TW202318131A - Power supply device for increasing output stability - Google Patents

Abstract

A power supply device for increasing output stability includes a first transformer, a power switch element, an output stage circuit, a feedback compensation circuit, a first detection circuit, a second detection circuit, a second transformer, a third transformer, a multiplier, and an MCU (Microcontroller Unit). The first detection circuit monitors the power switch element, and generates a first detection voltage. The second detection circuit monitors the output stage circuit, and generates a second detection voltage. The second transformer generates a second induced voltage according to the second detection voltage. The third transformer is coupled to the feedback compensation circuit, and generates a third induced voltage. The multiplier generates a product voltage according to the first detection voltage, a second induced voltage, and the third induced voltage. The MCU adjusts a duty cycle of a clock voltage according to the product voltage.

Description

Power supply with increased output stability

The present invention relates to a power supply, in particular to a power supply capable of increasing output stability.

With the development and upgrading of central processing units and graphics cards, power supplies require greater peak current and dynamic current. However, traditional power supplies often face problems such as insufficient compensation or slow response speed, which will cause the output stability of the system to decline. In view of this, it is necessary to propose a new solution to overcome the difficulties faced by the previous technology.

In a preferred embodiment, the present invention proposes a power supply with increased output stability, comprising: a first transformer including a first primary coil and a first secondary coil, wherein the first primary coil is used to receive An input potential, and the first secondary coil is used to generate a first induction potential; a power switch selectively couples the first main coil to a ground potential according to a clock potential; an output stage circuit , generating an output potential according to the first induction potential; a feedback compensation circuit, generating a feedback potential according to the output potential, wherein the feedback compensation circuit includes a linear optocoupler; a first detection circuit, monitor the power switch and generate a first detection potential; a second detection circuit monitor the output stage circuit and generate a second detection potential; a second transformer includes a second main coil and a The second secondary coil, wherein the second primary coil is used to receive the second detection potential, and the second secondary coil is used to generate a second induced potential; a third transformer includes a third primary coil and A third secondary coil, wherein the third main coil is coupled to the feedback compensation circuit, and the third secondary coil is used to generate a third induced potential; a multiplier, based on the first detection potential, The second induction potential and the third induction potential generate a product potential; and a microcontroller generates the clock potential according to the feedback potential, wherein the microcontroller further adjusts the clock according to the product potential One duty cycle of the pulse potential.

In order to make the purpose, features and advantages of the present invention more comprehensible, specific embodiments of the present invention are listed below, together with the accompanying drawings, for detailed description as follows.

Certain terms are used in the specification and claims to refer to particular elements. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This description and the scope of the patent application do not use the difference in name as a way to distinguish components, but use the difference in function of components as a criterion for distinguishing. The words "comprising" and "comprising" mentioned throughout the specification and scope of patent application are open-ended terms, so they should be interpreted as "including but not limited to". The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. In addition, the term "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if it is described that a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connection means. Two devices.

FIG. 1 is a schematic diagram of a power supply 100 according to an embodiment of the present invention. For example, the power supply 100 can be applied to a desktop computer, a notebook computer, or an all-in-one computer. As shown in Figure 1, the power supply 100 includes: a first transformer 110, a power switch 120, an output stage circuit 130, a feedback compensation circuit 140, a first detection circuit 150, a second detection circuit Measuring circuit 160, a second transformer 170, a third transformer 180, a multiplier 190, and a microcontroller 199. It should be noted that although not shown in FIG. 1 , the power supply 100 may further include other components, such as a voltage regulator and/or a negative feedback circuit.

The first transformer 110 includes a first primary coil 111 and a first secondary coil 112, wherein the first primary coil 111 can be located on one side of the first transformer 110, and the first secondary coil 112 can be located on the opposite side of the first transformer 110. side. The first primary coil 111 can be used to receive an input potential VIN, and the first secondary coil 112 can be used to generate a first induced potential VS1 in response to the input potential VIN. For example, the input potential VIN can be a DC potential, and its level can be between 120V and 380V. The power switch 120 can selectively couple the first main coil 111 to a ground potential VSS according to a clock potential VA. For example, if the clock potential VA is a high logic level, the power switch 120 can couple the first main coil 111 to the ground potential VSS (that is, the power switch 120 can be approximated as a short-circuit path); otherwise, if When the clock potential VA is at a low logic level, the power switch 120 will not couple the first main coil 111 to the ground potential VSS (that is, the power switch 120 can be approximated as an open-circuit path). The output stage circuit 130 can generate an output potential VOUT according to the first sensing potential VS1 . For example, the output potential VOUT can be another DC potential, and its level can be between 18V and 20V. The feedback compensation circuit 140 can generate a feedback potential VF according to the output potential VOUT, wherein the feedback compensation circuit 140 includes a linear optocoupler 142 . The first detection circuit 150 can monitor the relevant parameters of the power switch 120 and can generate a first detection potential VD1 accordingly. The second detection circuit 160 can monitor the relevant parameters of the output stage circuit 130 and generate a second detection potential VD2 accordingly. The second transformer 170 includes a second primary coil 171 and a second secondary coil 172, wherein the second primary coil 171 can be located on one side of the second transformer 170, and the second secondary coil 172 can be located on the opposite side of the second transformer 170. side. The second main coil 171 can be used to receive the second detection potential VD2 , and in response to the second detection potential VD2 , the second secondary coil 172 can be used to generate a second induced potential VS2 . The third transformer 180 includes a third primary coil 181 and a third secondary coil 182, wherein the third primary coil 181 can be located on one side of the third transformer 180, and the third secondary coil 182 can be located on the opposite side of the third transformer 180. side. The third primary coil 181 is coupled to the feedback compensation circuit 140 , and in response, the third secondary coil 182 can be used to generate a third induced potential VS3 . The multiplier 190 can generate a product potential VM according to the first detection potential VD1 , the second sensing potential VS2 , and the third sensing potential VS3 . The microcontroller 199 can generate the clock potential VA according to the feedback potential VF, wherein the microcontroller 199 can further adjust a duty cycle K of the clock potential VA according to the product potential VM. For example, if the product potential VM becomes high, the microcontroller 199 can extend the duty cycle K of the clock potential VA; conversely, if the product potential VM becomes low, the microcontroller 199 can shorten the duty cycle K of the clock potential VA K, but not limited to this. Under this design, even if the power supply 100 suddenly needs a larger output power, it can meet this demand by dynamically adjusting the duty cycle K of the clock potential VA. Therefore, the output stability of the power supply 100 will be reduced can be increased substantially.

The following embodiments will introduce the detailed structure and operation of the power supply 100 . It must be understood that these drawings and descriptions are examples only and are not intended to limit the scope of the present invention.

FIG. 2 is a schematic diagram of a power supply 200 according to an embodiment of the present invention. In the embodiment of FIG. 2, the power supply 200 has an input node NIN and an output node NOUT, and includes: a first transformer 210, a power switch 220, an output stage circuit 230, and a feedback compensation circuit 240 , a first detection circuit 250 , a second detection circuit 260 , a second transformer 270 , a third transformer 280 , a multiplier 290 , and a microcontroller 299 . The input node NIN of the power supply 200 can receive an input potential VIN from an external input power source, and the output node NOUT of the power supply 200 can be used to output an output potential VOUT to an electronic device (not shown).

The first transformer 210 includes a first primary coil 211 and a first secondary coil 212 , wherein the first transformer 210 can further have a built-in magnetizing inductor LM. The magnetizing inductor LM can be an inherent component produced by the manufacture of the first transformer 210 , and it is not an external independent component. Both the first main coil 211 and the magnetizing inductor LM can be located on the same side of the first transformer 210 (for example: the primary side), while the first secondary coil 212 can be located on the opposite side of the first transformer 210 (for example: the secondary side). side, which can be isolated from the primary side). The first main coil 211 has a first end and a second end, wherein the first end of the first main coil 211 is coupled to the input node NIN, and the second end of the first main coil 211 is coupled to a first end. A node N1. The magnetizing inductor LM has a first terminal and a second terminal, wherein the first terminal of the magnetizing inductor LM is coupled to the input node NIN, and the second terminal of the magnetizing inductor LM is coupled to the first node N1. The first secondary coil 212 has a first terminal and a second terminal, wherein the first terminal of the first secondary coil 212 is coupled to a second node N2 to output a first induced potential VS1, and the first secondary coil 212 The second terminal is coupled to a common node NCM. For example, the common node NCM can be another ground potential, which can be the same as or different from the aforementioned ground potential VSS.

The power switch 220 includes a transistor M1. For example, the transistor M1 can be an N-type metal oxide semiconductor field effect transistor. The transistor M1 has a control terminal (for example: a gate), a first terminal (for example: a source), and a second terminal (for example: a drain), wherein the control terminal of the transistor M1 is used for Receiving a clock potential VA, the first terminal of the transistor M1 is coupled to a first detection node ND1, and the second terminal of the transistor M1 is coupled to the first node N1. For example, if the clock potential VA is at a high logic level, the transistor M1 will be enabled; otherwise, if the clock potential VA is at a low logic level, the transistor M1 will be disabled.

The output stage circuit 230 includes a diode D1 and a first capacitor C1. The diode D1 has an anode and a cathode, wherein the anode of the diode D1 is coupled to the second node N2 to receive the first sense potential VS1 , and the cathode of the diode D1 is coupled to the output node NOUT. The first capacitor C1 has a first terminal and a second terminal, wherein the first terminal of the first capacitor C1 is coupled to the output node NOUT, and the second terminal of the first capacitor C1 is coupled to a third node N3 .

The feedback compensation circuit 240 includes a linear optocoupler 242, a voltage regulator 244, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first resistor R1, a second resistor R2 , and a third resistor R3.

In some embodiments, linear optocoupler 242 is implemented by a PC817 electronics. The linear optical coupler 242 includes a light emitting diode DL and a bicarrier junction transistor Q2 (for example: NPN type). The light emitting diode DL has an anode and a cathode, wherein the anode of the light emitting diode DL is coupled to the output node NOUT to receive the output potential VOUT, and the cathode of the light emitting diode DL is coupled to a fourth node N4 . The bicarrier junction transistor Q2 has a collector and an emitter, wherein the collector of the bicarrier junction transistor Q2 is used to output a feedback potential VF to the microcontroller 299, and the bicarrier junction transistor Q2 The emitter of the transistor Q2 is coupled to a fifth node N5.

The first resistor R1 has a first end and a second end, wherein the first end of the first resistor R1 is coupled to the output node NOUT, and the second end of the first resistor R1 is coupled to a first end. Six nodes N6. The second resistor R2 has a first end and a second end, wherein the first end of the second resistor R2 is coupled to the sixth node N6, and the second end of the second resistor R2 is coupled to the common Node NCM. The second capacitor C2 has a first terminal and a second terminal, wherein the first terminal of the second capacitor C2 is coupled to the fourth node N4, and the second terminal of the second capacitor C2 is coupled to the sixth node N6 . The third resistor R3 has a first end and a second end, wherein the first end of the third resistor R3 is coupled to the fourth node N4, and the second end of the third resistor R3 is coupled to a The seventh node N7. The third capacitor C3 has a first terminal and a second terminal, wherein the first terminal of the third capacitor C3 is coupled to the seventh node N7, and the second terminal of the third capacitor C3 is coupled to the sixth node N6 . The fourth capacitor C4 has a first terminal and a second terminal, wherein the first terminal of the fourth capacitor C4 is coupled to the fifth node N5, and the second terminal of the fourth capacitor C4 is coupled to the ground potential VSS.

In some embodiments, voltage regulator 244 is implemented by a TL431 electronic component. The voltage regulator 244 has an anode, a cathode, and a reference terminal, wherein the anode of the voltage regulator 244 is coupled to the common node NCM, the cathode of the voltage regulator 244 is coupled to the fourth node N4, and the voltage regulator 244 is coupled to the fourth node N4. The reference terminal of 244 is coupled to the sixth node N6.

The first detection circuit 250 includes an averaging circuit 252 and a fourth resistor R4. The fourth resistor R4 has a first end and a second end, wherein the first end of the fourth resistor R4 is coupled to the first detection node ND1, and the second end of the fourth resistor R4 is coupled to to ground potential VSS. An input current IIN may flow through the fourth resistor R4, wherein the current value of the input current IIN may fluctuate up and down according to the clock potential VA. The average circuit 252 can calculate an average potential at the first detection node ND1 to generate the first detection potential VD1. For example, the level of the first detection potential VD1 can be equal to the average value of the fluctuation voltage at the first detection node ND1 within a predetermined period of time.

The second detection circuit 260 includes a divider 262, an integration circuit 264, an inductor L1, and a fifth resistor R5. The inductor L1 has a first end and a second end, wherein the first end of the inductor L1 is coupled to the third node N3 to output an inductor potential VL, and the second end of the inductor L1 is coupled to the common Node NCM. An output current IOUT can flow through the inductor L1. The divider 262 can divide the inductor potential VL by the inductance value of the inductor L1 to generate a differential current ID. The integration circuit 264 can integrate the differential current ID to generate a reduction current IR. The reduction current IR may be substantially equal to the output current IOUT, and may flow through the fifth resistor R5. The fifth resistor R5 has a first end and a second end, wherein the first end of the fifth resistor R5 is coupled to a second detection node ND2 to output a second detection potential VD2, and the fifth The second end of the resistor R5 is coupled to the common node MCM.

In some embodiments, the operation principle of the second detection circuit 260 can be described in the following equations (1)-(4).

………………………………(1)

………………………………(1)

………………………………(2)

………………………………(2)

…………………………(3)

………………………(3)

………………………………(4) 其中「VL」代表電感電位VL之電位位準，「L1」代表電感器L1之電感值，「IOUT」代表輸出電流IOUT之電流值，「ID」代表微分電流ID(亦即，輸出電流IOUT對時間作微分之結果)，「IR」代表還原電流IR之電流值，「VD2」代表第二偵測電位VD之電位位準，而「R5」代表第五電阻器R5之電阻值。

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………(4) Among them, "VL" represents the potential level of the inductor potential VL, "L1" represents the inductance value of the inductor L1, and "IOUT" represents the current value of the output current IOUT, "ID" represents the differential current ID (that is, the result of differential output current IOUT with respect to time), "IR" represents the current value of the reduction current IR, "VD2" represents the potential level of the second detection potential VD, and "R5" represents the resistance value of the fifth resistor R5.

The second transformer 270 includes a second primary winding 271 and a second secondary winding 272 . The second main coil 271 can be located on one side of the second transformer 270 (for example: the secondary side), and the second secondary coil 272 can be located on the opposite side of the second transformer 270 (for example: the primary side, which can be connected with the two secondary sides are isolated from each other). The second main coil 271 has a first end and a second end, wherein the first end of the second main coil 271 is coupled to the second detection node ND2 to receive the second detection potential VD2, and the second main coil The second end of 271 is coupled to the common node NCM. The second sub-coil 272 has a first end and a second end, wherein the first end of the second sub-coil 272 is used to output a second induced potential VS2 to the multiplier 290, and the second end of the second sub-coil 272 The terminal is coupled to the ground potential VSS.

The third transformer 280 includes a third primary coil 281 and a third secondary coil 282 . The third main coil 281 can be located on one side of the third transformer 280 (for example: the secondary side), and the third secondary coil 282 can be located on the opposite side of the third transformer 280 (for example: the primary side, which can be connected with the second transformer 280). secondary sides are isolated from each other). The third main coil 281 has a first end and a second end, wherein the first end of the third main coil 281 is coupled to the sixth node N6 to receive a divided potential VG, and the third main coil 281 The second end is coupled to the common node NCM. The third sub-coil 282 has a first end and a second end, wherein the first end of the third sub-coil 282 is used to output a third induced potential VS3 to the multiplier 290, and the second end of the third sub-coil 282 The terminal is coupled to the ground potential VSS.

The multiplier 290 can generate a product potential VM according to the first detection potential VD1 , the second sensing potential VS2 , and the third sensing potential VS3 . In some embodiments, the operation principle of the multiplier 290 can be described as the following equation (5).

………………………(5) 其中「VM」代表乘積電位VM之電位位準，「VD1」代表第一偵測電位VD1之電位位準，「VS2」代表第二感應電位VS2之電位位準，而「VS3」代表第三感應電位VS3之電位位準。

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………(5) Among them, "VM" represents the potential level of the product potential VM, "VD1" represents the potential level of the first detection potential VD1, and "VS2" represents the potential level of the second induced potential VS2 potential level, and "VS3" represents the potential level of the third sensing potential VS3.

The microcontroller 299 can generate the clock potential VA according to the feedback potential VF, and the microcontroller 299 can further adjust a duty cycle K of the clock potential VA according to the product potential VM.

FIG. 3 shows a waveform diagram of the clock potential VA according to an embodiment of the present invention. As shown in FIG. 3 , in each complete period T of the clock potential VA, the duration of its high logic level is TON. In some embodiments, the duty period K of the clock potential VA can be expressed as the following equation (6).

………………………………………(6)

……………………………………(6)

FIG. 4 is a graph showing the relationship between the product potential VM and the duty cycle K according to an embodiment of the present invention. In the embodiment of Figure 4, if the product potential VM becomes high, the microcontroller 299 can extend the duty cycle K of the clock potential VA, and if the product potential VM becomes low, the microcontroller 299 can shorten the clock potential VA's duty cycle K.

The power supply 200 has three situations that need to be adjusted dynamically, which are respectively described as follows.

In the first case, the input power of the power supply 200 changes instantaneously (eg, suddenly increases). Since the input potential VIN is roughly a fixed value, the input current IIN must be increased to generate greater input power. At this time, the first detection potential VD1 will become higher, which will cause the product potential VM to become higher, and eventually the duty cycle K of the clock potential VA will be extended accordingly.

In the second case, the output load of the power supply 200 changes instantaneously (eg, increases suddenly). As the output current IOUT increases, the reduction current IR also increases, and the second detection potential VD2 is pulled up. At this time, the second induced potential VS2 will become higher, which will cause the product potential VM to become higher, and eventually the duty cycle K of the clock potential VA will be extended accordingly.

In the third case, the output voltage of the power supply 200 changes instantaneously (for example, drops suddenly). Since the output potential VOUT becomes smaller, the divided potential VG also becomes smaller. At this time, the third sensing potential VS3 will become lower, and cause the product potential VM to become lower, and eventually the duty period K of the clock potential VA will be shortened accordingly.

Regardless of any of the three situations, because the comprehensive judgment and dynamic adjustment can be made according to the changes in the input power, output load, and output voltage, the output stability of the power supply 200 of the present invention will be obtained. Greatly improved.

In some embodiments, the component parameters of the power supply 200 may be as follows. The inductance value of the magnetizing inductor LM can be between 384 μH to 576 μH, preferably 480 μH. The inductance of the inductor L1 can be between 2.85 μH to 3.15 μH, preferably 3 μH. The capacitance of the first capacitor C1 can range from 544 μF to 816 μF, preferably 680 μF. The capacitance of the second capacitor C2 may be approximately equal to 1.5nF. The capacitance of the third capacitor C3 may be approximately equal to 47nF. The capacitance of the fourth capacitor C4 may be approximately equal to 1 nF. The resistance value of the first resistor R1 can be between 66.31KΩ to 73.29KΩ, preferably 69.8KΩ. The resistance value of the second resistor R2 can be between 9.69KΩ and 10.71KΩ, preferably 10.2KΩ. The resistance value of the third resistor R3 can be between 44.65KΩ and 49.35KΩ, preferably 47KΩ. The resistance value of the fourth resistor R4 may be approximately equal to 1Ω. The resistance value of the fifth resistor R5 may be approximately equal to 1Ω. The turn ratio of the first primary coil 211 to the first secondary coil 212 can be between 1 and 100, preferably 20. The turn ratio of the second primary coil 271 to the second secondary coil 272 can be between 1 and 10, preferably 2.67. The turn ratio of the third primary coil 281 to the third secondary coil 282 may be between 1 and 10, preferably 1.5. The duty cycle K of the clock potential VA can be between 0.4 and 0.9. The above parameter ranges are obtained according to the results of multiple experiments, which help to optimize the output stability of the power supply 200 .

The present invention proposes a novel power supply, which includes a multiplier and a microcontroller that can dynamically adjust the duty cycle. According to the actual measurement results, using the power supply of the above design can effectively improve the output stability of the power supply, so it is very suitable for various devices.

It should be noted that the potential, current, resistance value, inductance value, capacitance value, and other component parameters mentioned above are not limiting conditions of the present invention. Designers can adjust these settings according to different needs. The power supply of the present invention is not limited to the states shown in FIGS. 1-4. The present invention may only include any one or multiple features of any one or multiple embodiments of Figures 1-4. In other words, not all the illustrated features must be implemented in the power supply of the present invention at the same time. Although the embodiment of the present invention uses a metal oxide half field effect transistor as an example, the present invention is not limited thereto, and those skilled in the art can use other types of transistors, such as junction field effect transistors, or fin Type field effect transistors, etc., and will not affect the effect of the present invention.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., have no sequential relationship with each other, and are only used to mark and distinguish between two The different elements of the name.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in this art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the scope of the appended patent application.

100,200: Power supply 110,210: first transformer 111,211: the first main coil 112,212: the first secondary coil 120,220: Power Switcher 130,230: output stage circuit 140,240: feedback compensation circuit 142,242: Linear optocoupler 150,250: the first detection circuit 160,260: the second detection circuit 170,270: Second Transformer 171,271: second main coil 172,272: second secondary coil 180,280: Third Transformer 181,281: the third main coil 182,282: the third secondary coil 190,290: multiplier 199,299: Microcontrollers 244:Voltage regulator 252: average circuit 262: Divider 264: Integrator circuit C1: first capacitor C2: second capacitor C3: the third capacitor C4: Fourth capacitor D1: Diode DL: light emitting diode IIN: input current IOUT: output current ID: differential current IR: reduction current L1: Inductor LM: Exciting inductor K: Responsibility cycle M1: Transistor N1: the first node N2: second node N3: the third node N4: the fourth node N5: fifth node N6: sixth node N7: seventh node NCM: common node ND1: the first detection node ND2: Second detection node NIN: input node NOUT: output node Q2: BJT R1: first resistor R2: second resistor R3: Third resistor R4: Fourth resistor R5: fifth resistor T: The complete period of the clock potential TON: duration of high logic level VA: clock potential VD1: the first detection potential VD2: the second detection potential VG: partial voltage potential VIN: input potential VL: Inductance potential VF: feedback potential VM: product potential VOUT: output potential VS1: the first induced potential VS2: the second induction potential VS3: the third induction potential VSS: ground potential

FIG. 1 is a schematic diagram showing a power supply according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a power supply according to an embodiment of the present invention. FIG. 3 shows a waveform diagram of a clock potential according to an embodiment of the present invention. Fig. 4 is a graph showing the relationship between product potential and duty cycle according to an embodiment of the present invention.

100: Power supply

110: The first transformer

111: The first main coil

112: The first secondary coil

120: Power switcher

130: Output stage circuit

140: Feedback compensation circuit

142: Linear optocoupler

150: the first detection circuit

160: the second detection circuit

170: second transformer

171: Second main coil

172: Second secondary coil

180: The third transformer

181: The third main coil

182: The third secondary coil

190: Multiplier

199: Microcontroller

K: Responsibility cycle

VA: clock potential

VD1: the first detection potential

VD2: the second detection potential

VIN: input potential

VF: feedback potential

VM: product potential

VOUT: output potential

VS1: the first induced potential

VS2: the second induction potential

VS3: the third induction potential

VSS: ground potential

Claims (10)

A power supply with increased output stability, including: A first transformer, including a first main coil and a first secondary coil, wherein the first primary coil is used to receive an input potential, and the first secondary coil is used to generate a first induced potential; a power switch selectively couples the first primary coil to a ground potential according to a clock potential; an output stage circuit, which generates an output potential according to the first induced potential; A feedback compensation circuit for generating a feedback potential according to the output potential, wherein the feedback compensation circuit includes a linear optocoupler; A first detection circuit monitors the power switch and generates a first detection potential; A second detection circuit monitors the output stage circuit and generates a second detection potential; A second transformer, including a second main coil and a second secondary coil, wherein the second primary coil is used to receive the second detection potential, and the second secondary coil is used to generate a second induced potential ; A third transformer, including a third main coil and a third secondary coil, wherein the third primary coil is coupled to the feedback compensation circuit, and the third secondary coil is used to generate a third induced potential; A multiplier generates a product potential according to the first detection potential, the second sensing potential, and the third sensing potential; and A microcontroller generates the clock potential according to the feedback potential, wherein the microcontroller further adjusts a duty cycle of the clock potential according to the product potential. The power supply of claim 1, wherein if the product potential becomes high, the microcontroller will extend the duty cycle of the clock potential, and if the product potential becomes low, the microcontroller will shorten The duty cycle of the clock potential. The power supply as described in claim 1, wherein the first transformer further has a built-in magnetizing inductor, the first main coil has a first end and a second end, and the first end of the first main coil is coupled to an input node to receive the input potential, the second terminal of the first main coil is coupled to a first node, the magnetizing inductor has a first terminal and a second terminal, the magnetizing inductor The first end of the magnetizing inductor is coupled to the input node, the second end of the magnetizing inductor is coupled to the first node, the first secondary coil has a first end and a second end, the first The first end of the secondary coil is coupled to a second node to output the first induced potential, and the second end of the first secondary coil is coupled to a common node. The power supply as described in claim 3, wherein the power switch includes: A transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the transistor is used to receive the clock potential, and the first terminal of the transistor is coupled to a The first detection node, and the second end of the transistor is coupled to the first node. The power supply as described in Claim 4, wherein the output stage circuit includes: A diode having an anode and a cathode, wherein the anode of the diode is coupled to the second node to receive the first induced potential, and the cathode of the diode is coupled to an output node to output the output potential; and A first capacitor having a first terminal and a second terminal, wherein the first terminal of the first capacitor is coupled to the output node, and the second terminal of the first capacitor is coupled to a first Three nodes. The power supply as described in Claim 5, wherein the linear optocoupler includes a light emitting diode and a bicarrier junction transistor, the light emitting diode has an anode and a cathode, the light emitting diode The anode of the light emitting diode is coupled to the output node to receive the output potential, the cathode of the light emitting diode is coupled to a fourth node, the bicarrier junction transistor has a collector and an emitter, The collector of the BJT is used to output the feedback potential to the microcontroller, and the emitter of the BJT is coupled to a fifth node. The power supply as described in Claim 6, wherein the feedback compensation circuit further includes: a first resistor having a first end and a second end, wherein the first end of the first resistor is coupled to the output node, and the second end of the first resistor is coupled to to a sixth node; A second resistor has a first end and a second end, wherein the first end of the second resistor is coupled to the sixth node, and the second end of the second resistor is coupled to connected to the common node; a second capacitor having a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the fourth node, and the second terminal of the second capacitor is coupled to the sixth node; A third resistor having a first end and a second end, wherein the first end of the third resistor is coupled to the fourth node, and the second end of the third resistor is coupled to connected to a seventh node; a third capacitor having a first terminal and a second terminal, wherein the first terminal of the third capacitor is coupled to the seventh node, and the second terminal of the third capacitor is coupled to the sixth node; a voltage regulator having an anode, a cathode, and a reference terminal, wherein the anode of the voltage regulator is coupled to the common node, the cathode of the voltage regulator is coupled to the fourth node, and the reference terminal of the voltage regulator is coupled to the sixth node; and a fourth capacitor having a first terminal and a second terminal, wherein the first terminal of the fourth capacitor is coupled to the fifth node, and the second terminal of the fourth capacitor is coupled to the ground potential. The power supply according to claim 4, wherein the first detection circuit includes: A fourth resistor has a first end and a second end, wherein the first end of the fourth resistor is coupled to the first detection node, and the second end of the fourth resistor is coupled to the ground potential, and an input current flows through the fourth resistor; and An average circuit calculates an average potential at the first detection node to generate the first detection potential. The power supply according to claim 7, wherein the second detection circuit includes: An inductor having a first end and a second end, wherein the first end of the inductor is coupled to the third node to output an inductance potential, and the second end of the inductor is coupled to to the common node; a divider for dividing the inductance potential by an inductance value of the inductor to generate a differential current; an integrating circuit for integrating the differential current to generate a reducing current; and a fifth resistor having a first end and a second end, wherein the reduction current flows through the fifth resistor, and the first end of the fifth resistor is coupled to a second detection node to output a second detection potential, and the second end of the fifth resistor is coupled to the common node. The power supply as described in claim 9, wherein the second main coil has a first end and a second end, and the first end of the second main coil is coupled to the second detection node to receive The second detection potential, the second terminal of the second primary coil is coupled to the common node, the second secondary coil has a first terminal and a second terminal, the first terminal of the second secondary coil terminal is used to output the second induction potential to the multiplier, the second terminal of the second secondary coil is coupled to the ground potential, the third main coil has a first terminal and a second terminal, the The first end of the third main coil is coupled to the sixth node, the second end of the third main coil is coupled to the common node, the third secondary coil has a first end and a second terminal, the first terminal of the third secondary coil is used to output the third induced potential to the multiplier, and the second terminal of the third secondary coil is coupled to the ground potential.

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