Power switching circuits and electrical equipment

Abstract

The present application relates to a power switching circuit and an electrical device, which is provided with a switching circuit and a driving circuit. The driving circuit is connected to an external power supply and is connected to a power supply circuit and an energy storage power supply circuit through the switching circuit. The driving circuit can distinguish between multiple external power supplies of different voltages, and when the voltage of the connected external power supply drops to a corresponding preset voltage threshold, a switching control signal is output to the switching circuit, so that under the control of the switching circuit, the energy storage power supply circuit is turned on in time, and the power supply circuit is cut off, and the load is directly switched to the energy storage device for power supply. Through this solution, as long as the voltage of the external power supply drops to the corresponding preset voltage threshold, the load can be switched to the energy storage device for power supply in time, without waiting for the external power supply to be powered off, avoiding the influence of the large electrolytic capacitor output by the external power supply on the power switching, and ensuring the timeliness of the power supply switching when the electrical device is disconnected for charging.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a power switching circuit and an electrical device. Background Art

[0002] With the advancement of science and technology and the continuous improvement of people's living standards, portable power devices equipped with power modules are becoming increasingly common in our daily lives, bringing great convenience to people's lives. When these power devices are not connected to an external power source, the power module can power the device's load. When an external power source is connected, the external power source powers the load and simultaneously charges the power module.

[0003] However, the adapter used for external power access has a large electrolytic capacitor, which cannot be powered off in time when the charging is disconnected, resulting in the power module being unable to switch to powering the load in time. Summary of the Invention

[0004] Based on this, it is necessary to provide a power switching circuit and an electrical device to address the problem that the power module cannot switch to powering the load in time when the electrical device is disconnected from charging.

[0005] A power switching circuit comprises: an energy storage power supply circuit, a power supply circuit, a switching circuit and a driving circuit, wherein the energy storage power supply circuit is connected to a load and an energy storage device of an electrical device, the power supply circuit is connected to an external power supply, the load and the energy storage power supply circuit, the switching circuit is connected to the external power supply, the power supply circuit and the energy storage power supply circuit, and the driving circuit is connected to the external power supply and the switching circuit; the driving circuit is used to distinguish between external power supplies of different voltages and output a switching control signal to the switching circuit when the voltage of the external power supply drops to a corresponding preset voltage threshold; the switching circuit is used to control the energy storage power supply circuit to turn on to connect the load and the energy storage device, and to control the power supply circuit to turn off to disconnect the external power supply and the load according to the switching control signal.

[0006] The power switching circuit is provided with a switching circuit and a driving circuit. The driving circuit is connected to an external power supply and is connected to a power supply circuit and an energy storage power supply circuit through the switching circuit. The driving circuit can distinguish between multiple external power supplies of different voltages and output a switching control signal to the switching circuit when the voltage of the connected external power supply drops to a corresponding preset voltage threshold. This allows the energy storage power supply circuit to be turned on in a timely manner under the control of the switching circuit, and the power supply circuit to be cut off, directly switching to the energy storage device to supply power to the load. Through this solution, as long as the voltage of the external power supply drops to the corresponding preset voltage threshold, the load can be switched to the energy storage device to supply power in a timely manner. There is no need to wait for the external power supply to power off, avoiding the impact of the large electrolytic capacitor output by the external power supply on the power switching, and ensuring the timeliness of the power supply switching when the electrical equipment is disconnected from charging.

[0007] In one embodiment, the driving circuit includes a first voltage driving circuit and a second voltage driving circuit, the first voltage driving circuit is connected to the external power supply and the switching circuit, and the second voltage driving circuit is connected to the external power supply, the first voltage driving circuit and the switching circuit.

[0008] In one embodiment, the first voltage driving circuit includes a switching device U1, a resistor R1, a resistor R2 and a resistor R3, the first end of the resistor R1 is connected to the external power supply and the first end of the resistor R2, the second end of the resistor R1 is connected to the control end of the switching device U1 and the first end of the resistor R3, the second end of the resistor R3 is grounded, the first end of the switching device U1 is connected to the second end of the resistor R2, the switching circuit and the second voltage driving circuit, and the second end of the switching device U1 is connected to the second end of the resistor R3.

[0009] In one embodiment, the second voltage driving circuit includes a first switching delay circuit and a first driving control circuit, the first voltage driving circuit and the first driving control circuit are respectively connected to the first switching delay circuit, and the first driving control circuit is connected to the external power supply and the switching circuit.

[0010] In one embodiment, the first switching delay circuit includes a switch tube Q1, a switch tube Q2, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, and a capacitor C1, a first end of the resistor R4 is connected to the first voltage driving circuit, a second end of the resistor R4 is connected to the first end of the resistor R5 and the control end of the switch tube Q1, a second end of the resistor R5 is connected to the first end of the switch tube Q1, a first end of the resistor R6 is connected to the first end of the switch tube Q1 and the first driving control circuit, a second end of the switch tube Q1 is connected to the first end of the resistor R7 and the first end of the resistor R8, a second end of the resistor R7 is connected to the control end of the switch tube Q2, a first end of the switch tube Q2 is connected to the second end of the resistor R6 and the first end of the capacitor C1, a second end of the switch tube Q2 is connected to the second end of the resistor R8 and the second end of the capacitor C1, a first end of the capacitor C1 is connected to the first driving control circuit, and a second end of the capacitor C1 is grounded;

[0011] And / or, in one embodiment, the first drive control circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a switching device U2 and a switching tube Q3, a first end of the resistor R9 is connected to the first switching delay circuit and the first end of the resistor R10, the first end of the resistor R10 is connected to an external power supply, a second end of the resistor R9 is connected to the first end of the resistor R11 and the control end of the switching device U2, a second end of the resistor R11 is connected to the first switching delay circuit and the first end of the resistor R12, a second end of the resistor R12 is connected to the control end of the switching tube Q3, a first end of the resistor R12 is grounded, a first end of the switching device U2 is connected to the second end of the resistor R10 and the switching circuit, a second end of the switching device U2 is connected to the first end of the switching tube Q3, and a second end of the switching tube Q3 is grounded.

[0012] In one embodiment, the driving circuit further includes a third voltage driving circuit, wherein the third voltage driving circuit is connected to the first voltage driving circuit and the second voltage driving circuit, and the third voltage driving circuit is connected to the external power supply and the switching circuit.

[0013] In one embodiment, the third voltage driving circuit includes a second switching delay circuit and the second driving control circuit, the second switching delay circuit is connected to the first voltage driving circuit and the second voltage driving circuit, the second driving control circuit is connected to the second switching delay circuit, and the second driving control circuit is connected to the external power supply and the switching circuit.

[0014] In one embodiment, the second switching delay circuit includes a switch tube Q4, a switch tube Q5, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17 and a capacitor C2, a first end of the resistor R13 is connected to the first voltage driving circuit and the second voltage driving circuit, a second end of the resistor R13 is connected to the first end of the resistor R14 and the control end of the switch tube Q4, a second end of the resistor R14 is connected to the first end of the switch tube Q4, a first end of the resistor R15 is connected to the first end of the switch tube Q4 and the second drive control circuit, a second end of the switch tube Q4 is connected to the first end of the resistor R16 and the first end of the resistor R17, a second end of the resistor R16 is connected to the control end of the switch tube Q5, a first end of the switch tube Q5 is connected to the second end of the resistor R15 and the first end of the capacitor C2, a second end of the switch tube Q5 is connected to the second end of the resistor R17 and the second end of the capacitor C2, a first end of the capacitor C2 is connected to the second drive control circuit, and a second end of the capacitor C2 is grounded;

[0015] And / or, in one embodiment, the second drive control circuit includes a resistor R18, a resistor R19, a resistor R20, a resistor R21, a switching device U3 and a switching tube Q6, a first end of the resistor R18 is connected to the second switching delay circuit and the first end of the resistor R19, the first end of the resistor R19 is connected to an external power supply, a second end of the resistor R18 is connected to the first end of the resistor R20 and the control end of the switching device U3, a second end of the resistor R20 is connected to the first end of the resistor R21 and the control end of the switching tube Q6, a second end of the resistor R21 is connected to the second switching delay circuit, a first end of the resistor R21 is grounded, a first end of the switching device U3 is connected to the second end of the resistor R19 and the switching circuit, a second end of the switching device U3 is connected to the first end of the switching tube Q6, and the second end of the switching tube Q6 is grounded.

[0016] In one embodiment, the third voltage driving circuit further includes a first isolation circuit, and the second switch delay circuit is connected to the first voltage driving circuit and the second voltage driving circuit via the first isolation circuit.

[0017] In one embodiment, the switching circuit includes a resistor R22, a resistor R23 and a switch tube Q7, the first end of the resistor R22 is connected to the drive circuit, the second end of the resistor R22 is connected to the first end of the resistor R23 and the control end of the switch tube Q7, the second end of the resistor R23 is connected to the external power supply, the first end of the switch tube Q7 is connected to the second end of the resistor R23 and the power supply circuit, and the second end of the switch tube Q7 is connected to the power supply circuit and the energy storage power supply circuit.

[0018] In one embodiment, the power supply circuit includes a resistor R24, a resistor R25, a resistor R26, a switch tube Q8, a switch device U4, and a switch device U5. The first end of the switch device U4 is connected to the switch circuit and the external power supply, the second end of the switch device U4 is connected to the first end of the resistor R24 ​​and the first end of the switch device U5, the second end of the switch device U5 is connected to the load and the energy storage power supply circuit, the second end of the resistor R24 ​​is connected to the control end of the switch device U4, the control end of the switch device U5, and the first end of the resistor R25, the control end of the switch tube Q8 is connected to the switch circuit and the energy storage power supply circuit through the resistor R26, the first end of the switch tube Q8 is connected to the second end of the resistor R25, and the second end of the switch tube Q8 is grounded.

[0019] In one embodiment, the energy storage power supply circuit includes a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a switch tube Q9, a switch tube Q10, a switch device U6 and a switch device U7, wherein the first end of the switch device U6 is connected to the load and the power supply circuit, the second end of the switch device U6 is connected to the first end of the resistor R27 and the first end of the switch device U7, the second end of the switch device U7 is connected to the energy storage device and the first end of the resistor R28, and the second end of the resistor R27 is connected to the The control end of the switching device U6, the control end of the switching device U7, and the first end of the resistor R29, the second end of the resistor R29 is connected to the first end of the switching tube Q9, the second end of the switching tube Q9 is grounded, the control end of the switching tube Q9 is connected to the first end of the resistor R30, the second end of the resistor R30 is connected to the second end of the resistor R28 and the first end of the switching tube Q10, the control end of the switching tube Q10 is connected to the switching circuit and the power supply circuit through the resistor R31, and the second end of the switching tube Q10 is grounded.

[0020] In one embodiment, the power switching circuit further includes a second isolation circuit, and the switch circuit is connected to the drive circuit via the second isolation circuit.

[0021] An electrical device comprises an energy storage device, a load and the above-mentioned power switching circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a schematic diagram of the power switching circuit structure in one embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of the power switching circuit structure in another embodiment of the present application;

[0025] Figure 3 This is a schematic diagram of the structure of a first voltage driving circuit in an embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the structure of the second voltage driving circuit in one embodiment of the present application;

[0027] Figure 5 This is a schematic diagram of the power switching circuit structure in another embodiment of the present application;

[0028] Figure 6 This is a schematic diagram of the structure of the third voltage driving circuit in one embodiment of the present application;

[0029] Figure 7 This is a schematic diagram of the power switching circuit structure in another embodiment of the present application. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0031] See also Figure 1A power switching circuit includes: an energy storage power supply circuit 20, a power supply circuit 10, a switching circuit 30 and a driving circuit 40. The energy storage power supply circuit 20 is connected to the load and energy storage device of the electrical equipment, the power supply circuit 10 is connected to the external power supply VIN, the load and the energy storage power supply circuit 20, the switching circuit 30 is connected to the external power supply VIN, the power supply circuit 10 and the energy storage power supply circuit 20, and the driving circuit 40 is connected to the external power supply VIN and the switching circuit 30; the driving circuit 40 is used to distinguish between external power supplies VIN with different voltages, and when the voltage of the external power supply VIN drops to a corresponding preset voltage threshold, output a switching control signal to the switching circuit 30; the switching circuit 30 is used to control the energy storage power supply circuit 20 to turn on to connect the load and the energy storage device, and control the power supply circuit 10 to turn off to disconnect the connection between the external power supply VIN and the load according to the switching control signal.

[0032] Specifically, energy storage power supply circuit 20 utilizes an energy storage device to store electrical energy and power a load. When energy storage power supply circuit 20 is in the on state, the load is connected to the energy storage device, and the energy storage device powers the load. The specific type of energy storage device is not unique and can be, for example, a battery, without specific limitation. The specific type of load is also not unique and can vary depending on the application scenario of the power switching circuit. For example, it can be a fan, a motor, etc., and similarly, there is no specific limitation.

[0033] The power supply circuit 10 utilizes an external power source VIN to power the load. When the power supply circuit 10 is turned on, the external power source VIN is directly transmitted to the load, providing the load with the required electrical energy. The switching circuit 30 outputs a switching control signal to control the on and off of the energy storage power supply circuit 20 and the power supply circuit 10. The driving circuit 40 drives the switching circuit 30. Under the action of the driving signal from the driving circuit 40, the switching circuit 30 outputs a corresponding signal to control the energy storage power supply circuit 20 and the power supply circuit 10 to be in the on state and the off state, respectively, thereby switching the load power supply.

[0034] In the solution of this embodiment, the driving circuit 40 can distinguish between external power supplies VIN of different voltages. That is, under external power supply VIN voltages of different magnitudes, the driving circuit 40 can analyze the actual situation and output a switching control signal to the switching circuit 30 when the voltage of the external power supply VIN drops to the corresponding preset voltage threshold, thereby switching the load power supply from the external power supply VIN power supply mode to the energy storage device power supply in a timely manner.

[0035] For example, when the voltage of the external power supply VIN is 12V (volts), the driving circuit 40 can output a switching control signal to the switch circuit 30 when the voltage drops to the corresponding preset voltage threshold (for example, 11V). Then, under the control of the switch circuit 30, the energy storage power supply circuit 20 is turned on, and the power supply circuit 10 is turned off, and the energy storage device is used to power the load. When the voltage of the external power supply VIN is 9V, the driving circuit 40 can also output a switching control signal to the switch circuit 30 when the voltage drops to the corresponding preset voltage threshold (for example, 8V). Then, under the control of the switch circuit 30, the energy storage power supply circuit 20 is turned on, and the power supply circuit 10 is turned off, and the energy storage device is used to power the load. Through this setting, the power switching circuit is suitable for a variety of different external power supply VIN scenarios. Under different external power supplies VIN, when the external power supply VIN stops supplying power, it can switch to the energy storage device in time to power the load, so that the power switching circuit has a wider range of application scenarios.

[0036] It can be understood that in one embodiment, if the external power supply VIN is in a connected state, the voltage of the external power supply VIN will be greater than the corresponding preset voltage threshold. At this time, the driving circuit 40 will not have a switching control signal, and the power switching circuit will continue to use the external power supply VIN to power the load, while charging the energy storage device through the external power supply VIN (the charging method is not unique and can be achieved by setting an additional charging circuit, etc., which is not specifically limited).

[0037] In another embodiment, if the load power supply mode switches from energy storage device power to external load power supply, then at the moment the external power source VIN is connected, the voltage of the external power source VIN detected by the driver circuit 40 will be greater than the corresponding preset voltage threshold. At this time, the driver circuit 40 will output a control signal opposite to the switching control signal to the switch circuit 30. Ultimately, under the action of this control signal, the energy storage power supply circuit 20 is disconnected and the power supply circuit 10 is turned on, thereby powering the load through the external power source VIN and charging the energy storage device.

[0038] The power switching circuit is provided with a switch circuit 30 and a drive circuit 40. The drive circuit 40 is connected to the external power supply VIN and is connected to the power supply circuit 10 and the energy storage power supply circuit 20 through the switch circuit 30. The drive circuit 40 can distinguish between multiple external power supplies VIN with different voltages, and when the voltage of the connected external power supply VIN drops to the corresponding preset voltage threshold, it outputs a switching control signal to the switch circuit 30, so that under the control of the switch circuit 30, the energy storage power supply circuit 20 is promptly turned on and the power supply circuit 10 is cut off, directly switching to the energy storage device for powering the load. Through this solution, as long as the voltage of the external power supply VIN drops to the corresponding preset voltage threshold, it can be switched to the energy storage device for powering the load in a timely manner, without having to wait too long for the external power supply VIN to power off, avoiding the influence of the large electrolytic capacitor output by the external power supply VIN on the power switching, and ensuring the timeliness of the power supply switching when the electrical equipment is disconnected from charging.

[0039] See also Figure 2 In one embodiment, the driving circuit 40 includes a first voltage driving circuit 41 and a second voltage driving circuit 42, the first voltage driving circuit 41 is connected to the external power supply VIN and the switching circuit 30, and the second voltage driving circuit 42 is connected to the external power supply VIN, the first voltage driving circuit 41 and the switching circuit 30.

[0040] Specifically, the first voltage driving circuit 41 is a circuit that outputs a switching control signal to the switch circuit 30 when the voltage of the external power supply VIN is a first voltage and the voltage of the external power supply VIN drops below a preset voltage threshold corresponding to the first voltage. The second voltage driving circuit 42 is a circuit that outputs a switching control signal to the switch circuit 30 when the voltage of the external power supply VIN is a second voltage and the voltage of the external power supply VIN drops below a preset voltage threshold corresponding to the second voltage.

[0041] The example of the driver circuit 40 distinguishing between two external power supplies VIN of different voltages, with the first voltage being greater than the second voltage, is used for explanation. In the case of a first voltage type power supply of the external power supply VIN, if the voltage of the external power supply VIN is greater than the preset voltage threshold corresponding to the first voltage, the first voltage driver circuit 41 can output an identical control signal to the switch circuit 30 and the second voltage driver circuit 42. The second voltage driver circuit 42 generates another control signal based on the control signal. Both control signals are transmitted to the switch circuit 30. Under the control of the switch circuit 30, the energy storage power supply circuit 20 is disconnected and the power supply circuit 10 is turned on, ultimately providing power through the external power supply VIN. If the voltage of the external power supply VIN is less than or equal to the preset voltage threshold corresponding to the first voltage, the first voltage driver circuit 41 can output another control signal to the second voltage driver circuit 42 and the switch circuit 30. The second voltage driver circuit 42 also generates another control signal based on the control signal. Both control signals are transmitted to the switch circuit 30. Under the control of the switch circuit 30, the energy storage power supply circuit 20 is turned on and the power supply circuit 10 is disconnected, ultimately providing power through the energy storage device.

[0042] When the external power supply VIN is a second voltage type power supply, the first voltage driving circuit 41 will continue to output a type of control signal to the second voltage driving circuit 42 and the switch circuit 30. If the voltage of the external power supply VIN is greater than the preset voltage threshold corresponding to the second voltage, the second voltage driving circuit 42 will output the first type of control signal to the switch circuit 30. At this time, the switch circuit 30, under the action of the output control signal of the first voltage driving circuit 41 and the first type of control signal, disconnects the energy storage power supply circuit 20 and connects the power supply circuit 10, and finally supplies power through the external power supply VIN. If the voltage of the external power supply VIN is less than or equal to the preset voltage threshold corresponding to the second voltage, the second voltage driving circuit 42 will output the second type of control signal to the switch circuit 30. At this time, the switch circuit 30, under the action of the output control signal of the first voltage driving circuit 41 and the second type of control signal, connects the energy storage power supply circuit 20 and disconnects the power supply circuit 10, and finally supplies power through the energy storage device.

[0043] It is understood that the magnitudes of the first voltage and the second voltage are not unique. In a more detailed embodiment, the first voltage is 12 V and the second voltage is 9 V. Correspondingly, in one embodiment, the preset voltage threshold corresponding to the first voltage can be set to 11 V, and the preset voltage threshold corresponding to the second voltage can be set to 8 V.

[0044] The above solution, through the design of the first voltage driving circuit 41 and the second voltage driving circuit 42, enables the power switching circuit to meet the power supply switching under two external voltage sources with different voltages, thereby being suitable for application scenarios where two external power supplies VIN are used for power supply.

[0045] See also Figure 3 In one embodiment, the first voltage driving circuit 41 includes a switching device U1, a resistor R1, a resistor R2, and a resistor R3. The first end of the resistor R1 is connected to the external power supply VIN and the first end of the resistor R2. The second end of the resistor R1 is connected to the control end of the switching device U1 and the first end of the resistor R3. The second end of the resistor R3 is grounded. The first end of the switching device U1 is connected to the second end of the resistor R2, the switching circuit 30, and the second voltage driving circuit 42. The second end of the switching device U1 is connected to the second end of the resistor R3.

[0046] Specifically, resistors R1 and R3 form a voltage divider circuit that divides the voltage of the external power supply VIN and transmits it to the control terminal of the switching device U1. Switching device U1 can be turned on or off under the action of this divided voltage. For ease of understanding, the explanation assumes that switching device U1 is turned on when the divided voltage of switching device U1 is greater than a preset value. When the voltage of the external power supply VIN does not drop, the divided voltage after the first voltage is divided can turn switching device U1 on, and the first voltage drive circuit 41 then outputs a low-level signal to the switching circuit 30. In response to this low-level signal, the switching circuit 30 controls the energy storage power supply circuit 20 to turn off, controls the power supply circuit 10 to turn on, and maintains power supply from the external power supply VIN.

[0047] When the voltage of the external power supply VIN drops to a preset voltage threshold, the divided voltage is insufficient to drive the switching device U1, causing the switching device U1 to turn off. Under the pull-up effect of the external power supply VIN, the first voltage driving circuit 41 outputs a high-level signal to the switching circuit 30. Under the action of this high-level signal, the switching circuit 30 controls the energy storage power supply circuit 20 to turn on and the power supply circuit 10 to turn off, switching to the energy storage device for power supply.

[0048] It should be noted that the specific type of switching device U1 is not limited to a specific device; any device capable of determining whether it is in an on or off state based on the magnitude of the input voltage at the control terminal can be used. For example, in a more detailed embodiment, switching device U1 is a controllable precision voltage regulator chip. Furthermore, switching device U1 can employ a controllable precision voltage regulator chip model TL431.

[0049] See also Figure 4In one embodiment, the second voltage driving circuit 42 includes a first switching delay circuit 421 and a first driving control circuit 422. The first voltage driving circuit 41 and the first driving control circuit 422 are respectively connected to the first switching delay circuit 421, and the first driving control circuit 422 is connected to the external power supply VIN and the switching circuit 30.

[0050] Specifically, in this embodiment, the second voltage drive circuit 42 includes a first switching delay circuit 421 and a first drive control circuit 422. The first switching delay circuit 421 implements a switching delay function based on the output signal of the first voltage drive circuit 41. The first drive control circuit 422 outputs a drive control signal to the switch circuit 30 under the influence of the first switching delay circuit 421 and the external power supply VIN.

[0051] To prevent the output of the second voltage driving circuit 42 from affecting the switch circuit 30 when the voltage of the external power supply VIN drops below a preset voltage threshold corresponding to the first voltage, and to ensure the reliability of power supply mode switching, the first voltage driving circuit 41 can simultaneously output a switching control signal to the first switching delay circuit 421. Under the influence of this switching control signal, the second voltage driving circuit 42 outputs a signal consistent with that of the first voltage driving circuit 41, thereby maintaining the operation of powering the external power supply VIN through the switch circuit 30.

[0052] Taking the first voltage driving circuit 41 in the above embodiment outputting a high-level signal as a switching control signal as an example for explanation, the first voltage driving circuit 41 simultaneously transmits the high-level signal to the first switch delay circuit 421, and delays the conduction time of the first driving control circuit 422 through the first switch delay circuit 421, ensuring that under the pull-up action of the first voltage, the second driving control circuit also outputs a high-level signal to the switching power circuit.

[0053] Please refer to Figure 4In one embodiment, the first switching delay circuit 421 includes a switch tube Q1, a switch tube Q2, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, and a capacitor C1. A first end of the resistor R4 is connected to the first voltage driving circuit 41, a second end of the resistor R4 is connected to the first end of the resistor R5 and the control end of the switch tube Q1, a second end of the resistor R5 is connected to the first end of the switch tube Q1, a first end of the resistor R6 is connected to the first end of the switch tube Q1 and the first driving control circuit 422, a second end of the switch tube Q1 is connected to the first end of the resistor R7 and the first end of the resistor R8, a second end of the resistor R7 is connected to the control end of the switch tube Q2, a first end of the switch tube Q2 is connected to the second end of the resistor R6 and the first end of the capacitor C1, a second end of the switch tube Q2 is connected to the second end of the resistor R8 and the second end of the capacitor C1, a first end of the capacitor C1 is connected to the first driving control circuit 422, and a second end of the capacitor C1 is grounded.

[0054] And / or, in one embodiment, please refer to Figure 4 The first drive control circuit 422 includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a switching device U2, and a switching tube Q3. The first end of the resistor R9 is connected to the first switching delay circuit 421 and the first end of the resistor R10. The first end of the resistor R10 is connected to the external power supply VIN. The second end of the resistor R9 is connected to the first end of the resistor R11 and the control end of the switching device U2. The second end of the resistor R11 is connected to the first switching delay circuit 421 and the first end of the resistor R12. The second end of the resistor R12 is connected to the control end of the switching tube Q3. The first end of the resistor R12 is grounded. The first end of the switching device U2 is connected to the second end of the resistor R10 and the switching circuit 30. The second end of the switching device U2 is connected to the first end of the switching tube Q3. The second end of the switching tube Q3 is grounded.

[0055] Specifically, using the example of the first voltage drive circuit 41 outputting a high-level signal as the switching control signal in the above embodiment, resistor R6 and capacitor C1 form an RC circuit, and the high-level signal is transmitted through resistor R4 to the first switch delay circuit 421. Specifically, by controlling the charging time of capacitor C1, the on-time of the switch Q3 is delayed. The delay time can be set by changing the resistance value of resistor R6 and the capacitance value of capacitor C1 to ensure that the switch Q3 remains off for the required time. Since the switch Q3 is in the off state and the switch device U2 is in the off state, the first drive control circuit 422 can output a high-level signal to the switch circuit 30 under the pull-up effect of the external power supply VIN.

[0056] It can be understood that if the voltage of the external power supply VIN is the second voltage, then under the influence of the second voltage, the first voltage driving circuit 41 will inevitably output a high-level signal due to the pull-up effect of the external power supply VIN due to the excessively low divided voltage. At this time, the second voltage is divided by resistors R9 and R11, causing the second switch device U2 to turn on, and the signal output by the first drive control circuit 422 to the switch circuit 30 is pulled down to a low level. Under the influence of the high-level signal output by the first voltage driving circuit 41 and the low-level signal output by the second voltage driving circuit 42, the switch circuit 30 controls the energy storage power supply circuit 20 to turn off and controls the power supply circuit 10 to turn on, thereby powering the load through the external power supply VIN. However, when the voltage of the external power supply VIN drops to the preset voltage threshold corresponding to the second voltage, the divided voltage is insufficient to control the second switch device U2 to turn on. At the same time, due to the delay effect of the first switch delay circuit 421, the signal output by the first drive control circuit 422 to the switch circuit 30 is pulled up to a high level. Finally, under the action of the high level signal output by the first voltage driving circuit 41 and the high level signal output by the second voltage driving circuit 42 , the switch circuit 30 controls the energy storage power supply circuit 20 to be turned on and turns off the power supply circuit 10 .

[0057] Please refer to Figure 5 In one embodiment, the driving circuit 40 further includes a third voltage driving circuit 43 , which is connected to the first voltage driving circuit 41 and the second voltage driving circuit 42 , and is connected to the external power supply VIN and the switch circuit 30 .

[0058] Specifically, the third voltage driving circuit 43 is a circuit that outputs a switching control signal to the switch circuit 30 when the voltage of the external power supply VIN drops below a preset voltage threshold corresponding to the third voltage when the voltage of the external power supply VIN is at the third voltage. In this embodiment, the voltage of the external power supply VIN can be set to three different levels, thereby implementing three different voltage switching operations for the external power supply VIN.

[0059] When the external power supply VIN is of the first voltage type, if the voltage of the external power supply VIN is greater than the preset voltage threshold corresponding to the first voltage, the first voltage driving circuit 41 can output an identical control signal to the switching circuit 30, the second voltage driving circuit 42, and the third voltage driving circuit 43. The second voltage driving circuit 42 and the third voltage driving circuit 43 generate two other control signals based on the control signal. Finally, all three control signals are transmitted to the switching circuit 30, and then, under the control of the switching circuit 30, the energy storage power supply circuit 20 is disconnected and the power supply circuit 10 is turned on, and power is supplied through the external power supply VIN.

[0060] If the voltage of the external power supply VIN is less than or equal to the preset voltage threshold corresponding to the first voltage, the first voltage driving circuit 41 can output another control signal to the second voltage driving circuit 42, the third voltage driving circuit 43 and the switching circuit 30. The second voltage driving circuit 42 and the third voltage driving circuit 43 will also generate another control signal based on the control signal. The three control signals are all transmitted to the switching circuit 30, and then under the control of the switching circuit 30, the energy storage power supply circuit 20 is turned on and the power supply circuit 10 is disconnected, and power is supplied through the energy storage device.

[0061] When the external power supply VIN is a second voltage type power supply and a third voltage type power supply, under the action of the various control signals output to the switch circuit 30, the switch circuit 30 respectively turns on the energy storage power supply circuit 20 and the power supply circuit 10, thereby realizing switching between different power supply modes. The specific method is similar to the above embodiment and will not be repeated here.

[0062] It can be understood that in other embodiments, the driving circuit 40 may also include a fourth voltage driving circuit 40, a fifth voltage driving circuit 40, etc., to achieve switching control of four, five or even more external power supplies VIN with different voltages. The implementation method is similar to the above-mentioned three external power supplies VIN with different voltages, and will not be repeated here.

[0063] It should be noted that the magnitude of the third voltage is not unique, and in a more detailed embodiment, the third voltage is 5 V. Accordingly, in one embodiment, the preset voltage threshold corresponding to the third voltage is 4 V.

[0064] See also Figure 6 In one embodiment, the third voltage driving circuit 43 includes a second switching delay circuit 431 and a second driving control circuit 432, the second switching delay circuit 431 is connected to the first voltage driving circuit 41 and the second voltage driving circuit 42, the second driving control circuit 432 is connected to the second switching delay circuit 431, and the second driving control circuit 432 is connected to the external power supply VIN and the switching circuit 30.

[0065] Specifically, the third voltage drive circuit 43 is similar to the second voltage drive circuit 42, and both include a switch delay circuit and a drive control circuit. The second switch delay circuit 431 implements the switch delay function based on the output signals of the first and second voltage drive circuits 41 and 42. The second drive control circuit 432 outputs a drive control signal to the switch circuit 30 in response to the second switch delay circuit 431 and the external power supply VIN.

[0066] Similarly, through the solution of this embodiment, it is possible to avoid the output of the third voltage driving circuit 43 affecting the switching circuit 30 when the voltage of the external power supply VIN drops below the preset voltage threshold corresponding to the first voltage, or below the preset voltage threshold corresponding to the second voltage, thereby ensuring the reliability of the power supply mode switching.

[0067] See also Figure 6 In one embodiment, the second switching delay circuit 431 includes a switch transistor Q4, a switch transistor Q5, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, and a capacitor C2. A first end of the resistor R13 is connected to the first voltage driving circuit 41 and the second voltage driving circuit 42. A second end of the resistor R13 is connected to the first end of the resistor R14 and the control end of the switch transistor Q4. A second end of the resistor R14 is connected to the first end of the switch transistor Q4. A first end of the resistor R15 is connected to the first end of the switch transistor Q4 and the second driving control circuit 432. A second end of the switch transistor Q4 is connected to the first end of the resistor R16 and the first end of the resistor R17. A second end of the resistor R16 is connected to the control end of the switch transistor Q5. A first end of the switch transistor Q5 is connected to the second end of the resistor R15 and the first end of the capacitor C2. A second end of the switch transistor Q5 is connected to the second end of the resistor R17 and the second end of the capacitor C2. A first end of the capacitor C2 is connected to the second driving control circuit 432. A second end of the capacitor C2 is grounded.

[0068] And / or, in one embodiment, the second drive control circuit 432 includes a resistor R18, a resistor R19, a resistor R20, a resistor R21, a switch device U3 and a switch tube Q6, a first end of the resistor R18 is connected to the second switch delay circuit 431 and the first end of the resistor R19, the first end of the resistor R19 is connected to the external power supply VIN, the second end of the resistor R18 is connected to the first end of the resistor R20 and the control end of the switch device U3, the second end of the resistor R20 is connected to the first end of the resistor R21 and the control end of the switch tube Q6, the second end of the resistor R21 is connected to the second switch delay circuit 431, the first end of the resistor R21 is grounded, the first end of the switch device U3 is connected to the second end of the resistor R19 and the switch circuit 30, the second end of the switch device U3 is connected to the first end of the switch tube Q6, and the second end of the switch tube Q6 is grounded.

[0069] Specifically, the specific structure of the third voltage drive circuit 43 is similar to that of the second voltage drive circuit 42. Taking the external power supply VIN as a power supply of the third voltage type as an example, during actual operation, if the voltage of the external power supply VIN is greater than the preset voltage threshold corresponding to the third voltage, the first voltage drive circuit 41 and the second voltage drive circuit 42 will be pulled up to output a high level. The second drive control circuit 432 will be in the on state because the voltage after the voltage division of the resistors R18 and R20 is greater than the set value. At this time, the signal output by the second drive control circuit 432 to the switch circuit 30 is a low level signal. That is, at this time, the switch circuit 30 receives the high level signal output by the first voltage drive circuit 41, the high level signal output by the second voltage drive circuit 42, and the low level signal output by the third voltage drive circuit 43. Ultimately, the switch circuit 30 receives the low level signal. At this time, the switch circuit 30 will control the power supply circuit 10 to be turned on and the energy storage power supply circuit 20 to be turned off, and the external power supply VIN will be used to power the load.

[0070] If the voltage of the external power supply VIN is less than or equal to the preset voltage threshold corresponding to the third voltage, the first voltage drive circuit 41 and the second voltage drive circuit 42 will both be pulled up to output a high level. Since the voltage divided by the resistors R18 and R20 is less than or equal to the set value, the second drive control circuit 432 will be in the off state of the switch device U3. At this time, the signal output by the second drive control circuit 432 to the switch circuit 30 is a high level signal. That is, at this time, the switch circuit 30 receives the high level signal output by the first voltage drive circuit 41, the high level signal output by the second voltage drive circuit 42, and the high level signal output by the third voltage drive circuit 43. Ultimately, the switch circuit 30 receives the high level signal. At this time, the switch circuit 30 will control the power supply circuit 10 to be off and the energy storage power supply circuit 20 to be on, so that the energy storage device can power the load.

[0071] See also Figure 6 In one embodiment, the third voltage driving circuit 43 further includes a first isolation circuit 433 , and the second switch delay circuit 431 is connected to the first voltage driving circuit 41 and the second voltage driving circuit 42 through the first isolation circuit 433 .

[0072] Specifically, in the solution of this embodiment, an isolation circuit is further provided between the second switch delay circuit 431 and the first voltage drive circuit 41 and the second voltage drive circuit 42. Electrical isolation is performed through the isolation circuit to avoid mutual interference between the third voltage drive circuit 43 and the first voltage drive circuit 41 and the second voltage drive circuit 42.

[0073] It should be noted that the specific type of the first isolation circuit 433 is not unique. In a more specific embodiment, see Figure 6 The first isolation circuit 433 includes a diode D1 and a diode D2, the anode of the diode D1 and the anode of the diode D2 are respectively connected to the second switch delay circuit 431, the cathode of the diode D1 is connected to the first voltage driving circuit 41, and the cathode of the diode D2 is connected to the second voltage driving circuit 42.

[0074] See also Figure 7 In one embodiment, the switching circuit 30 includes a resistor R22, a resistor R23, and a switch tube Q7. The first end of the resistor R22 is connected to the drive circuit 40, the second end of the resistor R22 is connected to the first end of the resistor R23 and the control end of the switch tube Q7, the second end of the resistor R23 is connected to the external power supply VIN, the first end of the switch tube Q7 is connected to the second end of the resistor R23 and the power supply circuit 10, and the second end of the switch tube Q7 is connected to the power supply circuit 10 and the energy storage power supply circuit 20.

[0075] Specifically, in this embodiment, the switching circuit 30 includes a switch Q7 and resistors R22 and R23. When a switching control signal is output by the drive circuit 40, the switch Q7 is turned off, thereby turning off the power supply circuit 10 and turning on the energy storage power supply circuit 20, thereby switching the power supply mode from the external power supply VIN to the energy storage device. When the switching control signal is not received, the switch Q7 is turned on, thereby turning on the power supply circuit 10 and turning off the energy storage power supply circuit 20, thereby switching power to the external power supply VIN.

[0076] In a more detailed embodiment, the switching control signal is a high-level signal. When each voltage driving circuit 40 outputs a high-level signal, the switch circuit 30 controls the energy storage power supply circuit 20 to conduct, thereby connecting the load and the energy storage device, and controls the power supply circuit 10 to shut down, thereby disconnecting the external power supply VIN from the load. Conversely, when any voltage driving circuit 40 outputs a low-level signal, the switch circuit 30 receives a low-level signal, which in turn controls the energy storage power supply circuit 20 to shut down and controls the power supply circuit 10 to conduct.

[0077] It is understood that the specific structure of the power supply circuit 10 is not unique. Figure 7In one embodiment, the power supply circuit 10 includes a resistor R24, a resistor R25, a resistor R26, a switch tube Q8, a switch device U4, and a switch device U5. A first end of the switch device U4 is connected to the switch circuit 30 and the external power supply VIN, a second end of the switch device U4 is connected to the first end of the resistor R24 ​​and the first end of the switch device U5, a second end of the switch device U5 is connected to the load and the energy storage power supply circuit 20, a second end of the resistor R24 ​​is connected to the control end of the switch device U4, the control end of the switch device U5, and the first end of the resistor R25, a control end of the switch tube Q8 is connected to the switch circuit 30 and the energy storage power supply circuit 20 via the resistor R26, a first end of the switch tube Q8 is connected to the second end of the resistor R25, and a second end of the switch tube Q8 is grounded.

[0078] Specifically, under the action of the switching control signal output by the drive circuit 40, when the switch tube Q7 is disconnected, the switch tube Q8 in the power supply circuit 10 is in the cut-off state, and the switch device U4 and the switch device U5 are in the disconnected state. Correspondingly, the connection between the external power supply VIN and the load is disconnected at this time, and the external power supply VIN stops supplying power.

[0079] See also Figure 7 In one embodiment, the energy storage power supply circuit 20 includes a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a switch tube Q9, a switch tube Q10, a switch device U6, and a switch device U7. A first end of the switch device U6 is connected to the load and the power supply circuit 10. A second end of the switch device U6 is connected to the first end of the resistor R27 and the first end of the switch device U7. A second end of the switch device U7 is connected to the energy storage device and the first end of the resistor R28. A second end of the resistor R27 is connected to the control end of the switch device U6, the control end of the switch device U7, and the first end of the resistor R29. A second end of the resistor R29 is connected to the first end of the switch tube Q9. The second end of the switch tube Q9 is grounded. The control end of the switch tube Q9 is connected to the first end of the resistor R30. The second end of the resistor R30 is connected to the second end of the resistor R28 and the first end of the switch tube Q10. The control end of the switch tube Q10 is connected to the switch circuit 30 and the power supply circuit 10 via the resistor R31. The second end of the switch tube Q10 is grounded.

[0080] Specifically, under the action of the switching control signal output by the drive circuit 40, when the switch tube Q7 is disconnected, the switch tube Q10 in the energy storage power supply circuit 20 is in the off state, and the switch tube Q9 is in the on state, so that the switch device U6 and the switch device U7 are turned on. Correspondingly, the connection between the energy storage device and the load is turned on at this time, and the energy storage device enters the power supply state.

[0081] See also Figure 7In one embodiment, the power switching circuit further includes a second isolation circuit 50 , and the switch circuit 30 is connected to the drive circuit 40 via the second isolation circuit 50 .

[0082] Specifically, in the solution of this embodiment, an isolation circuit is further provided between the switch circuit 30 and the drive circuit 40, and electrical isolation is performed by the isolation circuit to avoid mutual interference between the drive circuit 40 and the switch circuit 30. It should be noted that the specific type of the second isolation circuit 50 is not unique. In a more specific embodiment, see Figure 7 The second isolation circuit 50 includes a diode D3, a diode D4 and a diode D5. The anodes of the diode D3, the anodes of the diode D4 and the anodes of the diode D5 are respectively connected to the switching circuit 30, the cathode of the diode D3 is connected to the first voltage driving circuit 41, the cathode of the diode D4 is connected to the second voltage driving circuit 42, and the cathode of the diode D5 is connected to the third voltage driving circuit 43.

[0083] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with a detailed circuit structure.

[0084] Taking a 12V external power supply VIN as an example, when the external power supply VIN is not powered off (i.e., when the power adapter is not unplugged), the voltage of the external power supply VIN is greater than the corresponding preset voltage threshold (11V). At this point, after the voltage is divided by resistors R1 and R3 at point a, the resulting voltage value is greater than the turn-on voltage (2.5V) of switch device U1. At this time, switch device U1 is in the on state, and the signal output from the ON1 terminal of the first voltage drive circuit 41 to the second voltage drive circuit 42, the third voltage drive circuit 43, and the switch circuit 30 is a low-level signal. At this time, the divided voltage at points b and c are both greater than the corresponding preset voltage thresholds, and switch devices U2 and U3 are turned on. In response to the received low-level signal, the second voltage drive circuit 42 turns on switch Q1 and turns off switch Q3. At this time, the second voltage drive circuit 42 is pulled up and outputs a high-level signal to the third drive circuit 40 and the switch circuit 30. When the third drive circuit 40 receives the high and low levels, the switch Q4 turns on and the switch Q6 turns off. At this point, the third voltage drive circuit 43 is pulled up and outputs a high level to the switch circuit 30. Finally, when the switch circuit 30 receives the high and low levels, the switch Q7 turns on, the switch Q8 in the power supply circuit 10 turns on, and the switch devices U4 and U5 turn on. Accordingly, the external power supply VIN and the load are now connected, enabling power supply from the external power supply VIN. The switch Q10 in the energy storage power supply circuit 20 turns on, while the switch Q9 turns off, causing the switch devices U6 and U7 to disconnect, thereby disconnecting the energy storage device from the load.

[0085] When the external power supply VIN loses power, that is, when the power adapter is unplugged, the voltage of the external power supply VIN gradually decreases until it falls below the corresponding preset voltage threshold (11V). At this point, after the voltage is divided by resistors R1 and R3 at point a, the resulting voltage value is less than the on-state voltage (2.5V) of the switch device U1. At this time, the switch device U1 is in the off state, and the signal output from the ON1 terminal of the first voltage drive circuit 41 to the second voltage drive circuit 42, the third voltage drive circuit 43, and the switch circuit 30 is a high-level signal. Under the influence of the received high-level signal, the second voltage drive circuit 42, through the switching delay effect, turns the switch tube Q3 into the off state, and the switch device U2 into the off state. Therefore, under the pull-up effect of the external power supply VIN, the ON2 terminal of the first drive control circuit 422 can output a high-level signal to the switch circuit 30 and the third voltage drive circuit 43. In response to the received high-level signal, the third voltage drive circuit 43, through a switching delay, turns switch Q6 off and switches U3 off. Consequently, under the pull-up action of the external power supply VIN, the ON3 terminal of the second drive control circuit 432 can output a high-level signal to the switch circuit 30. Ultimately, in response to the received high-level signal, switch Q7 in the switch circuit 30 turns off, switches Q8 in the power supply circuit 10 turn off, and switches U4 and U5 are disconnected. Consequently, the connection between the external power supply VIN and the load is disconnected. Switch Q10 in the energy storage power supply circuit 20 turns off, while switch Q9 turns on, turning on switches U6 and U7. Consequently, the connection between the energy storage device and the load is established, enabling the energy storage device to power the load.

[0086] When the external power supply VIN is 9V or 5V, the operating principle of the power switching circuit is similar to that described above for the 12V case. Under the control of each driver circuit 40, if the external power supply VIN is not powered down, that is, the voltage of the external power supply VIN is greater than the corresponding preset voltage threshold, the signals output by the three driver circuits 40 to the switch circuit 30 will always be one low-level signal and two high-level signals, thereby maintaining power supply from the external power supply VIN. If the external power supply VIN is not powered down, that is, the voltage of the external power supply VIN is less than or equal to the corresponding preset voltage threshold, the signals output by the three driver circuits 40 to the switch circuit 30 will all be high-level signals, thereby switching power to the energy storage device. Details will not be repeated here.

[0087] An electrical device comprises an energy storage device, a load and the above-mentioned power switching circuit.

[0088] Specifically, the electrical equipment is as shown in the above-mentioned embodiments and drawings, and will not be described in detail here. The specific type of electrical equipment is not unique, and can be a fan, a humidifier, etc., which is not specifically limited. The above-mentioned electrical equipment is provided with a switching circuit 30 and a driving circuit 40. The driving circuit 40 is connected to the external power supply VIN and is connected to the power supply circuit 10 and the energy storage power supply circuit 20 through the switching circuit 30. The driving circuit 40 can distinguish between multiple external power supplies VIN with different voltages, and when the voltage of the connected external power supply VIN drops to the corresponding preset voltage threshold, the switching control signal is output to the switching circuit 30, so that the energy storage power supply circuit 20 is turned on in time under the control of the switching circuit 30, and the power supply circuit 10 is cut off, and the load is directly switched to the energy storage device for power supply. Through this solution, only when the voltage of the external power supply VIN drops to the corresponding preset voltage threshold, it can be switched to the energy storage device for powering the load in time, without waiting for too much time for the external power supply VIN to power off, avoiding the influence of the large electrolytic capacitor output by the external power supply VIN on the power switching, and ensuring the timeliness of the power supply switching when the electrical equipment is disconnected from charging.

[0089] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A power switching circuit, characterized in that: include: Energy storage power supply circuit, connecting the load of the electrical equipment and the energy storage device; A power supply circuit, connected to an external power supply, the load and the energy storage power supply circuit; a switch circuit, connecting the external power supply, the power supply circuit and the energy storage power supply circuit; a driving circuit, connected to the external power supply and the switching circuit; The driving circuit is used to distinguish between external power sources of different voltages, and when the voltage of the external power source drops to a corresponding preset voltage threshold, output a switching control signal to the switching circuit; the switching circuit is used to control the energy storage power supply circuit to be turned on to connect the load and the energy storage device, and to control the power supply circuit to be turned off to disconnect the external power source and the load according to the switching control signal; The driving circuit includes a first voltage driving circuit and a second voltage driving circuit, the first voltage driving circuit is connected to the external power supply and the switching circuit, and the second voltage driving circuit is connected to the external power supply, the first voltage driving circuit and the switching circuit; The first voltage is greater than the second voltage; in the case where the external power supply is a first voltage type power supply, when the voltage of the external power supply drops to less than or equal to a preset voltage threshold corresponding to the first voltage, the first voltage driving circuit outputs the same control signal to the switching circuit and the second voltage driving circuit, the second voltage driving circuit generates a control signal based on the control signal output by the first voltage driving circuit and outputs the control signal to the switching circuit, and the switching circuit turns on the energy storage power supply circuit and turns off the power supply circuit based on the two received control signals; In the case of a second voltage type power supply of the external power supply, the first voltage driving circuit maintains outputting one type of control signal to the second voltage driving circuit and the switching circuit. When the voltage of the external power supply drops to a value less than or equal to a preset voltage threshold corresponding to the second voltage, the second voltage driving circuit outputs a second type of control signal to the switching circuit. The switching circuit turns on the energy storage power supply circuit and disconnects the power supply circuit according to the two received control signals.

2. The power switching circuit according to claim 1, wherein: The first voltage driving circuit includes a switching device U1, a resistor R1, a resistor R2 and a resistor R3, the first end of the resistor R1 is connected to the external power supply and the first end of the resistor R2, the second end of the resistor R1 is connected to the control end of the switching device U1 and the first end of the resistor R3, the second end of the resistor R3 is grounded, the first end of the switching device U1 is connected to the second end of the resistor R2, the switching circuit and the second voltage driving circuit, and the second end of the switching device U1 is connected to the second end of the resistor R3.

3. The power switching circuit according to claim 1, wherein: The second voltage driving circuit includes a first switching delay circuit and a first driving control circuit. The first voltage driving circuit and the first driving control circuit are respectively connected to the first switching delay circuit. The first driving control circuit is connected to the external power supply and the switching circuit.

4. The power switching circuit according to claim 3, wherein: The first switching delay circuit includes a switch tube Q1, a switch tube Q2, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8 and a capacitor C1, a first end of the resistor R4 is connected to the first voltage driving circuit, a second end of the resistor R4 is connected to the first end of the resistor R5 and the control end of the switch tube Q1, a second end of the resistor R5 is connected to the first end of the switch tube Q1, a first end of the resistor R6 is connected to the first end of the switch tube Q1 and the first driving control circuit, a second end of the switch tube Q1 is connected to the first end of the resistor R7 and the first end of the resistor R8, a second end of the resistor R7 is connected to the control end of the switch tube Q2, a first end of the switch tube Q2 is connected to the second end of the resistor R6 and the first end of the capacitor C1, a second end of the switch tube Q2 is connected to the second end of the resistor R8 and the second end of the capacitor C1, a first end of the capacitor C1 is connected to the first driving control circuit, and a second end of the capacitor C1 is grounded; And / or, the first drive control circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a switching device U2 and a switching tube Q3, a first end of the resistor R9 is connected to the first switching delay circuit and the first end of the resistor R10, the first end of the resistor R10 is connected to an external power supply, a second end of the resistor R9 is connected to the first end of the resistor R11 and the control end of the switching device U2, a second end of the resistor R11 is connected to the first switching delay circuit and the first end of the resistor R12, a second end of the resistor R12 is connected to the control end of the switching tube Q3, a first end of the resistor R12 is grounded, a first end of the switching device U2 is connected to the second end of the resistor R10 and the switching circuit, a second end of the switching device U2 is connected to the first end of the switching tube Q3, and a second end of the switching tube Q3 is grounded.

5. The power switching circuit according to any one of claims 1 to 4, characterized in that: The driving circuit further includes a third voltage driving circuit, wherein the third voltage driving circuit is connected to the first voltage driving circuit and the second voltage driving circuit, and the third voltage driving circuit is connected to the external power supply and the switching circuit.

6. The power switching circuit according to claim 5, wherein: The third voltage driving circuit includes a second switch delay circuit and a second drive control circuit, the second switch delay circuit is connected to the first voltage driving circuit and the second voltage driving circuit, the second drive control circuit is connected to the second switch delay circuit, and the second drive control circuit is connected to the external power supply and the switch circuit.

7. The power switching circuit according to claim 6, wherein: The second switching delay circuit includes a switch tube Q4, a switch tube Q5, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17 and a capacitor C2, wherein a first end of the resistor R13 is connected to the first voltage driving circuit and the second voltage driving circuit, a second end of the resistor R13 is connected to the first end of the resistor R14 and the control end of the switch tube Q4, a second end of the resistor R14 is connected to the first end of the switch tube Q4, a first end of the resistor R15 is connected to the first end of the switch tube Q4 and the second drive control circuit, a second end of the switch tube Q4 is connected to the first end of the resistor R16 and the first end of the resistor R17, a second end of the resistor R16 is connected to the control end of the switch tube Q5, a first end of the switch tube Q5 is connected to the second end of the resistor R15 and the first end of the capacitor C2, a second end of the switch tube Q5 is connected to the second end of the resistor R17 and the second end of the capacitor C2, a first end of the capacitor C2 is connected to the second drive control circuit, and a second end of the capacitor C2 is grounded; And / or, the second drive control circuit includes a resistor R18, a resistor R19, a resistor R20, a resistor R21, a switching device U3 and a switching tube Q6, a first end of the resistor R18 is connected to the second switching delay circuit and the first end of the resistor R19, the first end of the resistor R19 is connected to an external power supply, the second end of the resistor R18 is connected to the first end of the resistor R20 and the control end of the switching device U3, the second end of the resistor R20 is connected to the first end of the resistor R21 and the control end of the switching tube Q6, the second end of the resistor R21 is connected to the second switching delay circuit, the first end of the resistor R21 is grounded, the first end of the switching device U3 is connected to the second end of the resistor R19 and the switching circuit, the second end of the switching device U3 is connected to the first end of the switching tube Q6, and the second end of the switching tube Q6 is grounded.

8. The power switching circuit according to claim 6, wherein: The third voltage driving circuit further includes a first isolation circuit, and the second switch delay circuit is connected to the first voltage driving circuit and the second voltage driving circuit via the first isolation circuit.

9. The power switching circuit according to any one of claims 1 to 4, wherein: The switching circuit includes a resistor R22, a resistor R23 and a switching tube Q7. The first end of the resistor R22 is connected to the drive circuit, the second end of the resistor R22 is connected to the first end of the resistor R23 and the control end of the switching tube Q7, the second end of the resistor R23 is connected to the external power supply, the first end of the switching tube Q7 is connected to the second end of the resistor R23 and the power supply circuit, and the second end of the switching tube Q7 is connected to the power supply circuit and the energy storage power supply circuit.

10. The power switching circuit according to any one of claims 1 to 4, characterized in that: The power supply circuit includes a resistor R24, a resistor R25, a resistor R26, a switch tube Q8, a switch device U4 and a switch device U5. The first end of the switch device U4 is connected to the switch circuit and the external power supply, the second end of the switch device U4 is connected to the first end of the resistor R24 ​​and the first end of the switch device U5, the second end of the switch device U5 is connected to the load and the energy storage power supply circuit, the second end of the resistor R24 ​​is connected to the control end of the switch device U4, the control end of the switch device U5 and the first end of the resistor R25, the control end of the switch tube Q8 is connected to the switch circuit and the energy storage power supply circuit through the resistor R26, the first end of the switch tube Q8 is connected to the second end of the resistor R25, and the second end of the switch tube Q8 is grounded.

11. The power switching circuit according to any one of claims 1 to 4, wherein: The energy storage power supply circuit includes a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a switch tube Q9, a switch tube Q10, a switch device U6, and a switch device U7. A first end of the switch device U6 is connected to the load and the power supply circuit, a second end of the switch device U6 is connected to the first end of the resistor R27 and the first end of the switch device U7, a second end of the switch device U7 is connected to the energy storage device and the first end of the resistor R28, a second end of the resistor R27 is connected to the control end of the switch device U6, the control end of the switch device U7, and the first end of the resistor R29, a second end of the resistor R29 is connected to the first end of the switch tube Q9, a second end of the switch tube Q9 is grounded, a control end of the switch tube Q9 is connected to the first end of the resistor R30, a second end of the resistor R30 is connected to the second end of the resistor R28 and the first end of the switch tube Q10, a control end of the switch tube Q10 is connected to the switch circuit and the power supply circuit via the resistor R31, and a second end of the switch tube Q10 is grounded.

12. The power switching circuit according to any one of claims 1 to 4, characterized in that: The power switching circuit further includes a second isolation circuit, and the switch circuit is connected to the drive circuit via the second isolation circuit.

13. An electrical device, characterized in that: The invention comprises an energy storage device, a load and the power switching circuit according to any one of claims 1 to 12.

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