An adaptive power switching control system and device

Abstract

The application provides an adaptive power switching control system and device, wherein the adaptive power switching control system comprises a power switching control circuit, an external power supply circuit and an internal power supply circuit connected with a power supply end of a target device, a three-terminal voltage stabilizing circuit and a first controlled switch, wherein the reference end of the three-terminal voltage stabilizing circuit is connected with the input end of the external power supply circuit, the input end is connected with the input end of the external power supply circuit, and the output end is connected with the control end of the first controlled switch; the first end of the first controlled switch is connected with the input end of the external power supply circuit, and the second end is connected with the control end of the external power supply circuit and the control end of the power switching control circuit; and the output end of the three-terminal voltage stabilizing circuit outputs a high / low level signal according to the relationship between the voltage connected with the reference end and the preset reference voltage. By setting the three-terminal voltage stabilizing circuit, the machine shutdown caused by long power-off time of the target device is avoided, and the voltage switching time is greatly shortened.

Description

Technical Field

[0001] This invention relates to the field of circuit control, and more specifically to an adaptive power switching control system and device. Background Technology

[0002] As portable devices continue to upgrade, users are placing higher demands on them. For portable devices with built-in rechargeable power modules, they can be charged via their internal modules when used outdoors or in scenarios without external power. Conversely, when used indoors or in scenarios with external power, they can be charged via an external power source. This allows the portable device to operate normally while simultaneously charging its internal rechargeable power module, achieving a cycle of use. However, in existing technologies, the large electrolytic capacitors in the external adapters of portable devices cause a prolonged power outage when switching from external power to the internal rechargeable power module. This prevents the overall system voltage from quickly switching from the external power supply voltage to the internal battery voltage, potentially leading to device shutdown and affecting user experience. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art where the large electrolytic capacitor in the external adapter of portable devices causes a long power outage time when switching from external power supply to internal rechargeable power module charging. This makes it impossible for the overall system voltage of the portable device to switch quickly from the external power supply voltage to the internal battery voltage, which may eventually lead to the shutdown of the entire device and affect the user's use of the device. Therefore, the present invention provides an adaptive power switching control system and device.

[0004] According to a first aspect, embodiments of the present invention provide an adaptive power switching control system, the adaptive power switching control system comprising: a power switching control circuit and an external power supply circuit and an internal power supply circuit respectively connected to the power supply terminal of a target device, the power switching control circuit being used to switch between the external power supply circuit and the internal power supply circuit to supply power to the target device, the system further comprising: a three-terminal voltage regulator circuit and a first controlled switch, wherein...

[0005] The reference terminal of the three-terminal voltage regulator circuit is connected to the input terminal of the external power supply circuit, the input terminal is connected to the input terminal of the external power supply circuit, and the output terminal is connected to the control terminal of the first controlled switch.

[0006] The first terminal of the first controlled switch is connected to the input terminal of the external power supply circuit, and the second terminal is connected to the control terminal of the external power supply circuit and the control terminal of the power switching control circuit, respectively.

[0007] The output terminal of the three-terminal voltage regulator circuit outputs a high / low level signal based on the relationship between the voltage connected to its reference terminal and the preset reference voltage to control the first controlled switch to be turned on or off, thereby realizing the switching between the external power supply circuit and the internal power supply circuit. The preset reference voltage is less than or equal to the power supply voltage of the external power supply circuit.

[0008] Optionally, the three-terminal voltage regulator circuit includes: a three-terminal adjustable shunt parallel voltage regulator and a voltage divider circuit, wherein,

[0009] The input terminal of the voltage divider circuit is connected to the input terminal of the external power supply circuit, and the output terminal is connected to the reference terminal of the three-terminal adjustable shunt parallel voltage regulator. The input terminal of the three-terminal adjustable shunt parallel voltage regulator is connected to the input terminal of the external power supply circuit, and the output terminal is connected to the control terminal of the first controlled switch.

[0010] When the reference voltage of the three-terminal adjustable shunt parallel regulator is less than the corresponding reference voltage of the three-terminal adjustable shunt parallel regulator, the output terminal of the three-terminal adjustable shunt parallel regulator outputs a high-level signal.

[0011] When the reference terminal voltage of the three-terminal adjustable shunt parallel regulator is not less than the corresponding reference voltage of the three-terminal adjustable shunt parallel regulator, the output terminal of the three-terminal adjustable shunt parallel regulator outputs a low-level signal.

[0012] Optionally, the three-terminal voltage regulator circuit further includes: a first resistor, one end of which is connected to the input terminal of the external power supply circuit, and the other end of which is connected to the input terminal of the three-terminal adjustable shunt parallel voltage regulator.

[0013] Optionally, the three-terminal adjustable shunt parallel voltage regulator is a TL431.

[0014] Optionally, the adaptive power switching control system further includes: a second resistor and a third resistor, wherein,

[0015] One end of the second resistor is connected to the output terminal of the three-terminal adjustable shunt parallel voltage regulator, and the other end is connected to one end of the third resistor and the control terminal of the first controlled switch, respectively.

[0016] The other end of the third resistor is connected to the input terminal of the external power supply circuit.

[0017] Optionally, the external power supply circuit includes: a second controlled switch and a first power supply circuit, wherein,

[0018] The first terminal of the second controlled switch is connected to the control terminal of the first power supply circuit, the second terminal is grounded, and the control terminal is connected to the second terminal of the first controlled switch.

[0019] The input terminal of the first power supply circuit is connected to an external power supply, and the output terminal is connected to the power supply terminal of the target device.

[0020] Optionally, the internal power supply circuit includes: a third controlled switch and a second power supply circuit, wherein,

[0021] The first terminal of the third controlled switch is connected to the control terminal of the second power supply circuit, the second terminal is grounded, and the control terminal is connected to the output terminal of the power switching control circuit.

[0022] The input terminal of the second power supply circuit is connected to the internal power supply of the target device, and the output terminal is connected to the power supply terminal of the target device.

[0023] Optionally, the power switching control circuit includes: a fourth controlled switch, the control terminal of the fourth controlled switch being connected to the second terminal of the first controlled switch, the first terminal being connected to the control terminal of the third controlled switch, and the second terminal being grounded.

[0024] Optionally, the first controlled switch is a PNP transistor.

[0025] According to a second aspect, embodiments of the present invention provide an adaptive power switching control device, the adaptive power switching control device comprising: an adaptive power switching control system as described in the first aspect, or any optional embodiment of the first aspect.

[0026] The technical solution of this invention has the following advantages:

[0027] 1. The adaptive power switching control system provided by this invention switches between the external power supply circuit and the internal power supply circuit through a power switching control circuit and a first controlled switch. By using the relationship between the voltage connected to the reference terminal of the three-terminal voltage regulator circuit and the preset reference voltage, a high / low level signal is output at the output terminal to control the operation of the power switching control circuit and the external power supply circuit, thereby realizing the switching between the external power supply circuit and the internal power supply circuit. By setting the three-terminal voltage regulator circuit, not only is the shutdown of the target device due to long power outage time avoided, but the time for the voltage of the target device to switch from the external power supply voltage to the internal battery voltage is further shortened, and the user experience is greatly improved.

[0028] 2. The adaptive power switching control system provided by this invention includes a three-terminal adjustable shunt parallel regulator and a voltage divider circuit. Due to the special working principle of the three-terminal adjustable shunt parallel regulator, it can output a high / low level signal according to the relationship between the reference terminal voltage and the corresponding reference voltage, thereby realizing the switching between the external power supply circuit and the internal power supply circuit. By setting the voltage divider circuit, a corresponding reference voltage is provided for the three-terminal adjustable shunt parallel regulator, ensuring the efficient and stable operation of the adaptive power switching control system.

[0029] 3. The adaptive power switching control system provided by the present invention, by setting a first resistor, one end of the first resistor is connected to the input terminal of the external power supply circuit, and the other end is connected to the input terminal of the three-terminal adjustable shunt parallel voltage regulator, the circuit is current limited by the first resistor, thereby realizing the power supply control of the target device by the external power supply circuit.

[0030] 4. The adaptive power switching control system provided by the present invention uses a TL431 three-terminal adjustable shunt parallel voltage regulator. By utilizing the voltage regulation characteristics of the TL431, the adaptive power switching control system is ensured to always operate under a stable operating voltage, further ensuring the stable operation of the target equipment and improving user satisfaction.

[0031] 5. The adaptive power switching control system provided by the present invention, by setting a second resistor and a third resistor, not only effectively ensures the stable operation of the three-terminal voltage regulator circuit, but also assists the first controlled switch and the power switching control circuit in realizing the flexible switching of the adaptive power switching control system, avoiding the situation where the target equipment stops due to excessive power outage time, and greatly improving user satisfaction.

[0032] 6. The adaptive power switching control system provided by the present invention includes an external power supply circuit comprising a second controlled switch and a first power supply circuit. Through the coordinated operation of the second controlled switch and the first power supply circuit, the external power supply circuit provides power to the target device. When the second controlled switch and the first power supply circuit are turned off, the power switching control circuit switches the control to the internal power supply circuit, which then provides power to the target device, thereby preventing the target device from interrupting operation and providing a better user experience.

[0033] 7. The adaptive power switching control system provided by the present invention includes an internal power supply circuit comprising a third controlled switch and a second power supply circuit. Through the coordinated operation of the third controlled switch and the second power supply circuit, the power supply circuit provides power to the target device. When the third controlled switch and the second power supply circuit are controlled to be connected, the power switching control circuit will control the switch to the internal power supply circuit to provide power to the target device, thereby avoiding interruption of the target device's operation and bringing a better user experience.

[0034] 8. The adaptive power switching control system provided by the present invention is equipped with a fourth controlled switch. The control terminal of the fourth controlled switch is connected to the second terminal of the first controlled switch, the first terminal is connected to the control terminal of the third controlled switch, and the second terminal is grounded. The switching between the external power supply circuit and the internal power supply circuit is performed through the fourth controlled switch to ensure the normal use of the target equipment by the user, avoid the mid-term shutdown of the target equipment, and greatly improve user satisfaction.

[0035] 9. The adaptive power switching control device provided by the present invention, by setting the adaptive power switching control system as described in another embodiment of the present invention, not only avoids the situation where the target device will shut down due to a long power outage time, but also further shortens the time for the target device's voltage to switch from the external power supply voltage to the internal battery voltage, thus greatly improving the user experience. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a switching circuit structure in the prior art according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the adaptive power switching control system according to an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the adaptive power switching control device according to an embodiment of the present invention. Detailed Implementation

[0040] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] In existing technologies, such as Figure 1 As shown, existing technologies do not consider the inability to quickly switch charging power due to large electrolytic capacitors in the external adapter. Portable devices with internal charging circuits cannot be powered off immediately, and users may encounter situations where the portable device stops midway and needs to be restarted, resulting in a poor user experience. Based on this, embodiments of the present invention provide an adaptive power switching control system and device. By improving the pure hardware circuit, it not only reduces the control of the main MCU but also further accelerates the hardware response speed, preventing power loss from the entire device load.

[0045] Example 1

[0046] like Figure 2 As shown, this embodiment of the invention provides an adaptive power switching control system, including: a power switching control circuit 10 and an external power supply circuit 20 and an internal power supply circuit 30 respectively connected to the power supply terminal of a target device. The power switching control circuit 10 is used to switch between the external power supply circuit 20 and the internal power supply circuit 30 to supply power to the target device. The system further includes: a three-terminal voltage regulator circuit 40 and a first controlled switch Q7, wherein...

[0047] The reference terminal of the three-terminal voltage regulator circuit 40 is connected to the input terminal of the external power supply circuit 20, the input terminal is connected to the input terminal of the external power supply circuit 20, and the output terminal is connected to the control terminal of the first controlled switch Q7.

[0048] The first terminal of the first controlled switch Q7 is connected to the input terminal of the external power supply circuit 20, and the second terminal is connected to the control terminal of the external power supply circuit 20 and the control terminal of the power switching control circuit 10, respectively.

[0049] The output terminal of the three-terminal voltage regulator circuit 40 outputs a high / low level signal according to the relationship between the voltage connected to its reference terminal and the preset reference voltage, so as to control the first controlled switch Q7 to be turned on or off, thereby realizing the switching between the external power supply circuit 20 and the internal power supply circuit 30. The preset reference voltage is less than or equal to the power supply voltage of the external power supply circuit 20.

[0050] As one implementation of this embodiment, the first controlled switch Q7 is a PNP transistor, but the actual situation is not limited to this. The selection and quantity of the first controlled switch Q7 can be changed according to actual needs.

[0051] Specifically, such as Figure 2 As shown, V_IN represents the voltage of the external power supply circuit 20, VBAT represents the circuit voltage of the internal power supply circuit 30, and VCC represents the power supply voltage of the entire system. The external power supply circuit 20 is equipped with U1 / U2 switching transistors; the internal power supply circuit 30 is equipped with U3 / U4 switching transistors. By turning on and off the U1 / U2 / U3 / U4 switching transistors, VCC is switched to V_IN or VBAT, thereby realizing the switching between the external power supply circuit 20 and the internal power supply circuit 30.

[0052] Specifically, the preset reference voltage is used to determine whether an external power supply failure has occurred, and to execute the switching action from external power supply to internal power supply. When the supply voltage is lower than the preset reference voltage, it is considered that the external power supply has failed. The closer the value is to the supply voltage of the external power supply circuit 20, the faster the power supply circuit switches, but the corresponding anti-interference capability will be reduced. Therefore, the preset reference voltage can be flexibly set according to the stability of the supply voltage of the external power supply circuit 20 and the requirements of the power supply circuit switching speed. This invention is not limited to this. In practical applications, taking V_IN as 12V as an example, the preset reference voltage can be set to 11V, but the actual situation is not limited to this. The values ​​of the external power supply circuit 20 voltage and the preset reference voltage can be set according to the actual situation. The preset reference voltage is the critical voltage for switching under the desired state set according to actual needs. Taking V_IN as 12V as an example, since the desired voltage drops to 11V before power switching, the preset reference voltage is set to 11V to meet the power switching control requirements.

[0053] The adaptive power switching control system provided in this embodiment of the invention switches the external power supply circuit 20 and the internal power supply circuit 30 through the power switching control circuit 10 and the first controlled switch Q7. The relationship between the voltage at the reference terminal of the three-terminal voltage regulator circuit 40 and a preset reference voltage is used to output high / low level signals at the output terminal, thereby controlling the operation of the power switching control circuit 10 and the external power supply circuit 20, realizing the switching between the external power supply circuit 20 and the internal power supply circuit 30. By setting the three-terminal voltage regulator circuit 40, not only is the shutdown of the target device due to a long power outage time avoided, but the time for the target device's voltage to switch from the external power supply voltage to the internal battery voltage is further shortened, significantly improving the user experience.

[0054] Specifically, such as Figure 2 As shown, the three-terminal voltage regulator circuit 40 includes: a three-terminal adjustable shunt parallel voltage regulator U5 and a voltage divider circuit, wherein,

[0055] The input terminal of the voltage divider circuit is connected to the input terminal of the external power supply circuit 20, and the output terminal is connected to the reference terminal of the three-terminal adjustable shunt parallel regulator U5. The input terminal of the three-terminal adjustable shunt parallel regulator U5 is connected to the input terminal of the external power supply circuit 20, and the output terminal is connected to the control terminal of the first controlled switch Q7.

[0056] When the reference terminal voltage of the three-terminal adjustable shunt parallel regulator U5 is less than the corresponding reference voltage of the three-terminal adjustable shunt parallel regulator U5, the output terminal of the three-terminal adjustable shunt parallel regulator U5 outputs a high-level signal.

[0057] When the reference terminal voltage of the three-terminal adjustable shunt parallel regulator U5 is not less than the corresponding reference voltage of the three-terminal adjustable shunt parallel regulator U5, the output terminal of the three-terminal adjustable shunt parallel regulator U5 outputs a low-level signal.

[0058] As one implementation of this embodiment, the three-terminal adjustable shunt parallel regulator U5 is a TL431. By utilizing the fixed threshold voltage of 2.5V of the TL431 chip, the power-down time of the V_IN voltage is segmented into intervals, reducing the interference caused by the power-down time, enabling the external power supply to quickly switch to the internal power supply, and avoiding power loss of the entire load.

[0059] The adaptive power switching control system provided in this embodiment of the invention uses a TL431 three-terminal adjustable shunt parallel voltage regulator U5. By utilizing the voltage regulation characteristics of the TL431, the adaptive power switching control system is ensured to always operate under a stable operating voltage, further ensuring the stable operation of the target equipment and improving user satisfaction.

[0060] like Figure 2As shown, the voltage divider circuit consists of voltage divider resistors R10 and R11, and voltage division is achieved by setting R10 and R11. Specifically, under normal power supply conditions, the voltage at point a is greater than 2.5V. When a power failure occurs, when the V_IN voltage drops to the preset reference voltage (i.e., the threshold voltage), the voltage at point a drops to 2.5V. When the V_IN voltage is less than the threshold voltage, the voltage at point a is less than 2.5V, the TL431 stops working, and the ON-1 output level becomes high, thus completing the circuit switching, that is, switching from external power supply circuit to internal power supply circuit.

[0061] It should be noted that the reference voltage of the aforementioned three-terminal adjustable shunt parallel regulator U5 is a fixed 2.5V. This embodiment of the invention utilizes this operating characteristic of the TL431, such as... Figure 2 As shown, when the reference terminal voltage is reduced to the desired voltage (i.e., the voltage at point a Va = the reference voltage 2.5V), the adaptive power switching control function is realized by using two different output results: Va>2.5V and Va<2.5V.

[0062] The adaptive power switching control system provided in this embodiment of the invention includes a three-terminal voltage regulator circuit 40 comprising a three-terminal adjustable shunt parallel regulator U5 and a voltage divider circuit. Due to the special working principle of the three-terminal adjustable shunt parallel regulator U5, it can output high / low level signals according to the relationship between the reference terminal voltage and the corresponding reference voltage, thereby realizing the switching between the external power supply circuit 20 and the internal power supply circuit 30. By setting the voltage divider circuit, a corresponding reference voltage is provided for the three-terminal adjustable shunt parallel regulator, ensuring the efficient and stable operation of the adaptive power switching control system.

[0063] Specifically, such as Figure 2 As shown, the three-terminal voltage regulator circuit 40 further includes a first resistor R9, one end of which is connected to the input terminal of the external power supply circuit 20, and the other end is connected to the input terminal of the three-terminal adjustable shunt parallel voltage regulator U5.

[0064] The adaptive power switching control system provided in this embodiment of the invention uses a first resistor R9. One end of the first resistor R9 is connected to the input terminal of the external power supply circuit 20, and the other end is connected to the input terminal of the three-terminal adjustable shunt parallel regulator U5. The first resistor R9 limits the current of the circuit, thereby realizing the power supply control of the target device by the external power supply circuit 20.

[0065] Taking a 12V V_IN voltage as an example, this embodiment of the invention uses a voltage divider circuit composed of voltage divider resistors R10 and R11 to achieve a reference terminal voltage (point a voltage) Va = 2.5V for the three-terminal adjustable shunt parallel regulator U5 when V_IN = 11V. That is, when V_IN > 11V, Va > 2.5V; conversely, when V_IN < 11V, Va < 2.5V. According to the operating characteristics of the U5 (TL431) chip, when Va > 2.5V, U5 is turned on, and the voltage at point ON-1 is low; conversely, the voltage at point ON-1 is pulled up to a high level through resistor R9.

[0066] Specifically, such as Figure 2 As shown, the system further includes: a second resistor R12 and a third resistor R13, wherein,

[0067] One end of the second resistor R12 is connected to the output terminal of the three-terminal adjustable shunt parallel regulator U5, and the other end is connected to one end of the third resistor R13 and the control terminal of the first controlled switch Q7 respectively.

[0068] The other end of the third resistor R13 is connected to the input terminal of the external power supply circuit 20.

[0069] The adaptive power switching control system provided in this embodiment of the invention, by setting a second resistor R12 and a third resistor R13, not only effectively ensures the stable operation of the three-terminal voltage regulator circuit 40, but also assists the first controlled switch Q7 and the power switching control circuit 10 in realizing flexible switching of the adaptive power switching control system, avoiding the situation where the target equipment stops due to excessive power outage time, and greatly improving user satisfaction.

[0070] Specifically, such as Figure 2 As shown, the external power supply circuit 20 includes: a second controlled switch Q1 and a first power supply circuit (not shown in the figure), wherein,

[0071] The first terminal of the second controlled switch Q1 is connected to the control terminal of the first power supply circuit, the second terminal is grounded, and the control terminal is connected to the second terminal of the first controlled switch Q7.

[0072] The input terminal of the first power supply circuit is connected to an external power supply, and the output terminal is connected to the power supply terminal of the target device.

[0073] As one implementation of this embodiment, the second controlled switch Q1 can be a transistor, but the actual situation is not limited to this.

[0074] Specifically, such as Figure 2As shown, the first power supply circuit includes two switching transistors, U1 and U2, and corresponding voltage divider resistors. Detailed control procedures can be found in existing technologies and will not be repeated here. The specific selection process for switching transistors U1 and U2 can also be found in existing technologies and will not be repeated here.

[0075] The adaptive power switching control system provided in this embodiment of the invention includes an external power supply circuit 20 comprising a second controlled switch Q1 and a first power supply circuit. Through the coordinated operation of the second controlled switch Q1 and the first power supply circuit, the external power supply circuit 20 provides power to the target device. When the second controlled switch Q1 and the first power supply circuit are controlled to be turned off, the power switching control circuit 10 switches the control to the internal power supply circuit 30, which then provides power to the target device, thereby preventing the target device from interrupting its operation and providing a better user experience.

[0076] Specifically, such as Figure 2 As shown, the internal power supply circuit 30 includes: a third controlled switch Q2 and a second power supply circuit (not shown in the figure), wherein,

[0077] The first terminal of the third controlled switch Q2 is connected to the control terminal of the second power supply circuit, the second terminal is grounded, and the control terminal is connected to the output terminal of the power switching control circuit 10.

[0078] The input terminal of the second power supply circuit is connected to the internal power supply of the target device, and the output terminal is connected to the power supply terminal of the target device.

[0079] As one implementation of this embodiment, the third controlled switch Q2 can be a transistor, but the actual situation is not limited to this.

[0080] Specifically, such as Figure 2 As shown, the second power supply circuit includes two switching transistors, U3 and U4, and corresponding voltage divider resistors. Detailed control procedures can be found in existing technologies and will not be repeated here. The specific selection process for switching transistors U3 and U4 can also be found in existing technologies and will not be repeated here.

[0081] The adaptive power switching control system provided in this embodiment of the invention includes an internal power supply circuit 30 comprising a third controlled switch Q2 and a second power supply circuit. Through the coordinated operation of the third controlled switch Q2 and the second power supply circuit, the power supply circuit provides power to the target device. When the third controlled switch Q2 and the second power supply circuit are controlled to be turned on, the power switching control circuit 10 will control the switch to the internal power supply circuit 30 to provide power to the target device, thereby avoiding interruption of the target device's operation and bringing a better user experience.

[0082] Specifically, such as Figure 2 As shown, the power switching control circuit 10 includes: a fourth controlled switch Q3, the control terminal of the fourth controlled switch Q3 is connected to the second terminal of the first controlled switch Q7, the first terminal is connected to the control terminal of the third controlled switch Q2, and the second terminal is grounded.

[0083] As one implementation of this embodiment, the fourth controlled switch Q3 can be a transistor, but the actual situation is not limited to this.

[0084] Specifically, such as Figure 2 As shown, the power switching control circuit 10 also includes a corresponding current-limiting resistor R8. For detailed control process, please refer to the relevant description in the prior art, which will not be repeated here.

[0085] Specifically, in practical applications, such as Figure 2 As shown, taking V_IN as a 12V voltage as an example, assuming the input V_IN is 12V, after the input power is lost, the V_IN voltage needs to drop to 11V to ensure that transistors Q1 and Q3 stop working, ensure that U1 and U2 stop working, and U3 and U4 are turned on so that VCC is connected to VBAT, and the VCC voltage switches from V_IN to VBAT power supply.

[0086] Specifically, when the operating conditions of the first controlled switch Q7 are met (low-level drive of the PNP transistor base), after Q7 is turned on, the bases of transistors Q1 and Q3 are connected to V_IN through resistors R1 and R8. This satisfies the operating conditions of transistors Q1 and Q3. After Q1 is turned on, U1 and U2 are turned on, and the VCC voltage is connected to V_IN. After Q3 is turned on, the base of Q3 is pulled low, Q2 is turned off, and simultaneously U3 and U4 are disconnected, disconnecting VCC from VBAT. At this time, the entire target device is powered by V_IN.

[0087] When V_IN is de-energized, the voltage drops from 12V to below 11V, Va < 2.5V, which does not meet the operating conditions of U5, so U5 is cut off. At this time, the voltage at point ON-1 is pulled up to V_IN (high level) by R9. At this time, the conduction condition of transistor Q7 is not met, so Q7 is turned off. Q1 and Q3 have no driving voltage and do not meet the operating conditions, so Q1 and Q3 are cut off. Since Q1 is cut off, U1 and U2 are turned off. Since Q3 is cut off, Q2 is connected to VBAT through resistors R6 and R4, which meets the turn-on condition, so Q2 is turned on. U3 and U4 are turned on, and the VCC voltage switches from V_IN to VBAT, thus quickly completing the voltage conversion.

[0088] The adaptive power switching control system provided in this embodiment of the invention includes a fourth controlled switch Q3. The control terminal of the fourth controlled switch Q3 is connected to the second terminal of the first controlled switch Q7, and the first terminal is connected to the control terminal of the third controlled switch Q2. The second terminal is grounded. The fourth controlled switch Q3 switches between the external power supply circuit 20 and the internal power supply circuit 30, ensuring normal use of the target device by the user, avoiding mid-term shutdown of the target device, and greatly improving user satisfaction.

[0089] In practical applications, external power supplies typically have large electrolytic capacitors at the output. These capacitors store energy, and when the external power is turned off, the output voltage doesn't immediately drop to zero but decreases slowly in a curve. The power-down time varies depending on the capacitor value, generally ranging from tens to hundreds of milliseconds. For Q1 and Q3 to completely turn off, the base voltage needs to drop below 0.7V, which takes a considerable amount of time. The internal battery voltage cannot switch immediately, causing a power outage at VCC, resulting in system shutdown and affecting overall machine operation. Based on this, this invention provides an adaptive power switching control system that solves the problem of the original switching circuit's inability to quickly switch to battery power due to the large electrolytic capacitors in the external adapter.

[0090] As a specific implementation, the working process of the adaptive power switching control system provided in this embodiment of the invention is as follows: Figure 2 As shown:

[0091] The reference voltage (i.e., threshold voltage) is set via U5. Assuming an external input voltage of 12V, to minimize the impact of power-down time, Q1 and Q3 are immediately shut off when the voltage drops to 11V. Resistors R10 and R11 are configured so that the voltage at point a is 2.5V when V_IN is 11V. At this time, when V_IN is greater than 11V, the U5 (TL431) chip operates, and ON-1 outputs a low level. When V_IN drops below 11V, the U5 chip stops operating, and ON-1 is pulled high through resistor R9 (V_IN...). The N voltage), through the high and low level changes of ON-1, drives the PNP transistor Q7 to turn on and off, thereby driving the turn-on and turn-off of Q1 and Q3. Before the improvement, the voltage needed to drop from V_IN to 0.7V for transistors Q1 and Q3 to turn off. After the improvement, the voltage can drop from V_IN to any voltage within the range (such as 12V to 11V) for transistors Q1 and Q3 to turn off, greatly shortening the turn-off time. This allows the internal VBAT to quickly connect to VCC to power the entire system, avoiding the risk of power failure.

[0092] Example 2

[0093] like Figure 3As shown, an embodiment of the present invention provides an adaptive power switching control device, including: an adaptive power switching control system as described in another embodiment of the present invention.

[0094] For details regarding the adaptive power switching control device described above, please refer to the relevant description and effects of the adaptive power switching control system in the other embodiment above. These details will not be repeated here.

[0095] The adaptive power switching control device provided in this embodiment of the invention, by setting an adaptive power switching control system as described in another embodiment of the invention, not only avoids the situation where the target device will shut down due to a long power outage, but also further shortens the time for the target device's voltage to switch from the external power supply voltage to the internal battery voltage, thus greatly improving the user experience.

[0096] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An adaptive power switching control system, comprising: The system includes a power switching control circuit and an external power supply circuit and an internal power supply circuit respectively connected to the power supply terminal of the target device. The power switching control circuit is used to switch between the external power supply circuit and the internal power supply circuit to supply power to the target device. The system further includes a three-terminal voltage regulator circuit and a first controlled switch. The reference terminal of the three-terminal voltage regulator circuit is connected to the input terminal of the external power supply circuit, the input terminal is connected to the input terminal of the external power supply circuit, and the output terminal is connected to the control terminal of the first controlled switch. The first terminal of the first controlled switch is connected to the input terminal of the external power supply circuit, and the second terminal is connected to the control terminal of the external power supply circuit and the control terminal of the power switching control circuit, respectively. The output terminal of the three-terminal voltage regulator circuit outputs a high / low level signal based on the relationship between the voltage connected to its reference terminal and the preset reference voltage to control the first controlled switch to be turned on or off, so as to realize the switching between the external power supply circuit and the internal power supply circuit. The preset reference voltage is less than or equal to the power supply voltage of the external power supply circuit. The preset reference voltage is set according to the stability of the power supply voltage of the external power supply circuit and the requirements of the switching speed of the power supply circuit. The external power supply circuit includes: a second controlled switch and a first power supply circuit, wherein, The first terminal of the second controlled switch is connected to the control terminal of the first power supply circuit, the second terminal is grounded, and the control terminal is connected to the second terminal of the first controlled switch. The input terminal of the first power supply circuit is connected to an external power supply, and the output terminal is connected to the power supply terminal of the target device. The internal power supply circuit includes: a third controlled switch and a second power supply circuit, wherein... The first terminal of the third controlled switch is connected to the control terminal of the second power supply circuit, the second terminal is grounded, and the control terminal is connected to the output terminal of the power switching control circuit. The input terminal of the second power supply circuit is connected to the internal power supply of the target device, and the output terminal is connected to the power supply terminal of the target device. The power switching control circuit includes: a fourth controlled switch, the control terminal of the fourth controlled switch being connected to the second terminal of the first controlled switch, the first terminal being connected to the control terminal of the third controlled switch, and the second terminal being grounded.

2. The adaptive power switching control system according to claim 1, characterized in that, The three-terminal voltage regulator circuit includes: a three-terminal adjustable shunt parallel voltage regulator and a voltage divider circuit, wherein... The input terminal of the voltage divider circuit is connected to the input terminal of the external power supply circuit, and the output terminal is connected to the reference terminal of the three-terminal adjustable shunt parallel voltage regulator. The input terminal of the three-terminal adjustable shunt parallel voltage regulator is connected to the input terminal of the external power supply circuit, and the output terminal is connected to the control terminal of the first controlled switch. When the reference voltage of the three-terminal adjustable shunt parallel regulator is less than the corresponding reference voltage of the three-terminal adjustable shunt parallel regulator, the output terminal of the three-terminal adjustable shunt parallel regulator outputs a high-level signal. When the reference terminal voltage of the three-terminal adjustable shunt parallel regulator is not less than the corresponding reference voltage of the three-terminal adjustable shunt parallel regulator, the output terminal of the three-terminal adjustable shunt parallel regulator outputs a low-level signal.

3. The adaptive power switching control system according to claim 2, characterized in that, The three-terminal voltage regulator circuit further includes: a first resistor, one end of which is connected to the input terminal of the external power supply circuit, and the other end of which is connected to the input terminal of the three-terminal adjustable shunt parallel voltage regulator.

4. The adaptive power switching control system according to claim 2, characterized in that, The three-terminal adjustable shunt parallel voltage regulator is TL431.

5. The adaptive power switching control system according to claim 2, characterized in that, The system further includes: a second resistor and a third resistor, wherein, One end of the second resistor is connected to the output terminal of the three-terminal adjustable shunt parallel voltage regulator, and the other end is connected to one end of the third resistor and the control terminal of the first controlled switch, respectively. The other end of the third resistor is connected to the input terminal of the external power supply circuit.

6. The adaptive power switching control system according to claim 1, characterized in that, The first controlled switch is a PNP transistor.

7. An adaptive power switching control device, characterized in that, include: The adaptive power switching control system as described in any one of claims 1-6.

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