C9, the other end of the resistor R33 and the transistors Q2 and Q3 are simultaneously electrically connected with the other input end of a filter LF 3. The absorption circuit can be eliminated as needed to further reduce cost.

Further, the first feedback circuit comprises two resistors R29 and R26, one end of each resistor R29 is electrically connected with one input end of the filter LF3, the other end of each resistor R29 is electrically connected with a reference electrode of the voltage stabilizing chip U2, one end of each resistor R31, R32 and R28, the other ends of the resistors R31 and R32 are electrically connected with an anode of the voltage stabilizing chip U2 and the other input end of the filter LF3, the other end of the resistor R28 is electrically connected with one end of the capacitor C11, the other end of the resistor R26 is electrically connected with a pin 1 of the optocoupler U4 and one end of the resistor R25, the other ends of the resistor R25 and the capacitor C11, and a cathode of the voltage stabilizing chip U2 are electrically connected with a pin 2 of the optocoupler U4, the pin 3 of the optocoupler U4 is grounded, a pin 4 of the U4 is electrically connected with one end of the resistor R23, and the other end of the resistor R23 is electrically connected with a pin 2 of the control chip U1.

Optionally, the second feedback circuit includes a capacitor C3 having one end electrically connected to the a terminal, the other end of the capacitor C3 is electrically connected to one end of a resistor R6, the other end of the resistor R6 is electrically connected to one end of resistors R7 and R4, and the base of a transistor Q4, the emitter of the transistor Q4 is electrically connected to one end of a resistor R8, the other end of R8 is electrically connected to the feedback terminal of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4 and R4, and the collector of the transistor Q4 are grounded, and the other end of the resistor R7 is electrically connected to the output terminal of the first power supply circuit.

The working principle of the scheme is briefly described as follows:

1) the first feedback circuit is also called secondary side (i.e. secondary side) constant voltage feedback: the output constant voltage sampling signal is fed back to the feedback pin 2 of the primary side (namely the initial end) of the control chip U1 through comparison of the voltage stabilizing chip U2 and transmission of the feedback signal isolated by the optocoupler U4, so that output constant voltage modulation is performed, the constant voltage sampling signal is a main feedback loop of a constant voltage power supply, and the constant voltage sampling signal output circuit cannot be influenced by a feedforward circuit (namely a second feedback circuit).

2) The second feedback circuit is also called the primary side improved THD harmonic feedforward: the alternating current input voltage is rectified by a rectifier bridge BD1 (namely a rectifier circuit), and is subjected to alternating current and direct current isolation by a capacitor C3, the alternating current voltage flows through resistors R5 and R6 and a resistor R4 for voltage division and then is sampled, the amplitude of the alternating current voltage can be adjusted by a voltage division resistor proportion, meanwhile, the resistor R7 is connected with stable direct current voltage (in the embodiment 1, the resistor R7 is connected with a first power supply circuit) to provide bias for the alternating current sampling voltage, the bias can be determined by the proportion of R7 and R4, the voltage value is coupled to be an appropriate voltage value, the voltage value is coupled to a feedback pin (2 pin) of a control chip U1 through a PNP triode Q4 (or a MOS tube, which is not shown in the figure) and a current limiting resistor R8, the voltage of the feedback pin of the control chip U1 is consistent with the input voltage fluctuation, and a fluctuation control power supply device (namely an adaptor product formed by the scheme) switch (namely a switch MOS tube Q1) of the fluctuation control power supply device (namely the fluctuation of the feedback voltage is switched on the switch), namely, the switching current of the power supply device is enabled to fluctuate along with the input voltage, so that the PF value and the harmonic component of the power supply are improved while the constant voltage output is kept.

3) The secondary constant voltage feedback loop and the primary improved THD harmonic wave feedforward loop act together, so that the power supply device can keep constant voltage output, improve harmonic waves and meet the THD requirement of illumination.

Example 2:

as shown in fig. 3 and 4, unlike embodiment 1, the second feedback circuit includes a diode D6 having an anode connected to the live line L between the ac input circuit and the rectifying circuit, a diode D7 having an anode connected to the neutral line N between the ac input circuit and the rectifying circuit, cathodes of the diodes D6 and D7 are electrically connected to one end of a capacitor C3, the other end of a capacitor C3 is electrically connected to one end of a resistor R6, the other end of a resistor R6 is electrically connected to one ends of resistors R7 and R4 and a base of a transistor Q4, an emitter of the transistor Q4 is electrically connected to one end of the resistor R8, the other end of R8 is electrically connected to a feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4 and the resistor R4 and a collector of the transistor Q4 are electrically connected to ground, and the other end of the resistor R7 is electrically connected to an output end of the first power supply circuit. The rest of the contents are the same as those of embodiment 1, and are not described again here. Description of the drawings: in the embodiment 2, the rectifier diodes D6 and D7 are added to sample the live line L and the zero line N, and the diodes D6 and D7 can be wired at any position behind the fuse (F1) in front of the rectifier bridge (BD1), so that the connection at the position can reduce the interference of the filter device behind the rectifier bridge on the sampled voltage.

Example 3:

as shown in fig. 5 and 6, unlike embodiment 1, the second feedback circuit includes a diode D6 having an anode connected to the live line L between the ac input circuit and the rectifying circuit, a diode D7 having an anode connected to the neutral line N between the ac input circuit and the rectifying circuit, cathodes of the diodes D6 and D7 are electrically connected to one end of a capacitor C3, the other end of a capacitor C3 is electrically connected to one end of a resistor R6, the other end of a resistor R6 is electrically connected to one ends of resistors R7 and R4 and a base of a transistor Q4, an emitter of the transistor Q4 is electrically connected to one end of the resistor R8, the other end of R8 is electrically connected to a feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4 and the resistor R4 and a collector of the transistor Q4 are electrically connected to ground, and the other end of the resistor R7 is electrically connected to an output end of the second power supply circuit. The rest of the contents are the same as those of embodiment 1, and are not described again here. Description of the drawings: in this embodiment 3, the dc voltage sampling position (i.e., the resistor R7) can be changed to the second power supply circuit, so that the fluctuation of the first power supply circuit (i.e., the pin 6 of the U1) can be effectively reduced to interfere with the bias of the dc voltage, and the bias voltage is more stable.

The model of the control chip U1 in this scheme is OB5269 or other replacement models, the model of steady voltage chip U2 is TL431 or other replacement models, the model of opto-coupler U4 is 817 series, second supply circuit U3 is the step-down circuit, switch MOS pipe Q1, filter circuit, rectifier circuit, exchange input circuit these all belong to prior art, do not detailed here.

(4) The cost of the LED driving power supply (namely the adapter) is reduced, the complexity of a power supply circuit is reduced, and the volume of a finished product is reduced.

The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the above-described embodiments should be included in the protection scope of the technical solution.

Claims

1. Power supply circuit based on general adapter power IC of low PF, including exchanging input circuit, the rectifier circuit of being connected with exchanging input circuit electricity, the filter circuit of being connected with rectifier circuit electricity, its characterized in that: the output of the filter circuit is electrically connected with the end A, the end A is respectively electrically connected with one end of a primary main winding of the transformer, one end of the absorption circuit and the input end of the main control circuit, the control end of the main control circuit is electrically connected with a grid electrode of the switch MOS tube, a drain electrode of the switch MOS tube is respectively electrically connected with the other end of the absorption circuit and the other end of the primary main winding of the transformer, a primary feedback winding of the transformer is electrically connected with the input end of a first power supply circuit, the output end of the first power supply circuit is electrically connected with the power supply end of the main control circuit, a secondary winding of the transformer is electrically connected with the output circuit, and the output circuit is electrically connected with the bleeder circuit;

the output end of the first feedback circuit is electrically connected with the feedback end of the main control circuit;

the input end of the second feedback circuit is electrically connected with the end A or the end B between the alternating current input circuit and the rectifying circuit, the output end of the second feedback circuit is electrically connected with the feedback end of the main control circuit, the power supply end of the second feedback circuit is electrically connected with the output end of the first power supply circuit or the output end of the second power supply circuit, and the input end of the second power supply circuit is electrically connected with the end A.

2. The low PF universal adapter power IC-based power circuit of claim 1, wherein: the absorption circuit comprises resistors R20 and R22 which are electrically connected with one end of a primary main winding of the transformer at the same time, and one end of a capacitor C8, the other ends of the resistors R20 and R22 and the capacitor C8 are electrically connected with one ends of resistors R19 and R24 at the same time, the other ends of the resistors R19 and R24 are electrically connected with a cathode of a diode D2 at the same time, and an anode of a diode D2 is electrically connected with the other end of the primary main winding of the transformer.

3. The low PF universal adapter power IC-based power circuit of claim 2, wherein: the first power supply circuit comprises an anode of a diode D3 electrically connected with one end of a primary feedback winding of the transformer, a cathode of a diode D3 is electrically connected with one end of a resistor R21, the other end of the resistor R21 is electrically connected with an anode of an electrolytic C7 and one end of a capacitor C6, and a cathode of an electrolytic C7 and the other end of a capacitor C6 are electrically connected with the other end of the primary feedback winding of the transformer and are grounded.

4. The low PF universal adapter power IC based power supply circuit of claim 3, wherein: the main control circuit comprises a control chip U, wherein 8 pins of the control chip U are electrically connected with one end of a resistor R, the other end of the resistor R is electrically connected with one end of the resistor R, the other end of the resistor R is electrically connected with an end A, 5 pins of the control chip U are electrically connected with one end of the resistor R, the other end of the resistor R is electrically connected with one end of a diode D, the other end of the resistor R and the anode of the diode D are simultaneously electrically connected with one end of the resistor R and the grid of a switch MOS tube Q, the source electrode of the switch MOS tube Q is electrically connected with one end of the resistor R, the drain electrode of the switch MOS tube Q is electrically connected with the anode of the diode D, 3 pins of the control chip U are simultaneously electrically connected with one ends of the resistor R and a capacitor C, the other end of the resistor R, the one end of the R, the other end of the resistor R, the other end of the resistor R, the other end of the resistor R, and the other end of the resistor R of the other end of the resistor R of the control chip U are simultaneously, and the other end of the control chip U are simultaneously grounded, pin 2 of the control chip U1 is the feedback terminal.

5. The low PF universal adapter power IC based power supply circuit of claim 4, wherein: the output circuit comprises an anode of a diode D4 and one end of a capacitor C10 which are simultaneously and electrically connected with one end of a secondary winding of the transformer, the other end of the capacitor C10 is simultaneously and electrically connected with one ends of resistors R27 and R30, the other ends of resistors R27 and R30 and a cathode of a diode D4 are simultaneously and electrically connected with anodes of the electrolytic capacitors C12 and C13 and one input end of a filter LF3, and the other end of the secondary winding of the transformer is simultaneously and electrically connected with cathodes of the electrolytic capacitors C12 and C13 and the other input end of the filter LF 3.

6. The low PF universal adapter power IC based power supply circuit of claim 5, wherein: the absorption circuit comprises an anode of a diode D5 electrically connected with one end of a secondary winding of the transformer, a cathode of a diode D5 is electrically connected with one ends of a capacitor C9 and a resistor R34, the other end of the resistor R34 is electrically connected with one end of a resistor R33 and a base of a triode Q2, a collector of a triode Q2 is electrically connected with one end of the resistor R35 and a base of a triode Q3, a collector of the triode Q3 is electrically connected with one end of a resistor R36, the other ends of the resistors R35 and R36 are electrically connected with one input end of a filter LF3, and emitters of the capacitor C9, the other end of the resistor R33 and the triodes Q2 and Q3 are electrically connected with the other input end of a filter LF 3.

7. The low PF universal adapter power IC based power supply circuit of claim 6, wherein: the first feedback circuit comprises two resistors R29 and R26, one end of each resistor R29 is electrically connected with one input end of a filter LF3, the other end of each resistor R29 is simultaneously electrically connected with a reference electrode of a voltage stabilizing chip U2, one end of each resistor R31, one end of each resistor R32 and one end of each R28 are electrically connected, the other ends of the resistors R31 and R32 are simultaneously electrically connected with an anode of a voltage stabilizing chip U2 and the other end of a filter LF3, the other end of the resistor R28 is electrically connected with one end of a capacitor C11, the other end of the resistor R26 is simultaneously electrically connected with a pin 1 of an optical coupler U4 and one end of a resistor R25, the other ends of the resistors R25 and C11 and a cathode of the voltage stabilizing chip U2 are simultaneously electrically connected with a pin 2 of an optical coupler U4, a pin 3 of the optical coupler U4 is grounded, a pin 4 of the optical coupler U4 is electrically connected with one end of a resistor R23, and the other end of the resistor R23 is electrically connected with a pin 2 of a control chip U1.

8. The low PF universal adapter power IC-based power circuit of claim 1, wherein: the second feedback circuit comprises a capacitor C3 with one end electrically connected with the end A, the other end of the capacitor C3 is electrically connected with one end of a resistor R6, the other end of the resistor R6 is simultaneously electrically connected with one end of a resistor R7, one end of a resistor R4 and the base of a triode Q4, the emitter of a triode Q4 is electrically connected with one end of a resistor R8, the other end of a resistor R8 is simultaneously electrically connected with the feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4, the resistor R4 and the collector of a triode Q4 are simultaneously grounded, and the other end of the resistor R7 is electrically connected with the output end of the first power supply circuit.

9. The low PF universal adapter power IC-based power circuit of claim 1, wherein: the second feedback circuit comprises a diode D6 with the anode connected to the AC input circuit and the live wire L between the rectification circuits, a diode D7 with the anode connected to the AC input circuit and the zero line N between the rectification circuits, the cathodes of the diodes D6 and D7 are electrically connected with one end of a capacitor C3, the other end of a capacitor C3 is electrically connected with one end of a resistor R6, the other end of the resistor R6 is electrically connected with one end of resistors R7 and R4 and the base of a triode Q4, the emitter of the triode Q4 is electrically connected with one end of the resistor R8, the other end of the R8 is electrically connected with the feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitors C4 and R4 and the collector of the triode Q4 are grounded, and the other end of the resistor R7 is electrically connected with the output end of the first power supply circuit.

10. The low PF universal adapter power IC-based power circuit of claim 1, wherein: the second feedback circuit comprises a diode D6 with the anode connected to the AC input circuit and the live wire L between the rectification circuits, a diode D7 with the anode connected to the AC input circuit and the zero line N between the rectification circuits, the cathodes of the diodes D6 and D7 are electrically connected with one end of a capacitor C3, the other end of a capacitor C3 is electrically connected with one end of a resistor R6, the other end of the resistor R6 is electrically connected with one ends of a resistor R7 and a resistor R4 and the base of a triode Q4, the emitter of the triode Q4 is electrically connected with one end of the resistor R8, the other end of the R8 is electrically connected with the feedback end of the main control circuit and one end of the capacitor C4, the other ends of the capacitor C4, the resistor R4 and the collector of the triode Q4 are grounded, and the other end of the resistor R7 is electrically connected with the output end of the second power supply circuit.