A lithium battery charging circuit and a pneumatic hand function rehabilitation circuit

Abstract

The utility model discloses a lithium battery charging circuit and air pressure hand function rehabilitation circuit, wherein, power input protection circuit is connected between power supply and power boost circuit and is grounded, thereby when appearing in inrush voltage, inrush voltage is discharged to the ground terminal to carry out protection to the post stage circuit and lithium battery, and power boost circuit can carry out the output voltage of power supply voltage pressure processing and exports preset power supply voltage, and then makes charging management circuit constant current constant voltage charging based on preset power supply voltage to lithium battery, because preset power supply voltage is greater than the maximum output voltage of lithium battery, but not greater than the rated voltage of lithium battery, and the constant current constant voltage charging to lithium battery can ensure that the electric quantity of lithium battery is sufficient after charging while ensuring safe charging of lithium battery, and then ensure that lithium battery can stably power supply for power supply equipment.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery charging, and in particular to a lithium battery charging circuit and a pneumatic hand function rehabilitation circuit. Background Technology

[0002] Lithium batteries, as a stable and high-energy-density energy storage power source, are widely used in various scenarios to power electrical equipment, especially in the power supply of medical equipment. However, how to safely charge lithium batteries and ensure that they can stably supply power to electrical equipment after charging is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0003] The purpose of this invention is to provide a lithium battery charging circuit and a pneumatic hand rehabilitation circuit. The power input protection circuit is connected between the power supply and the power boost circuit and grounded. This allows the surge voltage to be discharged to the ground terminal, protecting the subsequent circuits and the lithium battery. The power boost circuit boosts the output voltage of the power supply to output a preset power supply voltage. This allows the charging management circuit to perform constant current and constant voltage charging of the lithium battery based on the preset power supply voltage. Since the preset power supply voltage is greater than the maximum output voltage of the lithium battery but not greater than its rated voltage, and the constant current and constant voltage charging ensures safe charging of the lithium battery while ensuring sufficient charge after charging, thus ensuring a stable power supply to the equipment.

[0004] To solve the above-mentioned technical problems, this utility model provides a lithium battery charging circuit, including a power input protection circuit, a power boost circuit, and a charging management circuit.

[0005] The input terminal of the power input protection circuit is connected to the power supply, the output terminal of the power input protection circuit is connected to the input terminal of the power boost circuit, the output terminal of the power boost circuit is connected to the power input terminal of the charging management circuit, and the output terminal of the charging management circuit is connected to the input terminal of the lithium battery; the ground terminal of the power input protection circuit is grounded.

[0006] The power input protection circuit is used to connect the input terminal of the power boost circuit to the power supply when charging the lithium battery, and to discharge the surge voltage received at its own input terminal to the ground terminal.

[0007] The power boost circuit is used to boost the output voltage of the power supply and then output a preset power supply voltage; the preset power supply voltage is greater than the maximum output voltage of the lithium battery, but not greater than the rated voltage of the lithium battery;

[0008] The charging management circuit is used to charge the lithium battery with constant current and constant voltage based on the preset power supply voltage.

[0009] Preferably, the power boost circuit includes a positive feedback inductor, a power boost chip, and a voltage detection circuit;

[0010] The input terminal of the power boost chip is the input terminal of the power boost circuit, and the output terminal of the power boost chip is the output terminal of the power boost circuit. The feedback input terminal of the power boost chip is connected to the output terminal of the voltage detection circuit. The first terminal of the positive feedback inductor is connected to the output terminal of the power boost chip, and the second terminal of the positive feedback inductor is connected to the input terminal of the power boost chip. The input terminal of the voltage detection circuit is connected to the output terminal of the power boost chip.

[0011] The power boost chip is used to boost the input voltage received at its own input terminal, and stably output the preset power supply voltage when the output voltage at its own output terminal is determined to be the preset power supply voltage based on the feedback voltage received at its own feedback input terminal.

[0012] The input voltage is the voltage obtained by superimposing the output voltage of the power supply and the output voltage of the positive feedback inductor;

[0013] The positive feedback inductor is used to charge when the output voltage of the power boost chip rises, and outputs the stored electrical energy to the input terminal of the power boost chip.

[0014] The voltage detection circuit is used to acquire the output voltage of the power boost chip and convert the acquired output voltage of the power boost chip into the feedback voltage.

[0015] Preferably, the power boost circuit further includes a first TVS diode, a first filter circuit, a first anti-reverse diode, and a second filter circuit;

[0016] The first end of the first TVS diode is connected to the input terminal of the power boost chip, and the second end of the first TVS diode is grounded. It is used to switch to a low-impedance state when it receives a surge voltage at its first end in order to discharge the surge voltage to ground, and otherwise switch to a high-impedance state.

[0017] The first terminal of the first filter circuit is connected to the input terminal of the power boost chip, and the second terminal of the first filter circuit is grounded, which is used to filter out the ripple output by the power supply.

[0018] The input terminal of the first anti-reverse diode is connected to the output terminal of the power boost chip, and the output terminal of the first anti-reverse diode is connected to the power input terminal of the charging management circuit and the input terminal of the voltage detection circuit.

[0019] The first terminal of the second filter circuit is connected to the output terminal of the first anti-reverse diode, and the second terminal of the second filter circuit is grounded, which is used to filter out the ripple output by the power boost chip.

[0020] Preferably, the charging management circuit includes a charging management chip, a first switching transistor, a freewheeling inductor, a current acquisition circuit, and a voltage acquisition circuit.

[0021] The first terminal of the first switching transistor is the power input terminal of the charging management circuit, the control terminal of the first switching transistor is connected to the output terminal of the charging management chip, the second terminal of the first switching transistor is connected to the first terminal of the freewheeling inductor, and the second terminal of the freewheeling inductor is the output terminal of the charging management circuit; the input terminal of the current acquisition circuit is connected to the second terminal of the freewheeling inductor, and the output terminal of the current acquisition circuit is connected to the current feedback input terminal of the charging management chip; the input terminal of the voltage acquisition circuit is connected to the second terminal of the freewheeling inductor, and the output terminal of the voltage acquisition circuit is connected to the voltage feedback input terminal of the charging management chip.

[0022] The current acquisition circuit is used to acquire the charging current of the lithium battery;

[0023] The voltage acquisition circuit is used to acquire the charging voltage of the lithium battery;

[0024] The charging management chip is used to control the conduction state of the first switch based on the charging voltage and the charging current.

[0025] The freewheeling inductor is used to charge or discharge the lithium battery based on the conduction state of the first switch, so as to perform constant current and constant voltage charging of the lithium battery based on the preset supply voltage.

[0026] Preferably, the charging management circuit further includes a charging status indication circuit;

[0027] The input terminal of the charging status indication circuit is connected to the first terminal of the first switching transistor, and the output terminal of the charging status indication circuit is connected to the indication output terminal of the charging management chip, for indicating the charging status of the lithium battery based on the control of the charging management chip.

[0028] Preferably, the charging status indication circuit includes a first light-emitting diode and a second light-emitting diode;

[0029] The input terminal of the first light-emitting diode is connected to the first terminal of the first switching transistor, and the output terminal of the charging status indication circuit is connected to the first indication output terminal of the charging management chip, for indicating that the lithium battery is charging based on the control of the charging management chip.

[0030] The input terminal of the second light-emitting diode is connected to the first terminal of the first switching transistor, and the output terminal of the charging status indication circuit is connected to the second indication output terminal of the charging management chip, for indicating the status of the lithium battery being fully charged based on the control of the charging management chip.

[0031] Preferably, the charging management circuit further includes a third filter circuit, a fourth filter circuit, a second anti-reverse diode, and a second TVS diode;

[0032] The first terminal of the third filter circuit is connected to the output terminal of the power boost circuit and the first terminal of the first switching transistor, and the second terminal of the third filter circuit is grounded to filter out the ripple output by the power boost circuit.

[0033] The first terminal of the fourth filter circuit is connected to the second terminal of the freewheeling inductor, and the second terminal of the fourth filter circuit is grounded, which is used to filter out the ripple output by the freewheeling inductor.

[0034] The input terminal of the second anti-reverse diode is connected to the first terminal of the fourth filter circuit and the second terminal of the freewheeling inductor, and the output terminal is connected to the input terminal of the lithium battery.

[0035] The first end of the second TVS diode is connected to the output end of the second anti-reverse diode and the input end of the lithium battery, and the second end of the second TVS diode is grounded to discharge the surge voltage received at its first end to ground.

[0036] Preferably, the current acquisition circuit includes a current sampling resistor, the first end of which is connected to the second end of the freewheeling inductor and the first current feedback input terminal of the charging management chip, and the second end of which is connected to the input terminal of the lithium battery and the second current feedback input terminal of the charging management chip, for acquiring the charging current of the lithium battery;

[0037] The voltage acquisition circuit includes a first voltage sampling resistor and a second voltage sampling resistor. The first end of the first voltage sampling resistor is connected to the second end of the current sampling resistor. The second end of the first voltage sampling resistor is connected to the first end of the second voltage sampling resistor. The second end of the second voltage sampling resistor is grounded. The second end of the first voltage sampling resistor and the first end of the second voltage sampling resistor are connected to the voltage feedback input terminal of the charging management chip for acquiring the charging voltage of the lithium battery.

[0038] Preferably, the power input protection circuit includes a third TVS diode, an input filter capacitor, and a second switching transistor;

[0039] The first terminal of the third TVS diode, the first terminal of the input filter capacitor, and the first terminal of the second switching transistor are connected and serve as the input terminal of the power input protection circuit; the second terminal of the third TVS diode, the second terminal of the input filter capacitor, and the control terminal of the second switching transistor are connected and serve as the ground terminal of the power input protection circuit; the second terminal of the second switching transistor is the output terminal of the power input protection circuit.

[0040] The third TVS diode is used to switch to a low-impedance state when it receives a surge voltage at its first terminal in order to discharge the surge voltage to ground; otherwise, it switches to a high-impedance state.

[0041] The second switch is used to turn on when its control terminal is grounded and to connect the power supply to its control terminal, and to turn off when its first terminal is grounded;

[0042] The input filter capacitor is used to filter out the ripple output by the power supply.

[0043] To solve the above-mentioned technical problems, this utility model provides a pneumatic hand function rehabilitation circuit, including the lithium battery charging circuit as described above.

[0044] This application provides a lithium battery charging circuit and a pneumatic hand function rehabilitation circuit. The power input protection circuit is connected between the power supply and the power boost circuit and grounded, thereby discharging the surge voltage to the ground terminal to protect the subsequent circuits and the lithium battery. The power boost circuit can boost the output voltage of the power supply to output a preset power supply voltage, which in turn enables the charging management circuit to perform constant current and constant voltage charging on the lithium battery based on the preset power supply voltage. Since the preset power supply voltage is greater than the maximum output voltage of the lithium battery but not greater than the rated voltage of the lithium battery, and the constant current and constant voltage charging of the lithium battery ensures safe charging of the lithium battery while ensuring sufficient charge after charging, thus ensuring that the lithium battery can stably supply power to the power supply equipment. Attached Figure Description

[0045] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This application provides a schematic diagram of the structure of a lithium battery charging circuit.

[0047] Figure 2 A schematic diagram of a power input protection circuit and a power boost circuit provided in this application;

[0048] Figure 3 This is a schematic diagram of a charging management circuit provided in this application. Detailed Implementation

[0049] The core of this invention is to provide a lithium battery charging circuit and a pneumatic hand rehabilitation circuit. The power input protection circuit is connected between the power supply and the power boost circuit and grounded, thereby discharging the surge voltage to the ground terminal to protect the subsequent circuits and the lithium battery. The power boost circuit can boost the output voltage of the power supply to output a preset power supply voltage, which in turn enables the charging management circuit to perform constant current and constant voltage charging on the lithium battery based on the preset power supply voltage. Since the preset power supply voltage is greater than the maximum output voltage of the lithium battery but not greater than the rated voltage, and the constant current and constant voltage charging of the lithium battery ensures safe charging while ensuring sufficient charge after charging, thus ensuring that the lithium battery can stably supply power to the equipment.

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0051] Please refer to Figure 1 , Figure 1 This application provides a schematic diagram of a lithium battery charging circuit, which includes a power input protection circuit 1, a power boost circuit 2, and a charging management circuit 3.

[0052] The input terminal of the power input protection circuit 1 is connected to the power supply, the output terminal of the power input protection circuit 1 is connected to the input terminal of the power boost circuit 2, the output terminal of the power boost circuit 2 is connected to the power input terminal of the charging management circuit 3, and the output terminal of the charging management circuit 3 is connected to the input terminal of the lithium battery; the ground terminal of the power input protection circuit 1 is grounded.

[0053] The power input protection circuit 1 is used to connect the input terminal of the power boost circuit 2 to the power supply when charging the lithium battery, and to discharge the surge voltage received at its own input terminal to the ground terminal.

[0054] The power boost circuit 2 is used to boost the output voltage of the power supply and output a preset power supply voltage; the preset power supply voltage is greater than the maximum output voltage of the lithium battery, but not greater than the rated voltage of the lithium battery.

[0055] The charging management circuit 3 is used to charge the lithium battery with constant current and constant voltage based on a preset power supply voltage.

[0056] In a lithium battery charging circuit, the power input protection circuit 1 is connected between the power supply and the power boost circuit 2. When the input terminal of the power input protection circuit 1 comes into contact with the power supply, a surge voltage may be generated. This surge voltage can rise to several kilovolts or higher, resulting in an electric spark. If the surge voltage is directly connected to the power boost circuit 2, it may cause the power boost circuit 2 to be unable to withstand the excessive surge voltage and burn out, failing to function properly and thus preventing the lithium battery from being charged. This is especially problematic for lithium batteries and lithium battery charging circuits used in medical equipment with stringent safety requirements. If the lithium battery cannot be charged, it cannot ensure a stable power supply to the equipment in the medical device. In this application, by setting up the power input protection circuit 1, the power input protection circuit 1 can discharge the surge voltage to the ground terminal when it receives a surge voltage at its input terminal, preventing the surge voltage from being transmitted to the power boost circuit 2, thereby protecting the power boost circuit 2, the charging management circuit 3, and the lithium battery.

[0057] It should be noted that a DC (direct current) plug can be connected to the input terminal and ground terminal of the power input protection circuit 1. A surge voltage may occur when the DC plug comes into contact with the power supply.

[0058] The power boost circuit 2 is connected to the power supply through the power input protection circuit 1. After boosting the output voltage of the power supply, it outputs a preset power supply voltage, so that the charging management circuit 3 can charge the lithium battery with constant voltage and constant current based on the preset power supply voltage. Since the preset power supply voltage is greater than the maximum output voltage of the lithium battery, but not greater than the rated voltage of the lithium battery, it can overcome the electromotive force of the lithium battery itself and ensure that the lithium battery is fully charged.

[0059] Furthermore, the charging management circuit 3 is used to perform constant current and constant voltage charging of the lithium battery based on a preset supply voltage. Specifically, during the constant current charging stage, the charging management circuit 3 quickly and efficiently fills most of the lithium battery with its charge. At this time, the charging management circuit 3 charges the lithium battery with a set, safe, high current. During this stage, the charging current remains constant, while the lithium battery voltage steadily rises from a lower value. The constant current charging stage improves charging efficiency and shortens charging time. That is, when the lithium battery voltage is low, it can accept a larger charging current. This stage can quickly restore 70%-80% of the lithium battery's charge, significantly reducing charging time. The overall charging time is controlled, and by controlling a fixed charging current within the lithium battery's tolerance range, the internal temperature rise and chemical reaction rate of the lithium battery can be effectively managed, avoiding the risks caused by current runaway. During the constant voltage charging stage, the final filling of the lithium battery can be safely completed. When the lithium battery voltage rises to the preset full charge voltage threshold, the charging management circuit 3 switches the charging mode. At this time, the charging voltage output by the charging management circuit 3 remains unchanged, while the charging current begins to decrease continuously until it decreases to a lower charging current threshold. The charging management circuit 3 then stops charging. During the constant voltage charging process, overcharging can be prevented, ensuring the safety of the lithium battery. If a lithium battery is continuously charged with a constant current, the battery voltage will exceed the rated voltage, leading to overcharging. The consequences of overcharging are extremely dangerous. It can cause the positive electrode material structure of the lithium battery to collapse and the electrolyte to decompose and produce gas. It can also cause lithium metal to precipitate on the surface of the negative electrode, forming dendrites. These dendrites can easily pierce the separator, causing an internal short circuit in the lithium battery, leading to thermal runaway, fire, or even explosion. The constant voltage stage, by stabilizing the charging voltage, fundamentally eliminates the possibility of overcharging.

[0060] In summary, the power input protection circuit 1 is connected between the power supply and the power boost circuit 2 and grounded, thereby discharging the surge voltage to the ground terminal when a surge voltage occurs, thus protecting the downstream circuits and the lithium battery. The power boost circuit 2 can boost the output voltage of the power supply and output a preset power supply voltage, which in turn enables the charging management circuit 3 to perform constant current and constant voltage charging on the lithium battery based on the preset power supply voltage. Since the preset power supply voltage is greater than the maximum output voltage of the lithium battery but not greater than the rated voltage of the lithium battery, and the constant current and constant voltage charging of the lithium battery can ensure that the lithium battery is safely charged while ensuring that the lithium battery has sufficient charge after charging, thereby ensuring that the lithium battery can stably supply power to the power supply equipment.

[0061] Based on the above embodiments:

[0062] Please refer to Figure 2 and Figure 3 , Figure 2 This application provides a schematic diagram of the structure of a power input protection circuit and a power boost circuit. Figure 3 This is a schematic diagram of a charging management circuit provided in this application.

[0063] In a preferred embodiment, the power boost circuit 2 includes a positive feedback inductor L1, a power boost chip U1, and a voltage detection circuit;

[0064] The input terminal of the power boost chip U1 is the input terminal of the power boost circuit 2, and the output terminal of the power boost chip U1 is the output terminal of the power boost circuit 2. The feedback input terminal of the power boost chip U1 is connected to the output terminal of the voltage detection circuit. The first terminal of the positive feedback inductor L1 is connected to the output terminal of the power boost chip U1, and the second terminal of the positive feedback inductor L1 is connected to the input terminal of the power boost chip U1. The input terminal of the voltage detection circuit is connected to the output terminal of the power boost chip U1.

[0065] The power boost chip U1 is used to boost the input voltage received at its own input terminal, and stably output the preset power supply voltage when the output voltage at its own output terminal is determined to be the preset power supply voltage based on the feedback voltage received at its own feedback input terminal.

[0066] The input voltage is the sum of the output voltage of the power supply and the output voltage of the positive feedback inductor L1.

[0067] The positive feedback inductor L1 is used to charge when the output voltage of the power boost chip U1 rises, and outputs the stored electrical energy to the input terminal of the power boost chip U1.

[0068] The voltage detection circuit is used to acquire the output voltage of the power boost chip U1 and convert the acquired output voltage of the power boost chip U1 into a feedback voltage.

[0069] The power boost chip U1 in the power boost circuit 2 is mainly used to boost the received input voltage. The input voltage is the voltage resulting from the superposition of the output voltage of the power supply and the output voltage of the positive feedback inductor L1. The output voltage of the power boost circuit 2 starts from 0 and rises. During the rise of the output voltage of the power boost chip U1, the positive feedback inductor L1 is charged and the electrical energy is transferred to the input terminal of the power boost chip U1. The larger the output voltage of the power boost chip U1, the larger the output voltage of the positive feedback inductor L1, and the larger the input voltage at the input terminal of the power boost chip U1, the higher the efficiency of the power boost circuit 2 in boosting the input voltage to the preset power supply voltage.

[0070] During the boost process, the voltage detection circuit collects the output voltage of the power boost chip U1 and converts it into a feedback voltage. When the power boost chip U1 determines that its output voltage has not reached the preset supply voltage based on the feedback voltage, it maintains the boost process, that is, the voltage of the power boost chip U1 continues to rise. When the power boost chip U1 determines that its output voltage has reached the preset supply voltage based on the feedback voltage, it stabilizes and outputs the preset supply voltage. That is, the output voltage of the power boost chip U1 no longer rises, but stabilizes at the preset supply voltage. Figure 2 In this configuration, the VIN terminal of the power boost chip U1 is the input terminal of the power boost chip U1, the SW terminal of the power boost chip U1 is the output terminal of the power boost chip U1, the FB terminal of the power boost chip U1 is the feedback input terminal of the power boost chip U1, the GND terminal of the power boost chip U1 is the ground terminal of the power boost chip U1, and the EN terminal of the power boost chip U1 is the enable terminal of the power boost chip U1. The EN terminal of the power boost chip U1 is kept floating and is at a high level.

[0071] Specifically, the voltage detection circuit may include a first voltage detection resistor R1 and a second voltage detection resistor R2. The first end of the first voltage detection resistor R1 is connected to the output terminal of the power boost chip U1, and the second end of the first voltage detection resistor R1 is connected to the first end of the second voltage detection resistor R2. The second end of the second voltage detection resistor R2 is grounded. The connection point between the first voltage detection resistor R1 and the second voltage detection resistor R2 is the output terminal of the voltage detection circuit. The voltage at the connection point between the first voltage detection resistor R1 and the second voltage detection resistor R2 is the voltage drop across the second voltage detection resistor R2 after the first voltage detection resistor R1 and the second voltage detection resistor R2 are connected in series. If the voltage at the connection point between the first voltage detection resistor R1 and the second voltage detection resistor R2 is the first reference voltage at the feedback input terminal of the power boost chip U1, then the power boost chip U1 can determine that its output voltage has reached the preset supply voltage. Assuming the preset supply voltage is 26.25V, the feedback voltage at the feedback input terminal of the power boost chip U1 is 1.25V, the first reference voltage is 1.25V, and R1=100... R²=5 For example, the output voltage Vout of the power boost chip U1 can be calculated as Vout = 1.25 × (1 + R1 / R2), which is 26.25V, the preset supply voltage. Based on this, the power boost chip U1 can maintain a stable output of the preset supply voltage.

[0072] In a preferred embodiment, the power boost circuit 2 further includes a first TVS (Transient Voltage Suppressor) D1, a first filter circuit, a first anti-reverse diode D2, and a second filter circuit.

[0073] The first terminal of the first TVS diode D1 is connected to the input terminal of the power boost chip U1, and the second terminal of the first TVS diode D1 is grounded. It is used to switch to a low-impedance state when it receives a surge voltage at its first terminal in order to discharge the surge voltage to ground, otherwise it switches to a high-impedance state.

[0074] The first terminal of the first filter circuit is connected to the input terminal of the power boost chip U1, and the second terminal of the first filter circuit is grounded to filter out the ripple of the power supply output.

[0075] The input terminal of the first anti-reverse diode D2 is connected to the output terminal of the power boost chip U1, and the output terminal of the first anti-reverse diode D2 is connected to the power input terminal of the charging management circuit 3 and the input terminal of the voltage detection circuit.

[0076] The first terminal of the second filter circuit is connected to the output terminal of the first anti-reverse diode D2, and the second terminal of the second filter circuit is grounded, which is used to filter out the ripple output of the power boost chip U1.

[0077] In this embodiment, the first TVS diode D1 has an extremely fast surge voltage response speed and a relatively high surge voltage absorption capability. Under normal circumstances, the first TVS diode D1 is in a high-impedance state, and the output voltage of the power supply is directly transmitted to the power boost chip U1. When a surge voltage occurs, the first TVS diode D1 changes from a high-impedance state to a low-impedance state, thereby shunting and clamping the surge voltage, and discharging the surge voltage to the ground terminal, protecting the various components in the lithium battery charging circuit from being damaged by the instantaneous surge voltage.

[0078] The first and second filter circuits respectively filter out the input and output ripple of the power boost chip U1 to ensure the stability of the input and output voltages of the power boost chip U1.

[0079] The first anti-reverse diode D2 is positioned between the output terminal of the power boost chip U1 and the power input terminal of the charging management circuit 3 to prevent the voltage at the power input terminal of the charging management circuit 3 from being reverse-transmitted to the power boost chip U1, thereby protecting the power boost chip U1.

[0080] The first filter circuit may, but is not limited to, include a first filter capacitor C1, a second filter capacitor C2, and a third filter capacitor C3. The capacitance value of the first filter capacitor C1 may be 470. The capacitance of the second filter capacitor C2 can be 10. The capacitance of the third filter capacitor C3 can be 100. This allows for the filtering out of ripples at different frequencies.

[0081] The second filter circuit may, but is not limited to, include a fourth filter capacitor C4 and a fifth filter capacitor C5. The capacitance value of the fourth filter capacitor C4 can be 1. The capacitance of the fifth filter capacitor C5 can be 470. This allows for the filtering out of ripples at different frequencies.

[0082] In a preferred embodiment, the charging management circuit 3 includes a charging management chip U2, a first switching transistor G1, a freewheeling inductor L2, a current acquisition circuit, and a voltage acquisition circuit.

[0083] The first terminal of the first switching transistor G1 is the power input terminal of the charging management circuit 3. The control terminal of the first switching transistor G1 is connected to the output terminal of the charging management chip U2. The second terminal of the first switching transistor G1 is connected to the first terminal of the freewheeling inductor L2, and the second terminal of the freewheeling inductor L2 is the output terminal of the charging management circuit 3. The input terminal of the current acquisition circuit is connected to the second terminal of the freewheeling inductor L2, and the output terminal of the current acquisition circuit is connected to the current feedback input terminal of the charging management chip U2. The input terminal of the voltage acquisition circuit is connected to the second terminal of the freewheeling inductor L2, and the output terminal of the voltage acquisition circuit is connected to the voltage feedback input terminal of the charging management chip U2.

[0084] The current acquisition circuit is used to acquire the charging current of the lithium battery;

[0085] The voltage acquisition circuit is used to acquire the charging voltage of the lithium battery;

[0086] The charging management chip U2 is used to control the conduction state of the first switching transistor G1 based on the charging voltage and charging current.

[0087] The freewheeling inductor L2 is used to charge or discharge based on the conduction state of the first switch G1, so as to perform constant current and constant voltage charging of the lithium battery based on the preset supply voltage.

[0088] In this embodiment, the charging management chip U2 in the charging management circuit 3 controls the conduction state of the first switch G1 based on the charging current collected by the current acquisition circuit and the charging voltage collected by the voltage acquisition circuit. For example, during the constant current charging stage, by adjusting the duty cycle of the first switch G1, the freewheeling inductor L2 is charged or discharged, so that the freewheeling inductor L2 outputs a stable current, thereby performing constant current charging on the lithium battery. The charging current collected by the current acquisition circuit is used to determine whether the charging current of the lithium battery is constant. If the charging current is unstable, the first switch G1 is controlled according to the charging current. The duty cycle of the switching transistor G1 is finely adjusted to ensure a constant charging current, i.e., constant current charging. During the constant voltage charging stage, the duty cycle of the first switching transistor G1 is adjusted to charge or discharge the freewheeling inductor L2, so that the freewheeling inductor L2 outputs a stable voltage, thereby performing constant voltage charging on the lithium battery. The charging voltage collected by the voltage acquisition circuit is used to determine whether the charging voltage of the lithium battery is constant. If the charging voltage is unstable, the duty cycle of the first switching transistor G1 is finely adjusted according to the charging voltage to ensure that the charging voltage is constant, i.e., constant voltage charging.

[0089] Specifically, when the charging management circuit 3 determines that the charging voltage of the lithium battery has reached the full charge voltage threshold based on the charging voltage of the lithium battery collected by the voltage acquisition circuit, it switches from the constant current charging stage to the constant voltage charging stage.

[0090] The first switch G1 can be, but is not limited to, a PMOS (Positive-Channel Metal Oxide Semiconductor). The gate of the PMOS is the control terminal of the first switch G1, the source of the PMOS is the first terminal of the first switch G1, and the drain of the PMOS is the second terminal of the first switch G1.

[0091] In a preferred embodiment, the charging management circuit 3 further includes a charging status indication circuit;

[0092] The input terminal of the charging status indication circuit is connected to the first terminal of the first switching transistor G1, and the output terminal of the charging status indication circuit is connected to the indication output terminal of the charging management chip U2, which is used to indicate the charging status of the lithium battery based on the control of the charging management chip U2.

[0093] To facilitate staff in determining the status of the lithium battery, a charging status indication circuit is also provided in this embodiment. The charging management chip U2 controls the charging status indication circuit based on the charging voltage of the lithium battery, so that the charging status indication circuit can indicate the charging status of the lithium battery.

[0094] from Figure 3As can be seen from the diagram, the power supply terminal VCC of the charging management chip U2 is also connected to the first terminal of the first switching transistor G1, meaning that the charging management chip U2 is powered by the power boost circuit 2.

[0095] In a preferred embodiment, the charging status indication circuit includes a first light-emitting diode D11 and a second light-emitting diode D12;

[0096] The input terminal of the first light-emitting diode D11 is connected to the first terminal of the first switching transistor G1, and the output terminal of the charging status indication circuit is connected to the first indication output terminal of the charging management chip U2, which is used to indicate the status of the lithium battery being charged based on the control of the charging management chip U2.

[0097] The input terminal of the second light-emitting diode D12 is connected to the first terminal of the first switching transistor G1, and the output terminal of the charging status indication circuit is connected to the second indication output terminal of the charging management chip U2, which is used to indicate the status of the lithium battery being fully charged based on the control of the charging management chip U2.

[0098] The charging status indication circuit in this embodiment includes a first light-emitting diode D11 and a second light-emitting diode D12. When the charging management chip U2 determines that the lithium battery is not fully charged and is still in the charging state based on the charging voltage of the lithium battery, it controls the first light-emitting diode D11 to light up to indicate that the lithium battery is charging.

[0099] When the charging management chip U2 determines that the lithium battery is fully charged based on the charging voltage of the lithium battery, it controls the second light-emitting diode D12 to light up to indicate that the lithium battery is fully charged.

[0100] The input terminals of the first LED D11 and the second LED D12 can both be connected to the first terminal of the first switching transistor G1 through the third current-limiting resistor R3, so as to provide current-limiting protection for the first LED D11 and the second LED D12.

[0101] The first light-emitting diode D11 can emit red light when lit, and the second light-emitting diode D12 can emit green light when lit; this application does not limit this.

[0102] In a preferred embodiment, the charging management circuit 3 further includes a third filter circuit, a fourth filter circuit, a second anti-reverse diode D3, and a second TVS diode D4;

[0103] The first terminal of the third filter circuit is connected to the output terminal of the power boost circuit 2 and the first terminal of the first switching transistor G1. The second terminal of the third filter circuit is grounded and used to filter out the ripple output of the power boost circuit 2.

[0104] The first terminal of the fourth filter circuit is connected to the second terminal of the freewheeling inductor L2, and the second terminal of the fourth filter circuit is grounded to filter out the ripple output of the freewheeling inductor L2.

[0105] The input terminal of the second anti-reverse diode D3 is connected to the first terminal of the fourth filter circuit and the second terminal of the freewheeling inductor L2, and the output terminal is connected to the input terminal of the lithium battery.

[0106] The first terminal of the second TVS diode D4 is connected to the output terminal of the second anti-reverse diode D3 and the input terminal of the lithium battery. The second terminal of the second TVS diode D4 is grounded to discharge the surge voltage received at its first terminal to ground.

[0107] The charging management circuit 3 also includes a third filter circuit, a fourth filter circuit, a second anti-reverse diode D3, and a second TVS diode D4. The third filter circuit and the fourth filter circuit filter out the input ripple and output ripple of the charging management chip U2 to ensure the stability of the input and output of the charging management chip U2.

[0108] The second anti-reverse diode D3 prevents the lithium battery from supplying power to the charging management chip U2 in reverse, thus protecting the charging management chip U2.

[0109] Considering that surge voltage may occur when the charging management circuit 3 is connected to the lithium battery, in this embodiment, the second TVS diode D4 is placed at the output terminal of the charging management circuit 3 to ground the surge voltage at the output terminal of the charging management circuit 3, thereby preventing the surge voltage from affecting the lithium battery and the lithium battery charging circuit.

[0110] The third filter circuit may, but is not limited to, include the sixth filter capacitor C6, the seventh filter capacitor C7, and the eighth filter capacitor C8. The capacitance value of the sixth filter capacitor C6 can be 470. The capacitance of the seventh filter capacitor C7 can be 10. The capacitance of the eighth filter capacitor C8 can be 100. This allows for the filtering out of ripples at different frequencies.

[0111] The fourth filter circuit may, but is not limited to, include the ninth filter capacitor C9, the tenth filter capacitor C10, and the eleventh filter capacitor C11. The capacitance value of the ninth filter capacitor C9 can be 100. The capacitance of the tenth filter capacitor C10 can be 10. The capacitance of the eleventh filter capacitor C11 can be 470. This allows for the filtering out of ripples at different frequencies.

[0112] In addition, by Figure 3It can be seen that a third anti-reverse diode D5 can also be set between the second terminal of the first switching transistor G1 and the first terminal of the freewheeling inductor L2 to prevent the freewheeling inductor L2 from transmitting electrical energy in reverse to the first switching transistor G1 when it discharges, which would cause the lithium battery charging circuit to malfunction and fail to charge the lithium battery normally.

[0113] In a preferred embodiment, the current acquisition circuit includes a current sampling resistor R4. The first end of the current sampling resistor R4 is connected to the second end of the freewheeling inductor L2 and the first current feedback input terminal of the charging management chip U2. The second end of the current sampling resistor R4 is connected to the input terminal of the lithium battery and the second current feedback input terminal of the charging management chip U2, for acquiring the charging current of the lithium battery.

[0114] The voltage acquisition circuit includes a first voltage sampling resistor R5 and a second voltage sampling resistor R6. The first end of the first voltage sampling resistor R5 is connected to the second end of the current sampling resistor R4, and the second end of the first voltage sampling resistor R5 is connected to the first end of the second voltage sampling resistor R6. The second end of the second voltage sampling resistor R6 is grounded. The second end of the first voltage sampling resistor R5 and the first end of the second voltage sampling resistor R6 are connected to the voltage feedback input terminal of the charging management chip U2 for acquiring the charging voltage of the lithium battery.

[0115] In the current acquisition circuit, the current sampling resistor R4 is connected in series between the freewheeling inductor L2 and the lithium battery. The current across the current sampling resistor R4 is the charging current of the lithium battery. The voltage between the first and second current feedback input terminals of the charging management chip U2 is the voltage across the current sampling resistor R4. According to Ohm's law, the ratio between the voltage between the first and second current feedback input terminals of the charging management chip U2 and the resistance of the current sampling resistor R4 is the charging current. A first current-limiting resistor R7 can also be set between the first terminal of the current sampling resistor R4 and the first current feedback input terminal of the charging management chip U2, and a second current-limiting resistor R8 can be set between the second terminal of the current sampling resistor R4 and the second current feedback input terminal of the charging management chip U2 for current limiting. This application does not limit this specific application.

[0116] For example, if the preset constant current charging current is 3.6A, the voltage difference between the first current feedback input terminal and the second current feedback input terminal of the charging management chip U2 is 120mV, and the charging voltage Ich = 120mV / R4, and the resistance of the current sampling resistor R4 is 0.033R, then the charging current Ich = 0.12 / 0.033 = 3.6A, which is equal to the constant current charging current. It can be determined that the charging current of the lithium battery remains stable during the constant current charging stage.

[0117] In the voltage acquisition circuit, the first voltage sampling resistor R5 and the second voltage sampling resistor R6 are connected in series between the second terminal of the freewheeling inductor L2 and the ground terminal. Therefore, the voltage at the voltage feedback input terminal of the charging management chip U2 is the voltage division across the second voltage sampling resistor R6. For example, during the constant voltage charging stage, when the constant voltage charging voltage is 25.2V, the voltage division across the second voltage sampling resistor R6 is 1.205V. The charging voltage VBAT at the input terminal of the lithium battery is 1.205 × (1 + R5 / R6). If R5 = 200... R6=10 Therefore, VBAT = 1.205 × 21V = 25.3V ≈ 25.2V, which is the same as the constant voltage charging voltage, and the charging voltage of the lithium battery remains stable.

[0118] Figure 3 In the diagram, the output terminal of the charging management chip U2 is the DRV terminal, the current feedback input terminal of the charging management chip U2 is the FB terminal, the first current feedback input terminal of the charging management chip U2 is the CSP terminal, the second current feedback input terminal of the charging management chip U2 is the BAT terminal, the first prompt output terminal of the charging management chip U2 is the DONE terminal, and the second prompt output terminal of the charging management chip U2 is the CHR terminal.

[0119] Figure 2 In this example, the output voltage of the power supply is 24V. Figure 3 In the example of a preset power supply voltage of 26V, the constant voltage charging voltage of the lithium battery is less than 26V after being divided by the current sampling resistor R4.

[0120] In a preferred embodiment, the power input protection circuit 1 includes a third TVS transistor D6, an input filter capacitor C12, and a second switching transistor G2;

[0121] The first terminal of the third TVS transistor D6, the first terminal of the input filter capacitor C12, and the first terminal of the second switch G2 are connected and serve as the input terminal of the power input protection circuit 1; the second terminal of the third TVS transistor D6, the second terminal of the input filter capacitor C12, and the control terminal of the second switch G2 are connected and serve as the ground terminal of the power input protection circuit 1; the second terminal of the second switch G2 serves as the output terminal of the power input protection circuit 1.

[0122] The third TVS diode D6 is used to switch to a low-impedance state when it receives a surge voltage at its first terminal in order to discharge the surge voltage to ground; otherwise, it switches to a high-impedance state.

[0123] The second switch G2 is used to turn on when its control terminal is grounded and to connect to the power supply at its control terminal, and to turn off when its first terminal is grounded.

[0124] The input filter capacitor C12 is used to filter out the ripple in the power supply output.

[0125] The power input protection circuit 1 in this embodiment includes a third TVS diode D6, a filter capacitor, and a second switching transistor G2. Under normal circumstances, the third TVS diode D6 maintains a high impedance state, and the output voltage of the power supply is directly transmitted to the power boost circuit 2. When the first terminal of the third TVS diode D6 receives a surge voltage, the third TVS diode D6 switches to a low impedance state to discharge the surge voltage to ground, thereby preventing the surge voltage from affecting the normal operation of the power boost circuit 2.

[0126] The input filter capacitor C12 filters out the ripple in the power supply output to ensure the stability of the voltage output from the power supply to the power boost circuit 2.

[0127] In addition, the control terminal of the second switch G2 is grounded. When the input terminal of the power input protection circuit 1 is normally connected to the power supply and the ground terminal is normally grounded, the second switch G2 remains in the conducting state. Conversely, if the input terminal of the power input protection circuit 1 is reversed with the ground terminal, in order to protect the lithium battery charging circuit and the lithium battery, the control terminal of the second switch G2 will be connected to the power supply along with the ground terminal, and the second switch G2 will be turned off.

[0128] The second switch G2 can be, but is not limited to, a PMOS. The gate of the PMOS is the control terminal of the second switch G2, the source of the PMOS is the first terminal of the second switch G2, and the drain of the PMOS is the second terminal of the second switch G2.

[0129] The pneumatic hand function rehabilitation circuit in this application includes the lithium battery charging circuit described above.

[0130] For a description of the pneumatic hand function rehabilitation circuit provided by this utility model, please refer to the above embodiments; this utility model will not be described again here.

[0131] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0132] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lithium battery charging circuit, characterized in that, This includes a power input protection circuit, a power boost circuit, and a charging management circuit; The input terminal of the power input protection circuit is connected to the power supply, the output terminal of the power input protection circuit is connected to the input terminal of the power boost circuit, the output terminal of the power boost circuit is connected to the power input terminal of the charging management circuit, and the output terminal of the charging management circuit is connected to the input terminal of the lithium battery; the ground terminal of the power input protection circuit is grounded. The power input protection circuit is used to connect the input terminal of the power boost circuit to the power supply when charging the lithium battery, and to discharge the surge voltage received at its own input terminal to the ground terminal. The power boost circuit is used to boost the output voltage of the power supply and then output a preset power supply voltage; the preset power supply voltage is greater than the maximum output voltage of the lithium battery, but not greater than the rated voltage of the lithium battery; The charging management circuit is used to charge the lithium battery with constant current and constant voltage based on the preset power supply voltage.

2. The lithium battery charging circuit as described in claim 1, characterized in that, The power boost circuit includes a positive feedback inductor, a power boost chip, and a voltage detection circuit. The input terminal of the power boost chip is the input terminal of the power boost circuit, and the output terminal of the power boost chip is the output terminal of the power boost circuit. The feedback input terminal of the power boost chip is connected to the output terminal of the voltage detection circuit. The first terminal of the positive feedback inductor is connected to the output terminal of the power boost chip, and the second terminal of the positive feedback inductor is connected to the input terminal of the power boost chip. The input terminal of the voltage detection circuit is connected to the output terminal of the power boost chip. The power boost chip is used to boost the input voltage received at its own input terminal, and stably output the preset power supply voltage when the output voltage at its own output terminal is determined to be the preset power supply voltage based on the feedback voltage received at its own feedback input terminal. The input voltage is the voltage obtained by superimposing the output voltage of the power supply and the output voltage of the positive feedback inductor; The positive feedback inductor is used to charge when the output voltage of the power boost chip rises, and outputs the stored electrical energy to the input terminal of the power boost chip. The voltage detection circuit is used to acquire the output voltage of the power boost chip and convert the acquired output voltage of the power boost chip into the feedback voltage.

3. The lithium battery charging circuit as described in claim 2, characterized in that, The power boost circuit also includes a first TVS diode, a first filter circuit, a first anti-reverse diode, and a second filter circuit. The first end of the first TVS diode is connected to the input terminal of the power boost chip, and the second end of the first TVS diode is grounded. It is used to switch to a low-impedance state when it receives a surge voltage at its first end in order to discharge the surge voltage to ground, and otherwise switch to a high-impedance state. The first terminal of the first filter circuit is connected to the input terminal of the power boost chip, and the second terminal of the first filter circuit is grounded, which is used to filter out the ripple output by the power supply. The input terminal of the first anti-reverse diode is connected to the output terminal of the power boost chip, and the output terminal of the first anti-reverse diode is connected to the power input terminal of the charging management circuit and the input terminal of the voltage detection circuit. The first terminal of the second filter circuit is connected to the output terminal of the first anti-reverse diode, and the second terminal of the second filter circuit is grounded, which is used to filter out the ripple output by the power boost chip.

4. The lithium battery charging circuit as described in claim 1, characterized in that, The charging management circuit includes a charging management chip, a first switching transistor, a freewheeling inductor, a current acquisition circuit, and a voltage acquisition circuit. The first terminal of the first switching transistor is the power input terminal of the charging management circuit, the control terminal of the first switching transistor is connected to the output terminal of the charging management chip, the second terminal of the first switching transistor is connected to the first terminal of the freewheeling inductor, and the second terminal of the freewheeling inductor is the output terminal of the charging management circuit; the input terminal of the current acquisition circuit is connected to the second terminal of the freewheeling inductor, and the output terminal of the current acquisition circuit is connected to the current feedback input terminal of the charging management chip; the input terminal of the voltage acquisition circuit is connected to the second terminal of the freewheeling inductor, and the output terminal of the voltage acquisition circuit is connected to the voltage feedback input terminal of the charging management chip. The current acquisition circuit is used to acquire the charging current of the lithium battery; The voltage acquisition circuit is used to acquire the charging voltage of the lithium battery; The charging management chip is used to control the conduction state of the first switch based on the charging voltage and the charging current. The freewheeling inductor is used to charge or discharge the lithium battery based on the conduction state of the first switch, so as to perform constant current and constant voltage charging of the lithium battery based on the preset supply voltage.

5. The lithium battery charging circuit of claim 4, wherein, The charging management circuit also includes a charging status indication circuit; The input terminal of the charging status indication circuit is connected to the first terminal of the first switching transistor, and the output terminal of the charging status indication circuit is connected to the indication output terminal of the charging management chip, for indicating the charging status of the lithium battery based on the control of the charging management chip.

6. The lithium battery charging circuit as described in claim 5, characterized in that, The charging status indication circuit includes a first light-emitting diode and a second light-emitting diode; The input terminal of the first light-emitting diode is connected to the first terminal of the first switching transistor, and the output terminal of the charging status indication circuit is connected to the first indication output terminal of the charging management chip, for indicating that the lithium battery is charging based on the control of the charging management chip. The input terminal of the second light-emitting diode is connected to the first terminal of the first switching transistor, and the output terminal of the charging status indication circuit is connected to the second indication output terminal of the charging management chip, for indicating the status of the lithium battery being fully charged based on the control of the charging management chip.

7. The lithium battery charging circuit as described in claim 4, characterized in that, The charging management circuit also includes a third filter circuit, a fourth filter circuit, a second anti-reverse diode, and a second TVS diode; The first terminal of the third filter circuit is connected to the output terminal of the power boost circuit and the first terminal of the first switching transistor, and the second terminal of the third filter circuit is grounded to filter out the ripple output by the power boost circuit. The first terminal of the fourth filter circuit is connected to the second terminal of the freewheeling inductor, and the second terminal of the fourth filter circuit is grounded, which is used to filter out the ripple output by the freewheeling inductor. The input terminal of the second anti-reverse diode is connected to the first terminal of the fourth filter circuit and the second terminal of the freewheeling inductor, and the output terminal is connected to the input terminal of the lithium battery. The first end of the second TVS diode is connected to the output end of the second anti-reverse diode and the input end of the lithium battery, and the second end of the second TVS diode is grounded to discharge the surge voltage received at its first end to ground.

8. The lithium battery charging circuit as described in claim 4, characterized in that, The current acquisition circuit includes a current sampling resistor. The first end of the current sampling resistor is connected to the second end of the freewheeling inductor and the first current feedback input terminal of the charging management chip. The second end of the current sampling resistor is connected to the input terminal of the lithium battery and the second current feedback input terminal of the charging management chip, and is used to acquire the charging current of the lithium battery. The voltage acquisition circuit includes a first voltage sampling resistor and a second voltage sampling resistor. The first end of the first voltage sampling resistor is connected to the second end of the current sampling resistor. The second end of the first voltage sampling resistor is connected to the first end of the second voltage sampling resistor. The second end of the second voltage sampling resistor is grounded. The second end of the first voltage sampling resistor and the first end of the second voltage sampling resistor are connected to the voltage feedback input terminal of the charging management chip for acquiring the charging voltage of the lithium battery.

9. The lithium battery charging circuit according to any one of claims 1-8, characterized in that, The power input protection circuit includes a third TVS transistor, an input filter capacitor, and a second switching transistor. The first terminal of the third TVS diode, the first terminal of the input filter capacitor, and the first terminal of the second switching transistor are connected and serve as the input terminal of the power input protection circuit; the second terminal of the third TVS diode, the second terminal of the input filter capacitor, and the control terminal of the second switching transistor are connected and serve as the ground terminal of the power input protection circuit; the second terminal of the second switching transistor is the output terminal of the power input protection circuit. The third TVS diode is used to switch to a low-impedance state when it receives a surge voltage at its first terminal in order to discharge the surge voltage to ground; otherwise, it switches to a high-impedance state. The second switch is used to turn on when its control terminal is grounded and to connect the power supply to its control terminal, and to turn off when its first terminal is grounded; The input filter capacitor is used to filter out the ripple output by the power supply.

10. A pneumatic hand function rehabilitation circuit, characterized in that, Includes the lithium battery charging circuit as described in any one of claims 1-9.

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