Auxiliary power supply circuit

Abstract

The invention discloses an auxiliary power supply circuit which comprises a control circuit and a flyback circuit. The control circuit is used for controlling a mains supply loop to be conducted after receiving a power supply signal and when the first input end of the flyback circuit is connected to the mains supply, so that the flyback circuit generates an output voltage according to the mains supply; the control module is also used for controlling the battery loop to be switched on after receiving the power supply signal and when the second input end of the flyback circuit is connected to the battery, so that the flyback circuit generates an output voltage according to the voltage of the battery; the flyback circuit is also used for generating an output voltage according to the voltage of the battery when the mains supply loop and the battery loop are conducted and the connection between the first input end of the flyback circuit and the mains supply is cut off; and the control circuit is also used for generating an output voltage according to the voltage of the mains supply when the mains supply loop and the battery loop are both conducted and the connection between the second input end of the flyback circuit and the battery is cut off, or when the mains supply loop and the battery loop are both conducted. The auxiliary power supply circuit can stably output voltage in different states.

Description

Technical Field

[0001] The present invention relates to the technical field of switching power supplies, and in particular to an auxiliary power supply circuit. Background Art

[0002] In the whole system of auxiliary power circuit, auxiliary power circuit is an important part. Common auxiliary power circuit converts DC battery voltage into low voltage such as 3.3V, 5V, 12V, or converts AC mains into low voltage such as 3.3V, 5V, 12V, but now the auxiliary power circuit is required to have stable output under different conditions, so the application of auxiliary power circuit of a single system has limitations, and the combination of multiple circuits in parallel will increase the cost and the printed circuit board (PCB) occupies too much space, which does not meet the current market demand for miniaturization and high cost performance. Summary of the invention

[0003] The present invention provides an auxiliary power supply circuit, which can stably output an output voltage in different states, effectively reducing costs and shrinking space.

[0004] According to one aspect of the present invention, there is provided an auxiliary power supply circuit, comprising: a control circuit and a flyback circuit;

[0005] The first input end of the flyback circuit is connected to the mains, and the second input end of the flyback circuit is connected to the battery;

[0006] The output end of the control circuit is connected to the control end of the flyback circuit, and the control circuit is used to control the mains power circuit to be turned on after receiving the power signal and when the first input end of the flyback circuit is connected to the mains power, so that the flyback circuit generates at least one output voltage according to the mains power;

[0007] The control circuit is further used to control the battery circuit to be turned on after receiving the power signal and when the second input terminal of the flyback circuit is connected to the battery, so that the flyback circuit generates at least one output voltage according to the voltage of the battery;

[0008] The flyback circuit is also used to generate at least one output voltage according to the voltage of the battery when the mains circuit and the battery circuit are both turned on and the connection between the first input end of the flyback circuit and the mains is cut off;

[0009] The flyback circuit is also used to generate at least one output voltage according to the voltage of the mains when both the mains circuit and the battery circuit are turned on and the connection between the second input end of the flyback circuit and the battery is cut off, or when both the mains circuit and the battery circuit are turned on.

[0010] Optionally, the flyback circuit includes: a first unidirectional conductive device, a second unidirectional conductive device, a third unidirectional conductive device, a fourth unidirectional conductive device, a first control switch, a first transformer and a first rectifier module; the output end of the control circuit includes a first output end;

[0011] The input end of the first rectifier module is connected to the mains power, the output end of the first rectifier module is connected to the input end of the first unidirectional conductive device, and the output end of the first unidirectional conductive device is connected to the first input end of the first transformer;

[0012] The positive terminal of the battery is connected to the input terminal of the second unidirectional conductive device, and the output terminal of the second unidirectional conductive device is connected to the second input terminal of the first transformer;

[0013] The third input terminal of the first voltage generator is connected to the first terminal of the first control switch, the second terminal of the first control switch is connected to the input terminal of the third unidirectional conductive device and the input terminal of the fourth unidirectional conductive device respectively, and the control terminal of the first control switch is connected to the first output terminal of the control circuit;

[0014] The output end of the third unidirectional conductive device is connected to the negative terminal of the battery, and the output end of the fourth unidirectional conductive device is connected to the first ground terminal;

[0015] Wherein, a coil is connected between the first input terminal and the second input terminal of the first transformer, and a coil is connected between the second input terminal and the third input terminal of the first transformer;

[0016] The first transformer includes an output terminal corresponding to the output voltage, and the output terminal of the first transformer is used to output the corresponding output voltage.

[0017] Optionally, the auxiliary power supply circuit further includes: a power factor correction circuit;

[0018] The power factor correction circuit is used to generate a first stable voltage according to the mains power;

[0019] The first input end of the flyback circuit is also used to connect to the first stable voltage, and the control circuit is also used to control the conduction of the AC power circuit after receiving the power signal and when the first input end of the flyback circuit is connected to the first stable voltage, so that the flyback circuit generates at least one output voltage according to the first stable voltage; wherein, at the same time, the first input end of the flyback circuit is only connected to one of the first stable voltage and the AC power.

[0020] Optionally, the flyback circuit further includes a switching switch; the input end of the first rectifier module includes a first input end and a second input end;

[0021] The first end of the switching switch is connected to the first output end of the mains, the second end of the switching switch is connected to the first input end of the first rectifier module, the second input end of the first rectifier module is connected to the second output end of the mains, and the third end of the switching switch is floating;

[0022] The fourth end of the switch is used to access the first stable voltage, the fifth end of the switch is floating, and the sixth end of the switch is connected to the input end of the first unidirectional conductive device;

[0023] The control end of the switching switch is used to control the first end and the second end of the switching switch to be connected, and to control the fourth end and the fifth end to be connected when receiving a first control signal, and is also used to control the first end and the third end of the switching switch to be connected, and the fourth end and the sixth end to be connected when receiving a second control signal; wherein the first control signal is one of a power-off signal and a power-on signal, and the second control signal is the other of the power-off signal and the power-on signal.

[0024] Optionally, the power factor correction circuit is used to generate a second stable voltage according to the mains power, the second stable voltage having the same voltage value and opposite polarity as the first stable voltage; the output end of the control circuit also includes a second output end;

[0025] The flyback circuit further includes a fifth unidirectional conductive device and a second control switch;

[0026] The input end of the fifth unidirectional conductive device is connected to the first ground end, the output end of the fifth unidirectional conductive device is connected to the fourth input end of the first transformer, the fifth input end of the first transformer is connected to the first end of the second control switch, the control end of the second control switch is connected to the second output end of the control circuit, and the second end of the second control switch is used to access the second stable voltage; a coil is connected between the fourth input end and the fifth input end of the first transformer;

[0027] The control circuit is also used to control the AC power circuit and the auxiliary circuit where the second control switch is located to be turned on when the power supply signal is received and the power factor correction circuit outputs the second stable voltage, so that the flyback circuit is used to generate at least one output voltage based on the first stable voltage and the second stable voltage.

[0028] Optionally, the control circuit includes: a control module and a second transformer;

[0029] The power supply end of the control module is used to receive the power supply signal, the output end of the control module is connected to the input end of the second transformer, the first output end of the second transformer is connected to the control end of the first control switch, the second output end of the second transformer is connected to the second end of the first control switch, and a coil is connected between the first output end and the second output end of the second transformer;

[0030] The third output end of the second transformer is connected to the control end of the second control switch, the fourth output end of the second transformer is connected to the second end of the second control switch, and a coil is connected between the third output end and the fourth output end of the second transformer.

[0031] Optionally, the control circuit further includes a current acquisition module;

[0032] The current acquisition module is connected to the second end of the first control switch, the second end of the second control switch and the feedback end of the control module respectively, and the current acquisition module is used to collect the current in the mains circuit, the battery circuit and the auxiliary circuit;

[0033] The control module is used for adjusting a duty cycle of a signal output to the second transformer according to the current.

[0034] Optionally, the current acquisition module includes a third transformer, a first resistor and a second resistor;

[0035] The first input end of the third transformer is electrically connected to the second end of the first control switch, the second input end of the third transformer is respectively connected to the input ends of the third unidirectional conductive device and the fourth unidirectional conductive device, and a coil is connected between the first input end and the second input end of the third transformer;

[0036] The third input end of the third transformer is connected to the second end of the second control switch, the fourth input end of the third transformer is used to access the second stable voltage, and a coil is connected between the third input end and the fourth input end of the third transformer;

[0037] The first output end of the third transformer is connected to the first ends of the first resistor and the second resistor respectively, the second output end of the third transformer is connected to the second end of the first resistor, and the second end of the first resistor is connected to the third ground end;

[0038] The second end of the second resistor is connected to the feedback end of the control module.

[0039] Optionally, the power factor correction circuit includes: a third control switch, an inductor, a second rectifier module, a sixth unidirectional conductive device, a seventh unidirectional conductive device, a first capacitor, a second capacitor and a transistor;

[0040] The first output end of the AC power is connected to the first end of the third control switch, the second end of the third control switch is connected to the first end of the inductor, the second end of the inductor is connected to the input end of the sixth unidirectional conductive device, and the output end of the sixth unidirectional conductive device is used to output a first stable voltage;

[0041] The first end of the first capacitor is connected to the output end of the sixth unidirectional conductive device, the second end of the first capacitor is connected to the first ground end, the first end of the second capacitor is connected to the second end of the first capacitor, and the second end of the second capacitor is used to output a second stable voltage;

[0042] The input end of the seventh unidirectional conductive device is connected to the second end of the second capacitor, and the output end of the seventh unidirectional conductive device is connected to the input end of the sixth unidirectional conductive device;

[0043] The first input end of the second rectifier module is connected to the second end of the inductor, the second input end of the second rectifier module is connected to the first ground end, the first output end of the second rectifier module is connected to the first end of the transistor, and the second output end of the second rectifier module is connected to the second end of the transistor.

[0044] Optionally, the auxiliary power supply circuit further includes: a power supply circuit, the power supply circuit includes: a key switch, a third resistor and a fourth resistor; the power supply signal includes a battery power supply signal and a mains power supply signal;

[0045] The first end of the third resistor is connected to the positive terminal of the battery, the second end of the third resistor is connected to the first end of the key switch, and the second end of the key switch is connected to the power supply end of the control circuit;

[0046] A first end of the fourth resistor is connected to the input end of the first unidirectional conductive device, and a second end of the fourth resistor is connected to the power supply end of the control circuit;

[0047] The power supply circuit is used to generate the battery power supply signal when the key switch is closed and the battery voltage is connected, and is also used to generate the mains power supply signal when the mains power is connected.

[0048] The technical solution of the embodiment of the present invention is that when only the battery is powered, the flyback circuit is used to generate at least one output voltage according to the battery voltage, or, when only the mains power is powered, the flyback circuit is used to generate at least one output voltage according to the mains power, or, when the mains power and the battery are powered at the same time and the mains power is suddenly cut off, the flyback circuit can still be powered by the battery, so that the flyback circuit generates at least one output voltage according to the battery voltage, and when the mains power and the battery are powered at the same time and the battery power is cut off, the flyback circuit can still be powered by the mains power, so that the flyback circuit generates at least one output voltage according to the mains power. The auxiliary power supply circuit provided by the present invention can meet the output of output voltages under various working conditions, can be applied to different systems, and has a certain promotion effect.

[0049] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0051] Figure 1 A schematic diagram of the structure of an auxiliary power supply circuit provided by an embodiment of the present invention;

[0052] Figure 2 A schematic diagram of the structure of another auxiliary power supply circuit provided by an embodiment of the present invention;

[0053] Figure 3 A schematic diagram of the structure of another auxiliary power supply circuit provided by an embodiment of the present invention;

[0054] Figure 4 A schematic diagram of the structure of a power factor correction circuit provided by an embodiment of the present invention;

[0055] Figure 5 A schematic diagram of the structure of another auxiliary power supply circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0058] Figure 1 A schematic diagram of the structure of an auxiliary power supply circuit provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the auxiliary power supply circuit includes: a control circuit 1 and a flyback circuit 2;

[0059] The first input terminal of the flyback circuit 2 is connected to the mains, and the second input terminal of the flyback circuit 2 is connected to the battery;

[0060] The output end of the control circuit 1 is connected to the control end of the flyback circuit 2. The control circuit 1 is used to control the mains circuit to be turned on after receiving the power signal and when the first input end of the flyback circuit 2 is connected to the mains, so that the flyback circuit 2 generates at least one output voltage according to the mains;

[0061] The control circuit 1 is also used to control the battery circuit to be turned on after receiving the power signal and when the second input terminal of the flyback circuit 2 is connected to the battery, so that the flyback circuit 2 generates at least one output voltage according to the voltage of the battery;

[0062] The flyback circuit 2 is also used to generate at least one output voltage according to the voltage of the battery when both the mains circuit and the battery circuit are turned on and the connection between the first input terminal of the flyback circuit 2 and the mains is cut off;

[0063] The flyback circuit 2 is also used to generate at least one output voltage according to the voltage of the mains when both the mains circuit and the battery circuit are turned on and the connection between the second input terminal of the flyback circuit 2 and the battery is cut off, or when both the mains circuit and the battery circuit are turned on.

[0064] The first input end of the flyback circuit 2 may include two input ends, one for connecting to the live wire INPUT-L in the mains, and the other for connecting to the neutral wire INPUT-N in the mains. The second input end of the flyback circuit 2 may include two input ends, one for connecting to the positive terminal BAT+ of the battery, and the other for connecting to the negative terminal BAT- of the battery. The power signal may be a power voltage generated according to the voltage of the mains or the battery. When the control circuit 1 receives the power signal, it indicates that the control circuit 1 is powered on. After the control circuit 1 is powered on, it can output a control signal such as a conduction signal to the control end of the flyback circuit 2.

[0065] The auxiliary power supply circuit in this embodiment can generate and output the output voltage under at least four working conditions, which are as follows:

[0066] The first working condition: the flyback circuit 2 is connected to the battery and there is no mains access. After the control circuit 1 receives the power signal, it outputs a conduction signal to the control end of the flyback circuit 2 to conduct the battery circuit. After the battery circuit is conducted, the flyback circuit 2 generates and outputs at least one output voltage according to the voltage of the battery. After the battery circuit is conducted, the positive terminal BAT+ and the negative terminal BAT- of the battery are connected. Exemplarily, the flyback circuit 2 includes a transformer, the battery circuit is located on the primary side of the transformer, and the flyback circuit 2 includes at least one output terminal, and different output terminals are used to output different output voltages. After the battery circuit is conducted, at least one coil on the secondary side of the transformer generates at least one output voltage according to the voltage of the battery on the primary side through coupling.

[0067] The second working condition: the flyback circuit 2 is connected to the mains and not to the battery. After the control circuit 1 receives the power signal, it outputs a conduction signal to the control end of the flyback circuit 2 to conduct the mains circuit. After the mains circuit is conducted, the flyback circuit 2 generates and outputs at least one output voltage according to the mains. After the mains circuit is conducted, the live wire INPUT-L and the neutral wire INPUT-N of the mains are connected. After the mains circuit is conducted, at least one coil on the secondary side of the transformer generates at least one output voltage according to the voltage of the mains on the primary side through coupling.

[0068] The third working condition: the flyback circuit 2 is connected to both the mains and the battery. After the control circuit 1 receives the power signal, it outputs a conduction signal to the control end of the flyback circuit 2 to conduct the mains circuit and the battery circuit at the same time. Because the voltage of the mains is greater than the voltage of the battery, when both the mains circuit and the battery circuit are turned on, the flyback circuit 2 finally generates and outputs at least one output voltage according to the mains. Then, if the mains is no longer output, there is no mains input in the mains circuit, the battery circuit is normally turned on, and the flyback circuit 2 generates and outputs at least one output voltage according to the battery voltage.

[0069] Fourth working condition: the flyback circuit 2 is connected to both the mains and the battery. After the control circuit 1 receives the power signal, it outputs a conduction signal to the control end of the flyback circuit 2 to simultaneously conduct the mains circuit and the battery circuit. When the battery no longer outputs voltage, that is, the connection between the battery and the flyback circuit 2 is disconnected, only the mains circuit is turned on, and the flyback circuit 2 generates and outputs at least one output voltage according to the voltage of the mains. Because in the prior art, the flyback circuit 2 is generally powered by the voltage of the battery, so that the flyback circuit 2 generates an output voltage according to the voltage of the battery. In actual applications, after the battery is fully charged, the charger needs to be turned off for a period of time to allow the battery to self-discharge to a certain extent, thereby improving the life and stability of the battery. If the charger is turned off and the battery is allowed to self-discharge, the connection between the battery and the flyback circuit 2 is disconnected, resulting in the auxiliary power supply circuit being unable to output the output voltage during the battery self-discharge stage, resulting in system power supply interruption. In this embodiment, during the battery self-discharge stage, the mains can be used to continue to provide power so that the flyback circuit 2 can stably output the output voltage to ensure uninterrupted power supply.

[0070] The technical solution of the embodiment of the present invention is that when only the battery is powered, the flyback circuit is used to generate at least one output voltage according to the battery voltage, or, when only the mains power is powered, the flyback circuit is used to generate at least one output voltage according to the mains power, or, when the mains power and the battery are powered at the same time and the mains power is suddenly cut off, the flyback circuit can still be powered by the battery, so that the flyback circuit generates at least one output voltage according to the battery voltage, and when the mains power and the battery are powered at the same time and the battery power is cut off, the flyback circuit can still be powered by the mains power, so that the flyback circuit generates at least one output voltage according to the mains power. The auxiliary power supply circuit provided by the present invention can meet the output of output voltages under various working conditions, can be applied to different systems, and has a certain promotion effect.

[0071] Figure 2 A schematic diagram of another auxiliary power supply circuit provided in an embodiment of the present invention, referring to Figure 2 Optionally, the flyback circuit 2 includes: a first unidirectional conductive device D1, a second unidirectional conductive device D2, a third unidirectional conductive device D3, a fourth unidirectional conductive device D4, a first control switch Q1, a first transformer T1 and a first rectifier module 21; the output end of the control circuit 1 includes a first output end;

[0072] The input end of the first rectifier module 21 is connected to the mains, the output end of the first rectifier module 21 is connected to the input end A2 of the first unidirectional conductive device D1, and the output end of the first unidirectional conductive device D1 is connected to the first input end of the first transformer T1;

[0073] The positive terminal BAT+ of the battery is connected to the input terminal of the second unidirectional conductive device D2, and the output terminal of the second unidirectional conductive device D2 is connected to the second input terminal of the first transformer T1;

[0074] The third input terminal of the first voltage device T1 is connected to the first terminal of the first control switch Q1, the second terminal of the first control switch Q1 is connected to the input terminal of the third unidirectional conductive device D3 and the input terminal of the fourth unidirectional conductive device D4 respectively, and the control terminal of the first control switch Q1 is connected to the first output terminal of the control circuit 1;

[0075] The output end of the third unidirectional conductive device D3 is connected to the negative terminal BAT- of the battery, and the output end of the fourth unidirectional conductive device D4 is connected to the first ground terminal GND0;

[0076] Wherein, a coil is connected between the first input terminal and the second input terminal of the first transformer T1, and a coil is connected between the second input terminal and the third input terminal of the first transformer T1;

[0077] The first transformer T1 includes an output terminal corresponding to the output voltage, and the output terminal of the first transformer T1 is used to output the corresponding output voltage.

[0078] In this embodiment and in the following description, each unidirectional conducting device is a diode, which will not be described in detail later. In this embodiment, the input terminal A2 of the first unidirectional conducting device D1 can be used as the first input terminal of the flyback circuit 2, that is, the first input terminal of the flyback circuit 2 is indirectly connected to the mains through the first rectifier module 21, and the first input terminal of the flyback circuit 2 can be the rectified voltage after the mains is rectified. The first rectifier module 21 can be a bridge rectifier circuit, including four diodes. For specific connection relationship, refer to Figure 2As shown, no further details are given here. The input end of the first rectifier module 21 includes two ports, one port is connected to the live wire INPUT-L of the mains, and the other port is connected to the neutral wire INPUT-N of the mains. The mains output is an alternating current that is rectified by the first rectifier module 21 and output to the first unidirectional conductive device D1 through the eighth unidirectional conductive device D8. Among them, the flyback circuit 2 also includes a third capacitor C3, the input end A2 of the first unidirectional single-pass device D1 is connected to the first end of the third capacitor C3, the second end of the third capacitor C3 is connected to the third ground terminal GND2, and the voltage output by the eighth unidirectional conductive device D8 is filtered by the third capacitor C3. The first transformer T1 includes a primary side and a secondary side, the primary side can be understood as a power supply side, the secondary side can be understood as an output side, and the primary side and the secondary side each include at least one coil, and the voltage of the primary side is coupled to the secondary side through the coupling between the coils. A coil is connected between the first input terminal and the second input terminal of the first transformer T1, which is recorded as the first coil N1, and a coil is connected between the second input terminal and the third input terminal of the first transformer T1, which is recorded as the second coil N2. The flyback circuit 2 also includes a ninth unidirectional conductive device D9, a tenth unidirectional conductive device D10, an eleventh unidirectional conductive device D11, a twelfth unidirectional conductive device D12, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a seventh capacitor C7. The input terminal of the ninth unidirectional conductive device D9 is connected to the first output terminal of the first transformer T1, the output terminal of the ninth unidirectional conductive device D9 is used to output the first output voltage VCC1, the second output terminal of the first transformer T1 is connected to the fourth ground terminal GND3, the third coil N3 is connected between the first output terminal and the second output terminal of the first transformer T1, and the fourth capacitor C4 is connected between the output terminal of the ninth unidirectional conductive device D9 and the second output terminal of the first transformer T1 to filter the first output voltage VCC1. The input terminal of the tenth unidirectional conducting device D10 is connected to the third output terminal of the first transformer T1, the output terminal of the tenth unidirectional conducting device D10 is used to output the second output voltage VCC2, the fourth output terminal of the first transformer T1 is connected to the third ground terminal GND2, the fourth coil N4 is connected between the third output terminal and the fourth output terminal of the first transformer T1, and the fifth capacitor C5 is connected between the output terminal of the tenth unidirectional conducting device D10 and the fourth output terminal of the first transformer T1 to filter the second output voltage VCC2. The input terminal of the eleventh unidirectional conducting device D11 is connected to the fifth output terminal of the first transformer T1, the output terminal of the eleventh unidirectional conducting device D11 is used to output the third output voltage VDD, the sixth output terminal of the first transformer T1 is connected to the second ground terminal GND1, the fifth coil N5 is connected between the fifth output terminal and the sixth output terminal of the first transformer T1, and the sixth capacitor C6 is connected between the output terminal of the eleventh unidirectional conducting device D11 and the sixth output terminal of the first transformer T1 to filter the third output voltage VDD.The seventh output terminal of the first transformer T1 is connected to the output terminal of the twelfth unidirectional conduction device D12, and the input terminal of the twelfth unidirectional conduction device D12 is used to output the fourth output voltage -VDD. The sixth coil N6 is connected between the sixth output terminal and the seventh output terminal of the first transformer T1, and the seventh capacitor C7 is connected between the input terminal of the twelfth unidirectional conduction device D12 and the sixth output terminal of the first transformer T1 to filter the fourth output voltage -VDD, wherein the third output voltage VDD and the fourth output voltage -VDD have the same voltage value and opposite polarity. Exemplarily, the first output voltage VCC1 is 3.3V, the second output voltage VCC2 is 5V, the third output voltage VDD is 12V, and the fourth output voltage VDD is -12V. In this embodiment, it is exemplified that the flyback circuit 2 can output four output voltages to power different devices, such as the first output voltage VCC1 can power the control circuit 1. In other embodiments, the flyback circuit 2 can also output other output voltages, which is not specifically limited in this embodiment. In this embodiment, it is exemplified that the first control switch Q1 is an NMOS tube.

[0079] After the control circuit 1 is powered on, a control signal is sent to the first control switch Q1 to control the first control switch Q1 to be turned on. A mains circuit is formed between the first unidirectional conductive device D1, the first coil N1, the second coil N2, the first control switch Q1 and the fourth unidirectional conductive device D4. When the flyback circuit 2 is only connected to the mains, the loop between the live wire INPUT-L of the mains, the first rectifier module 21, the eighth unidirectional conductive device D8, the first unidirectional conductive device D1, the first coil N1, the second coil N2, the first control switch Q1 and the fourth unidirectional conductive device D4 is turned on, and current flows between the first coil N1 and the second coil N2, thereby causing the four coils on the secondary side of the first transformer T1 to generate the above-mentioned four output voltages according to the coupling effect. The second unidirectional conductive device D2, the second coil N2, the first control switch Q1, and the third unidirectional conductive device D3 form a battery circuit. When the flyback circuit 2 is only connected to the battery, the loop between the positive terminal BAT+ of the battery, the second unidirectional conductive device D2, the second coil N2, the first control switch Q1, the third unidirectional conductive device D3 and the negative terminal BAT- of the battery is turned on, and current flows through the second coil N2, thereby causing the four coils on the secondary side of the first transformer T1 to generate the above-mentioned four output voltages according to the coupling effect.

[0080] When the flyback circuit 2 is connected to the mains and the battery at the same time, and the mains circuit and the battery circuit are both turned on, the secondary side of the first transformer T1 generates four output voltages according to the voltage of the mains. When the mains is no longer output, the current on the first coil N1 gradually disappears, and finally the first transformer T1 generates the above four output voltages according to the voltage of the battery. Alternatively, when the battery voltage is no longer output, the mains still exists, so that the current still exists in the first coil N1 and the second coil N2, and the first transformer T1 generates the above four output voltages according to the voltage of the mains.

[0081] Figure 3 A schematic diagram of another auxiliary power supply circuit provided in an embodiment of the present invention, based on the above embodiment, Figure 3 , Optionally, the auxiliary power supply circuit further includes: a power factor correction circuit;

[0082] The power factor correction circuit is used to generate a first stable voltage +BUS according to the mains power;

[0083] The first input terminal of the flyback circuit 2 is also used to connect to the first stable voltage +BUS, and the control circuit 1 is also used to control the mains circuit to be turned on after receiving the power signal and when the first input terminal of the flyback circuit 2 is connected to the first stable voltage +BUS, so that the flyback circuit 2 generates at least one output voltage according to the first stable voltage +BUS; wherein, at the same time, the first input terminal of the flyback circuit 2 is only connected to one of the first stable voltage +BUS and the mains.

[0084] Under the condition that the mains is connected to the auxiliary power supply circuit, the mains can generate at least one output voltage through the first rectifier module 21 and then through the first transformer T1. However, due to the fluctuation of the mains, the output voltage generated by the flyback circuit 2 according to the mains will be unstable, which will cause the entire system where the auxiliary power supply circuit is located to operate abnormally. Therefore, under the premise that the mains has established an auxiliary power supply, the power factor correction circuit is controlled to generate and output the first stable voltage +BUS, and the first input end of the flyback circuit 2 is controlled to switch from connecting to the mains to connecting to the first stable voltage +BUS, and a path is formed between the first stable voltage +BUS, the first unidirectional conductive device D1, the first coil N1, the second coil N2, the first control switch Q1, the fourth unidirectional conductive device D4, and the first ground terminal GND0, so that the flyback circuit 2 generates a stable output voltage according to the first stable voltage +BUS. Among them, the first input end of the flyback circuit 2 can be connected to the mains or the first stable voltage +BUS through the selection switch.

[0085] Figure 4 A schematic diagram of a power factor correction circuit according to an embodiment of the present invention is provided. Figure 4The power factor correction circuit includes: a third control switch Q3, an inductor L1, a second rectifier module 22, a sixth unidirectional conductive device D6, a seventh unidirectional conductive device D7, a first capacitor C1, a second capacitor C2 and a transistor Q4;

[0086] The first output end of the AC power is connected to the first end of the third control switch Q3, the second end of the third control switch Q3 is connected to the first end of the inductor L1, the second end of the inductor L1 is connected to the input end of the sixth unidirectional conductive device D6, and the output end of the sixth unidirectional conductive device D6 is used to output a first stable voltage +BUS;

[0087] A first end of the first capacitor C1 is connected to the output end of the sixth unidirectional conductive device D6, a second end of the first capacitor C1 is connected to the first ground terminal GND0, a first end of the second capacitor C2 is connected to the second end of the first capacitor C1, and a second end of the second capacitor C2 is used to output a second stable voltage -BUS;

[0088] An input end of the seventh unidirectional conducting device D7 is connected to the second end of the second capacitor C2, and an output end of the seventh unidirectional conducting device D7 is connected to an input end of the sixth unidirectional conducting device D6;

[0089] The first input end of the second rectifier module 22 is connected to the second end of the inductor L1, the second input end of the second rectifier module 22 is connected to the first ground end GND0, the first output end of the second rectifier module 22 is connected to the first end of the transistor Q4, the second output end of the second rectifier module 22 is connected to the second end of the transistor Q4, and the control end of the transistor is connected to the pulse output end MCU-PWM of the control circuit.

[0090] The first output end of the mains is connected to the first end of the third control switch Q3, that is, the live wire INPUT-L of the mains is connected to the first end of the third control switch Q3. The mains is rectified by the second rectifier module 22 and filtered by the first capacitor C1 and the second capacitor C2 to generate a stable first stable voltage +BUS and a second stable voltage -BUS. Among them, the control end of the third control switch Q3 can also be connected to the control circuit 1, and is turned on or off by the control of the control circuit 1. For example, the control circuit 1 is set to control the third control switch Q3 to be closed within a set time after the flyback circuit 2 generates at least one output voltage according to the mains, so that the power factor correction circuit generates the first stable voltage +BUS and the second stable voltage -BUS, and at the same time controls the first input end of the flyback circuit to switch from connecting to the mains to connecting to the first stable voltage +BUS. When there is a mains input, the control circuit 1 detects that the mains is connected, and outputs a pulse signal to the control end of the transistor Q4 through the pulse output end MCU-PWM to control the transistor Q4 to be turned on or off, and the size of the output first stable voltage +BUS is adjusted by the duty cycle of the pulse signal. The neutral line INPUT-N of the mains power is connected to the first ground terminal GND0.

[0091] Continue to refer Figure 3 Optionally, the flyback circuit 2 further includes a switch 23; the input end of the first rectifier module 21 includes a first input end and a second input end;

[0092] The first end I1 of the switch 23 is connected to the first output end of the mains, that is, connected to the live wire INPUT-L of the mains, the second end I2 of the switch 23 is connected to the first input end of the first rectifier module 21, the second input end of the first rectifier module 21 is connected to the second output end of the mains, that is, the neutral wire INPUT-N, and the third end I3 of the switch 23 is floating;

[0093] The fourth terminal I4 of the switch 23 is used to access the first stable voltage +BUS, the fifth terminal I5 of the switch 23 is floating, and the sixth terminal I6 of the switch 23 is connected to the input terminal A2 of the first unidirectional conducting device D1;

[0094] The control end SPSRLY of the switching switch 23 is used to control the first end I1 and the second end I2 of the switching switch 23 to be connected, and to control the fourth end I4 and the fifth end I5 to be connected when a first control signal is received, and is also used to control the first end I1 and the third end I3 and the fourth end I4 and the sixth end I6 of the switching switch 23 to be connected when a second control signal is received; wherein the first control signal is one of the power-off signal and the power-on signal, and the second control signal is the other of the power-off signal and the power-on signal.

[0095] In this embodiment, the flyback circuit 2 also includes a thirteenth unidirectional conductive device D13 connected between the sixth terminal I6 of the switching switch 23 and the input terminal A2 of the first unidirectional conductive device D1. Optionally, the switching switch 23 is a relay, the relay includes a relay coil 231 and a first group of contacts, the first group of contacts includes the first terminal I1 to the sixth terminal I6 of the switching switch 23, the first end of the relay coil 231 is used as the control terminal SPSRLY of the switching switch 23, and the second end of the relay coil 231 is connected to the second ground terminal GND1. Among them, the first control signal can be a power-off signal such as a low level, and the second control signal is a power-on signal such as a high level. When the potential received by the control terminal SPSRLY of the switching switch 23 is a low level, the first terminal I1 and the second terminal I2 are connected, the third terminal I3 is floating, and the fourth terminal I4 and the fifth terminal I5 are connected, so that the mains power is connected to the first rectifier module 21 for rectification and then output to the first unidirectional conductive device D1, so that the first transformer T1 of the flyback circuit 2 couples the voltage after the mains power is rectified to the secondary side to generate at least one output voltage. When the potential received by the control terminal SPSRLY of the switching switch 23 is a high level, the first terminal I1 and the third terminal I3 are connected, thereby disconnecting the mains power supply from the first rectifier module 21, and the fourth terminal I4 and the sixth terminal I6 are connected, and the first stable voltage +BUS is output to the input terminal A2 of the first unidirectional conducting device D1, so that the first transformer T1 of the flyback circuit 2 couples the first stable voltage +BUS to the secondary side to generate at least one output voltage. Optionally, the third control switch Q3 in the power factor correction circuit can be the second set of contacts of the switching switch 23, which acts simultaneously with the first set of contacts and is closed when the control terminal SPSRLY of the switching switch 23 receives a high level.

[0096] Continue to refer Figure 3 , Optionally, the power factor correction circuit is used to generate a second stable voltage -BUS according to the mains, the second stable voltage -BUS has the same voltage value as the first stable voltage +BUS and has an opposite polarity; the output end of the control circuit 1 also includes a second output end;

[0097] The flyback circuit 2 further includes a fifth unidirectional conducting device D5 and a second control switch Q2;

[0098] The input end of the fifth unidirectional conductive device D5 is connected to the first ground end GND0, the output end of the fifth unidirectional conductive device D5 is connected to the fourth input end of the first transformer T1, the fifth input end of the first transformer T1 is connected to the first end of the second control switch Q2, the control end of the second control switch Q2 is connected to the second output end of the control circuit 1, and the second end of the second control switch Q2 is used to access the second stable voltage -BUS; a coil is connected between the fourth input end and the fifth input end of the first transformer T1, which is recorded as the seventh coil N7;

[0099] The control circuit 1 is also used to control the mains circuit and the auxiliary circuit where the second control switch Q2 is located to be turned on when a power signal is received and the power factor correction circuit outputs a second stable voltage -BUS, so that the flyback circuit 2 is used to generate at least one output voltage according to the first stable voltage +BUS and the second stable voltage -BUS.

[0100] The second control switch Q2 can be an NMOS tube. After the control circuit 1 is powered on, the first control switch Q1 and the second control switch Q2 are controlled to be turned on. When the control terminal SPSRLY of the switching switch 23 does not receive a high level, the AC power is rectified and input into the first coil N1 and the second coil N2, so that the secondary side of the first transformer T1 generates at least one output voltage according to the AC power. Within the set time after the flyback circuit 2 is activated, the control circuit 1 sends a high level to the control terminal SPSRLY of the switching switch 23, on the one hand, so that the power factor correction circuit generates and outputs the first stable voltage +BUS and the second stable voltage -BUS, and on the other hand, so that the flyback circuit 2 switches the AC power to the first stable voltage +BUS and inputs it into the first transformer T1. A path is formed between the first stable voltage +BUS, the first unidirectional conductive device D1, the first coil N1, the second coil N2, the first control switch Q1, the fourth unidirectional conductive device D4 and the first ground terminal GND0, and at the same time, an auxiliary loop formed by the first ground terminal GND0, the fifth unidirectional conductive device D5, the seventh coil N7, the second control switch Q2 and the second stable voltage -BUS forms a path, thereby enabling the first transformer T1 to generate at least one output voltage on the secondary side according to the first stable voltage +BUS and the second stable voltage -BUS.

[0101] Figure 5 A schematic diagram of another auxiliary power supply circuit provided in an embodiment of the present invention, referring to Figure 5 , based on the above embodiments, optionally, the control circuit 1 includes: a control module 11 and a second transformer T2;

[0102] The power supply terminal A1 of the control module 11 is used to receive a power supply signal. The output terminal of the control module 11 is connected to the input terminal of the second transformer T2. The first output terminal of the second transformer T2 is connected to the control terminal of the first control switch Q1. The second output terminal of the second transformer T2 is connected to the second terminal of the first control switch Q1. A coil is connected between the first output terminal and the second output terminal of the second transformer T2, which is recorded as the eighth coil N8.

[0103] The third output terminal of the second transformer T2 is connected to the control terminal of the second control switch Q2, the fourth output terminal of the second transformer T2 is connected to the second terminal of the second control switch Q2, and a coil is connected between the third output terminal and the fourth output terminal of the second transformer T2, which is recorded as the ninth coil N9.

[0104] The primary side of the second transformer T2 includes a tenth coil N10, and both ends of the tenth coil N10 are connected to the output end of the control module 11 as the input end of the second transformer. After the power supply end A1 of the control module 11 receives the power supply signal, the control module 11 is powered on and outputs a voltage to the tenth coil N10. The secondary side of the second transformer T2 includes an eighth coil N8 and a ninth coil N9. The eighth coil N8 generates and outputs a voltage according to the voltage on the tenth coil N10 through coupling to control the first control switch Q1 to be turned on or off. The ninth coil N9 generates and outputs a voltage according to the voltage on the tenth coil N10 through coupling to control the second control switch Q2 to be turned on or off.

[0105] Continue to refer Figure 3 , Optionally, the control circuit 1 further includes a current acquisition module 12;

[0106] The current acquisition module 12 is respectively connected to the second end of the first control switch Q1, the second end of the second control switch Q2 and the feedback end IS of the control module 11, and the current acquisition module 12 is used to collect currents in the mains circuit, the battery circuit and the auxiliary circuit;

[0107] The control module 11 is used to adjust the duty cycle of the signal output to the second transformer T2 according to the current in the mains circuit, the battery circuit and the auxiliary circuit.

[0108] The current acquisition module 12 is used to collect the current flowing through the first control switch Q1 and the second control switch Q2 in the flyback circuit 2 when the flyback circuit 2 is working, so that the control module 11 adjusts the duty cycle of the voltage output by the control module 11 according to the collected current, thereby adjusting the voltage on the primary side of the first transformer T1, and finally adjusting the output voltage generated on the secondary side of the first transformer T1, forming feedback regulation, so that the output voltage value is more accurate.

[0109] Furthermore, the current acquisition module 12 includes a third transformer T3, a first resistor R1 and a second resistor R2;

[0110] A first input terminal of the third transformer T3 is electrically connected to the second terminal of the first control switch Q1, a second input terminal of the third transformer T3 is respectively connected to the input terminals of the third unidirectional conducting device D3 and the fourth unidirectional conducting device D4, and a coil is connected between the first input terminal and the second input terminal of the third transformer T3, which is recorded as the eleventh coil N11;

[0111] The third input terminal of the third transformer T3 is connected to the second terminal of the second control switch Q2. The fourth input terminal of the third transformer T3 is used to access the second stable voltage -BUS. A coil is connected between the third input terminal and the fourth input terminal of the third transformer T3, which is recorded as the twelfth coil N12.

[0112] The first output end of the third transformer T3 is connected to the first ends of the first resistor R1 and the second resistor R2 respectively, the second output end of the third transformer T3 is connected to the second end of the first resistor R1, and the second end of the first resistor R1 is connected to the third ground terminal GND2;

[0113] The second end of the second resistor R2 is connected to the feedback end IS of the control module 11 .

[0114] The first output terminal and the second output terminal of the third transformer T3 are connected to the thirteenth coil N13, and the current collected at the secondary side is coupled to the primary side through the coupling effect between the coils, and the current is converted into a voltage through the first resistor R1 and the second resistor R2 and transmitted to the feedback terminal IS of the control module 11, so that the control module 11 adjusts the duty cycle of the voltage output by the control module 11 according to the voltage value of the feedback terminal IS.

[0115] Continue to refer Figure 5 Optionally, the auxiliary power supply circuit further includes: a power supply circuit 3, the power supply circuit 3 includes: a key switch SW1, a third resistor R3 and a fourth resistor R4; the power supply signal includes a battery power supply signal and a mains power supply signal;

[0116] A first end of the third resistor R3 is connected to the positive terminal BAT+ of the battery, a second end of the third resistor R3 is connected to a first end of the key switch SW1, and a second end of the key switch SW1 is connected to a power supply end of the control circuit 1, that is, a power supply end A1 of the control module 11;

[0117] A first end of the fourth resistor R4 is connected to the input end A2 of the first unidirectional conductive device D1, and a second end of the fourth resistor R4 is connected to the power supply end of the control circuit 1;

[0118] The power supply circuit 3 is used to generate a battery power supply signal when the key switch SW1 is closed and the battery voltage is connected, and is also used to generate a mains power supply signal when the mains is connected. When the auxiliary power supply circuit also includes a power factor correction circuit, the power supply circuit 3 is also used to generate a stabilized voltage power supply signal when the flyback circuit 2 is connected to the first stable voltage +BUS.

[0119] When the auxiliary power supply circuit is connected to the battery, the control key switch SW1 is closed, and the battery voltage is stepped down by the resistor R3 and then output to the power supply end of the control circuit 1 through the fourteenth unidirectional conductive device D14 to activate the control circuit 1. When the auxiliary power supply circuit is connected to the mains, when either the mains or the first stable voltage is connected to the input end A2 of the first unidirectional conductive device D1, the voltage at the input end A2 of the first unidirectional conductive device D1 is stepped down by the fourth resistor R4 and then output to the power supply end of the control circuit 1 through the fifteenth unidirectional conductive device D15 to activate the control circuit 1. In addition, at least one output voltage generated and output by the flyback circuit 2, such as the first output voltage VCC1, can also be stepped down by the fifth resistor R5 and then output to the power supply end of the control circuit 1 through the sixteenth unidirectional conductive device D16.

[0120] The auxiliary power supply circuit in this embodiment can be applied to various working conditions:

[0121] The first working condition: starting with a battery: the control button switch SW1 is closed, the third resistor R3 and the fourteenth unidirectional conductive device D14 are connected, and the battery voltage is provided to the power supply terminal A1 of the control module 11, and the control module 11 will work and emit a PWM wave, thereby controlling the first control switch tube Q1 to work, so that the flyback circuit 2 works and generates a first output voltage VCC1, a second output voltage VCC2, a third output voltage VDD and a fourth output voltage -VDD.

[0122] Second working condition: Start under the condition of AC power: Connect to the AC power, the AC power will generate a DC voltage after passing through the first rectifier module 21 and output to the input terminal A2 of the first unidirectional conductive device D1, and the DC voltage will be output to the power supply terminal A1 of the control module 11 through the fourth resistor R4 and the fifteenth unidirectional conductive device D15, and the control module 11 will work, send out a PWM wave, and then control the first control switch Q1 to work, further make the flyback circuit 2 work, and generate the above four output voltages. Due to the fluctuation of the AC power, this will cause the generated output voltage to be unstable, and then cause the entire system to operate abnormally. Therefore, under the premise that the AC power has established an auxiliary power supply, the power factor correction circuit is controlled to generate a first stable voltage +BUS and a second stable voltage -BUS, the control end SPSRLY of the switching switch 23 is controlled to be a high level, the first contact group is actuated, the first end I1 and the third end I3 of the switching switch 23 are connected, and the fourth end I4 and the sixth end I6 are connected, that is, the AC power input is disconnected, the first stable voltage +BUS is connected, the first control switch Q1 and the second control switch Q2 are in operation, and a stable output voltage can be generated by the first stable voltage +BUS and the second stable voltage -BUS.

[0123] The third working condition: in the AC power mode, disconnect the AC power: due to the lack of AC power input, the first stable voltage +BUS and the second stable voltage -BUS will continue to drop. When the first stable voltage +BUS is lower than the battery voltage, the battery voltage will provide input to the auxiliary power supply circuit, so that the first transformer T1 can continue to work normally and generate output voltage.

[0124] The fifth working condition: in battery mode, connected to the mains: at this time, the power factor correction circuit will work to generate a stable first stable voltage +BUS and a second stable voltage -BUS, and control the control terminal SPSRLY of the switching switch 23 to be high level, the first contact group is actuated, the first terminal I1 and the third terminal I3 of the switching switch 23 are connected, and the fourth terminal I4 and the sixth terminal I6 are connected, that is, the mains input is disconnected, the first stable voltage +BUS is connected, the first control switch Q1 and the second control switch Q2 are working, and a stable output voltage can be generated by the first stable voltage +BUS and the second stable voltage -BUS.

[0125] Fourth working condition: the flyback circuit 2 is connected to both the mains and the battery, and after the control module 11 receives the power signal, the first control switch Q1 is controlled to be turned on, so as to simultaneously turn on the mains circuit and the battery circuit. When the battery no longer outputs voltage, that is, the connection between the battery and the input end of the second unidirectional conducting device D2 is disconnected, only the mains circuit is turned on, and the flyback circuit 2 generates and outputs at least one output voltage according to the voltage of the mains.

[0126] This design has taken many aspects into consideration from the application environment of the auxiliary power supply circuit, and can meet the normal use under different conditions. The circuit can be applied to different systems, and has a certain promotion effect, which is in line with the future development trend of the product.

[0127] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0128] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An auxiliary power supply circuit, characterized in that: include: Control circuit and flyback circuit; The first input end of the flyback circuit is connected to the mains, and the second input end of the flyback circuit is connected to the battery; The output end of the control circuit is connected to the control end of the flyback circuit, and the control circuit is used to control the mains circuit to be turned on after receiving a power signal and when the first input end of the flyback circuit is connected to the mains, so that the flyback circuit generates at least one output voltage according to the mains; The control circuit is further used to control the battery circuit to be turned on after receiving the power signal and when the second input terminal of the flyback circuit is connected to the battery, so that the flyback circuit generates at least one output voltage according to the voltage of the battery; The flyback circuit is also used to generate at least one output voltage according to the voltage of the battery when the mains circuit and the battery circuit are both turned on and the connection between the first input end of the flyback circuit and the mains is cut off; The flyback circuit is also used to generate at least one output voltage according to the voltage of the mains when both the mains circuit and the battery circuit are turned on and the connection between the second input terminal of the flyback circuit and the battery is cut off, or when both the mains circuit and the battery circuit are turned on.

2. The auxiliary power supply circuit according to claim 1, characterized in that: The flyback circuit comprises: a first unidirectional conductive device, a second unidirectional conductive device, a third unidirectional conductive device, a fourth unidirectional conductive device, a first control switch, a first transformer and a first rectifier module; the output end of the control circuit comprises a first output end; The input end of the first rectifier module is connected to the mains power, the output end of the first rectifier module is connected to the input end of the first unidirectional conductive device, and the output end of the first unidirectional conductive device is connected to the first input end of the first transformer; The positive terminal of the battery is connected to the input terminal of the second unidirectional conductive device, and the output terminal of the second unidirectional conductive device is connected to the second input terminal of the first transformer; The third input terminal of the first voltage generator is connected to the first terminal of the first control switch, the second terminal of the first control switch is connected to the input terminal of the third unidirectional conductive device and the input terminal of the fourth unidirectional conductive device respectively, and the control terminal of the first control switch is connected to the first output terminal of the control circuit; The output end of the third unidirectional conductive device is connected to the negative terminal of the battery, and the output end of the fourth unidirectional conductive device is connected to the first ground terminal; Wherein, a coil is connected between the first input terminal and the second input terminal of the first transformer, and a coil is connected between the second input terminal and the third input terminal of the first transformer; The first transformer includes an output terminal corresponding to the output voltage, and the output terminal of the first transformer is used to output the corresponding output voltage.

3. The auxiliary power supply circuit according to claim 2, characterized in that: The auxiliary power supply circuit also includes: a power factor correction circuit; The power factor correction circuit is used to generate a first stable voltage according to the mains power; The first input end of the flyback circuit is also used to connect to the first stable voltage, and the control circuit is also used to control the conduction of the AC power circuit after receiving the power signal and when the first input end of the flyback circuit is connected to the first stable voltage, so that the flyback circuit generates at least one output voltage according to the first stable voltage; wherein, at the same time, the first input end of the flyback circuit is only connected to one of the first stable voltage and the AC power.

4. The auxiliary power supply circuit according to claim 3, characterized in that: The flyback circuit further includes a switching switch; the input end of the first rectifier module includes a first input end and a second input end; The first end of the switching switch is connected to the first output end of the mains, the second end of the switching switch is connected to the first input end of the first rectifier module, the second input end of the first rectifier module is connected to the second output end of the mains, and the third end of the switching switch is floating; The fourth end of the switch is used to access the first stable voltage, the fifth end of the switch is floating, and the sixth end of the switch is connected to the input end of the first unidirectional conductive device; The control end of the switching switch is used to control the first end and the second end of the switching switch to be connected, and to control the fourth end and the fifth end to be connected when receiving a first control signal, and is also used to control the first end and the third end of the switching switch to be connected, and the fourth end and the sixth end to be connected when receiving a second control signal; wherein the first control signal is one of a power-off signal and a power-on signal, and the second control signal is the other of the power-off signal and the power-on signal.

5. The auxiliary power supply circuit according to claim 3, characterized in that: The power factor correction circuit is used to generate a second stable voltage according to the mains power, wherein the second stable voltage has the same voltage value and opposite polarity as the first stable voltage; the output end of the control circuit also includes a second output end; The flyback circuit further includes a fifth unidirectional conductive device and a second control switch; The input end of the fifth unidirectional conductive device is connected to the first ground end, the output end of the fifth unidirectional conductive device is connected to the fourth input end of the first transformer, the fifth input end of the first transformer is connected to the first end of the second control switch, the control end of the second control switch is connected to the second output end of the control circuit, and the second end of the second control switch is used to access the second stable voltage; a coil is connected between the fourth input end and the fifth input end of the first transformer; The control circuit is also used to control the AC power circuit and the auxiliary circuit where the second control switch is located to be turned on when the power supply signal is received and the power factor correction circuit outputs the second stable voltage, so that the flyback circuit is used to generate at least one output voltage based on the first stable voltage and the second stable voltage.

6. The auxiliary power supply circuit according to claim 5, characterized in that: The control circuit comprises: a control module and a second transformer; The power supply end of the control module is used to receive the power supply signal, the output end of the control module is connected to the input end of the second transformer, the first output end of the second transformer is connected to the control end of the first control switch, the second output end of the second transformer is connected to the second end of the first control switch, and a coil is connected between the first output end and the second output end of the second transformer; The third output end of the second transformer is connected to the control end of the second control switch, the fourth output end of the second transformer is connected to the second end of the second control switch, and a coil is connected between the third output end and the fourth output end of the second transformer.

7. The auxiliary power supply circuit according to claim 6, characterized in that: The control circuit also includes a current acquisition module; The current acquisition module is connected to the second end of the first control switch, the second end of the second control switch and the feedback end of the control module respectively, and the current acquisition module is used to collect the current in the mains circuit, the battery circuit and the auxiliary circuit; The control module is used for adjusting a duty cycle of a signal output to the second transformer according to the current.

8. The auxiliary power supply circuit according to claim 7, characterized in that: The current acquisition module includes a third transformer, a first resistor and a second resistor; The first input end of the third transformer is electrically connected to the second end of the first control switch, the second input end of the third transformer is respectively connected to the input ends of the third unidirectional conductive device and the fourth unidirectional conductive device, and a coil is connected between the first input end and the second input end of the third transformer; The third input end of the third transformer is connected to the second end of the second control switch, the fourth input end of the third transformer is used to access the second stable voltage, and a coil is connected between the third input end and the fourth input end of the third transformer; The first output end of the third transformer is connected to the first ends of the first resistor and the second resistor respectively, the second output end of the third transformer is connected to the second end of the first resistor, and the second end of the first resistor is connected to the third ground end; The second end of the second resistor is connected to the feedback end of the control module.

9. The auxiliary power supply circuit according to claim 5, characterized in that: The power factor correction circuit includes: a third control switch, an inductor, a second rectifier module, a sixth unidirectional conductive device, a seventh unidirectional conductive device, a first capacitor, a second capacitor and a transistor; The first output end of the AC power is connected to the first end of the third control switch, the second end of the third control switch is connected to the first end of the inductor, the second end of the inductor is connected to the input end of the sixth unidirectional conductive device, and the output end of the sixth unidirectional conductive device is used to output a first stable voltage; The first end of the first capacitor is connected to the output end of the sixth unidirectional conductive device, the second end of the first capacitor is connected to the first ground end, the first end of the second capacitor is connected to the second end of the first capacitor, and the second end of the second capacitor is used to output a second stable voltage; The input end of the seventh unidirectional conductive device is connected to the second end of the second capacitor, and the output end of the seventh unidirectional conductive device is connected to the input end of the sixth unidirectional conductive device; The first input end of the second rectifier module is connected to the second end of the inductor, the second input end of the second rectifier module is connected to the first ground end, the first output end of the second rectifier module is connected to the first end of the transistor, and the second output end of the second rectifier module is connected to the second end of the transistor.

10. The auxiliary power supply circuit according to claim 2, characterized in that: The auxiliary power supply circuit further comprises: a power supply circuit, the power supply circuit comprising: a key switch, a third resistor and a fourth resistor; the power supply signal comprises a battery power supply signal and a mains power supply signal; The first end of the third resistor is connected to the positive terminal of the battery, the second end of the third resistor is connected to the first end of the key switch, and the second end of the key switch is connected to the power supply end of the control circuit; A first end of the fourth resistor is connected to the input end of the first unidirectional conductive device, and a second end of the fourth resistor is connected to the power supply end of the control circuit; The power supply circuit is used to generate the battery power supply signal when the key switch is closed and the battery voltage is connected, and is also used to generate the mains power supply signal when the mains power is connected.

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