Power switching circuit

Abstract

The invention relates to the technical field of power supplies, and provides a power supply switching circuit. The power supply switching circuit comprises a state detection module, a state clamping module and an output control module. The state detection module is used for detecting power supply access states of the first power input end and the second power input end respectively; the state clamping module generates a first output control signal and a second output control signal according to the power supply sequence; the output control module is connected with the state clamping module, is connected with an external load, responds to the first output control signal, controls the connection state of the first power input end and the power supply output end, responds to the second output control signal, controls the connection state of the second power input end and the power supply output end, and supplies power to the external load. According to the power supply switching circuit, the power supply for supplying power to the load can be determined according to the power supply access sequence of the power supplies, so that the power supply selection flexibility is improved.

Description

Technical Field

[0001] This application relates to the field of power supply technology, specifically to a power switching circuit. Background Technology

[0002] In the field of power supply for electronic devices, a single power supply method is no longer sufficient to meet the requirements for power continuity and stability in special scenarios. For example, in the field of medical equipment, battery power has the inherent drawback of limited battery life. If the battery runs out of power during surgery, the equipment will shut down, seriously affecting the safety of the operation.

[0003] Therefore, most systems currently employ dual or multiple power supply methods to ensure power continuity. Taking a dual power supply as an example, this system typically involves two independent power sources (such as a main power source and a backup power source), with one of these sources selected to supply power to the load during power supply operations.

[0004] In related technologies, most dual-power supply methods achieve automatic switching by pre-setting the priorities of the two power sources and then switching to the backup power source when the main power source fails (such as power outage or abnormal voltage). However, the power switching in these technologies relies on a fixed priority method, which lacks flexibility. Summary of the Invention

[0005] In view of this, this application aims to propose a power switching circuit to improve the flexibility of power supply selection.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: A power switching circuit, the power switching circuit comprising: The status detection module includes a first power input terminal and a second power input terminal, which respectively detect the power supply connection status of the first power input terminal and the second power input terminal, and obtain and output a first status signal and a second status signal; A state clamping module, connected to the state detection module, receives the first state signal and the second state signal, and generates a first output control signal corresponding to the first power input terminal and a second output control signal corresponding to the second power input terminal according to the triggering order of the first state signal and the second state signal. An output control module is connected to the status clamping module. The output control module includes a power supply output terminal, which is connected to an external load. The output control module responds to the first output control signal to control the connection between the first power input terminal and the power output terminal, and also responds to the second output control signal to control the connection between the second power input terminal and the power output terminal, so as to supply power to the external load.

[0007] Furthermore, the status clamping module includes a first power interlock unit and a second power interlock unit; One input terminal of the first power interlock unit is connected to the status detection module to receive the first status signal, and the other input terminal is connected to the output terminal of the second power interlock unit. The output terminal of the first power interlock unit is used to output the second output control signal. One input terminal of the second power interlock unit is connected to the status detection module to receive the second status signal, and the other input terminal is connected to the output terminal of the first power interlock unit. The output terminal of the second power interlock unit is used to output the first output control signal. Specifically, when the first power interlock unit and the second power interlock unit receive an output control signal that enables output from another power interlock unit, they restrict their own output control signal to an output control signal that locks and stops output.

[0008] Furthermore, the first power interlock unit includes a first interlock circuit and a first clamping circuit; One input terminal of the first interlock circuit is connected to the state detection module to receive the first state signal, and the other input terminal is connected to the output terminal of the second power interlock unit to receive the first output control signal output by the second power interlock unit. One input terminal of the first clamping circuit is connected to the output terminal of the first interlock circuit, and the other input terminal is connected to the other input terminal of the first interlock circuit. The output terminal is used to output the second output control signal.

[0009] Furthermore, the first interlock circuit includes a first AND gate, and the first clamping circuit includes a first NOR gate; One input terminal of the first AND gate is connected to the state detection module; The output of the first AND gate is connected to one input of the first NOR gate; The other input terminal of the first NOR gate and the other input terminal of the first AND gate are connected to the output terminal of the second power interlock unit. The output of the first NOR gate is used to output the second output control signal.

[0010] Furthermore, the output control module includes a first switch control unit and a second switch control unit; The first switch control unit is connected to the first power input terminal and also to the power output terminal. The controlled terminal of the first switch control unit is connected to the state clamping module, receives the first output control signal, and responds to the first output control signal to control the on / off state of the first power input terminal and the power output terminal. The second switch control unit is connected to the second power input terminal and also to the power output terminal. The controlled terminal of the second switch control unit is connected to the state clamping module, receives the second output control signal, responds to the second output control signal, and controls the on / off state of the second power input terminal and the power output terminal.

[0011] Furthermore, the first power input terminal includes a first power input positive terminal and a first power input negative terminal; The power output terminal includes a positive power output terminal and a negative power output terminal; The first power input positive terminal is connected to the power output positive terminal; The first switch control unit includes a first switching device; One end of the first switching device is connected to the negative terminal of the first power input, and the other end is connected to the negative terminal of the power output. The controlled end of the first switching device is connected to the state clamping module. In response to the first output control signal, it switches to the on or off state to control the on / off state of the first power input negative terminal and the negative terminal of the power output.

[0012] Furthermore, the output control module also includes an energy storage output unit; The two ends of the energy storage output unit are respectively connected to the positive power output terminal and the negative power output terminal, and are used to store the electrical energy transmitted by the external power supply connected to the first power input terminal or the second power input terminal.

[0013] Furthermore, the output control module also includes a first anti-backflow unit and a second anti-backflow unit; The first backflow prevention unit is connected in series between the first power input terminal and the power output terminal to prevent current from the external load from flowing into the first power input terminal; The second backflow prevention unit is connected in series between the second power input terminal and the power output terminal.

[0014] Furthermore, the state detection module includes a first state detection unit and a second state detection unit; The first state detection unit is connected to the first power input terminal and is used to detect the power supply access status of the first power input terminal, and output the first state signal after a first delay period. The second state detection unit is connected to the second power input terminal and is used to detect the power supply access status of the second power input terminal, and output the second state signal after a second delay period. Wherein, the first delay duration is less than the second delay duration.

[0015] Furthermore, the first state detection unit includes a first voltage divider resistor, a second voltage divider resistor, and a first delay capacitor; One end of the first voltage divider resistor is connected to the positive terminal of the first power input terminal; One end of the second voltage divider resistor is connected to the negative terminal of the first power input terminal; One end of the first delay capacitor is connected to the negative terminal of the first power input terminal; The other ends of the first voltage divider resistor, the second voltage divider resistor, and the first delay capacitor are connected to the same common terminal, which is used to output the first status signal.

[0016] Compared with related technologies, this application has at least the following advantages: The power switching circuit described in this application, through the coordinated operation of three modules—a status detection module, a status clamping module, and an output control module—can select the power supply according to the power supply access sequence of the external power source. This does not fix the primary or backup power supply or their priority, but rather selects the power supply according to the power supply access sequence, thereby improving the flexibility of power supply selection for the load.

[0017] Furthermore, the power supply priority is not fixed, but rather determined by the order in which power is supplied to the load. Thus, the power supply that supplies power first becomes the primary power supply, while the other power supply automatically becomes the backup power supply. When the primary power supply fails, it can automatically switch to the backup power supply, which in turn becomes the primary power supply. That is, when the primary power supply is restored, it automatically degrades back to the backup power supply, making the power supply more flexible. The power supply priority is not affected by the input voltage level; the voltage of the primary power supply can be lower or higher than that of the backup power supply, and the power supply order remains unaffected, making it more versatile. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1This is a module connection diagram of the power switching circuit described in the embodiments of this application; Figure 2 This is a circuit diagram of the power switching circuit described in an embodiment of this application; Explanation of reference numerals in the attached figures: 1. State detection module; 11. First state detection unit; 12. Second state detection unit; 2. Status clamping module; 21. First power supply interlock unit; 211. First interlock circuit; 212. First clamping circuit; 22. Second power supply interlock unit; 221. Second interlock circuit; 222. Second clamping circuit; 3. Output control module; 31. First switch control unit; 32. Second switch control unit; 33. Energy storage output unit; 34. First anti-backflow unit; 35. Second anti-backflow unit. Detailed Implementation

[0019] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0021] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0023] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0025] This application provides a power switching circuit. The status detection module 1 detects the power supply access status of the external power supply, and the status clamping module 2 generates a first output control signal and a second output control signal according to the triggering order of the first status signal and the second status signal, that is, according to the order in which the first power input terminal and the second power input terminal are connected to the power supply. Then, the output control module 3 controls the on / off state between the first power input terminal and the second power input terminal and the external load.

[0026] Thus, in this embodiment, the external power supply connected to the first power input terminal or the second power input terminal is controlled to supply power to the external load according to the order in which the external power supply is connected to the first power input terminal or the second power input terminal. In this way, the power supply to the external load can be determined according to the power supply order of the external power supply, thereby realizing the selection and switching of the power supply to the external load.

[0027] In the field of electronic device power supply, a single power supply method is no longer sufficient to meet the power supply requirements of applications such as medical equipment, industrial control devices, and communication terminals, which have stringent requirements for power supply continuity and stability. For example, in the field of medical equipment, battery power has the inherent drawback of limited battery life. If the battery runs out of power during surgery, the equipment will shut down, seriously affecting the safety of the operation.

[0028] Therefore, most systems currently employ dual or multiple power supply methods to ensure power continuity. Taking a dual power supply as an example, this system typically involves two independent power sources (such as a main power source and a backup power source), with one of these sources selected to supply power to the load during power supply operations.

[0029] In related technologies, among dual power supply methods, one method is traditional manual switching or switching using a simple switch. Specifically, the two power supplies are switched by manually operating the switch, or a simple mechanical contact switch is used, which triggers the switching action according to the physical state of the power supply connection, resulting in a low degree of automation.

[0030] To improve automation, another approach is to pre-set the priority of the two power supplies. Specifically, the main power supply and the backup power supply are determined in advance through circuit design. During normal operation, only the main power supply powers the load, while the backup power supply switches to power the load when the main power supply fails. That is, when the main power supply fails (such as power outage or abnormal voltage), the power supply is switched to the backup power supply to achieve automatic switching.

[0031] However, the power switching in related technologies relies on a fixed priority method, which lacks flexibility. For example, when the backup power supply is connected first and the main power supply is connected later, the load must wait for the main power supply to be connected before it can receive power.

[0032] In view of this, in order to overcome the shortcomings of related technologies, the power switching circuit of this embodiment combines... Figure 1-2 In terms of overall design, it includes a status detection module 1, a status clamping module 2, and an output control module 3.

[0033] The status detection module 1 includes a first power input terminal and a second power input terminal, which respectively detect the power supply access status of the first power input terminal and the second power input terminal, and obtain and output a first status signal and a second status signal.

[0034] The status clamping module 2 is connected to the status detection module 1, receives the first status signal and the second status signal, and generates the first output control signal corresponding to the first power input terminal and the second output control signal corresponding to the second power input terminal according to the triggering order of the first status signal and the second status signal.

[0035] The output control module 3 is connected to the status clamping module 2. The output control module 3 includes a power supply output terminal, which is connected to an external load.

[0036] The output control module 3 responds to the first output control signal to control the connection state between the first power input terminal and the power output terminal, and also responds to the second output control signal to control the connection state between the second power input terminal and the power output terminal, so as to supply power to the external load.

[0037] Therefore, the status detection module 1 detects the power supply connection status of the external power source, and the status clamping module 2 generates a first output control signal and a second output control signal respectively based on the triggering order of the first and second status signals, that is, based on the order in which the first power input terminal and the second power input terminal are connected to the power source. The output control module 3 then controls the on / off state between the first and second power input terminals and the external load. In this way, the power source supplied to the external load is determined according to the power supply sequence, realizing the selection and switching of the power supply to the external load. Compared with the method of fixedly setting the priority of the two connected external power sources, this method is more flexible, and can supply power to the load whenever either external power source is connected, regardless of whether the main power source is connected first.

[0038] Based on the above overview, specifically for the status detection module 1, its first power input terminal is used to connect to an external first power source ( Figure 2 (Indicated by IN1), this second power input terminal is used to connect to an external second power source ( Figure 2 (In Chinese, it is represented by IN2).

[0039] The first status signal indicates whether the first power source and its input terminal are connected (and providing power), including a first on status signal and a first off status signal. The first off status signal indicates that the first power source is not connected to the input terminal (and is not providing power). The first on status signal indicates that the first power source is connected to the input terminal (and providing power).

[0040] For example, the first on state signal can be a high-level signal, and the first off state signal can be a low-level signal. That is, when the first power supply is connected to the first power input terminal and power supply is started, the first state signal output by the state detection module 1 is high-level (indicating that the first power supply is connected to the first power input terminal and power supply is started); conversely, when the first power supply is not connected to the first power input terminal, or power supply is not started, the first state signal output by the state detection module 1 is low-level.

[0041] Similarly, the second status signal indicates whether the second power supply is connected to the second power supply input terminal (and provides power), including a second on status signal and a second off status signal. The second off status signal indicates that the second power supply is not connected to the second power supply input terminal (and is not providing power), and can be a low-level signal. The second on status signal indicates that the second power supply is connected to the second power supply input terminal (and is providing power), and can be a high-level signal.

[0042] It is worth noting that the first ON state signal and the second ON state signal can also be at a low level. In this case, the first OFF state signal and the second OFF state signal will be at a high level, and this is not a limitation. In this embodiment, the first ON state signal and the second ON state signal are at a high level for illustration.

[0043] The status detection module 1 may include a first status output terminal and a second status output terminal. The first status output terminal is used to output the first status signal, and the second status output terminal is used to output the second status signal.

[0044] Thus, the status detection module 1 detects the power supply connection status of the first power input terminal and the second power input terminal respectively. When it detects that the first power input terminal is connected to the first power supply, it outputs a high-level first status signal; when it detects that the second power input terminal is connected to the second power supply, it outputs a high-level second status signal. Conversely, when the first power input terminal is not connected to the power supply, it outputs a low-level first status signal; when the second power input terminal is not connected to the power supply, it outputs a low-level second status signal.

[0045] Then the first state signal and the second state signal are received by the state clamping module 2.

[0046] Specifically, the status clamping module 2 may include a first status receiving end and a second status receiving end, a first output control end and a second output control end.

[0047] The first state receiving terminal is connected to the first state output terminal and receives the first state signal. The second state receiving terminal is connected to the second state output terminal and receives the second state signal. The first output control terminal is used to output a first output control signal; the second output control terminal is used to output a second output control signal.

[0048] More specifically, the state clamping module 2 generates a first output control signal corresponding to the first power input terminal and a second output control signal corresponding to the second power input terminal based on the triggering order of the first state signal and the second state signal. The first output control signal may include a first enable output control signal and a first latch output control signal. The first enable output control signal indicates that the first power supply can be output to an external load to power it, and can be a high-level signal (or a low-level signal). The first latch output control signal indicates that the first power supply cannot be output to an external load, and can be a low-level signal (or a high-level signal).

[0049] Similarly, the second output control signal may include a second enable output control signal and a second latch output control signal. The second enable output control signal may also be a high-level signal (or a low-level signal), and the second latch output control signal may also be a low-level signal (or a high-level signal).

[0050] For ease of explanation, in the examples of the following embodiments, a high level indicates that output is allowed and a low level indicates that output is not allowed. This does not represent a limitation on this embodiment.

[0051] Specifically, when the state clamping module 2 receives the first state signal indicating the first power supply is connected before receiving the second state signal indicating the second power supply is connected, it generates a first enable output control signal and a second lockout output control signal.

[0052] That is, it means that the first power supply output is allowed to power the external load, but the second power supply output is not allowed to power the external load.

[0053] For example, when a high-level first state signal is received, the second state signal is low, and then the second state signal is converted to a high level. In this case, the state clamping module 2 will output a high-level first output control signal and a low-level second output control signal, indicating that the first power supply can supply power to the external load, and the second power supply cannot supply power to the external load.

[0054] Conversely, if the state clamping module 2 receives the second state signal indicating the second power supply is connected before receiving the first state signal indicating the first power supply is connected, it generates a first latching output control signal and a second enabling output control signal. That is, it indicates that the first power supply output is not allowed to power an external load, while the second power supply output is allowed to power an external load.

[0055] Furthermore, the output control module 3 includes a first input control terminal and a second input control terminal. The first input control terminal is connected to the first output control terminal of the state clamping module 2 and receives a first output control signal. The second input control terminal is connected to the second output control terminal of the state clamping module 2 and receives a second output control signal.

[0056] The output control module 3 also includes a first power supply input terminal and a second power supply input terminal. The first power supply input terminal is connected to the first power supply input terminal of the status detection module 1, and the second power supply input terminal is connected to the second power supply input terminal of the status detection module 1.

[0057] The power output terminal of the output control module 3 is used to connect to an external load.

[0058] Upon receiving the first enable output control signal and the second lockout output control signal, the output control module 3 controls the first power input terminal to conduct between the power supply output terminal and controls the second power input terminal to cut off (disconnected state) between the power supply output terminal, so that the external first power supply output supplies power to the external load.

[0059] Conversely, upon receiving the first lockout output control signal and the second enable output control signal, the output control module 3 controls the first power input terminal and the power supply output terminal to be cut off (disconnected state), and controls the second power input terminal and the power supply output terminal to be connected, so that the external second power supply output supplies power to the external load.

[0060] In this way, through the coordinated cooperation of the three modules—status detection module 1, status clamping module 2, and output control module 3—the power supply is selected according to the power supply access sequence of the external power supply. This does not limit the main and backup power supplies or fix their priorities, but selects the power supply according to the power supply access sequence, thereby improving the flexibility of power supply selection for the load.

[0061] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the state detection module 1 includes a first state detection unit 11 and a second state detection unit 12.

[0062] The first state detection unit 11 is connected to the first power input terminal and is used to detect the power supply access status of the first power input terminal. After a first delay period, it outputs a first state signal.

[0063] The second state detection unit 12 is connected to the second power input terminal and is used to detect the power supply connection status of the second power input terminal. After a second delay, it outputs a second state signal. The first delay is shorter than the second delay.

[0064] Specifically, the input terminal of the first state detection unit 11 is connected to the first power input terminal, and the output terminal serves as the first state output terminal of the state detection module 1. It can detect the power supply access status of the first power input terminal and output the first state signal from the first state output terminal according to the power supply access status of the first power input terminal.

[0065] In the initial state or when there is no power supply input, the first state output terminal of the first state detection unit 11 outputs a low-level first state signal.

[0066] When an external first power source (the external power supply connected to the first power input terminal is collectively referred to as the first power source) is connected to the first power input terminal, the first state detection unit 11 detects that the power supply access state of the first power input terminal is that an external power source is connected. At this time, after a first delay period, a high-level first state signal will be output.

[0067] Correspondingly, the input terminal of the second state detection unit 12 is connected to the second power input terminal, and the output terminal serves as the second state output terminal of the state detection module 1. It can detect the power supply access status of the second power input terminal and output the first state signal from the second state output terminal according to the power supply access status of the second power input terminal.

[0068] In the initial state or when there is no power input, the second state output terminal outputs a low-level second state signal. When the power supply connection state of the second power input terminal is that an external power supply is connected, a high-level second state signal is output from the second state output terminal after a second delay period.

[0069] When two external power sources are connected simultaneously, a conflict will be triggered, making it impossible to determine the order of power supply. This can lead to a situation where power cannot be supplied to the load. However, in this embodiment, because the first state detection unit 11 and the second state detection unit 12 employ differentiated delay durations, the conflict caused by simultaneous connection of two external power sources can be avoided when both the first and second power input terminals are connected. Furthermore, since the first delay duration is shorter than the second delay duration, the external power supplied to the first power input terminal can be output to the external load for power supply, thus ensuring that power is supplied to the load normally.

[0070] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the first state detection unit 11 includes a first voltage divider resistor, a second voltage divider resistor, and a first delay capacitor.

[0071] The first power input terminal includes a first power input positive terminal (i.e., the positive end of the first power input terminal) and a first power input negative terminal (i.e., the negative end of the first power input terminal).

[0072] Reference Figure 2 The first voltage divider resistor ( Figure 2 One end of the circuit (shown as R1) is connected to the positive terminal of the first power input terminal.

[0073] Second voltage divider resistor ( Figure 2 One end of the capacitor (shown as R2) is connected to the negative terminal of the first power supply input. The first delay capacitor (… Figure 2One end of the first power input terminal (shown as C1) is connected to the negative terminal of the first power input terminal. The negative terminal of the first power input terminal is grounded.

[0074] The other end of the first voltage divider resistor R1, the other end of the second voltage divider resistor R2, and the other end of the first delay capacitor C1 are connected to the same common terminal, and the common terminal is used to output the first state signal.

[0075] That is, the common terminal serves as the first state output terminal, used to output the first state signal.

[0076] Specifically, the first voltage divider resistor R1, the second voltage divider resistor R2, and the first delay capacitor C1 constitute an RC delay circuit. The delay is generated through the charging and discharging process of the capacitor. After the external power supply is connected, the first delay capacitor C1 starts to charge, and the voltage gradually increases. After the first delay capacitor C1 finishes charging, a high level is output.

[0077] The parameter values ​​of the second voltage divider resistor R2, the first voltage divider resistor R1, and the first delay capacitor C1 determine the magnitude of the first delay duration. Therefore, the parameters of each device can be set according to the actual situation to adjust the magnitude of the first delay duration.

[0078] Furthermore, the first voltage divider resistor R1 and the second voltage divider resistor R2 work together to adjust the received external power supply voltage to the voltage amplitude output corresponding to the high level, such as 3.3V.

[0079] For example, the status clamping module 2 is adapted to a high level of 3.3V. If the voltage applied is too high, it may damage the components inside the status clamping module 2. The power supply voltage (e.g., 12V) of the external power supply connected to the first power input terminal may be higher than the high level adapted to the status clamping module 2. Therefore, in this embodiment, the first voltage divider resistor R1 and the second voltage divider resistor R2 work together to limit the power supply voltage when the first power supply is connected to the adapted high level amplitude, which also prevents high voltage input to subsequent modules from causing component damage.

[0080] In some embodiments, similar to the first detection unit, the second detection unit can also be composed of an RC delay circuit, as described above. Figure 2 The second detection unit may include a third voltage divider resistor R3, a fourth voltage divider resistor R4, and a second delay capacitor C2.

[0081] The second power input terminal includes a second power input positive terminal (i.e., the positive end of the second power input terminal) and a second power input negative terminal (i.e., the negative end of the second power input terminal).

[0082] Reference Figure 2 The third voltage divider resistor ( Figure 2One end of the circuit (shown as R3) is connected to the positive terminal of the second power input.

[0083] Fourth voltage divider resistor ( Figure 2 One end of the capacitor (shown as R4) is connected to the negative terminal of the first power supply input. The second delay capacitor ( Figure 2 One end of the terminal (shown as C2) is connected to the negative terminal of the second power input. The negative terminal of the second power input is grounded.

[0084] The other end of the third voltage divider resistor R3, the other end of the fourth voltage divider resistor R4, and the other end of the second delay capacitor C2 are connected to the same common terminal, which is used to output the second state signal.

[0085] It is worth noting that the parameter values ​​of the third voltage divider resistor R3, the fourth voltage divider resistor R4, and the second delay capacitor C2 determine the magnitude of the second delay duration.

[0086] Furthermore, the working process of each device in the second detection unit can be referred to the working process of each device in the first detection unit, and will not be repeated here.

[0087] It's worth noting that the time difference between two power supplies being "normally connected sequentially" is typically on the order of seconds or even minutes, while the time difference between "instantaneous simultaneous connection" (such as power supply plugging / unplugging jitter or grid fluctuations) is only on the order of milliseconds or microseconds. Therefore, when setting up, the difference between the first and second delay durations should be less than the normal sequential connection time difference. Furthermore, the first and second delay durations should be determined based on actual needs. For example, to meet emergency power supply requirements, the first and second delay durations can be set to the order of milliseconds or microseconds.

[0088] In this way, since the delay time difference is much smaller than the normal access time difference, when the second power supply is connected before the first power supply and the time difference is greater than the delay time difference, the second state detection unit 12 will output the second state signal first. The state clamping module 2 can accurately determine that the second power supply is the priority power supply and there will be no judgment deviation. Similarly, when the first power supply is connected first, its priority can also be accurately determined.

[0089] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the state clamping module 2 may specifically include a first power interlock unit 21 and a second power interlock unit 22.

[0090] One input terminal of the first power interlock unit 21 is connected to the status detection module 1, more specifically, to the first status output terminal of the status detection module 1 to receive the first status signal, and the other input terminal is connected to the output terminal of the second power interlock unit 22. The output terminal of the first power interlock unit 21 is used to output the second output control signal.

[0091] One input terminal of the second power interlock unit 22 is connected to the status detection module 1, and more specifically, to the second status output terminal of the status detection module 1 to receive the second status signal. The other input terminal is connected to the output terminal of the first power interlock unit 21. The output terminal of the second power interlock unit 22 is used to output the first output control signal.

[0092] Among them, when the first power interlock unit 21 and the second power interlock unit 22 receive an output control signal that indicates enable output from another power interlock unit, they limit their own output control signal to an output control signal that indicates lockout and stop output.

[0093] Specifically, for the first output control signal and the second output control signal, when representing the enable output, it is equivalent to indicating that the corresponding power input terminal and power output terminal can be controlled to be turned on, which is usually manifested as a high level signal (it can also be a low level in other embodiments, but a low level is used as an example in this embodiment).

[0094] When the output is locked and stopped, it means that the corresponding power input terminal and power output terminal cannot be connected, which means that the corresponding power input terminal and power output terminal are disconnected. This is usually represented by a low-level signal (in other embodiments, it can also be a high level, but in this embodiment, a low level is used as an example for explanation).

[0095] Reference Figure 2 When the first power input terminal is connected to an external power supply (such as the first power supply), the status detection module 1 outputs a high-level first status signal and a low-level second status signal.

[0096] At this time, the first power interlock unit 21 receives a high-level first state signal. The second power interlock unit 22 is still in the state of receiving a low-level second state signal.

[0097] The first power interlock unit 21 outputs a low-level second output control signal, and the second power interlock unit 22 outputs a high-level first output control signal.

[0098] A low-level second output control signal is output to the output control module 3, keeping the second power input terminal and the power output terminal disconnected. A high-level first output control signal is output to the output control module 3, making the first power input terminal and the power output terminal connected, so that the first power supply provides power to the load.

[0099] If an external power supply (such as a second power source) is subsequently connected to the second power input terminal, the first power interlock unit 21 and the second power interlock unit 22 will remain locked together. Therefore, the first power interlock unit 21 will continue to output a low-level second output control signal, and the second power interlock unit 22 will continue to output a high-level first output control signal.

[0100] Conversely, when the second power supply is connected first, the second power supply interlock unit 22 receives a high-level second status signal and outputs a low-level first output control signal; the first power supply interlock unit 21 receives a low-level first status signal and outputs a high-level second output control signal. If the first power supply is connected subsequently, the second power supply interlock unit 22 will be locked by receiving the second output control signal from the first power supply interlock unit 21, indicating that the output is enabled, and will maintain the output of the low-level first output control signal, thus avoiding conflict between the two power supplies. This bidirectional interlock logic effectively improves the reliability of power switching.

[0101] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the first power interlock unit 21 includes a first interlock circuit 211 and a first clamping circuit 212.

[0102] Among them, one input terminal of the first interlock circuit 211 is connected to the state detection module 1, more specifically, to the first state output terminal of the state detection module 1 to receive the first state signal, and the other input terminal is connected to the output terminal of the second power interlock unit 22 to receive the first output control signal output by the second power interlock unit 22. In this circuit, one input terminal of the first clamping circuit 212 is connected to the output terminal of the first interlocking circuit 211, the other input terminal is connected to the other input terminal of the first interlocking circuit 211, and the output terminal is used to output the second output control signal.

[0103] Specifically, when the first power supply is connected, the status detection module 1 outputs a high-level first status signal, and the second power supply interlock unit 22 outputs a high-level first output control signal (indicating enable output). The first interlock circuit 211 simultaneously receives the high-level first status signal and the high-level first output control signal, performs logical operations, and outputs a high level.

[0104] The first clamping circuit 212 receives a high-level signal from the first interlocking circuit 211 on one side and a high-level first output control signal (high level) on the other side. Since it receives the high-level first output control signal, it outputs a low-level second output control signal (indicating that power cannot be output). In this way, the latching logic of the first clamping circuit 212 keeps the power supply that is supplied later in a stable locked state, avoiding switching back and forth between the first power supply and the second power supply.

[0105] Correspondingly, when the second power supply is connected first, the second power supply interlock unit 22 outputs a low-level first output control signal (indicating that the output is locked and stopped), and the first interlock circuit 211 receives the low-level first status signal and the low-level first output control signal, processes them, and outputs a high level.

[0106] The first clamping circuit 212 receives a high-level signal from the first interlock circuit 211 on one side and a low-level first output control signal on the other side. Since it does not receive the first output control signal that enables output (there is no need to lock and stop output at this time), it outputs a high-level second output control signal (indicating that power can be output).

[0107] Continue to combine Figures 1 to 2 As shown, in some of the exemplary embodiments, the first interlock circuit 211 may include a first AND gate, and the first clamping circuit 212 may include a first NOR gate.

[0108] Reference Figure 2 The second power interlock unit 22 is similar to the first power interlock unit 21. It may also include a second interlock circuit 221 and a second clamping circuit 222. The second interlock circuit 221 may include a second AND gate, and the second clamping circuit 222 may include a second NOR gate.

[0109] In this configuration, one input of the first AND gate is connected to the state detection module 1 to receive a first state signal. The output of the first AND gate is connected to one input of the first NOR gate. The output of the first NOR gate is used to output a second output control signal.

[0110] The other input terminal of the first NOR gate and the other input terminal of the first AND gate are connected to the output terminal of the second power interlock unit 22 to receive the first output control signal output by the second power interlock unit 22.

[0111] More specifically, the other input of the first NOR gate, the other input of the first AND gate, and the output of the second AND-OR gate are connected to the same node. The first output control unit output by the second NOR gate is input to the other input of the first NOR gate and to the other input of the first AND gate.

[0112] It is worth noting that, referring to Figure 2 The connection relationships of the second AND gate and the second NOR gate can be referred to the connection relationships of the first AND gate and the second NOR gate, and will not be repeated here.

[0113] For example, when the first power supply is connected first, the first state signal is high, therefore, one input of the first AND gate receives a high level. And since the first power supply is connected first, the first output control signal of the second NOR gate is high (indicating an enabled output), therefore, the other input of the first AND gate receives a high level, and the other input of the first NOR gate receives a high level.

[0114] At this time, for the first AND gate, both inputs are at a high level. According to the logic operation rules of the AND gate, its output is at a high level and sent to one input of the first NOR gate.

[0115] When both inputs of the first NOR gate receive a high level, according to the logic operation rules of the NOR gate, when both inputs are high, the output will be low. That is, the first NOR gate will output a low-level second output control signal (indicating a lock-to-stop output), thereby locking the second power supply (ensuring that the second power supply does not supply power to the external load regardless of whether it is connected or not).

[0116] At this point, for the second AND gate, one input receives a low-level first state signal, and the other input receives a low-level second output control signal from the first NOR gate. Since both inputs of the second AND gate are low, it outputs a low level to the second NOR gate. The second NOR gate receives this low level at one end and the low-level second output control signal at the other, outputting a high-level first output control signal.

[0117] Therefore, when the first power supply is connected first, the state clamping module 2 ultimately outputs a low-level second output control signal (indicating that the output is disabled so as not to supply power to the load) and a high-level first output control signal (indicating that the output is enabled so as to supply power to the load). In this way, the first output control signal is received by the output control module 3 to control the first power supply to supply power to the external load and control the second power supply to be in a locked and stopped power supply state, that is, the second power supply does not supply power to the external load.

[0118] Conversely, when the second power supply is connected first, the status clamping module 2 will output a low-level first output control signal and a high-level second output control signal.

[0119] Additionally, it's worth noting that when the first power supply is connected first and the second power supply is connected later, if the first power supply is unavailable during its operation (e.g., its power is depleted and it stops supplying power), the first state signal will become low and the second state signal will become high. For state clamping module 2, following the same operational logic as when the second power supply is connected first, the second output control signal will be adjusted to a high level, and the first output control signal will be adjusted to a low level.

[0120] When the second power supply is connected first and the first power supply is connected later, if the second power supply becomes unavailable, the state clamping module 2 will switch from outputting a high-level second output control signal and a low-level first output control signal to outputting a low-level second output control signal and a high-level first output control signal, thereby switching the power supply.

[0121] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the output control module 3 includes a first switch control unit 31 and a second switch control unit 32.

[0122] The first switch control unit 31 is connected to the first power input terminal and also to the power output terminal. The controlled terminal of the first switch control unit 31 is connected to the status clamping module 2, receives the first output control signal, and responds to the first output control signal to control the on / off state of the first power input terminal and the power output terminal.

[0123] Specifically, when the output control signal is at a high level, indicating that the output is enabled, the first switch control unit 31 is configured to be turned on when the controlled terminal receives a high level, so that the first power input terminal is connected to the power supply output terminal, so as to supply power to the load connected by the first power supply output terminal.

[0124] Conversely, when the output control signal is low, indicating that the output is enabled, the first switch control unit 31 can be configured to turn on when the controlled terminal receives a low level, so that the first power supply supplies power to the load.

[0125] The second switch control unit 32 is connected to the second power input terminal and also to the power output terminal. The controlled terminal of the second switch control unit 32 is connected to the status clamping module 2, receives the second output control signal, responds to the second output control signal, and controls the on / off state of the second power input terminal and the power output terminal.

[0126] Specifically, when the output control signal is at a high level, indicating that the output is enabled, the second switch control unit 32 is configured to be turned on when the controlled terminal receives a high level, so that the second power input terminal is connected to the power supply output terminal to supply power to the load connected by the second power supply output terminal.

[0127] Conversely, when the output control signal is low, indicating that the output is enabled, the second switch control unit 32 can be configured to turn on when the controlled terminal receives a low level, so that the second power supply supplies power to the load.

[0128] For example, the case where the first output control signal (and the second output control signal) are high indicates that the output is enabled will be explained.

[0129] When the first power supply is connected, the first output control signal is high and the second output control signal is low. At this time, the controlled terminal of the first switch control unit 31 receives a high level and controls the first power input terminal to connect with the power supply output terminal. The controlled terminal of the second switch control unit 32 receives a low level and controls the second power input terminal to cut off from the power supply output terminal, so that the first power supply supplies power to the load.

[0130] Conversely, when the second power supply is connected first, the first output control signal is low and the second output control signal is high. At this time, the controlled terminal of the first switch control unit 31 receives a low level and controls the first power input terminal to be cut off from the power supply output terminal. The controlled terminal of the second switch control unit 32 receives a high level and controls the second power input terminal to be connected to the power supply output terminal, so that the second power supply supplies power to the load.

[0131] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the power supply output terminal includes a positive power supply output terminal and a negative power supply output terminal. The first switch control unit 31 includes a first switch device.

[0132] The first power input positive terminal is connected to the power output positive terminal.

[0133] One end of the first switching device is connected to the negative terminal of the first power input, and the other end is connected to the negative terminal of the power output and grounded. The controlled end of the first switching device is connected to the state clamping module 2, which responds to the first output control signal and switches to the on or off state to control the on / off state of the negative terminal of the first power input and the negative terminal of the power output.

[0134] Specifically, the first power input positive terminal is the positive interface of the first power input terminal, used to connect to the positive terminal of the power supply and transmit the positive voltage of the power supply. The first power input negative terminal is the negative interface of the first power input terminal, used to connect to the negative terminal of the power supply and form a power supply loop.

[0135] The positive terminal of the power supply output is the positive interface of the power supply output terminal, used to output positive voltage to the external load. The negative terminal of the power supply output is the negative interface of the power supply output terminal, used to output negative voltage to the external load, forming a power supply circuit with the positive terminal of the power supply output.

[0136] Similarly, the second switch control unit 32 may also include a second switch device. Likewise, the positive terminal of the second power input is also connected to the positive terminal of the power output, the negative terminal of the second power input is connected to one end of the second switch device, and the other end of the second switch device is connected to the negative terminal of the power output. The controlled terminal of the second switch device receives a second output control signal and switches to an on or off state according to the second output control signal to control the on / off state of the negative terminal of the second power input and the negative terminal of the power output.

[0137] More specifically, the first and second switching devices can be MOS transistors (Metal-Oxide-Semiconductor Field-Effect Transistors), transistors, or other switching electronic devices, which are not limited here.

[0138] This explanation uses MOSFETs as the first and second switching devices, with a high level for the first output control signal indicating activation and a high level for the second output control signal also indicating activation. (Refer to...) Figure 2 The first switching device may specifically be an NMOS transistor ( Figure 2 (shown as Q1 in the diagram), the second switching device can also be an NMOS transistor ( Figure 2 (shown as Q2 in the middle).

[0139] Specifically, an NMOS transistor consists of a gate, a source, and a drain. The gate acts as the controlled terminal; when it receives a high-level signal, its source and drain are connected. When it receives a low-level signal, its source and drain are cut off, and it is in an open state.

[0140] Therefore, when the first power supply is connected, the first switching device Q1 receives a high level, which makes the negative input terminal of the first power supply and the negative output terminal of the power supply conduct. The second switching device Q2 receives a low level, so the negative input terminal of the second power supply and the negative output terminal of the power supply are in a cut-off state. Thus, the external first power supply, the positive input terminal of the first power supply, the positive output terminal of the power supply, the external load, the negative output terminal of the power supply, and the negative output terminal of the first power supply form a complete current loop, so that the first power supply supplies power to the external load.

[0141] Conversely, when the second power supply is connected first, the controlled terminal of the first switching device Q1 receives a low level, which cuts off the connection between the negative input terminal and the negative output terminal of the first power supply. The second switching device Q2 receives a high level, which connects the negative input terminal and the negative output terminal of the second power supply, thereby supplying power to the external load from the second power supply.

[0142] Therefore, by directly connecting the positive terminal of the first power input to the positive terminal of the power output and connecting the negative terminal of the first power output to the negative terminal of the power output, the first switching device only needs to control the on / off state of the negative terminal of the first power input to achieve the output control of the first power supply. This simplifies the circuit architecture of the first switch control unit 31, reduces the voltage withstand requirements of the switching device, and thus improves the safety and economy of the circuit.

[0143] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the output control module 3 further includes an energy storage output unit 33.

[0144] The energy storage output unit 33 is connected to the positive power output terminal and the negative power output terminal at its two ends, respectively, and is used to store the electrical energy transmitted by the external power supply connected to the first power input terminal or the second power input terminal.

[0145] Thus, since the energy storage output unit 33 can store the electrical energy transmitted by the power supply, it can release the stored electrical energy to the external load at the moment of power switching, thereby avoiding power interruption during power switching, improving the continuity and stability of power output, and protecting the external load from voltage fluctuations.

[0146] Specifically, the energy storage output unit 33 can be a circuit unit with the function of storing and releasing electrical energy. It is usually composed of energy storage elements such as capacitors and inductors, and is used to realize the temporary storage and replenishment of electrical energy in the circuit.

[0147] When the first power supply supplies power to the external load, the electrical energy of the first power supply is not only transmitted to the external load through the power supply output terminal, but also transmitted to the energy storage output unit 33 through the positive power supply output terminal. The energy storage output unit 33 starts to store electrical energy until the stored electrical energy reaches a stable state (consistent with the voltage of the power supply output terminal).

[0148] When the circuit switches power (e.g., from the first power source to the second power source), the first switch control unit 31 turns off first, and the second switch control unit 32 turns on afterward, with a very short switching gap in between. During this switching gap, the first power source stops supplying power, and the second power source has not yet started supplying power. At this time, the energy storage output unit 33 immediately releases the stored electrical energy to the power supply output terminal to continuously supply power to the external load and avoid power interruption.

[0149] Once the second power source is successfully switched on and begins supplying power, the energy storage output unit 33 stops releasing electrical energy and instead receives and re-stores the electrical energy transmitted by the second power source, preparing for the next power switch. Through the energy storage and release functions of the energy storage output unit 33, the power supply gap during power switching is effectively filled, improving the continuity and stability of power output, preventing external loads from malfunctioning due to momentary power interruptions or voltage fluctuations, and protecting the external loads.

[0150] Continue to combine Figures 1 to 2 As shown, in some exemplary embodiments, the output control module 3 further includes a first anti-backflow unit 34 and a second anti-backflow unit 35 to prevent the current from the external load from flowing backward through the unconducted switch control unit, thereby avoiding damage to the switch control unit by reverse current and improving the reliability and service life of the circuit.

[0151] The first backflow prevention unit 34 is connected in series between the first power input terminal and the power output terminal to prevent current from external load from flowing into the first power input terminal.

[0152] The second backflow prevention unit 35 is connected in series between the second power input terminal and the power output terminal to prevent current from external loads from flowing into the second power input terminal.

[0153] Specifically, the first anti-backflow unit 34 can be a circuit unit with unidirectional conductivity, such as a diode. The cathode of the diode is connected to the power supply output terminal (power supply output positive terminal), and the anode is connected to the first power supply input positive terminal, in order to prevent current from flowing from the power supply output positive terminal to the first power supply input positive terminal and then into the first power supply.

[0154] Similarly, the second anti-backflow unit 35 can also have a circuit unit with unidirectional conductivity, such as a diode, to prevent current from flowing from the power supply output terminal to the positive terminal of the second power supply input.

[0155] In some embodiments, refer to Figure 2 The first backflow prevention unit 34 may include a third switching device (shown as Q3 in the figure) and a driver for driving the third switching device Q3. The driver controls the conduction state of the third switching device Q3. For example, when the first power supply is supplying power to the load, the driver outputs a high-level signal to the third switching device Q3, causing Q3 to conduct, thereby enabling the first power supply to output power to the load. When the first power supply is not supplying power to the load, the driver outputs a low-level signal to the third switching device Q3, causing Q3 to turn off, thereby preventing backflow.

[0156] Similarly, the second backflow prevention unit 35 may also include a fourth switching device (shown as Q4 in the figure) and a driver for driving the fourth switching device Q4. Further details will not be provided here.

[0157] Thus, through the unidirectional conductivity of the first anti-backflow unit 34 and the second anti-backflow unit 35, the impact of reverse current on the external power supply is effectively blocked, thereby improving the reliability of the circuit.

[0158] It is worth noting that, regarding the power switching circuit of this embodiment, based on the above exemplary implementations, in specific implementation, as a preferred embodiment, it still consists of... Figure 2 As shown, it may include, for example: Reference Figure 2 The power supply connection status of the first power input terminal and the second power input terminal can be divided into the following five cases: State 1: The first power supply (represented by IN1 in the diagram) and the second power supply (represented by IN2 in the diagram) are connected simultaneously; State 2: The first power supply IN1 is connected before the second power supply IN2; State 3: The first power supply IN1 is connected to the second power supply IN2; State 4: The first power supply IN1 is connected before the second power supply IN2 and then switches to the non-existent state; State 5: The second power supply IN2 is connected before the first power supply IN1 and then switches to the non-existent state.

[0159] In the five states, Figure 2 The level states of the output signals of the first AND gate U1, the first NOR gate U2, the second AND gate U3, and the second NOR gate U4 are shown in Table 1 below.

[0160] Table 1

[0161] Correspondingly, in the five states, the switching states of the second switching device Q2 and the fourth switching device Q4, and Figure 2 The output power at VO (equivalent to the power output terminal) is shown in Table 2 below.

[0162] Table 2

[0163] Thus, in this embodiment, the power supply priority is not fixed, but rather determined by the order in which the power supplies are supplied to the load. The power supply that supplies power first becomes the primary power supply, while the other power supply automatically becomes the backup power supply. When the primary power supply fails, it can automatically switch to the backup power supply, which will then be promoted to primary power supply. That is, when the primary power supply is restored, it will automatically degrade back to backup power supply, making the power supply more flexible. The power supply priority is not affected by the input voltage level; the voltage of the primary power supply can be lower or higher than that of the backup power supply, and the power supply order remains unaffected, making it more suitable for practical applications.

[0164] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A power switching circuit, characterized in that, The power switching circuit includes: The status detection module (1) includes a first power input terminal and a second power input terminal, which respectively detects the power supply access status of the first power input terminal and the second power input terminal, and obtains and outputs a first status signal and a second status signal; The state clamping module (2) is connected to the state detection module (1), receives the first state signal and the second state signal, and generates a first output control signal corresponding to the first power input terminal and a second output control signal corresponding to the second power input terminal according to the triggering order of the first state signal and the second state signal. The output control module (3) is connected to the state clamping module (2). The output control module (3) includes a power supply output terminal, which is connected to an external load. The output control module (3) responds to the first output control signal to control the connection state between the first power input terminal and the power output terminal, and also responds to the second output control signal to control the connection state between the second power input terminal and the power output terminal, so as to supply power to the external load.

2. The power switching circuit according to claim 1, characterized in that, The status clamping module (2) includes a first power interlock unit (21) and a second power interlock unit (22); One input terminal of the first power interlock unit (21) is connected to the state detection module (1) to receive the first state signal, and the other input terminal is connected to the output terminal of the second power interlock unit (22). The output terminal of the first power interlock unit (21) is used to output the second output control signal. One input terminal of the second power interlock unit (22) is connected to the status detection module (1) to receive the second status signal, and the other input terminal is connected to the output terminal of the first power interlock unit (21). The output terminal of the second power interlock unit (22) is used to output the first output control signal. Among them, when the first power interlock unit (21) and the second power interlock unit (22) receive an output control signal that indicates enable output from another power interlock unit, they limit their own output control signal to an output control signal that indicates lockout stop output.

3. The power switching circuit according to claim 2, characterized in that, The first power interlock unit (21) includes a first interlock circuit (211) and a first clamping circuit (212); One input terminal of the first interlock circuit (211) is connected to the state detection module (1) to receive the first state signal, and the other input terminal is connected to the output terminal of the second power interlock unit (22) to receive the first output control signal output by the second power interlock unit (22); One input terminal of the first clamping circuit (212) is connected to the output terminal of the first interlock circuit (211), and the other input terminal is connected to the other input terminal of the first interlock circuit (211). The output terminal is used to output the second output control signal.

4. The power switching circuit according to claim 3, characterized in that, The first interlock circuit (211) includes a first AND gate, and the first clamping circuit (212) includes a first NOR gate; One input terminal of the first AND gate is connected to the state detection module (1); The output of the first AND gate is connected to one input of the first NOR gate; The other input terminal of the first NOR gate and the other input terminal of the first AND gate are connected to the output terminal of the second power interlock unit (22); The output of the first NOR gate is used to output the second output control signal.

5. The power switching circuit according to claim 1, characterized in that, The output control module (3) includes a first switch control unit (31) and a second switch control unit (32); The first switch control unit (31) is connected to the first power input terminal and also to the power output terminal. The controlled terminal of the first switch control unit (31) is connected to the state clamping module (2), receives the first output control signal, and responds to the first output control signal to control the on / off state of the first power input terminal and the power output terminal. The second switch control unit (32) is connected to the second power input terminal and also to the power output terminal. The controlled terminal of the second switch control unit (32) is connected to the state clamping module (2), receives the second output control signal, responds to the second output control signal, and controls the on / off state of the second power input terminal and the power output terminal.

6. The power switching circuit according to claim 5, characterized in that, The first power input terminal includes a first power input positive terminal and a first power input negative terminal; The power output terminal includes a positive power output terminal and a negative power output terminal; The first power input positive terminal is connected to the power output positive terminal; The first switch control unit (31) includes a first switch device; One end of the first switching device is connected to the negative terminal of the first power input, and the other end is connected to the negative terminal of the power output. The controlled end of the first switching device is connected to the state clamping module (2). In response to the first output control signal, it switches to the on or off state to control the on / off state of the negative terminal of the first power input and the negative terminal of the power output.

7. The power switching circuit according to claim 5, characterized in that, The output control module (3) also includes an energy storage output unit (33); The two ends of the energy storage output unit (33) are respectively connected to the positive power output terminal and the negative power output terminal, and are used to store the electrical energy transmitted by the external power supply connected to the first power input terminal or the second power input terminal.

8. The power switching circuit according to claim 5, characterized in that, The output control module (3) further includes a first anti-backflow unit (34) and a second anti-backflow unit (35); The first backflow prevention unit (34) is connected in series between the first power input terminal and the power output terminal to prevent current from the external load from flowing into the first power input terminal; The second backflow prevention unit (35) is connected in series between the second power input terminal and the power output terminal.

9. The power switching circuit according to claim 1, characterized in that, The state detection module (1) includes a first state detection unit (11) and a second state detection unit (12); The first state detection unit (11) is connected to the first power input terminal and is used to detect the power supply access status of the first power input terminal, and output the first state signal after a first delay period. The second state detection unit (12) is connected to the second power input terminal and is used to detect the power supply access status of the second power input terminal, and output the second state signal after a second delay period; Wherein, the first delay duration is less than the second delay duration.

10. The power switching circuit according to claim 9, characterized in that, The first state detection unit (11) includes a first voltage divider resistor, a second voltage divider resistor, and a first delay capacitor; One end of the first voltage divider resistor is connected to the positive terminal of the first power input terminal; One end of the second voltage divider resistor is connected to the negative terminal of the first power input terminal; One end of the first delay capacitor is connected to the negative terminal of the first power input terminal; The other end of the first voltage divider resistor, the other end of the second voltage divider resistor, and the other end of the first delay capacitor are connected to the same common terminal, and the common terminal is used to output the first state signal.

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