TWI746081B - Low-loss and quick-start power supply device - Google Patents

Abstract

A power supply device includes a bridge rectifier, a first capacitor, a transformer, a power switch element, an output stage circuit, a feedback compensation circuit, and a PWM (Pulse Width Modulation) IC (Integrated Circuit). The bridge rectifier generates a rectified voltage according to a first input voltage and a second input voltage. The transformer includes a main coil, a secondary coil, and an auxiliary coil. The main coil receives the rectified voltage. The secondary coil generates an induced voltage. The output stage circuit generates an output voltage according to the induced voltage. The feedback compensation circuit includes an acceleration circuit, a first resistor, and a linear optical coupler. The acceleration circuit reduces an initialization time of the linear optical coupler. When the linear optical coupler has been fully started, the acceleration circuit is switched from an enable state into a disable state.

Description

Low-loss and fast-start power supply

The present invention relates to a power supply, and particularly relates to a low-loss and fast-start power supply.

In traditional power supplies, if the startup resistance of the feedback compensation circuit is too large, the startup speed will decrease, and if the startup resistance of the feedback compensation circuit is too small, there will be a problem of excessive startup loss. 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 provides a low-loss and fast-start power supply, including: a bridge rectifier that generates a rectified potential based on a first input potential and a second input potential; a first capacitor, Store the rectified potential; a transformer, including a main coil, a secondary coil, and an auxiliary coil, wherein the primary coil is used to receive the rectified potential, and the secondary coil is used to generate an induced potential; a power switch , According to a pulse width modulation potential to selectively couple the main coil to the ground; an output stage circuit to generate an output potential based on the induced potential; a feedback compensation circuit to generate an output potential based on the output potential Feedback potential, wherein the feedback compensation circuit includes an acceleration circuit, a first resistor, and a linear optical coupler, and the auxiliary coil is coupled to the linear optical coupling via the acceleration circuit and the first resistor And a pulse width modulation integrated circuit that generates the pulse width modulation potential according to the feedback potential; wherein the acceleration circuit is used to shorten an initialization time of the linear optical coupler, and when the linear optical When the coupler is fully activated, the acceleration circuit is switched from the enabled state to the disabled state.

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

Certain vocabulary is used to refer to specific elements in the specification and the scope of the patent application. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and the scope of the patent application do not use differences in names as a way to distinguish elements, but use differences in functions of elements as a criterion for distinguishing. The terms "including" and "including" mentioned in the entire specification and the scope of the patent application are open-ended terms and 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 "coupling" includes any direct and indirect electrical connection means in this specification. Therefore, if it is described in the text 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 invention. For example, the power supply 100 can be applied to a desktop computer, a notebook computer, or an integrated computer. As shown in Figure 1, the power supply 100 includes: a bridge rectifier 110, a first capacitor C1, a transformer 120, a power switch 130, an output stage circuit 140, a feedback compensation circuit 150, and a pulse Width modulation integrated circuit 160. It should be noted that although not shown in Figure 1, the power supply 100 may further include other components, such as a voltage regulator or (and) a negative feedback circuit.

The bridge rectifier 110 can generate a rectified potential VR according to a first input potential VIN1 and a second input potential VIN2. Both the first input potential VIN1 and the second input potential VIN2 can come from an external input power source, wherein an AC voltage having any frequency and any amplitude can be formed between the first input potential VIN1 and the second input potential VIN2. For example, the frequency of the AC voltage can be about 50Hz or 60Hz, and the root mean square value of the AC voltage can be 90V to 264V, but it is not limited to this. The first capacitor C1 can be used to receive and store the rectified potential VR. The transformer 120 includes a main coil 121, a secondary coil 122, and an auxiliary coil 123. The main coil 121 can be located on one side of the transformer 120, and the secondary coil 122 and the auxiliary coil 123 can be located on the opposite side of the transformer 120. The main coil 121 can be used to receive the rectified potential VR, and as a response to the rectified potential VR, the auxiliary coil 122 can be used to generate an induced potential VS. The power switch 130 can selectively couple the main coil 121 to the ground 190 according to a pulse width modulated potential VM. The earth 190 can refer to the earth or any ground path coupled to the earth, and it is not an internal component of the power supply 100. For example, if the pulse width modulation potential VM is at a high logic level, the power switch 130 will couple the main coil 121 to the ground 190 (that is, the power switch 130 can be approximated as a short-circuit path); otherwise, If the pulse width modulation potential VM is at a low logic level, the power switch 130 will not couple the main coil 121 to the ground 190 (that is, the power switch 130 can be approximated as an open path). The output stage circuit 140 can generate an output potential VOUT according to the induced potential VS. For example, the output potential VOUT may be approximately a DC potential, and its level may be about 19V, but it is not limited to this. The feedback compensation circuit 150 can generate a feedback potential VF according to the output potential VOUT. In detail, the feedback compensation circuit 150 at least includes an acceleration circuit 152, a first resistor R1, and a linear optocoupler 154, wherein the first resistor R1 can be regarded as a start resistor of the linear optocoupler 154. The auxiliary coil 123 is coupled to the linear optical coupler 154 via the acceleration circuit 152 and the first resistor R1 to provide power to the linear optical coupler 154. The pulse width modulation integrated circuit 160 can generate the pulse width modulation potential VM according to the feedback potential VF. Initially, the acceleration circuit 152 is in the enabled state, which can be used to shorten the initialization time of one of the linear optical couplers 154. Then, when the linear optical coupler 154 has been fully activated, the acceleration circuit 152 is switched from the enabled state to the disabled state to avoid negative effects on the operation of the first resistor R1. Under this design, even if the resistance value of the first resistor R1 is relatively large, the linear optocoupler 154 can still be fully activated within a relatively short initialization time, so the power supply 100 will be able to achieve both low loss and fast speed at the same time. Double advantages such as startup.

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 only examples, and are not used to limit the scope of the present invention.

FIG. 2 is a schematic diagram of the power supply 200 according to an embodiment of the invention. In the embodiment of Figure 2, the power supply 200 has a first input node NIN1, a second input node NIN2, and an output node NOUT, and includes: a bridge rectifier 210, a first capacitor C1, and a transformer 220, a power switch 230, an output stage circuit 240, a feedback compensation circuit 250, and a pulse width modulation integrated circuit 260. The first input node NIN1 and the second input node NIN2 of the power supply 200 can receive a first input potential VIN1 and a second input potential VIN2 from an external input power source, respectively, and the output node NOUT of the power supply 200 can be used for Output an output potential VOUT to an electronic device (not shown).

The bridge rectifier 210 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 is coupled to the first input node NIN1, and the cathode of the first diode D1 is coupled to a first node N1 to output a rectified potential VR. The anode of the second diode D2 is coupled to the second input node NIN2, and the cathode of the second diode D2 is coupled to the first node N1. The anode of the third diode D3 is coupled to the ground 290, and the cathode of the third diode D3 is coupled to the first input node NIN1. The anode of the fourth diode D4 is coupled to the ground 290, and the cathode of the fourth diode D4 is coupled to the second input node NIN2. The earth 290 can refer to the earth, or any ground path coupled to the earth, and it is not an internal component of the power supply 200.

The first terminal of the first capacitor C1 is coupled to the first node N1 to receive and store the rectified potential VR, and the second terminal of the first capacitor C1 is coupled to the ground 290.

The transformer 220 includes a main coil 221, a secondary coil 222, and an auxiliary coil 223. The main coil 221 can be located on one side of the transformer 220, and the secondary coil 222 and the auxiliary coil 223 can be located on the opposite side of the transformer 220. The first end of the main coil 221 is coupled to the first node N1 to receive the rectified potential VR, and the second end of the main coil 221 is coupled to a second node N2. The first terminal of the secondary coil 222 is coupled to a third node N3 to output an induced potential VS, and the second terminal of the secondary coil 222 is coupled to a ground potential VSS (for example, 0V). The first end of the auxiliary coil 223 is coupled to a fourth node N4 to output a supply potential VP, and the second end of the auxiliary coil 223 is coupled to the ground potential VSS.

The power switch 230 includes a first transistor M1. For example, the first transistor M1 can be an N-type MOSFET. The first 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 of the first transistor M1 The terminal receives a pulse width modulation potential VM from the pulse width modulation integrated circuit 260, the first terminal of the first transistor M1 is coupled to the ground 290, and the second terminal of the first transistor M1 is coupled Connect to the second node N2. The pulse width modulation potential VM can be used to adjust the duty cycle of the power switch 230. For example, if the pulse width modulation potential VM is at a high logic level, the first transistor M1 will be enabled; conversely, if the pulse width modulation potential VM is at a low logic level, the first transistor M1 will be Was banned.

The output stage circuit 240 includes a fifth diode D5 and a second capacitor C2. The anode of the fifth diode D5 is coupled to the third node N3 to receive the induced potential VS, and the cathode of the fifth diode D5 is coupled to the output node NOUT. The first end of the second capacitor C2 is coupled to the output node NOUT, and the second end of the second capacitor C2 is coupled to the ground potential VSS.

The feedback compensation circuit 250 includes at least an acceleration circuit 252, a first resistor R1, and a linear optocoupler 254. The acceleration circuit 252 includes a second transistor Q2, a second resistor R2, and a third capacitor. C3, a sixth diode D6, and a seventh diode D7. For example, the second transistor Q2 may be an NPN type two-carrier junction transistor Q2. The second transistor Q2 has a control terminal (e.g., a base), a first end (e.g., an emitter), and a second end (e.g., a collector), wherein the control of the second transistor Q2 The terminal is coupled to the output node NOUT to receive the output potential VOUT, the first terminal of the second transistor Q2 is coupled to a fifth node N5, and the second terminal of the second transistor Q2 is coupled to the fourth node N4 to receive the supply potential VP. For example, if the output potential VOUT is at a high logic level, the second transistor Q2 will be enabled; on the contrary, if the output potential VOUT is at a low logic level, the second transistor Q2 will be disabled. 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 sixth node N6. The first end of the second resistor R2 is coupled to the fifth node N5, and the second end of the second resistor R2 is coupled to a seventh node N7. The first end of the third capacitor C3 is coupled to the fifth node N5, and the second end of the third capacitor C3 is coupled to the seventh node N7. The anode of the sixth diode D6 is coupled to the fifth node N5, and the cathode of the sixth diode D6 is coupled to the output node NOUT. The anode of the seventh diode D7 is coupled to the seventh node N7, and the cathode of the seventh diode D7 is coupled to the sixth node N6.

In some embodiments, the linear optical coupler 254 is implemented by a PC817 electronic component. The linear optical coupler 254 includes a light emitting diode DL and a dual carrier junction transistor Q3. The light emitting diode DL has an anode and a cathode. The anode of the light emitting diode DL is coupled to the sixth node N6, and the cathode of the light emitting diode DL is coupled to an eighth node N8. The two-carrier junction transistor Q3 has a collector and an emitter. The collector of the two-carrier junction transistor Q3 is coupled to a ninth node N9 to output a feedback potential VF, and the two-carrier junction transistor Q3 The emitter of the junction transistor Q3 is coupled to the ground 290.

The feedback compensation circuit 250 may further include a fourth capacitor C4, a fifth capacitor C5, a third resistor R3, a fourth resistor R4, and a voltage regulator 256. The first end of the fourth capacitor C4 is coupled to the eighth node N8, and the second end of the fourth capacitor C4 is coupled to a tenth node N10. The first end of the fifth capacitor C5 is coupled to the ninth node N9, and the second end of the fifth capacitor C5 is coupled to the ground 290. The first end of the third resistor R3 is coupled to the output node NOUT, and the second end of the third resistor R3 is coupled to the tenth node N10. The first end of the fourth resistor R4 is coupled to the tenth node N10, and the second end of the fourth resistor R4 is coupled to the ground potential VSS.

In some embodiments, the voltage regulator 256 is implemented by a TL431 electronic component. The voltage stabilizer 256 has an anode, a cathode, and a reference terminal. The anode of the voltage stabilizer 256 is coupled to the ground potential VSS, the cathode of the voltage stabilizer 256 is coupled to the eighth node N8, and the voltage stabilizer 256 is coupled to the eighth node N8. The reference terminal of 256 is coupled to the tenth node N10.

The pulse width modulation integrated circuit 260 is coupled to the ninth node N9, and generates a pulse width modulation potential VM according to the feedback potential VF. For example, the pulse width modulation potential VM can be maintained at a fixed potential when the power supply 200 is initialized, and can provide a periodic clock waveform after the power supply 200 enters the normal use phase.

Fig. 3 shows a potential waveform diagram of the power supply 200 according to an embodiment of the present invention, in which the horizontal axis represents time, and the vertical axis represents the potential level of each signal. It must be noted that a potential difference between the first terminal and the second terminal of the third capacitor C3 is defined as a first potential difference VD1, and a potential difference between the first terminal and the second terminal of the first resistor R1 It is defined as a second potential difference VD2. Please also refer to Figures 2 and 3 to understand the operating principle of the present invention. The power supply 200 can operate in a first stage T1, a second stage T2, a third stage T3, and a fourth stage T4 in sequence. , And a fifth stage T5.

During the first stage T1, the power supply 200 has just received the first input potential VIN1 and the second input potential VIN2. At this time, the power switch 230 starts to perform the switching operation, and the linear optical coupler 254 has not been activated yet.

During the second stage T2, the output stage circuit 240 generates the output potential VOUT, and the auxiliary coil 223 of the transformer 220 outputs the supply potential VP with a high logic level to the acceleration circuit 252, so that the acceleration circuit 252 and its second transistor Q2 are enabled . At this time, the third capacitor C3 that does not store any charge can be regarded as an instant short circuit, so that one of the startup currents from the output node NOUT flows to the linear photocoupler 254 through the third capacitor C3 and the seventh diode D7 to emit light. Diode DL. Then, the third capacitor C3 will gradually be charged.

During the third stage T3, the third capacitor C3 has been fully charged, so it can be regarded as an open circuit. At this time, the startup current from the output node NOUT can flow to the light-emitting diode DL of the linear optical coupler 254 via the second resistor R2 and the seventh diode D7. In some embodiments, the length of the third stage T3 is approximately equal to a time constant, wherein the aforementioned time constant is approximately equal to the product of the resistance value of the second resistor R2 and the capacitance value of the third capacitor C3.

During the fourth stage T4, the third capacitor C3 can be gradually discharged through a first discharge path and a second discharge path. The first discharge path can be linear from the second resistor R2 through the seventh diode D7. The light-emitting diode DL of the optical coupler 254, and the second discharge path can be from the sixth diode D6 through the first resistor R1 to the light-emitting diode DL of the linear optical coupler 254. In some embodiments, the length of the fourth stage T4 is approximately equal to 4 times the aforementioned time constant.

During the fifth stage T5, when the linear optical coupler 254 has been fully activated, the acceleration circuit 252 is switched from the enabled state to the disabled state. At this time, although current still flows through the first resistor R1, no current flows through the acceleration circuit 252 anymore. Eventually, the second potential difference VD2 will increase and remain approximately at a fixed value VL.

In some embodiments, the component parameters of the power supply 200 may be as described below. The capacitance value of the first capacitor C1 may be between 108 μF and 132 μF, preferably 120 μF. The capacitance value of the second capacitor C2 may be between 612 μF and 748 μF, preferably 680 μF. The capacitance value of the third capacitor C3 may be between 297 nF and 363 nF, preferably 330 nF. The capacitance value of the fourth capacitor C4 may be between 1.43 nF and 1.58 nF, preferably 1.5 nF. The capacitance value of the fifth capacitor C5 may be between 90 pF and 110 pF, and preferably may be 100 pF. The resistance value of the first resistor R1 may be between 14.85KΩ and 15.15KΩ, and preferably may be 15KΩ. The resistance value of the second resistor R2 may be between 44.65Ω and 49.35Ω, preferably 47Ω. The resistance value of the third resistor R3 may be between 66.31KΩ and 73.29KΩ, preferably 69.8KΩ. The resistance value of the fourth resistor R4 may be between 9.69KΩ and 10.71KΩ, preferably 10.2KΩ. The ratio of the number of turns of the primary coil 221 to the secondary coil 222 can be between 1 and 100, and preferably can be 10. The ratio of the number of turns of the main coil 221 to the auxiliary coil 223 may be between 1 and 200, preferably 40. The high logic level of the supply potential VP may be about 5V. The final fixed value VL of the second potential difference VD2 may be between 15V and 18V, preferably about 16.8V. The length of the third stage T3 may be approximately equal to a time constant, which may be approximately the product of the resistance value of the second resistor R2 and the capacitance value of the third capacitor C3. The length of the fourth stage T4 can be approximately equal to 4 times the aforementioned time constant. After using the design of the present invention, the initialization time of the linear optocoupler 254 can be reduced to about 20ms (this value is about 300ms to 400ms in the traditional design), and the startup loss of the linear optocoupler 254 can be reduced to about 7mW ( This value is about 40mW to 50mW in traditional designs). The above parameter range is obtained based on the results of many experiments, which helps to minimize the overall loss and initialization time of the power supply 200.

The present invention proposes a novel power supply, which includes a feedback compensation circuit with an acceleration circuit and a linear optocoupler. According to the actual measurement results, using the power supply designed as described above can shorten the initialization time of the linear optocoupler by about 95%, and at the same time can reduce the startup loss of the linear optocoupler by about 80%, so it is very suitable for various applications. Type of device.

It is worth noting that the above-mentioned potential, current, resistance value, inductance value, capacitance value, and other component parameters are not limitations of the present invention. The designer can adjust these settings according to different needs. The power supply of the present invention is not limited to the state shown in Figures 1-3. The present invention may only include any one or more of the features of any one or more of the embodiments shown in FIGS. 1-3. In other words, not all the features shown in the figures need to be implemented in the power supply of the present invention at the same time.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., do not have a sequential relationship between each other, and they are only used to distinguish two having the same Different components of the name.

Although the present invention is disclosed as above in the preferred embodiment, it is not intended to limit the scope of the present invention. Anyone who is familiar with the 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 shall be subject to those defined by the attached patent scope.

100,200: power supply

110, 210: Bridge rectifier

120, 220: Transformer

121, 221: main coil

122,222: secondary coil

123,223: auxiliary coil

130, 230: power switch

140, 240: output stage circuit

150, 250: Feedback compensation circuit

152,252: acceleration circuit

154,254: Linear Optocoupler

160,260: Pulse width modulation integrated circuit

190,290: Earth

256: voltage regulator

C1: The first capacitor

C2: second capacitor

C3: third capacitor

C4: The fourth capacitor

C5: Fifth capacitor

D1: The first diode

D2: The second diode

D3: The third diode

D4: The fourth diode

D5: Fifth diode

D6: The sixth diode

D7: seventh diode

DL: Light-emitting diode

M1: The first transistor

N1: the first node

N2: second node

N3: third node

N4: Fourth node

N5: fifth node

N6: sixth node

N7: seventh node

N8: The eighth node

N9: Ninth node

N10: Tenth node

NIN1: the first input node

NIN2: second input node

NOUT: output node

Q2: The second transistor

Q3: Two-carrier junction transistor

R1: first resistor

R2: second resistor

R3: third resistor

R4: Fourth resistor

T1: first stage

T2: second stage

T3: The third stage

T4: Fourth stage

T5: fifth stage

VIN1: the first input potential

VIN2: second input potential

VD1: the first potential difference

VD2: second potential difference

VF: feedback potential

VL: fixed value

VM: Pulse width modulation potential

VOUT: output potential

VP: supply potential

VR: Rectified potential

VS: induced potential

VSS: Ground potential

Fig. 1 is a schematic diagram of a power supply according to an embodiment of the invention. FIG. 2 is a schematic diagram of the power supply according to an embodiment of the invention. Fig. 3 shows a potential waveform diagram of the power supply according to an embodiment of the present invention.

100: power supply

110: Bridge rectifier

120: Transformer

121: main coil

122: secondary coil

123: auxiliary coil

130: power switch

140: output stage circuit

150: Feedback compensation circuit

152: acceleration circuit

154: Linear Optocoupler

160: Pulse width modulation integrated circuit

190: The Earth

C1: The first capacitor

R1: first resistor

VIN1: the first input potential

VIN2: second input potential

VF: feedback potential

VM: Pulse width modulation potential

VOUT: output potential

VR: Rectified potential

VS: induced potential

Claims (10)

A low-loss and quick-start power supply includes: a bridge rectifier, which generates a rectified potential according to a first input potential and a second input potential; a first capacitor, which stores the rectified potential; and a transformer, including a The main coil, an auxiliary coil, and an auxiliary coil, wherein the main coil is used to receive the rectified potential, and the auxiliary coil is used to generate an induced potential; a power switch, which modulates the potential according to a pulse width The main coil is selectively coupled to the ground; an output stage circuit generates an output potential based on the induced potential; a feedback compensation circuit generates a feedback potential based on the output potential, wherein the feedback compensation circuit It includes an acceleration circuit, a first resistor, and a linear optical coupler, and the auxiliary coil is coupled to the linear optical coupler via the acceleration circuit and the first resistor; and a pulse width modulation integrated body The circuit generates the pulse width modulation potential according to the feedback potential; wherein the acceleration circuit is used to shorten an initialization time of the linear optical coupler, and when the linear optical coupler is fully activated, the acceleration circuit That is, switch from the enabled state to the disabled state; wherein the acceleration circuit includes: A second transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is coupled to an output node to receive the output potential, the second transistor The first terminal is coupled to a fifth node, and the second terminal of the second transistor is coupled to a fourth node to receive the supply potential; wherein the first resistor has a first terminal and A second terminal, the first terminal of the first resistor is coupled to the output node, and the second terminal of the first resistor is coupled to a sixth node. The power supply of claim 1, wherein the bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode of the first diode is coupled to a first input Node to receive the first input potential, and the cathode of the first diode is coupled to a first node to output the rectified potential; a second diode has an anode and a cathode, wherein the first diode The anode of the second diode is coupled to a second input node to receive the second input potential, and the cathode of the second diode is coupled to the first node; a third diode, Having an anode and a cathode, wherein the anode of the third diode is coupled to the ground, and the cathode of the third diode is coupled to the first input node; and a fourth diode A body having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground, and the cathode of the fourth diode is coupled to the second input node; The first capacitor has a first terminal and a second terminal, the first terminal of the first capacitor is coupled to the first node to receive the rectified potential, and the second terminal of the first capacitor is Coupled to the earth. The power supply of claim 2, wherein the main coil has a first end and a second end, the first end of the main coil is coupled to the first node to receive the rectified potential, and the main coil The second end of the coil is coupled to a second node, the auxiliary coil has a first end and a second end, and the first end of the auxiliary coil is coupled to a third node to output the induced potential , The second end of the auxiliary coil is coupled to a ground potential, the auxiliary coil has a first end and a second end, and the first end of the auxiliary coil is coupled to the fourth node to output a A potential is supplied, and the second end of the auxiliary coil is coupled to the ground potential. The power supply according to claim 3, wherein the power switch includes: a first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor For receiving the pulse width modulated potential, the first end of the first transistor is coupled to the ground, and the second end of the first transistor is coupled to the second node. The power supply of claim 3, wherein the output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the third node To receive the induced potential, and the cathode of the fifth diode is coupled to the output node to output the output potential; and A second capacitor having a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the output node, and the second terminal of the second capacitor is coupled to the ground Potential. The power supply of claim 5, wherein the acceleration circuit further includes: a second resistor having a first end and a second end, wherein the first end of the second resistor is coupled to The fifth node, and the second end of the second resistor is coupled to a seventh node; and a third capacitor having a first end and a second end, wherein the first end of the third capacitor One end is coupled to the fifth node, and the second end of the third capacitor is coupled to the seventh node. The power supply of claim 6, wherein the acceleration circuit further includes: a sixth diode having an anode and a cathode, wherein the anode of the sixth diode is coupled to the fifth node , And the cathode of the sixth diode is coupled to the output node; and a seventh diode having an anode and a cathode, wherein the anode of the seventh diode is coupled to the first Seven nodes, and the cathode of the seventh diode is coupled to the sixth node. The power supply according to claim 7, wherein the linear optical coupler includes a light-emitting diode and a bi-carrier junction transistor, the light-emitting diode has an anode and a cathode, and the light-emitting diode The anode is coupled to the sixth node, and the generator The cathode of the photodiode is coupled to an eighth node, the two-carrier junction transistor has a collector and an emitter, and the collector of the two-carrier junction transistor is coupled to a first Nine nodes are used to output the feedback potential, and the emitter of the bi-carrier junction transistor is coupled to the ground. The power supply of claim 8, wherein the feedback compensation circuit further includes: a fourth capacitor having a first terminal and a second terminal, wherein the first terminal of the fourth capacitor is coupled to The eighth node, and the second terminal of the fourth capacitor is coupled to a tenth node; a fifth capacitor having a first terminal and a second terminal, wherein the first terminal of the fifth capacitor Is coupled to the ninth node, and the second end of the fifth capacitor is coupled to the ground; a third resistor has a first end and a second end, wherein The first end is coupled to the output node, and the second end of the third resistor is coupled to the tenth node; a fourth resistor has a first end and a second end, wherein The first end of the fourth resistor is coupled to the tenth node, and the second end of the fourth resistor is coupled to the ground potential; and a voltage regulator having an anode and a cathode , And a reference terminal, wherein the anode of the regulator is coupled to the ground potential, the cathode of the regulator is coupled to the eighth node, and the reference terminal of the regulator is coupled To the tenth node. A low-loss and fast-start power supply, including: A bridge rectifier generates a rectified potential based on a first input potential and a second input potential; a first capacitor stores the rectified potential; a transformer includes a main coil, a secondary coil, and an auxiliary coil, wherein The main coil is used to receive the rectified potential, and the auxiliary coil is used to generate an induced potential; a power switcher selectively couples the main coil to the ground according to a pulse width modulated potential; The output stage circuit generates an output potential based on the induced potential; a feedback compensation circuit generates a feedback potential based on the output potential, wherein the feedback compensation circuit includes an acceleration circuit, a first resistor, and a wire Optical coupler, and the auxiliary coil is coupled to the linear optical coupler via the acceleration circuit and the first resistor; and a pulse width modulation integrated circuit that generates the pulse width modulation according to the feedback potential Variable potential; wherein the acceleration circuit is used to shorten the initialization time of one of the linear optocouplers, and when the linear optocoupler has been fully activated, the acceleration circuit is switched from the enabled state to the disabled state; wherein the The bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode of the first diode is coupled to a first input node to receive the first input potential, and the first The cathode of the diode is coupled to a first node to output the rectified potential; A second diode has an anode and a cathode, wherein the anode of the second diode is coupled to a second input node to receive the second input potential, and the second diode of the The cathode is coupled to the first node; a third diode has an anode and a cathode, wherein the anode of the third diode is coupled to the ground, and the third diode is The cathode is coupled to the first input node; and a fourth diode having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground, and the fourth diode The cathode is coupled to the second input node; wherein the first capacitor has a first terminal and a second terminal, and the first terminal of the first capacitor is coupled to the first node to receive the rectification Potential, and the second end of the first capacitor is coupled to the ground; wherein the main coil has a first end and a second end, and the first end of the main coil is coupled to the first node To receive the rectified potential, the second end of the main coil is coupled to a second node, the auxiliary coil has a first end and a second end, and the first end of the auxiliary coil is coupled to a The third node outputs the induced potential, the second end of the auxiliary coil is coupled to a ground potential, the auxiliary coil has a first end and a second end, and the first end of the auxiliary coil is coupled To a fourth node to output a supply potential, and the second end of the auxiliary coil is coupled to the ground potential; wherein the output stage circuit includes: A fifth diode has an anode and a cathode, wherein the anode of the fifth diode is coupled to the third node to receive the induced potential, and the cathode of the fifth diode is coupled Connected to an output node to output the output potential; and a second capacitor having a first terminal and a second terminal, wherein the first terminal of the second capacitor is coupled to the output node, and the second capacitor The second terminal of the capacitor is coupled to the ground potential; wherein the speed-up circuit includes: a second transistor having a control terminal, a first terminal, and a second terminal, wherein the second transistor The control terminal is coupled to the output node to receive the output potential, the first terminal of the second transistor is coupled to a fifth node, and the second terminal of the second transistor is coupled to the A fourth node to receive the supply potential; wherein the first resistor has a first end and a second end, the first end of the first resistor is coupled to the output node, and the first resistor The second end is coupled to a sixth node.

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