Wide-range DC drive circuit

Abstract

This utility model discloses a wide-range DC drive circuit, which includes a DC conversion circuit, a controller, an auxiliary power supply circuit, and a first interface terminal and a second interface terminal. The first interface terminal is used to connect a rechargeable battery to the DC conversion circuit, and the second interface terminal is used to connect a discharging load or a charging load to the DC conversion circuit. The controller is connected to the adjustment terminal of the DC conversion circuit and is used to control the operating state of the DC conversion circuit. The auxiliary power supply circuit includes an auxiliary power supply and a power processing circuit connected to the auxiliary power supply. The output terminal of the power processing circuit is connected to the power supply terminal of the controller to provide the power required for the controller's operation. The wide-range DC drive circuit provided by the above technical solution of this utility model provides a stable operating power supply to the controller through the auxiliary power supply circuit, enabling the controller to maintain normal operation even when the battery output voltage is as low as 1V, realizing a wide input range, especially suitable for single low-voltage batteries, thereby expanding the application scenarios of the DC drive circuit.

Description

Technical Field

[0001] This utility model relates to the field of DC drive circuit technology, and in particular to a wide-range DC drive circuit. Background Technology

[0002] With the rapid development of portable electronic devices and low-voltage energy storage systems, the demand for low-voltage, high-current DC boost circuits is increasing. However, existing technologies have significant limitations: traditional DC boost circuits struggle to achieve efficient high-current output when the input voltage is below 3V. This is because the boost chip they rely on requires a voltage above 4V to operate normally, forcing energy storage systems to use multiple batteries connected in series to boost the voltage. This approach not only increases the size and complexity of the battery pack but also necessitates the introduction of a battery equalization management circuit (BMS) to address voltage imbalances in the series-connected battery packs, leading to increased system costs and reduced reliability.

[0003] Furthermore, existing low-voltage (below 3V) boost technologies only support unidirectional energy transfer and cannot achieve reverse charging. Most mainstream bidirectional charge / discharge ICs on the market are compatible with input voltages above 5V and require the battery pack to consist of at least two cells connected in series, limiting their application in single-cell battery power supply scenarios. For example, in single-cell lithium batteries (nominal voltage 3.2V) or low-voltage energy storage modules, existing technologies cannot simultaneously meet the requirements for boost output and reverse charging, resulting in insufficient system flexibility and difficulty in adapting to the miniaturization trend of portable devices.

[0004] To address the aforementioned issues, existing solutions rely on complex peripheral circuits and battery management modules, further increasing design costs and power consumption. Utility Model Content

[0005] The purpose of this invention is to provide a wide-range DC drive circuit that is compatible with lower input voltages and supports bidirectional charging and discharging of batteries.

[0006] To achieve the above objectives, this utility model provides a wide-range DC drive circuit, which includes a DC conversion circuit, a controller, an auxiliary power supply circuit, a first interface terminal, and a second interface terminal.

[0007] The first interface terminal is used to connect the rechargeable battery to the DC conversion circuit, and the second interface terminal is used to connect the discharge load or the charging load to the DC conversion circuit.

[0008] The controller is connected to the adjustment terminal of the DC conversion circuit, and the controller is used to control the operating state of the DC conversion circuit;

[0009] The auxiliary power supply circuit includes an auxiliary power supply and a power processing circuit connected to the auxiliary power supply. The output terminal of the power processing circuit is connected to the power supply terminal of the controller to provide the power required for the controller to operate.

[0010] Preferably, the auxiliary power supply circuit includes a discharge auxiliary power supply circuit and a charging auxiliary power supply circuit;

[0011] The discharge auxiliary power supply circuit includes a first auxiliary power supply and a first power processing circuit connected to the first auxiliary power supply. The output terminal of the first power processing circuit is connected to the power supply terminal of the controller.

[0012] The charging auxiliary power supply circuit includes a second power processing circuit, which is connected to the second interface terminal to obtain a second auxiliary power supply from the charging load connected to the second interface terminal. The output terminal of the second power processing circuit is connected to the power supply terminal of the controller.

[0013] Preferably, it also includes a low-voltage protection circuit, the input terminal of which is connected to the first auxiliary power supply, and the output terminal of which is connected to the input terminal of the first power processing circuit. The controller is also connected to the first interface terminal to obtain the port voltage of the rechargeable battery.

[0014] The low-voltage protection circuit also includes a control port connected to the controller, and the controller controls the on / off state of the low-voltage protection circuit based on the port voltage.

[0015] Preferably, the low-voltage protection circuit includes an input circuit, an output circuit, an operational amplifier, and a power regulator;

[0016] One end of the input circuit is connected to the first auxiliary power supply of the peripheral device, the other end of the input circuit is connected to the non-inverting input of the operational amplifier, one end of the output circuit is connected to the inverting input of the operational amplifier, and the other end of the output circuit is connected to the first power processing circuit.

[0017] The power regulator is connected in series in the current loop of the operational amplifier's output terminal, and the control port is located on the power regulator. The control port is used to control the power regulator's on / off state.

[0018] The input circuit is used to generate a reference voltage based on the initial voltage provided by the first auxiliary power supply.

[0019] The output circuit is used to generate a sampling voltage based on the target voltage output to the first power processing circuit.

[0020] The operational amplifier is used to generate an error signal based on the reference voltage and the sampling voltage;

[0021] The power regulator can adaptively adjust the operating state of the operational amplifier according to the magnitude of the error signal, so that the target voltage output by the output circuit is stabilized at the target level.

[0022] Preferably, the input circuit includes a first resistor and a second resistor connected in series, the first resistor being connected to the first auxiliary power supply, the second resistor being grounded, and a first node between the first resistor and the second resistor being connected to the non-inverting input of the operational amplifier; the output circuit includes a third resistor and a fourth resistor connected in series, the third resistor being connected to the input terminal of the first power processing circuit, the fourth resistor being grounded, and a second node between the third resistor and the fourth resistor being connected to the inverting input of the operational amplifier.

[0023] Preferably, the operational amplifier has a fifth resistor between its non-inverting input and its output; the operational amplifier has a first capacitor between its inverting input and ground; the operational amplifier has a second capacitor between its positive and negative terminals; the operational amplifier's output is connected to the power regulator via a sixth resistor; a seventh resistor is also connected between the sixth resistor and the power modulator; and the other end of the seventh resistor is grounded.

[0024] Preferably, the power regulator includes a first power switch.

[0025] Preferably, at least one second power switch is further provided between the DC conversion circuit and the first interface terminal, and the control terminal of the second power switch is connected to the controller; the controller is also connected to the first interface terminal to obtain the port voltage of the rechargeable battery; the controller controls the on / off state of the second power switch according to the direction of the port voltage.

[0026] Preferably, a first current detection circuit connected to the controller is further provided between the DC conversion circuit and the first interface terminal, and a second current detection circuit connected to the controller is further provided between the DC conversion circuit and the second interface terminal.

[0027] When the second interface terminal is connected to the discharge load, the controller controls the operating state of the DC conversion circuit according to the current value detected by the second current detection circuit.

[0028] When the second interface is connected to the charging load, the controller controls the operating state of the DC conversion circuit according to the current value detected by the first current detection circuit.

[0029] Preferably, when the second interface terminal is connected to the discharge load, the controller can also control the operating state of the DC conversion circuit based on the comparison between the current value detected by the first current detection circuit and a preset first maximum threshold; when the second interface terminal is connected to the charging load, the controller controls the operating state of the DC conversion circuit based on the comparison between the current value detected by the second current detection circuit and a preset second maximum threshold.

[0030] Compared with the prior art, the wide-range DC drive circuit provided by the above-mentioned technical solution of this utility model provides a stable working power supply for the controller through an auxiliary power supply circuit. It is suitable for both charging and discharging modes, enabling the controller to maintain normal operation even when the battery output voltage is as low as 1V. This breaks through the bottleneck of traditional DC conversion circuits relying on the high voltage of the connected rechargeable battery, and realizes a wide input range (1V-35V). It is especially suitable for single low-voltage batteries, eliminating the need for multiple batteries to be connected in series for power supply. This expands the application scenarios of DC drive circuits and avoids the introduction of battery equalization management circuits (BMS) in traditional solutions, significantly reducing system complexity and cost. Attached Figure Description

[0031] Figure 1 This is a system schematic diagram of the wide-range DC drive circuit in an embodiment of this utility model.

[0032] Figure 2 This is a schematic diagram of the DC conversion circuit in an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the discharge auxiliary power supply circuit in one embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram of the charging auxiliary power supply circuit in an embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram of the discharge auxiliary power supply circuit in another embodiment of the present invention.

[0036] Figure 6 This is a circuit diagram of the low-voltage protection circuit in an embodiment of this utility model.

[0037] Figure 7 This is a circuit diagram of the wide-range DC drive circuit in an embodiment of this utility model.

[0038] Figure 8 This is a pin structure diagram of the controller in an embodiment of this utility model. Detailed Implementation

[0039] To explain in detail the technical content, structural features, objectives and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0040] This embodiment discloses a wide-range DC drive circuit for DC boost or buck conversion, in conjunction with the discharge or charging of a rechargeable battery BT.

[0041] like Figure 1 The DC drive circuit includes a DC conversion circuit 1, a controller U1, an auxiliary power supply circuit 6, a first interface terminal 2, and a second interface terminal 3.

[0042] DC converter circuit 1 is used to boost or buck the input electrical signal.

[0043] The first interface terminal 2 is used to connect the rechargeable battery BT to the DC conversion circuit 1, and the second interface terminal 3 is used to connect the discharge load 4 or the charging load 5 to the DC conversion circuit 1.

[0044] Specifically, the first interface terminal 2 is connected to the rechargeable battery BT to receive the discharge power signal output by the rechargeable battery BT, or to output the charging power signal to the rechargeable battery BT.

[0045] When the second interface terminal 3 is connected to the discharge load 4, the second interface terminal 3 outputs the boosted discharge power signal to the discharge load 4. When the second interface terminal 3 is connected to the charging load 5, the second interface terminal 3 receives the charging power signal provided by the charging load 5 and performs a step-down process.

[0046] The controller U1 is connected to the adjustment terminal of the DC converter circuit 1, and the controller U1 is used to control the working state of the DC converter circuit 1.

[0047] like Figure 2 In this embodiment, the DC conversion circuit 1 uses transistor group Q and inductor L to boost or buck the voltage signal. The controller U1 outputs a PWM wave, which controls the switching state of each transistor in transistor group Q to achieve the effect of boosting or bucking the voltage.

[0048] Specifically, the transistor group Q includes two third power switches Q3, two fourth power switches Q4, and several current-limiting resistors R8, R9, R10, R11, R12, R13, R14, and R15 respectively disposed at the control terminals of the third power switches Q3 and the fourth power switches Q4. The controller U1 alternately controls the on / off state and conduction time of the two third power switches Q3 and the two fourth power switches Q4 through ports TG1 and TG2 to change the operating state of the DC conversion circuit 1, so as to output signals with different voltages and currents.

[0049] Please refer to the following: Figure 1 and Figure 7 The auxiliary power supply circuit includes an auxiliary power supply and a power processing circuit connected to the auxiliary power supply. The output terminal of the power processing circuit is connected to the power supply terminal VCC of the controller U1 to provide the power required for the controller U1 to operate.

[0050] In this embodiment, the auxiliary power supply provides a constant operating power for the controller U1, suitable for both charging and discharging modes. This allows the controller U1 to maintain normal operation even when the voltage output by the rechargeable battery BT is as low as 1V. This overcomes the bottleneck of the traditional DC conversion circuit 1 relying on the high voltage of the connected rechargeable battery BT, achieving a wide input range (1V-35V). It is especially suitable for single low-voltage batteries, eliminating the need for multiple batteries to be connected in series for power supply. This expands the application scenarios of the DC drive circuit and avoids the introduction of the battery equalization management circuit (BMS) in the traditional solution, significantly reducing system complexity and cost.

[0051] On the other hand, the second interface 3 can be configured with one interface to share the discharge load 4 and the charging load 5, or it can be configured with two interfaces for the discharge load 4 and the charging load 5 respectively.

[0052] Preferably, in this embodiment, a first interface 3a and a second interface 3b are connected in parallel. The first interface 3a is used to connect to the discharge load 4, and the second interface 3b is used to connect to the charging load 5. By using only two interfaces, no corresponding interface control circuit is required, resulting in a simple structure that is easy to implement.

[0053] Regardless of whether the DC drive circuit is in a charging or discharging state, the controller U1 can be powered by the same set of auxiliary power supply circuit 6, or by two different sets of auxiliary power supply circuits 6.

[0054] On the other hand, such as Figure 3 and Figure 4 In this embodiment, two auxiliary power supplies are configured, namely: the auxiliary power supply circuit 6 includes a discharge auxiliary power supply circuit 60 and a charging auxiliary power supply circuit 61.

[0055] The discharge auxiliary power supply circuit 60 includes a first auxiliary power supply 600 and a first power processing circuit 601 connected to the first auxiliary power supply 600. The output terminal of the first power processing circuit 601 is connected to the power supply terminal VCC of the controller U1.

[0056] The charging auxiliary power supply circuit 61 includes a second power processing circuit 610, which is connected to the second interface terminal 3 to obtain a second auxiliary power supply from the charging load 5 connected to the second interface terminal 3. The output terminal of the second power processing circuit 610 is connected to the power supply terminal VCC of the controller U1. Specifically, the second power processing circuit 610 is connected to the second interface 3b.

[0057] In this embodiment, the first auxiliary power supply 600 is an external power supply, such as a storage battery. The second auxiliary power supply is derived from the charging load 5, which is convenient to power and can effectively extend the service life of the first auxiliary power supply 600 compared to using the first auxiliary power supply 600 to power the controller U1 in both charging and discharging states.

[0058] On the other hand, to avoid over-discharge of the rechargeable battery BT, such as Figure 5 In this embodiment, the discharge auxiliary power supply circuit 60 also includes a low-voltage protection circuit 602. The input terminal of the low-voltage protection circuit 602 is connected to the first auxiliary power supply 600, and the output terminal of the low-voltage protection circuit 602 is connected to the input terminal of the first power processing circuit 601. The controller U1 is also connected to the first interface terminal 2 to obtain the port voltage of the rechargeable battery BT.

[0059] The low-voltage protection circuit 602 also includes a control port EN connected to the controller U1, which controls the on / off state of the low-voltage protection circuit 602 based on the port voltage.

[0060] In this embodiment, the first auxiliary power supply 600 is connected to the first power processing circuit 601 via the low-voltage protection circuit 602. Thus, during the discharge process of the rechargeable battery BT, the controller U1 collects the port voltage of the rechargeable battery BT in real time through the first interface terminal 2. When the port voltage is lower than a preset value, it sends a stop-work command to the low-voltage protection circuit 602 through the control port EN, thereby causing the controller U1 to lose power supply and the DC drive circuit to stop working.

[0061] like Figure 6 The low-voltage protection circuit 602 includes an input circuit S1, an output circuit S2, an operational amplifier U2, and a power regulator Q1.

[0062] One end of the input circuit S1 is connected to the first auxiliary power supply 600 of the peripheral device. The first auxiliary power supply 600 outputs an initial voltage VC1 to the input circuit S1 and the operational amplifier U2. The other end of the input circuit S1 is connected to the non-inverting input of the operational amplifier U2. One end of the output circuit S2 is connected to the inverting input of the operational amplifier U2, and the other end of the output circuit S2 is connected to the first power processing circuit 601.

[0063] The power regulator Q1 is connected in series in the current loop of the output terminal of the operational amplifier U2. The control port EN is located on the power regulator Q1 and is used to control the power regulator Q1 to turn on / off.

[0064] The input circuit S1 is used to generate a reference voltage Vref based on the initial voltage VC1 provided by the first auxiliary power supply 600.

[0065] The output circuit S2 is used to generate a sampling voltage Vfb based on the target voltage VC2 output to the first power supply processing circuit 601.

[0066] Operational amplifier U2 is used to generate an error signal based on the reference voltage Vref and the sampling voltage Vfb.

[0067] The power regulator Q1 can adaptively adjust the operating state of the operational amplifier U2 according to the magnitude of the error signal, so that the target voltage VC2 output by the output circuit S2 is stabilized at the target level.

[0068] In this embodiment, the low-voltage protection circuit 602 is a linear regulated power supply based on operational amplifier U2, which adjusts the target voltage VC2 output by output circuit S2 through feedback control power regulator Q1.

[0069] During operation, the reference voltage Vref provided by the input circuit S1 sets the reference standard for the target voltage VC2. While outputting voltage to the first power supply processing circuit 601, the output circuit S2 also samples the voltage Vfb in real time and feeds it to the operational amplifier U2.

[0070] Operational amplifier U2 compares the reference voltage Vref with the sampled voltage Vfb to output an error signal. This error signal controls the state of power regulator Q1, which in turn controls the state of operational amplifier U2, thus stabilizing the voltage output by output circuit S2 at the target voltage VC2 level. When the target voltage VC2 deviates from its target value due to load changes, the error signal drives operational amplifier U2 to adjust its output, forcing the target voltage VC2 back to its set value.

[0071] Specifically, the input circuit S1 includes a first resistor R1 and a second resistor R2 connected in series. The first resistor R1 is connected to the first auxiliary power supply 600, the second resistor R2 is grounded, and the first node J1 between the first resistor R1 and the second resistor R2 is connected to the non-inverting input of the operational amplifier U2.

[0072] The output circuit S2 includes a third resistor R3 and a fourth resistor R4 connected in series. The third resistor R3 is connected to the input terminal of the first power supply processing circuit 601, and the fourth resistor R4 is grounded. The second node J2 between the third resistor R3 and the fourth resistor R4 is connected to the inverting terminal of the operational amplifier U2.

[0073] In this embodiment, the initial voltage VC1 provided by the first auxiliary power supply 600 is divided in series by the first resistor R1 and the second resistor R2 to generate the reference voltage Vref at the first node J1.

[0074] Similarly, the third resistor R3 and the fourth resistor R4 are connected in series to divide the voltage, forming a sampling voltage Vfb at the second node J2.

[0075] On the other hand, the power regulator Q1 includes a first power switch Q1.

[0076] When the first power switch Q1 is an NMOS transistor, the gate (G) of the first power switch Q1 is connected to the output terminal of the operational amplifier U2, the drain (D) of the first power switch Q1 is used as the control port EN and connected to the controller U1, and the source (S) of the first power switch Q1 is grounded.

[0077] The first power switch Q1, acting as a series regulator, directly affects the energy transfer efficiency from the initial voltage VC1 provided by the first auxiliary power supply 600 to the target voltage VC2 output by the output circuit S2. In other words, the first power switch Q1 dynamically controls the voltage distribution from the initial voltage VC1 to the target voltage VC2 by adjusting its own on-resistance. When conduction is enhanced, the voltage drop loss of the initial voltage VC1 decreases, and the target voltage VC2 rises; when conduction is weakened, the voltage drop loss increases, and the target voltage VC2 falls. This closed-loop control logic adjusts the conduction state of the first power switch Q1 in real time through an error signal, ultimately achieving precise voltage regulation of the target voltage VC2.

[0078] On the other hand, there is a fifth resistor R5 between the non-inverting input and the output of operational amplifier U2. There is a first capacitor C1 between the inverting input and ground, and a second capacitor C2 between the positive and negative terminals of operational amplifier U2. The output of operational amplifier U2 is connected to power regulator Q1 through a sixth resistor R6. A seventh resistor R7 is also connected between the sixth resistor R6 and the power modulator, and the other end of the seventh resistor R7 is grounded.

[0079] The fifth resistor, R5, is used to adjust the gain or phase characteristics of operational amplifier U2, enhancing stability. The first capacitor, C1, is a power supply decoupling capacitor, filtering out power supply noise. Simultaneously, the fifth resistor R5 and the first capacitor C1 work together to optimize the dynamic response of operational amplifier U2, ensuring rapid convergence.

[0080] The second capacitor C2 is used to suppress high-frequency interference and prevent the amplifier from self-oscillating.

[0081] The sixth resistor R6 limits the drive current at the control terminal of the power regulator Q1, and the seventh resistor R7 is a pull-down resistor to ensure that the power regulator Q1 is turned off when there is no drive, thus avoiding false triggering.

[0082] On the other hand, such as Figure 7At least one second power switch Q2 is also provided between the DC conversion circuit 1 and the first interface terminal 2. The control terminal of the second power switch Q2 is connected to the controller U1. The controller U1 is also connected to the first interface terminal 2 to obtain the port voltage of the rechargeable battery BT. The controller U1 controls the on / off state of the second power switch Q2 according to the direction of the port voltage. Specifically, the second power switch Q2 is connected to the port pin BG1 of the controller U1. The voltage node on the first open terminal 2 corresponding to the port voltage of the rechargeable battery BT is connected to the port pin IN of the controller.

[0083] In this embodiment, two second power switches Q2 are connected in parallel. When the rechargeable battery BT is connected in reverse to the first interface terminal 2, the direction of the port voltage detected by the controller U1 is different from the preset value. Therefore, the two second power switches Q2 will not be turned on, preventing the reverse power signal from flowing to the DC conversion circuit 1. When the controller U1 detects that the direction of the port voltage is the same as the preset value, it indicates that the rechargeable battery BT is connected correctly. Then, the two second power switches Q2 are turned on, allowing the power signal to enter the DC conversion circuit 1.

[0084] On the other hand, a first current detection circuit 7 connected to the controller U1 is also provided between the DC conversion circuit 1 and the first interface terminal 2, and a second current detection circuit 8 connected to the controller U1 is also provided between the DC conversion circuit 1 and the second interface terminal 3.

[0085] When the second interface terminal 3 is connected to the discharge load 4, the controller U1 controls the working state of the DC conversion circuit 1 according to the current value detected by the second current detection circuit 8, so that the current signal output by the DC conversion circuit 1 to the second interface terminal 3 meets the requirements.

[0086] When the second interface terminal 3 is connected to the charging load 5, the controller U1 controls the working state of the DC conversion circuit 1 according to the current value detected by the first current detection circuit 7, so that the current signal output by the DC conversion circuit 1 to the first interface terminal 2 meets the requirements.

[0087] Furthermore, the aforementioned adjustment of the output current of DC converter circuit 1 is a post-processing adjustment, requiring the detection of an abnormal output current before adjustment can begin. This means that if the detected output current is too high, it will damage subsequent components before adjustment is complete. Therefore, further improvements are needed:

[0088] When the second interface terminal 3 is connected to the discharge load 4, the controller U1 can also control the working state of the DC conversion circuit 1 by comparing the current value detected by the first current detection circuit 7 with the preset first maximum threshold.

[0089] When the second interface terminal 3 is connected to the charging load 5, the controller U1 controls the working state of the DC conversion circuit 1 based on the comparison between the current value detected by the second current detection circuit 8 and the preset second maximum threshold.

[0090] In this embodiment, if the current output by the rechargeable battery BT exceeds the first maximum threshold during the discharge process, the operating state of the DC conversion circuit 1 will be adjusted in advance to avoid the DC conversion circuit 1 outputting a large current signal instantaneously and damaging the discharge load 4.

[0091] Similarly, during the charging process, if the current output by the charging load 5 exceeds the second maximum threshold, the operating state of the DC conversion circuit 1 will be adjusted in advance to avoid the DC conversion circuit 1 outputting a large current signal instantaneously, which could damage the rechargeable battery BT.

[0092] Specifically, the first current detection circuit 8 includes resistors R19, R20, and R21, and capacitor C3. Resistor R19 is connected in series in the current loop between the second interface terminal 3 and the DC conversion circuit. Resistors R20 and R21 are connected in parallel across resistor R19. R20 and R21 are respectively connected to the signal pins ISP2 and ISN2 of controller U1. The two ends of capacitor C4 are respectively connected to the ends of resistors R19 and R20 connected to controller U1. Controller U1 obtains voltage signals from signal pins ISP2 and ISN2 and then converts them into current signals.

[0093] In summary, as Figures 1 to 8 This utility model discloses a wide-range DC drive circuit for driving the charging or discharging of rechargeable batteries.

[0094] During discharge:

[0095] The controller U1 turns on the first power switch Q1 in the low voltage protection circuit 602 through the control port EN to start the discharge auxiliary power supply circuit 60 to provide power to the controller U1.

[0096] The electrical signal output by the rechargeable battery BT enters the first interface terminal 2 and the first current detection circuit 7. When the controller U1 detects that the rechargeable battery BT is connected in reverse through the port pin IN, it controls the two second power switches Q2 to remain off. When the rechargeable battery BT is correctly connected to the first interface terminal 2, the controller U1 turns on the second power switches Q2, and then the electrical signal enters the DC conversion circuit 1.

[0097] The DC converter circuit outputs a processed electrical signal that passes through the second current detection circuit 8 to the second interface terminal 3, and is then transmitted to the discharge load 4 via the first interface 3a.

[0098] During this process, the controller U1 controls the working state of the DC conversion circuit in real time according to the current value detected by the second current detection circuit 8, so that the discharge load 4 can obtain the required electrical signal.

[0099] During charging:

[0100] The controller U1 shuts down the first power switch Q1 in the low-voltage protection circuit 602 through the control port EN, so as to turn off the power supply provided by the discharge auxiliary power supply circuit 60 to the controller U1.

[0101] At this time, the charging load 5 is connected to the second interface 3b of the second opening end 3. Then, the charging load 5 provides the second auxiliary power VC3 to the second power processing circuit 610 of the charging auxiliary power circuit 61, and the second power processing circuit 610 provides power supply to the controller U1.

[0102] The charging signal enters the DC conversion circuit 2 via the second current detection circuit 8, is processed by the DC conversion circuit 1, and enters the first current detection circuit 7 via the second power switch Q2. Then it enters the rechargeable battery BT via the first open terminal 2.

[0103] During this process, the controller U1 controls the working state of the DC conversion circuit 1 in real time according to the detection value of the first current detection circuit 7 to ensure that the electrical signal entering the rechargeable battery BT meets the requirements.

[0104] It should be noted that the specific configurations of the first power processing circuit 601 in the discharge auxiliary power circuit 60 and the second power processing circuit 610 in the charging auxiliary power circuit 61 in the above embodiments are conventional technologies in the field and will not be described in detail here. They can be implemented using commonly used power management chips.

[0105] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the scope of the present utility model application shall still fall within the scope of the present utility model.

Claims

1. A wide-range DC drive circuit, characterized in that, It includes a DC conversion circuit, a controller, an auxiliary power supply circuit, a first interface terminal, and a second interface terminal; The first interface terminal is used to connect the rechargeable battery to the DC conversion circuit, and the second interface terminal is used to connect the discharge load or the charging load to the DC conversion circuit. The controller is connected to the adjustment terminal of the DC conversion circuit, and the controller is used to control the operating state of the DC conversion circuit; The auxiliary power supply circuit includes an auxiliary power supply and a power processing circuit connected to the auxiliary power supply. The output terminal of the power processing circuit is connected to the power supply terminal of the controller to provide the power required for the controller to operate.

2. The wide-range DC drive circuit according to claim 1, characterized in that, The auxiliary power supply circuit includes a discharge auxiliary power supply circuit and a charging auxiliary power supply circuit. The discharge auxiliary power supply circuit includes a first auxiliary power supply and a first power processing circuit connected to the first auxiliary power supply. The output terminal of the first power processing circuit is connected to the power supply terminal of the controller. The charging auxiliary power supply circuit includes a second power processing circuit, which is connected to the second interface terminal to obtain a second auxiliary power supply from the charging load connected to the second interface terminal. The output terminal of the second power processing circuit is connected to the power supply terminal of the controller.

3. The wide-range DC drive circuit according to claim 2, characterized in that, It also includes a low-voltage protection circuit, the input of which is connected to the first auxiliary power supply, and the output of which is connected to the input of the first power processing circuit. The controller is also connected to the first interface to obtain the port voltage of the rechargeable battery. The low-voltage protection circuit also includes a control port connected to the controller, and the controller controls the on / off state of the low-voltage protection circuit based on the port voltage.

4. The wide-range DC drive circuit according to claim 3, characterized in that, The low-voltage protection circuit includes an input circuit, an output circuit, an operational amplifier, and a power regulator; One end of the input circuit is connected to the first auxiliary power supply of the peripheral device, the other end of the input circuit is connected to the non-inverting input of the operational amplifier, one end of the output circuit is connected to the inverting input of the operational amplifier, and the other end of the output circuit is connected to the first power processing circuit. The power regulator is connected in series in the current loop of the operational amplifier's output terminal, and the control port is located on the power regulator. The control port is used to control the power regulator's on / off state. The input circuit is used to generate a reference voltage based on the initial voltage provided by the first auxiliary power supply. The output circuit is used to generate a sampling voltage based on the target voltage output to the first power processing circuit. The operational amplifier is used to generate an error signal based on the reference voltage and the sampling voltage; The power regulator can adaptively adjust the operating state of the operational amplifier according to the magnitude of the error signal, so that the target voltage output by the output circuit is stabilized at the target level.

5. The wide-range DC drive circuit according to claim 4, characterized in that, The input circuit includes a first resistor and a second resistor connected in series. The first resistor is connected to the first auxiliary power supply, and the second resistor is grounded. A first node between the first resistor and the second resistor is connected to the non-inverting input of the operational amplifier. The output circuit includes a third resistor and a fourth resistor connected in series. The third resistor is connected to the input terminal of the first power processing circuit, and the fourth resistor is grounded. A second node between the third resistor and the fourth resistor is connected to the inverting input of the operational amplifier.

6. The wide-range DC drive circuit according to claim 4, characterized in that, The operational amplifier has a fifth resistor between its non-inverting input and its output; the operational amplifier has a first capacitor between its inverting input and ground; the operational amplifier has a second capacitor between its positive and negative terminals; the operational amplifier's output is connected to the power regulator via a sixth resistor; a seventh resistor is also connected between the sixth resistor and the power regulator; and the other end of the seventh resistor is grounded.

7. The wide-range DC drive circuit according to claim 4, characterized in that, The power regulator includes a first power switch.

8. The wide-range DC drive circuit according to claim 1, characterized in that, At least one second power switch is also provided between the DC conversion circuit and the first interface terminal, and the control terminal of the second power switch is connected to the controller; the controller is also connected to the first interface terminal to obtain the port voltage of the rechargeable battery; the controller controls the on / off state of the second power switch according to the direction of the port voltage.

9. The wide-range DC drive circuit according to claim 1, characterized in that, A first current detection circuit connected to the controller is further provided between the DC conversion circuit and the first interface terminal, and a second current detection circuit connected to the controller is further provided between the DC conversion circuit and the second interface terminal. When the second interface terminal is connected to the discharge load, the controller controls the operating state of the DC conversion circuit according to the current value detected by the second current detection circuit. When the second interface is connected to the charging load, the controller controls the operating state of the DC conversion circuit according to the current value detected by the first current detection circuit.

10. The wide-range DC drive circuit according to claim 9, characterized in that, When the second interface terminal is connected to the discharge load, the controller can also control the operating state of the DC conversion circuit based on the comparison between the current value detected by the first current detection circuit and the preset first maximum threshold; when the second interface terminal is connected to the charging load, the controller controls the operating state of the DC conversion circuit based on the comparison between the current value detected by the second current detection circuit and the preset second maximum threshold.

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