A two-wire recharging system with ultra-low standby power consumption

Abstract

The present invention relates to a two-wire recharging system with ultra-low standby power consumption, comprising a power supply unit and a charging unit; the power supply unit comprises a power control circuit, a first output terminal and a second output terminal connected to the power control circuit; the charging unit comprises a charging control circuit, a first input terminal corresponding to the first output terminal, a second input terminal corresponding to the second output terminal, and a power output terminal for supplying power to a load; the charging control circuit is respectively connected to the first input terminal, the second input terminal and the power output terminal; the first output terminal is responsible for providing a normal charging voltage for the battery, and each output terminal or input terminal can be used as a communication terminal after being fully charged. The present invention realizes the charging and recharging communication functions by using only two connecting wires, namely, a power supply and a ground, so as to switch between a normal charging mode and a standby mode, thereby achieving ultra-low power consumption.

Description

Technical Field

[0001] The present invention relates to a two-wire recharging system, and in particular to a two-wire recharging system with ultra-low standby power consumption. Technical Background

[0002] At present, when the power supply unit and the charging end are always in a normal connection state, the charging system does not enter a low-power standby state, or only the charging end enters the standby mode, while the power supply unit is still in a normal charging mode. After the battery is fully charged, the system will still consume a lot of power. If you want to achieve both normal recharging and the simultaneous entry of the power supply unit and the charging end into standby mode, you usually need pins other than the positive and negative ends of the power supply for communication, such as USB D+ / D-, CC, etc. When encountering a usage scenario with restrictions on the use of pins, the above solution is not applicable. In addition, the above solution requires the cooperation of other auxiliary communication modules, and the system will consume additional power, resulting in the entire system being unable to fully sleep to achieve the purpose of ultra-low power consumption. Summary of the invention

[0003] Purpose of the invention: In view of the shortcomings of the prior art, the present invention proposes a two-wire recharging system with ultra-low standby power consumption, which does not require additional communication modules and CPU cooperation and is suitable for most application scenarios with ultra-low standby power consumption and charging using only two pins.

[0004] Technical solution: On one hand, the present invention provides a two-wire recharging system with ultra-low standby power consumption. The system includes a power supply unit and a charging unit; the power supply unit includes a first output terminal, a second output terminal, a charging power supply, a standby power supply, a power switching circuit, a first voltage-dividing resistor and a first switch; the power switching circuit is respectively connected to the first output terminal, the second output terminal, the charging power supply and the standby power supply; the first voltage-dividing resistor and the first switch are both connected to the ground point at one end and the second output terminal at the other end; the charging power supply outputs a charging voltage greater than the charging start voltage, and the standby power supply outputs a standby voltage less than the charging start voltage; the charging unit includes a first input terminal corresponding to the first output terminal, a second input terminal corresponding to the second output terminal, a power supply output terminal for supplying power to the load, a charging control circuit, a second voltage-dividing resistor and a second switch; the second voltage-dividing resistor and the second switch are connected in series between the first input terminal and the second input terminal; when the input terminal and the output terminal corresponding to the power supply unit and the charging unit are connected, the power switching circuit provides the charging voltage to the first output terminal, and the first The switch and the second switch are closed and opened respectively; when the load is connected to the power output end and the power supply unit and the charging unit are connected: when the charging control circuit detects that the voltage at the first input end is greater than the charging start voltage, the power obtained from the first input end is provided to the load via the power output end; when the power switching circuit detects that the current at the first output end is less than the charging end threshold current, the power of the standby power supply is provided to the first output end, and the first switch is opened; when the charging control circuit detects that the voltage at the first input end is not greater than the charging start voltage, the power supply to the power output end is stopped; when the charging control circuit detects that the voltage at the power output end is lower than the recharging threshold voltage, the second switch is closed for a specific period of time and then opened; when the power switching circuit detects that the voltage at the second output end increases and then decreases, the charging voltage is provided to the first output end, and the first switch is closed.

[0005] Furthermore, the power switching circuit includes a wake-up signal detection circuit, a charging end detection circuit and a switching controller; the wake-up signal detection circuit is used to detect the voltage of the second output terminal, and when it is detected that the voltage of the second output terminal increases and then decreases, it sends a wake-up signal to the switching controller, and the switching controller provides the power generated by the charging power supply to the first output terminal in response to the wake-up signal; the charging end detection circuit is used to detect the current at the first output terminal, and when it is detected that the current at the first output terminal is less than the charging end threshold current, it sends a charging end signal to the switching controller, and the switching controller provides the power generated by the standby power supply to the first output terminal in response to the charging end signal.

[0006] Furthermore, the charging control circuit includes a load control circuit and a recharging detection circuit; the load control circuit is used to detect the voltage at the first input terminal, and compare the voltage at the first input terminal with the charging start voltage: if it is greater than the charging start voltage, the power at the first input terminal is provided to the load via the power supply output terminal; otherwise, the power supply to the load is stopped; the recharging detection circuit is used to detect the voltage at the power supply output terminal, and compare the voltage at the power supply output terminal with the recharging threshold voltage. Once the voltage at the power supply output terminal is greater than the recharging threshold voltage, the second switch is controlled to close for a specific time and then open.

[0007] On the other hand, the present invention provides a two-wire recharging system with ultra-low standby power consumption. The system includes a power supply unit and a charging unit; the power supply unit includes a first output terminal, a second output terminal, a charging power supply, a standby power supply, a power switching circuit, and a first voltage-dividing resistor; the power switching circuit is respectively connected to the first output terminal, the second output terminal, the charging power supply, and one end of the first voltage-dividing resistor; the other end of the first voltage-dividing resistor is connected to the standby power supply; the second output terminal is connected to the ground point; the charging unit includes a first input terminal corresponding to the first output terminal, a second input terminal corresponding to the second output terminal, a power supply output terminal for supplying power to the load, a charging control circuit, a second voltage-dividing resistor, and a second switch; the second voltage-dividing resistor and the second switch are connected in series between the first input terminal and the second input terminal; when the input terminal and output terminal corresponding to the power supply unit and the charging unit are connected, the power switching circuit provides a charging voltage greater than the charging start voltage to the first output terminal, and The second switch is disconnected; when a load is connected to the power output terminal and the power supply unit and the charging unit are connected: when the charging control circuit detects that the voltage at the first input terminal is greater than the charging start voltage, power is provided to the power output terminal; when the power switching circuit detects that the current at the first output terminal is less than the charging end threshold current, the power of the standby power supply is provided to the first output terminal; when the charging control circuit detects that the voltage at the first input terminal is not greater than the charging start voltage, the power supply to the power output terminal is stopped; when the charging control circuit detects that the voltage at the power output terminal is lower than the recharging threshold voltage, the second switch is closed for a specific period of time and then disconnected; when the power switching circuit detects that the voltage at the first output terminal decreases and then decreases, the charging voltage is provided to the first output terminal.

[0008] Furthermore, the power switching circuit includes a wake-up signal detection circuit, a charging end detection circuit and a switching controller; the wake-up signal detection circuit is used to detect the voltage of the first output terminal, and when it is detected that the voltage of the first output terminal decreases and then increases, it sends a wake-up signal to the switching controller, and the switching controller provides the power generated by the charging power supply to the first output terminal in response to the wake-up signal; the charging end detection circuit is used to detect the current at the first output terminal, and when it is detected that the current at the first output terminal is less than the charging end threshold current, it sends a charging end signal to the switching controller, and the switching controller provides the power generated by the standby power supply to the first output terminal in response to the charging end signal.

[0009] Furthermore, the charging control circuit includes a load control circuit and a recharging detection circuit; the load control circuit is used to detect the voltage at the first input terminal, and compare the voltage at the first input terminal with the charging start voltage: if it is greater than the charging start voltage, the power at the first input terminal is provided to the load via the power supply output terminal; otherwise, the power supply to the load is stopped; the recharging detection circuit is used to detect the voltage at the power supply output terminal, and compare the voltage at the power supply output terminal with the recharging threshold voltage. Once the voltage at the power supply output terminal is greater than the recharging threshold voltage, the second switch is controlled to close for a specific time and then open.

[0010] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. Fewer wires, only two wires, power and ground, are used to realize the charging and recharging communication functions. When the power supply and charging end are always connected, after charging is completed, the power supply and charging end circuits can enter the standby mode at the same time. Since the system does not require an MCU and most of the main function circuits can be powered off, ultra-low power consumption can be achieved.

[0012] 2. Since the system is implemented purely in hardware, most of the main functional circuits can be powered off to achieve ultra-low power consumption. There are few connections, and only two connections, power and ground, are used to achieve the communication functions of both charging and sending recharging commands.

[0013] 3. Only through the Vout voltage range, the charging circuit of the charging end is automatically turned on and off, and the charging mode and standby mode are automatically switched. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of a first embodiment of a recharging system of the present invention;

[0015] Figure 2 FIG. 1 is a structural diagram of a second embodiment of a recharging system according to the present invention. DETAILED DESCRIPTION

[0016] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0017] Embodiment 1

[0018] like Figure 1 The recharging system of the present invention includes two parts: a power supply part and a charging part.

[0019] The power supply unit includes a charging power supply generating a normal charging voltage Vcharge, a standby power supply generating a standby voltage Vsleep, a power switching circuit, a first voltage-dividing resistor R1, a first switch K1, a first output terminal whose output voltage is recorded as Vout+, and a second output terminal whose output voltage is recorded as Vout-. The power switching circuit is respectively connected to the first output terminal, the second output terminal, the charging power supply, and the standby power supply; the first voltage-dividing resistor R1 and the first switch K1 are both connected to the ground point at one end and connected to the second output terminal at the other end. The charging power supply outputs a charging voltage greater than the charging start voltage Vcharge_min, and the standby power supply outputs a standby voltage less than the charging start voltage Vcharge_min.

[0020] The power switching circuit further includes a wake-up signal detection circuit, a charge end detection circuit and a switching controller. The wake-up signal detection circuit is used to detect the voltage Vout- at the second output terminal, and after detecting that the voltage Vout- at the second output terminal changes (in this embodiment, it increases and then decreases), it sends a wake-up signal to the switching controller, and the switching controller responds to the wake-up signal to provide the power generated by the charging power supply to the first output terminal. The charge end detection circuit is used to detect the current Iout at the first output terminal, and when it is detected that the current Iout at the first output terminal is less than the charge end threshold current Imin, it sends a charge end signal to the switching controller, and the switching controller responds to the charge end signal to provide the power generated by the standby power supply to the first output terminal.

[0021] In addition, in order to enable the entire system to detect the connection and disconnection of the power supply unit and the charging unit, and to enable the system to automatically enter the charging mode and the standby mode respectively after detecting the connection and disconnection, the power switching circuit further includes a third resistor R3 (not shown). Figure 1). The third resistor R3 is connected in series between the first output terminal and the second output terminal, and its resistance is much larger than the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. Accordingly, the wake-up signal detection circuit is also configured to compare the voltage at the second output terminal with the connection threshold voltage Vout-_min. When the voltage at the second output terminal changes from less than the connection threshold voltage Vout-_min to greater than the connection threshold voltage Vout-_min, it indicates that the power supply unit and the charging unit are connected from disconnection, and the wake-up signal detection circuit will send a connection confirmation signal to the switching controller, and the switching controller will provide the power generated by the charging power supply to the first output terminal in response to the connection confirmation signal; when the voltage at the second output terminal changes from greater than the connection threshold voltage Vout-_min to less than the connection threshold voltage Vout-_min, it indicates that the power supply unit and the charging unit are disconnected from each other, and the wake-up signal detection circuit will send a disconnection confirmation signal to the switching controller, and the switching controller will provide the power generated by the standby power supply to the first output terminal in response to the disconnection confirmation signal.

[0022] In this embodiment, the switching controller includes a third switch K3, a fourth switch K4 and a selector. The third switch K3 is connected between the selector and the charging power supply. The fourth switch K4 is connected between the selector and the standby power supply. The selector is also connected to the wake-up signal detection circuit and the charging end detection circuit, respectively, and controls the third switch K3 and the fourth switch K4 according to the received wake-up signal and the charging end signal. This control specifically includes: the selector closes the third switch K3 and disconnects the fourth switch K4 in response to the received wake-up signal, or disconnects the third switch K3 and closes the fourth switch K4 in response to the received charging end signal.

[0023] The charging unit includes a first input terminal corresponding to the first output terminal, a second input terminal corresponding to the second output terminal, a power supply output terminal for supplying power to the load, a charging control circuit, a second voltage-dividing resistor R2 and a second switch K2. The second voltage-dividing resistor R2 and the second switch K2 are connected in series between the first input terminal and the second input terminal.

[0024] The charging control circuit includes a load control circuit and a recharge detection circuit. The load control circuit is used to detect the voltage at the first input terminal, and compare the voltage at the first input terminal with the charging start voltage Vcharge_min: if it is greater than the charging start voltage, the power at the first input terminal is provided to the load via the power output terminal. Otherwise, the power supply to the load is stopped. The recharge detection circuit is used to detect the voltage at the power output terminal, and compare the voltage Vbat at the power output terminal with the recharge threshold voltage Vrecharge. Once the voltage Vbat at the power output terminal is greater than the recharge threshold voltage, the second switch K2 is controlled to close for a specific time and then open.

[0025] In this embodiment, the wake-up signal detection circuit includes a voltage sampler and a plurality of voltage comparators. The charge end detection circuit includes a current sampler and a current comparator. The load control circuit includes a voltage sampler and a voltage comparator. The recharge detection circuit includes a voltage sampler and a voltage comparator. In other embodiments, the wake-up signal detection circuit, the charge end detection circuit, the load control circuit, and the recharge detection circuit can also be implemented using a programmable logic circuit.

[0026] Based on the above structure introduction, the working principle of the system of this embodiment is described below:

[0027] When the power supply unit and the charging unit leave the factory: in the power supply unit, the switching controller enables the standby power supply and disables the charging power supply by default, and the switch K1 is disconnected; in the charging unit, the load control circuit controls the circuit between the first input terminal and the power output terminal to be disconnected, and the switch K2 is disconnected.

[0028] When the power supply unit and the charging unit are connected and the charging unit is connected to a load, in the power supply unit, R1 and R3 are divided, and the wake-up signal detection circuit will detect that the voltage at the second output terminal rises from 0V to greater than the connection threshold voltage Vout-_min (for example, 0.2V), thereby sending a connection confirmation signal to the switching controller and controlling the switch K1 to close. The switching controller responds to the received connection confirmation signal and provides the power of the charging power supply to the first output terminal. When the load control circuit in the charging unit detects that the voltage at the first output terminal is greater than the charging start voltage Vcharge_min, it controls the connection between the first input terminal and the power supply output terminal, thereby providing the power input from the first input terminal to the power supply output terminal. At this time, both the power supply unit and the charging unit enter the charging mode.

[0029] When the power supply unit and the charging unit are connected to each other and are in charging mode, since the charging end detection module of the power supply unit includes a current sampling circuit, the charging end detection module can sample the current Iout flowing into the ground end of the power supply unit, and compare Iout with the threshold current Imin. When Iout is less than the threshold current Imin, it is determined that the charging current is too small and the battery is fully charged. After determining that the battery is fully charged, the charging end detection module switches the voltage Vout of the first output terminal to VSleep, and disconnects the first switch K1. Correspondingly, the charging control circuit in the charging terminal will detect that the voltage Vout+ corresponding to the first input terminal is equal to VSleep, and Vsleep is less than the charging start voltage Vcharge_min, thereby stopping power supply to the load and entering the standby state. In this way, the entire system is in standby mode. In standby mode, the charging control circuit in the charging terminal can detect that the voltage VSleep input at the first input terminal is not equal to 0, but is greater than the connection threshold voltage Vout-_min, so it can be determined that the charging unit has been in a normal connection state. After entering standby mode, the load control circuit of the charging section and the charging power supply with large current consumption in the power supply section are disabled, thereby reducing the standby current of the entire system.

[0030] When the recharge detection circuit in the charging unit detects that the load (e.g., battery) voltage Vbat is lower than the recharge threshold voltage Vrecharge, the second switch K2 will be controlled to close for a period of time and then open. When switch K2 is closed, R3 and R2 are connected in parallel. Since R3 is much larger than R2, the resistance after parallel connection is substantially equal to R2. Due to the voltage division of the voltage-dividing resistors R1 and R2, the wake-up signal detection circuit in the power supply unit will detect that the voltage Vout- at the second output terminal increases from Vout-_min close to 0v. When switch K2 is disconnected, the wake-up signal detection circuit will see that Vout- drops to Vout-_min close to 0v. In this way, the wake-up signal detection circuit in the power supply unit will be able to see the high and low changes of the voltage Vout- at the second output terminal, that is, the wake-up signal is detected. When the wake-up signal detection circuit detects that Vout- increases and then decreases, it will send a wake-up signal to the switching controller and close the first switch K1. In response to the wake-up signal, the switching controller will enable the charging power supply, switch switches K3 and K4 so that the charging power supply generating the charging voltage Vcharge provides power to the first output terminal, and the power supply unit and the charging unit will automatically switch back to the charging mode.

[0031] If the power supply unit and the charging unit are disconnected, no matter whether they are in the charging mode or the standby mode before the disconnection, the wake-up signal detection circuit in the power supply unit will detect that the voltage Vout- at the second output terminal changes from greater than Vout-_min to 0V less than Vout-_min, so that the wake-up signal detection circuit sends a disconnection confirmation signal to the switching controller and disconnects the first switch K1. The switching controller enables the standby power supply and disables the charging power supply in response to the disconnection confirmation signal.

[0032] This reciprocating process enables the entire system to automatically switch between the standby mode and the charging mode, and can automatically switch to the standby mode and the charging mode respectively when the charging part and the power supply part are disconnected and connected.

[0033] Embodiment 2

[0034] like Figure 2 As shown, the difference from the recharging system in the first embodiment is that the first switch K1 does not exist in the power supply unit, and the first voltage-dividing resistor R1 is not connected to the power ground, but is connected in series with the fourth switch K4. One end of the third resistor R3 (not shown) is connected to the first output end, and the other end is connected to the second output end and the power ground respectively. The wake-up signal detection circuit is used to detect the voltage Vout+ on the first output end to determine whether it is necessary to send a signal to the switching controller to perform power switching.

[0035] Specifically, in the standby state, R1 and R3 in the power supply unit divide the voltage, and at this time, the voltage Vout+ on the first output terminal is actually Vsleep_near, which is close to and less than Vsleep. If the charging unit and the power supply unit are already connected normally, when the wake-up signal detection circuit detects that the voltage Vout+ on the first output terminal decreases from the second connection threshold voltage Vsleep_near, which is close to and less than Vsleep, and then increases to Vsleep_near within a specific time, it means that the recharge detection circuit of the charging unit detects that the voltage at the power output terminal is lower than the recharge threshold voltage Vrecharge. At this time, the wake-up signal detection circuit sends a wake-up signal to the switching controller, and the switching controller closes the third switch K3 and opens the fourth switch K4 in response to the wake-up signal, so that the charging power supply generating the charging voltage Vcharge provides power to the first output terminal.

[0036] In addition, in order to determine whether the charging unit and the power supply unit are connected normally, when the wake-up signal detection circuit detects that the voltage Vout+ on the first output terminal increases from Vsleep_near to Vsleep or above (which can be determined by setting the second connection threshold voltage Vout+_max, where the value of Vout+_max is between Vsleep_near and Vsleep), it indicates that the charging unit and the power supply unit are disconnected, and the wake-up signal detection circuit will send a disconnection confirmation signal to the switching controller. In response to the disconnection confirmation signal, the switching controller disconnects K3 and closes K4, so that the standby power supply generating the standby voltage Vsleep provides power to the first output terminal. When the wake-up signal detection circuit detects that the voltage Vout+ on the first output terminal decreases from a voltage of Vsleep or above to Vsleep_near, it indicates that the charging unit and the power supply unit are connected normally. The wake-up signal detection circuit sends a connection confirmation signal to the switching controller. In response to the connection confirmation signal, the switching controller closes K3 and disconnects K4, so that the charging power supply generating the charging voltage Vcharge provides power to the first output terminal.

[0037] From the above embodiment 1 and embodiment 2, it can be seen that in a conventional charging system, when the power supply unit and the charging end are always connected, even if charging is completed, the power supply unit and the charging end circuit are still in a normal working state, and the standby power consumption is very large. After adopting this system, after charging is completed, the power supply unit and the charging end circuit can enter the standby mode at the same time, which greatly reduces the standby power consumption. When the battery voltage drops to the point where recharging is required, the system can automatically wake up and re-enter the normal charging state. At the same time, the present invention communicates through a simple voltage divider resistor, without the need for an additional complex communication module, nor does it require a CPU or MCU and software auxiliary control. After full charging, the main circuits of the power supply unit and the charging end can be completely turned off. Even if the power supply unit and the charging end are always in a normal connection state, the system can still achieve an ultra-low power standby mode without affecting the recharging function. No additional wiring is required. Only two power supply lines can be used to send a wake-up signal from the charging end to the power supply unit, and the connection between the power supply unit and the charging end can be reduced to two, which greatly reduces the complexity of the connection at both ends, so that the recharging function that can standby after full charging can be achieved through two lines.

Claims

1. A two-wire recharging system with ultra-low standby power consumption, characterized in that: It includes a power supply unit and a charging unit; The power supply unit includes a first output terminal, a second output terminal, a charging power supply, a standby power supply, a power supply switching circuit, a first voltage-dividing resistor R1 and a first switch K1; the power supply switching circuit is respectively connected to the first output terminal, the second output terminal, the charging power supply and the standby power supply; one end of the first voltage-dividing resistor R1 and the first switch K1 are both connected to the ground point, and the other end is connected to the second output terminal; the charging power supply outputs a charging voltage greater than the charging start voltage, and the standby power supply outputs a standby voltage less than the charging start voltage; The charging unit includes a first input terminal corresponding to the first output terminal, a second input terminal corresponding to the second output terminal, a power supply output terminal for supplying power to the load, a charging control circuit, a second voltage-dividing resistor R2 and a second switch K2; the second voltage-dividing resistor R2 and the second switch K2 are connected in series between the first input terminal and the second input terminal; After the input terminals and output terminals corresponding to the power supply unit and the charging unit are connected, the power supply switching circuit automatically provides the charging voltage to the first output terminal, and closes and opens the first switch K1 and the second switch K2 respectively; When the power output terminal is connected to a load and the power supply unit is connected to the charging unit: When the charging control circuit detects that the voltage at the first input terminal is greater than the charging start voltage, the power obtained from the first input terminal is provided to the load via the power output terminal; When the power switching circuit detects that the current at the first output terminal is less than the charge end threshold current, the power of the standby power supply is provided to the first output terminal, and the first switch K1 is disconnected; When the charging control circuit detects that the voltage at the first input terminal is not greater than the charging start voltage, stopping supplying power to the power output terminal; When the charging control circuit detects that the voltage at the output end of the power supply is lower than the recharging threshold voltage, the second switch K2 is closed for a specific period of time and then opened; When the power switching circuit detects that the voltage at the second output terminal increases and then decreases, the charging voltage is provided to the first output terminal, and the first switch K1 is closed; The power switching circuit includes a wake-up signal detection circuit, a charging end detection circuit and a switching controller; The wake-up signal detection circuit is used to detect the voltage of the second output terminal, and when it is detected that the voltage of the second output terminal increases and then decreases, sends a wake-up signal to the switching controller and controls the first switch K1 to close, and the switching controller provides the power generated by the charging power supply to the first output terminal in response to the wake-up signal; The charging end detection circuit is used to detect the current at the first output terminal, and when it is detected that the current at the first output terminal is less than the charging end threshold current, send a charging end signal to the switching controller, and the switching controller provides the power generated by the standby power supply to the first output terminal in response to the charging end signal; The power switching circuit also includes a third resistor R3; the wake-up signal detection circuit is also used to compare the voltage at the second output terminal with the connection threshold voltage. When the voltage at the second output terminal changes from less than the connection threshold voltage to greater than the connection threshold voltage, the wake-up signal detection circuit will send a connection confirmation signal to the switching controller, and the switching controller will provide the power generated by the charging power supply to the first output terminal in response to the connection confirmation signal; when the voltage at the second output terminal changes from greater than the connection threshold voltage to less than the connection threshold voltage, the wake-up signal detection circuit will send a disconnection confirmation signal to the switching controller, and the switching controller will provide the power generated by the standby power supply to the first output terminal in response to the disconnection confirmation signal.

2. A two-wire recharging system with ultra-low standby power consumption, characterized in that: It includes a power supply unit and a charging unit; The power supply unit includes a first output terminal, a second output terminal, a charging power supply, a standby power supply, a power supply switching circuit, and a first voltage-dividing resistor R1; the power supply switching circuit is respectively connected to the first output terminal, the second output terminal, the charging power supply, and one end of the first voltage-dividing resistor R1; the other end of the first voltage-dividing resistor R1 is connected to the standby power supply; the second output terminal is connected to the ground point; The charging unit includes a first input terminal corresponding to the first output terminal, a second input terminal corresponding to the second output terminal, a power supply output terminal for supplying power to the load, a charging control circuit, a second voltage-dividing resistor R2 and a second switch K2; the second voltage-dividing resistor R2 and the second switch K2 are connected in series between the first input terminal and the second input terminal; When the input terminal and the output terminal corresponding to the power supply unit and the charging unit are connected, the power switching circuit provides a charging voltage greater than the charging start voltage to the first output terminal and disconnects the second switch K2; When the power output terminal is connected to a load and the power supply unit is connected to the charging unit: When the charging control circuit detects that the voltage at the first input terminal is greater than the charging start voltage, providing power to the power output terminal; When the power switching circuit detects that the current at the first output terminal is less than the charge end threshold current, the power of the standby power supply is provided to the first output terminal; When the charging control circuit detects that the voltage at the first input terminal is not greater than the charging start voltage, stopping supplying power to the power output terminal; When the charging control circuit detects that the voltage at the output end of the power supply is lower than the recharging threshold voltage, the second switch K2 is closed for a specific period of time and then opened; When the power switching circuit detects that the voltage at the first output terminal decreases and then increases, the charging voltage is provided to the first output terminal; The power switching circuit includes a wake-up signal detection circuit, a charging end detection circuit and a switching controller; The wake-up signal detection circuit is used to detect the voltage of the first output terminal, and send a wake-up signal to the switching controller when detecting that the voltage of the first output terminal decreases and then increases, and the switching controller provides the power generated by the charging power supply to the first output terminal in response to the wake-up signal; The charging end detection circuit is used to detect the current at the first output terminal, and when it is detected that the current at the first output terminal is less than the charging end threshold current, send a charging end signal to the switching controller, and the switching controller provides the power generated by the standby power supply to the first output terminal in response to the charging end signal; The power switching circuit further includes a third resistor R3; the wake-up signal detection circuit is further configured to compare the voltage at the first output terminal with the second connection threshold voltage, and when the voltage at the first output terminal changes from less than the second connection threshold voltage to greater than the second connection threshold voltage, the wake-up signal detection circuit sends a disconnection confirmation signal to the switching controller, and the switching controller provides the power generated by the standby power supply to the first output terminal in response to the disconnection confirmation signal; When the voltage at the first output terminal changes from greater than the second connection threshold voltage to less than the second connection threshold voltage, the wake-up signal detection circuit will send a connection confirmation signal to the switching controller, and the switching controller will provide the power generated by the charging power supply to the first output terminal in response to the connection confirmation signal.

3. The two-wire recharging system with ultra-low standby power consumption according to claim 1 or 2, characterized in that: The switching controller includes a third switch K3, a fourth switch K4 and a selector; the third switch K3 is connected between the selector and the charging power supply; the fourth switch K4 is connected between the selector and the standby power supply; the selector is also connected to the wake-up signal detection circuit and the charging end detection circuit respectively, and controls the third switch K3 and the fourth switch K4 according to the received wake-up signal and charging end signal.

4. The two-wire recharging system with ultra-low standby power consumption according to claim 3, characterized in that: Controlling the third switch K3 and the fourth switch K4 according to the received wake-up signal and the charging end signal includes: In response to the received wake-up signal, the third switch K3 is closed and the fourth switch K4 is opened; In response to the received charging end signal, the third switch K3 is opened and the fourth switch K4 is closed.

5. The two-wire recharging system with ultra-low standby power consumption according to claim 1 or 2, characterized in that: The charging control circuit includes a load control circuit and a recharging detection circuit; The load control circuit is used to detect the voltage at the first input terminal, and compare the voltage at the first input terminal with the charge start voltage: if the voltage is greater than the charge start voltage, the power at the first input terminal is provided to the load via the power supply output terminal; Otherwise, the power supply to the load will be stopped; The recharging detection circuit is used to detect the voltage at the power output end, compare the voltage at the power output end with the recharging threshold voltage, and once the voltage at the power output end is greater than the recharging threshold voltage, control the second switch K2 to close for a specific time and then open.

6. The two-wire recharging system with ultra-low standby power consumption according to claim 1 or 2, characterized in that: The third resistor R3 is connected in series between the first output end and the second output end, and the resistance of the third resistor R3 is much greater than that of the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2.

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