Power supply circuit and power supply device

Abstract

The utility model discloses a power supply circuit and power supply equipment, and belongs to the technical field of power supplies. The power supply circuit comprises a power supply input end, an input filter circuit, a booster circuit, a temperature control switch circuit, a flyback circuit, an output rectification circuit, a protocol circuit and a power supply output end, the flyback circuit comprises a primary starting circuit and a first control chip which are electrically connected, and the temperature control switch circuit is electrically connected with the input filter circuit and the primary starting circuit. The temperature control switch circuit can detect the temperature of the power supply circuit in real time, and can be switched on when the first control chip is started and switched off after the first control chip is started, so that the primary starting circuit is powered off, the power consumption of the power supply circuit can be reduced, the efficiency of the power supply circuit is improved, and the fault rate of the starting circuit can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of power supply technology, and in particular to a power supply circuit and power supply device. Background Technology

[0002] With the development of electrical technology, the requirements for equipment circuits are becoming increasingly stringent. Currently, in order to ensure that equipment requiring DC power can operate normally in various operating environments, power supply equipment is typically used to convert the supply voltage or supply current into the voltage or current required by the equipment. For example, power supply equipment can convert AC power (such as mains power) into DC power.

[0003] However, the power circuits in existing power supply devices are inefficient. Utility Model Content

[0004] This utility model provides a power supply circuit and a power supply device. It can solve the problem of low efficiency in existing power supply circuits. The technical solution is as follows:

[0005] According to one aspect of the present invention, a power supply circuit is provided, the power supply circuit comprising:

[0006] Power input terminal, input filter circuit, boost circuit, temperature control switch circuit, flyback circuit, output rectifier circuit, protocol circuit and power output terminal;

[0007] The power input terminal, the input filter circuit, the boost circuit, the flyback circuit, the output rectifier circuit, the protocol circuit, and the power output terminal are connected in sequence, and the protocol circuit is also electrically connected to the flyback circuit.

[0008] The flyback circuit includes a primary start-up circuit and a first control chip that are electrically connected, and the temperature control switch circuit is electrically connected to the input filter circuit and the primary start-up circuit respectively.

[0009] Optionally, the temperature control switch circuit includes a normally closed temperature control switch;

[0010] The input terminal of the normally closed temperature control switch is electrically connected to the input filter circuit, and the output terminal of the normally closed temperature control switch is electrically connected to the primary start-up circuit.

[0011] Optionally, the temperature control switch circuit includes a temperature sensor, a comparator, and a first switch;

[0012] The temperature sensor is electrically connected to the comparator;

[0013] The first switch has a control terminal, an input terminal, and an output terminal; the control terminal is electrically connected to the comparator, the input terminal is electrically connected to the input filter circuit, and the output terminal is electrically connected to the primary start-up circuit.

[0014] Optionally, the primary start-up circuit includes a first resistor and a second resistor, and the first control chip has a start-up pin;

[0015] The first resistor is electrically connected to both the temperature control switch and the second resistor.

[0016] The second resistor is also electrically connected to the start pin of the first control chip.

[0017] Optionally, the flyback circuit further includes a second switch and a transformer;

[0018] The second switch has a gate, a source, and a drain; the gate is electrically connected to the first control chip, the source is electrically connected to the first control chip and grounded, and the drain is electrically connected to the transformer;

[0019] The transformer is also electrically connected to the output rectifier circuit.

[0020] Optionally, the second switch includes a gallium nitride switch, and the turns ratio of the transformer ranges from 3 to 5.

[0021] Optionally, the flyback circuit further includes a filter bead L01; the two ends of the filter bead L01 are electrically connected to the second switch and the first control chip, respectively.

[0022] Optionally, the protocol circuit includes a feedback circuit and a protocol sampling circuit;

[0023] The feedback circuit is electrically connected to the first control chip and the protocol sampling circuit, respectively.

[0024] The protocol sampling circuit is also electrically connected to the output rectifier circuit and the power output terminal.

[0025] Optionally, the boost circuit includes a boost inductor, a third switch, and a second control chip;

[0026] The two ends of the boost inductor are electrically connected to the input filter circuit and the third switch, respectively;

[0027] The second control chip is electrically connected to the third switch and the first control chip, respectively.

[0028] According to another aspect of the present invention, a power supply device is provided, the power supply device including the power supply circuit described above.

[0029] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following:

[0030] This utility model provides a power supply circuit including a power input terminal, an input filter circuit, a boost circuit, a temperature control switch circuit, a flyback circuit, an output rectifier circuit, a protocol circuit, and a power output terminal. The flyback circuit includes a primary startup circuit and a first control chip electrically connected to each other. The temperature control switch circuit is electrically connected to both the input filter circuit and the primary startup circuit. The temperature control switch circuit can detect the temperature of the power supply circuit in real time and can be turned on when the first control chip starts up and turned off after the first control chip starts up, thus de-energizing the primary startup circuit. This reduces the power consumption of the power supply circuit, improves its efficiency, and reduces the failure rate of the startup circuit. It solves the problem of low efficiency in power supply circuits in related technologies. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the functional module connection of a power supply circuit according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the functional module connection of another power supply circuit provided by this utility model;

[0034] Figure 3 This is a schematic diagram of a power supply circuit provided in an embodiment of the present invention;

[0035] Figure 4 yes Figure 3 The schematic diagram shows the structure of the temperature control switch circuit and the flyback circuit in the power supply circuit shown.

[0036] Figure 5 yes Figure 3 The schematic diagram shows the protocol circuit and power output terminal in the power supply circuit shown.

[0037] Figure 6 yes Figure 3 A schematic diagram of the boost circuit in the power supply circuit shown.

[0038] Figure 7 yes Figure 3 The diagram shows the structure of the input filter circuit and the normally closed temperature control switch in the power supply circuit. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0040] Although the present invention can be readily embodied in various forms, only some specific embodiments are shown in the accompanying drawings and will be described in detail in this specification. It is understood that this specification should be regarded as an exemplary illustration of the principles of the present invention and is not intended to limit the present invention to what is described herein.

[0041] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the present invention, and does not imply that every embodiment of the present invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0042] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 This is a schematic diagram showing the functional module connection of a power supply circuit according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the functional module connection of another power supply circuit provided by this utility model. Figure 3 This is a schematic diagram of a power supply circuit provided in an embodiment of the present invention. Figure 4 yes Figure 3 The diagram shows the structure of the temperature control switch circuit 13 and the flyback circuit 14 in the power supply circuit. The power supply circuit may include: a power input terminal, an input filter circuit 11, a boost circuit 12, a temperature control switch circuit 13, a flyback circuit 14, an output rectifier circuit 15, a protocol circuit 16, and a power output terminal.

[0043] The power input terminal, input filter circuit 11, boost circuit 12, flyback circuit 14, output rectifier circuit 15, protocol circuit 16 and power output terminal are connected in sequence. The protocol circuit 16 is also connected to the flyback circuit 14.

[0044] The flyback circuit 14 includes a primary start-up circuit and a first control chip U3 that are electrically connected, and the temperature control switch circuit 13 is electrically connected to the input filter circuit 11 and the primary start-up circuit respectively.

[0045] For example, the power input terminal can be electrically connected to the input terminal of the input filter circuit 11. The filter circuit can have a first output terminal and a second output terminal. The first output terminal of the input filter circuit 11 is electrically connected to the input terminal of the boost circuit 12, and the second output terminal of the input filter circuit 11 is electrically connected to the input terminal of the temperature control switch circuit 13.

[0046] The flyback circuit 14 has an input terminal, a start terminal, a feedback terminal, and an output terminal. The input terminal of the flyback circuit 14 is electrically connected to the output terminal of the boost circuit 12. The start terminal of the flyback circuit 14 is electrically connected to the output terminal of the temperature control switch circuit 13. The feedback terminal of the flyback circuit 14 is electrically connected to the protocol circuit 16. The output terminal of the flyback circuit 14 is electrically connected to the input terminal of the output rectifier circuit.

[0047] The output terminal of the output rectifier circuit is electrically connected to the protocol circuit 16, and the protocol circuit 16 is also electrically connected to the power output terminal.

[0048] The start-up terminal of the flyback circuit 14 is located on the first control chip U3. The model of the first control chip U3 may include SC3021C. Pin 10 of the first control chip U3 can be the start-up pin. The temperature control switch circuit 13 can be electrically connected to the start-up pin of the first control chip U3 through a primary start-up circuit. This start-up pin can also be called the high-voltage start-up pin.

[0049] The flyback circuit 14 also includes a power supply circuit, which can be electrically connected to the output rectifier circuit 15 and the power supply pin of the first control chip U3, respectively. The power supply circuit is used to provide operating current for the first control chip U3. The input filter circuit 11 provides initial voltage to the first control chip U3 through the temperature control switch circuit 13 and the primary start-up circuit. For example, after the power supply circuit is powered on, the temperature control switch circuit 13 is in the conducting state. The AC power is rectified by the input filter circuit 11 to form DC power, which flows through the temperature control switch circuit 13 and the primary start-up circuit to provide the start-up voltage for the first control chip U3. After the first control chip U3 is started, the power supply circuit begins to work normally. The voltage generated by the power supply circuit replaces the primary start-up circuit to provide the operating voltage for the first control chip U3. Since the power supply circuit generates heat during normal operation, the overall temperature of the power supply circuit rises. In this case, under the influence of the increased ambient temperature, the temperature control switch circuit 13 switches from the conducting state to the off state, so that the primary start-up circuit is also in the off state. In this way, the temperature control switch circuit 13 can be turned on when the first control chip U3 starts and turned off after the first control chip U3 starts, which can reduce the power consumption of the power supply circuit, improve the efficiency of the power supply circuit, and also reduce the failure rate of the start-up circuit.

[0050] In one exemplary embodiment, the temperature control switch circuit 13 can detect the temperature of the power supply circuit in real time, that is, the temperature of the power supply device in which the power supply circuit is located. When the temperature control switch circuit 13 detects that the temperature of the power supply circuit is lower than the threshold temperature, it can be considered that the power supply circuit is in a non-working state, and the first control chip U3 is also in a non-starting state. At this time, the temperature control switch circuit 13 is in a conducting state, and the input filter circuit 11 and the first control chip U3 are also in a conducting state. The input filter circuit 11 can provide the starting voltage to the first control chip U3 through the temperature control switch circuit 13 and the first control chip U3. When the temperature control switch circuit 13 detects that the temperature of the power supply circuit is greater than or equal to the threshold temperature, it can be considered that the power supply circuit is in a normal working state. Since the temperature rise indicates that the power supply circuit is in a stable working state, the temperature control switch circuit 13 can switch from the conducting state to the off state, so that the power supply circuit is de-energized, which can save the power consumption of the power supply circuit.

[0051] For example, the threshold temperature range can be 50℃ to 60℃, such as 50℃, 52℃, 55℃, 58℃ or 60℃, and the threshold temperature can be a pre-set a priori value.

[0052] In summary, this utility model embodiment provides a power supply circuit including a power input terminal, an input filter circuit 11, a boost circuit 12, a temperature control switch circuit 13, a flyback circuit 14, an output rectifier circuit 15, a protocol circuit 16, and a power output terminal. The flyback circuit 14 includes a primary startup circuit and a first control chip U3 electrically connected to each other. The temperature control switch circuit 13 is electrically connected to both the input filter circuit 11 and the primary startup circuit. The temperature control switch circuit 13 can detect the temperature of the power supply circuit in real time and can be turned on when the first control chip U3 starts and turned off after the first control chip U3 starts, thus de-energizing the primary startup circuit. This reduces the power consumption of the power supply circuit, improves its efficiency, and reduces the failure rate of the startup circuit. It solves the problem of low efficiency in power supply circuits in related technologies.

[0053] In one alternative implementation, please refer to Figure 4The temperature control switch circuit 13 may include a normally closed temperature control switch K1. The input terminal of the normally closed temperature control switch K1 is electrically connected to the input filter circuit 11, and the output terminal of the normally closed temperature control switch K1 is electrically connected to the primary start-up circuit. The normally closed temperature control switch K1 (abbreviated as NC) operates by adjusting its on or off state based on changes in the ambient temperature. When the temperature is below the set threshold temperature, the normally closed temperature control switch K1 is in the closed state, allowing current to flow. When the temperature is above the set threshold temperature, physical deformation occurs inside the normally closed temperature control switch K1 (such as the bimetallic strip springing open), causing the normally closed temperature control switch K1 to open, thereby cutting off the circuit. When the temperature drops below the set threshold temperature again, the normally closed temperature control switch K1 will return to the closed state, allowing current to flow again.

[0054] The normally closed temperature control switch K1 is highly sensitive to temperature changes and can quickly respond to and cut off or connect the circuit. In addition, the normally closed temperature control switch K1 has high reliability and durability and can maintain stable working performance during long-term use.

[0055] In one optional embodiment, the temperature control switch circuit 13 may include a temperature sensor, a comparator, and a first switch; the temperature sensor is electrically connected to the comparator; the first switch has a control terminal, an input terminal, and an output terminal; the control terminal is electrically connected to the comparator, the input terminal is electrically connected to the input filter circuit 11, and the output terminal is electrically connected to the primary start-up circuit. The temperature sensor may include a negative temperature coefficient thermistor (NTC thermistor). The resistance of an NTC thermistor decreases as the temperature increases, and NTC thermistors have a faster response and higher accuracy. The positive input terminal of the comparator is electrically connected to the output terminal of the temperature sensor, while the negative input terminal is connected to a preset temperature threshold or reference voltage. When the temperature detected by the temperature sensor exceeds the temperature threshold, the sampling signal voltage will be higher than the reference voltage, and the comparator can output a high-level signal; conversely, when the temperature detected by the temperature sensor is lower than the temperature threshold, the sampling signal voltage will be lower than the reference voltage, and the comparator can output a low-level signal. The first switch receives the output signal from the comparator and adjusts its off or on state according to the high or low level of the signal. The first switch may include a metal-oxide-semiconductor field-effect transistor (MOSFET), the control terminal may be the gate of the first switch, and the input terminal and output terminal may be the source and drain of the first switch, respectively.

[0056] Please refer to Figure 4In one optional embodiment, the initial startup circuit may include a first resistor R26 and a second resistor R27. The first control chip U3 has a startup pin 10. The first resistor R26 is electrically connected to both the temperature control switch and the second resistor R27. The second resistor R27 is also electrically connected to the startup pin 10 of the first control chip U3. The first resistor R26 and the second resistor R27 can serve as current limiters.

[0057] Optionally, the flyback circuit 14 may further include a second switch Q3 and a transformer T1A; the second switch Q3 has a gate, a source, and a drain; the gate is electrically connected to the first control chip U3, the source is electrically connected to the first control chip U3 and grounded, and the drain is electrically connected to the transformer T1A; the transformer T1A is also electrically connected to the output rectifier circuit. The second switch Q3 includes a gallium nitride switch, and the turns ratio of the transformer T1A is in the range of 3 to 5. For example, the turns ratio of the transformer T1A is 3, 4, or 5.

[0058] During the operation of the power supply circuit, the AC input AC power is first converted from pulsating AC power to stable high-voltage DC power by the input filter circuit 11. The flyback circuit 14 is powered and starts to work. The first control chip U3 controls the second switch Q3 to switch on and off. When the gallium nitride chip is turned on, the transformer T1A stores energy. Utilizing the principles of electromagnetic induction and mutual inductance, when the second switch Q3 is turned off, the transformer T1A provides energy to the output rectifier circuit 15.

[0059] For example, pin 4 of the first control chip U3 samples the voltage from the auxiliary winding T1B of the transformer via resistors R34, R36, and capacitor C18, and then controls the second switch Q3Q3 to turn on and off via pin 7. In this embodiment, because the transformer T1A has a relatively small number of turns, the secondary reflected voltage can be reduced. Simultaneously, using a gallium nitride switch as the second switch Q3 allows its breakdown voltage to reach 900V, preventing it from being damaged by the reflected voltage. Compared to power supply circuits in related technologies, this design eliminates the need for an RCD snubber circuit while ensuring circuit safety, thus reducing the size of the power supply circuit while improving its efficiency.

[0060] Please refer to Figure 4 In an optional embodiment, the flyback circuit 14 may further include a filter bead L01; the two ends of the filter bead L01 are electrically connected to the second switch Q3 and the first control chip U3, respectively. The filter bead L01 can be used to suppress high-frequency interference from the second switch Q3, thereby reducing the inductive interference that may be caused by the closer proximity of components due to the compression of the product size and the increase in frequency due to the improvement of device performance, thus playing an effective role in resisting electromagnetic interference and better meeting the requirements of conducted radiation.

[0061] Please refer to Figure 5 , Figure 5 yes Figure 3 The schematic diagram of the protocol circuit and power output terminal in the power supply circuit shown illustrates, in one optional embodiment, the protocol circuit may include a feedback circuit and a protocol sampling circuit. The feedback circuit is electrically connected to the first control chip U3 and the protocol sampling circuit, respectively. The protocol sampling circuit is also electrically connected to the output rectifier circuit 15 and the power output terminal. The feedback circuit may include an optocoupler U5, and the protocol sampling circuit may include a sampling control chip U4. The voltage and current detection information in the sampling control chip U4, together with the internally integrated reference voltage and current detection thresholds, forms a detection loop, and feedback information is sent to the first control chip U3 via the optocoupler U5.

[0062] Please refer to Figure 6 , Figure 6 yes Figure 3 The schematic diagram of the boost circuit in the power supply circuit shown shows that, in an optional embodiment, the boost circuit 12 may include a boost inductor L2, a third switch Q1, and a second control chip U1; the two ends of the boost inductor L2 are electrically connected to the input filter circuit 11 and the third switch Q1, respectively; the second control chip U1 is electrically connected to the third switch Q1 and the first control chip U3, respectively.

[0063] Please refer to Figures 3 to 7 , Figure 7 Figure 3 The schematic diagram of the input filter circuit and normally closed temperature control switch K1 in the power supply circuit shown illustrates, in one exemplary embodiment, the working principle of the power supply circuit in this utility model embodiment is as follows:

[0064] After the AC power is input from the power input terminal, it flows through the protection circuit formed by fuse F1 and thermistor NTC, and then reaches the input filter circuit. After EMI filtering by safety capacitor CX1 and inductor LF1, it is rectified into DC by bridge rectifier circuit BD1. The DC then passes through the π-type filter circuit composed of capacitor C12, inductor L4 and capacitor C9 to make the rectified DC smooth.

[0065] The DC power then reaches the boost circuit PFC, passes through the boost inductor L2, and is boosted to approximately 390V by the second control chip U1 via the third switch Q1. At 390V, the voltage is calibrated by the first pin of the second control chip U1, and a voltage divider consisting of resistors R1, R7, and R11 connected in series with resistors R15, R22, and capacitor C8 provides the detection signal to U1. Resistors R6, R9, R14, R10, and R20, along with capacitors C6 and C7, provide a current feedback signal to the second pin of the second control chip U1 to limit the output current of the boost circuit. Pin 3 of the second control chip U1 is the power supply pin, which only starts working upon receiving an electrical signal. Pin 4 is GND, and pin 5 is the drive Q1 signal pin, consisting of diode D4, resistors R23 and R21, capacitor C4, and resistor R18. Pin 6 is the reference compensation pin. The boosted voltage is stored and filtered by capacitors EC4, EC5, and EC6.

[0066] The first control chip U3 is the main control IC of the flyback circuit. The 8-pin W1 of the first control chip U3 is the chip power supply pin. The voltage rectified by diode D6 flows through resistor R32 for current limiting, and then goes to capacitor EC7 and capacitor C17 to store energy and filter it to provide voltage and current for the operation of the first control chip U3. The 10-pin of the first control chip U3 is the high-voltage power supply pin, which can be electrically connected to the primary start-up circuit. Specifically, the current drawn from AC by diodes D7 and D8 is rectified and then passes through normally closed temperature control switch K1 and current limiting resistors (resistors R26 and R27) to start the first control chip U3. When the normally closed temperature control switch K1 detects that the temperature of the power supply circuit is 55°C, it changes from the on state to the off state, and at the same time, it can discharge capacitor CX1. In this way, the primary start-up circuit does not consume energy when the power supply circuit is working normally, which can improve the efficiency of the power supply circuit. When the first control chip U3 is working, pin 4 of the first control chip U3 can sample the voltage from the auxiliary winding T1B of transformer T1 through resistor R34, resistor R36 and capacitor C18, and then control the second switch Q3 to turn on or off through pin 7 of the first control chip U3.

[0067] The output rectifier circuit uses the third control chip U2 to detect and control the fourth switch Q2 for rectification. Capacitors EC1, EC2, and EC3 filter and store energy before releasing it. The protocol circuit is a crucial part of the fast charging protocol handshake. It uses the sampling control chip U4's CC1, CC2, D+, and D- to transmit protocol handshake signals with the terminal, controlling the opening and closing of switch Q4. The sampling control chip U4 feeds back the detection signal to the first control chip U3 via optical signal. The first control chip U3 uses the feedback signal to adjust the switch's operating mode and duty cycle, thereby controlling the output power.

[0068] In summary, this utility model embodiment provides a power supply circuit including a power input terminal, an input filter circuit 11, a boost circuit 12, a temperature control switch circuit 13, a flyback circuit 14, an output rectifier circuit 15, a protocol circuit 16, and a power output terminal. The flyback circuit 14 includes a primary startup circuit and a first control chip U3 electrically connected to each other. The temperature control switch circuit 13 is electrically connected to both the input filter circuit 11 and the primary startup circuit. The temperature control switch circuit 13 can detect the temperature of the power supply circuit in real time and can be turned on when the first control chip U3 starts and turned off after the first control chip U3 starts, thus de-energizing the primary startup circuit. This reduces the power consumption of the power supply circuit, improves its efficiency, and reduces the failure rate of the startup circuit. It solves the problem of low efficiency in power supply circuits in related technologies.

[0069] This utility model embodiment also provides a power supply device, which includes the power circuit of any of the above embodiments. The power supply device can perform handshake communication and transmit signals based on a fast charging protocol; at the same time, the power output terminal is a Type-C interface, i.e., a USB Type-C interface. It can charge mobile phones, tablets, and laptops. For example, the power supply device in this utility model embodiment can be a 100W high-power power supply device, which can be applied to fields such as industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instruments and meters, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, liquid crystal displays, LED lamps, communication equipment, audio-visual products, security monitoring, LED light strips, computer cases, digital products, and instruments.

[0070] In this invention, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0071] In the several embodiments provided by this utility model, it should be understood that the disclosed apparatus and method can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0072] The above description is only an optional embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A power supply circuit, characterized in that, include: Power input terminal, input filter circuit, boost circuit, temperature control switch circuit, flyback circuit, output rectifier circuit, protocol circuit and power output terminal; The power input terminal, the input filter circuit, the boost circuit, the flyback circuit, the output rectifier circuit, the protocol circuit, and the power output terminal are connected in sequence, and the protocol circuit is also electrically connected to the flyback circuit. The flyback circuit includes a primary start-up circuit and a first control chip that are electrically connected, and the temperature control switch circuit is electrically connected to the input filter circuit and the primary start-up circuit respectively.

2. The power supply circuit according to claim 1, characterized in that, The temperature control switch circuit includes a normally closed temperature control switch. The input terminal of the normally closed temperature control switch is electrically connected to the input filter circuit, and the output terminal of the normally closed temperature control switch is electrically connected to the primary start-up circuit.

3. The power supply circuit according to claim 1, characterized in that, The temperature control switch circuit includes a temperature sensor, a comparator, and a first switch; The temperature sensor is electrically connected to the comparator; The first switch has a control terminal, an input terminal, and an output terminal; the control terminal is electrically connected to the comparator, the input terminal is electrically connected to the input filter circuit, and the output terminal is electrically connected to the primary start-up circuit.

4. The power supply circuit according to claim 1, characterized in that, The primary start-up circuit includes a first resistor and a second resistor, and the first control chip has a start-up pin. The first resistor is electrically connected to both the temperature control switch and the second resistor. The second resistor is also electrically connected to the start pin of the first control chip.

5. The power supply circuit according to claim 1, characterized in that, The flyback circuit also includes a second switch and a transformer; The second switch has a gate, a source, and a drain; the gate is electrically connected to the first control chip, the source is electrically connected to the first control chip and grounded, and the drain is electrically connected to the transformer; The transformer is also electrically connected to the output rectifier circuit.

6. The power supply circuit according to claim 5, characterized in that, The second switch includes a gallium nitride switch, and the turns ratio of the transformer is in the range of 3 to 5.

7. The power supply circuit according to claim 5, characterized in that, The flyback circuit also includes a filter bead; the two ends of the filter bead are electrically connected to the second switch and the first control chip, respectively.

8. The power supply circuit according to any one of claims 1 to 7, characterized in that, The protocol circuit includes a feedback circuit and a protocol sampling circuit; The feedback circuit is electrically connected to the first control chip and the protocol sampling circuit, respectively. The protocol sampling circuit is also electrically connected to the output rectifier circuit and the power output terminal.

9. The power supply circuit according to any one of claims 1 to 7, characterized in that, The boost circuit includes a boost inductor, a third switch, and a second control chip; The two ends of the boost inductor are electrically connected to the input filter circuit and the third switch, respectively; The second control chip is electrically connected to the third switch and the first control chip, respectively.

10. A power supply device, characterized in that, The power supply circuit includes any one of claims 1 to 9.

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