Low power consumption switching circuit and electric device with motor

Abstract

The application relates to a low-power-consumption switch circuit and an electric device with a motor, the low-power-consumption switch circuit comprising: a strong-current switch, an electronic switch, an electronic switch detection circuit and a fast switch circuit; the fast switch circuit is used for conducting a first current branch when the electronic switch is closed and a first capacitor branch is not full of electricity, the first current branch comprising: a first capacitor branch, a first diode, a fourth resistance branch and the electronic switch, conducting a second current branch, the second current branch comprising: the first capacitor branch, a second N-MOS tube and the electronic switch, and conducting a third current branch, the third current branch comprising: a second resistance branch, the fourth resistance branch and the electronic switch; when the first capacitor branch is full of electricity, only the third current branch is conducted, so that when the electronic switch is closed, the positive electrode of the battery pack and the electronic switch are conducted, and after being conducted, the leakage current from the battery pack to the electronic switch is limited.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a low-power switching circuit and an electric device with a motor. Background Technology

[0002] Currently, most power tools on the market that use battery packs for power supply (such as lawnmowers) have motor controllers that include a controller MCU, a high-voltage switch, and a low-voltage switch (electronic switch). When an electronic switch is installed, after the electronic switch is closed, there is a possibility of excessive leakage current in the branch containing the battery pack and the electronic switch, which consumes more battery pack energy and reduces the battery pack's usable time.

[0003] Therefore, there is a need to provide a low-power switching circuit that minimizes leakage current in the branch containing the battery pack and the electronic switch when the electronic switch is closed, thereby reducing the energy consumption of the battery pack and ensuring the usable power of the battery pack, thus solving the aforementioned technical problem. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a low-power switching circuit that solves the problem in the prior art where, after the electronic switch is closed, the leakage current in the branch containing the battery pack and the electronic switch is too large, resulting in excessive energy consumption of the battery pack and a reduction in the usable power of the battery pack.

[0005] The technical effects of this invention are achieved through the following:

[0006] A low-power switching circuit includes a high-voltage switch, an electronic switch, an electronic switch detection circuit, and a fast-switching circuit. One end of the fast-switching circuit is electrically connected to the positive electrode of a battery pack via the high-voltage switch. The other end of the fast-switching circuit, the positive electrode of the electronic switch, and one end of the electronic switch detection circuit are electrically connected. The other end of the electronic switch detection circuit is electrically connected to the MCU_SW port of an MCU. The MCU can detect whether the electronic switch is closed through the MCU_SW port and the electronic switch detection circuit.

[0007] The fast switching circuit includes a first capacitor branch, a first N-MOS transistor, a first resistor branch, a second resistor branch, a third resistor branch, a fourth resistor branch, a second N-MOS transistor, and a first diode. The input terminal of the first capacitor branch is electrically connected to the positive electrode of the battery pack. The first terminal of the first resistor branch and the third terminal of the second resistor branch are electrically connected to the input terminal of the first capacitor branch. The first drain of the first N-MOS transistor is electrically connected to the second terminal of the first resistor branch. The first gate of the first N-MOS transistor and the fifth terminal of the third resistor branch are electrically connected to the first diode of the second resistor branch. The four terminals are electrically connected as follows: the first source of the first N-MOS transistor, the sixth terminal of the third resistor branch, and the second drain of the second N-MOS transistor are electrically connected to the output terminal of the first capacitor branch; the seventh terminal of the fourth resistor branch, the second gate of the second N-MOS transistor, and the fifth terminal are electrically connected; the second source of the second N-MOS transistor is electrically connected to the eighth terminal of the fourth resistor branch; the eighth terminal is electrically connected to the positive terminal of the electronic switch and the MCU_SW port; the positive terminal of the first diode is electrically connected to the output terminal of the first capacitor branch, and the negative terminal is electrically connected to the fifth terminal.

[0008] The fast switching circuit is used to conduct a first current branch, a second current branch, and a third current branch when the electronic switch is closed and the first capacitor branch is not fully charged. The first current branch includes a first capacitor branch, a first diode, a fourth resistor branch, and an electronic switch. The second current branch includes a first capacitor branch, a second N-MOS transistor, and an electronic switch. The third current branch includes a second resistor branch, a fourth resistor branch, and an electronic switch. When the first capacitor branch is fully charged, only the third current branch is conducted, so that when the electronic switch is closed, the positive electrode of the battery pack and the electronic switch are connected, and after being connected, the leakage current flowing from the battery pack into the electronic switch is limited.

[0009] In one embodiment of this application, the fast switching circuit is further configured to disconnect the positive electrode of the battery pack and the electronic switch when the electronic switch is turned off, and to rapidly discharge the first capacitor branch through the first resistor branch, the second resistor branch, the third resistor branch and the first N-MOS transistor to ensure the response speed of the electronic switch.

[0010] In one embodiment of this application, the system further includes: a control circuit, an MCU self-locking circuit, and a low-voltage output module. The control circuit includes a switching transistor and a fifth resistor branch. The input terminal of the first capacitor branch is electrically connected to the positive electrode of the battery pack through the fifth resistor branch and the high-voltage switch. The fifth resistor branch is formed by connecting at least two first resistor units in series. One end of the fifth resistor branch is used to be electrically connected to the positive electrode of the battery pack through the high-voltage switch, and the other end of the fifth resistor branch is electrically connected to the input terminal of the fast switching circuit. The current inflow terminal of the switching transistor is electrically connected to the end of the fifth resistor branch near the positive electrode of the battery pack. The first control terminal of the switching transistor is electrically connected to the connection point between any two adjacent first resistor units in the fifth resistor branch. The current outflow terminal of the switching transistor is used to be electrically connected to the low-voltage output module.

[0011] The fast switching circuit is also used to turn on the switching transistor when the electronic switch is closed, so that the MCU self-locking circuit can operate and the low voltage output module can output voltage.

[0012] The fast switching circuit is also used to turn off the switching transistor when the electronic switch is turned off, so as to disconnect the MCU self-locking circuit and stop the low voltage output module from outputting voltage.

[0013] In one embodiment of this application, the electronic switch detection circuit includes a second capacitor branch, one end of which is electrically connected to the positive terminal of the electronic switch, and the other end of which is grounded.

[0014] In one embodiment of this application, the MCU self-locking circuit includes a resistor R2, an NPN transistor Q2, a resistor R4, a resistor R5, a capacitor C2, a diode D1, a resistor R6, a diode D2, and a capacitor C1. The resistor R2 is electrically connected to the first control terminal of the switching transistor, and its other end is electrically connected to the collector of the NPN transistor Q2. The resistor R4 is electrically connected between the base and emitter of the NPN transistor Q2. The emitter of the NPN transistor Q2 is grounded. One end of the capacitor C2 is electrically connected to the emitter of the NPN transistor Q2, and its other end is connected to the resistor R5. One end of the resistor R5 is electrically connected to the base of the NPN transistor Q2. The anode of the diode D1 is electrically connected to the emitter of the NPN transistor Q2. The cathode of the diode D1 is electrically connected to one end of the capacitor C1. The other end of the capacitor C1 is electrically connected to the MCU_LOCK port of the MCU. The connection point between the capacitor C2 and the resistor R5 is electrically connected to one end of the resistor R6. The other end of the resistor R6 is electrically connected to the cathode of the diode D2. The anode of the diode D2 is electrically connected to the cathode of the diode D1.

[0015] In one embodiment of this application, the MCU self-locking circuit includes a resistor R2, an N-MOS transistor Q2, a resistor R4, a resistor R5, a capacitor C2, a diode D1, a resistor R6, a diode D2, and a capacitor C1. The resistor R2 is electrically connected to the first control terminal of the switching transistor, and its other end is electrically connected to the drain of the N-MOS transistor Q2. The resistor R4 is electrically connected between the gate and source of the N-MOS transistor Q2. The source of the N-MOS transistor Q2 is grounded. One end of the capacitor C2 is electrically connected to the source of the N-MOS transistor Q2, and its other end is electrically connected to the resistor R2. One end of resistor R5 is electrically connected, and the other end of resistor R5 is electrically connected to the gate of N-MOS transistor Q2. The anode of diode D1 is electrically connected to the source of N-MOS transistor Q2. The cathode of diode D1 is electrically connected to one end of capacitor C1. The other end of capacitor C1 is electrically connected to the MCU_LOCK port of the MCU. The connection point of capacitor C2 and resistor R5 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the cathode of diode D2. The anode of diode D2 is electrically connected to the cathode of diode D1.

[0016] In one embodiment of this application, the switching transistor is a P-MOS transistor or a PNP transistor.

[0017] In one embodiment of this application, the resistance value of the second resistor branch is greater than the resistance value of the fourth resistor branch.

[0018] In one embodiment of this application, the resistance value of the second resistor branch is greater than the resistance value of the first resistor branch.

[0019] In addition, an electric device with a motor is also provided, including the low-power switching circuit described above, wherein the motor is electrically connected to the MCU, and the MCU is used to control the operation of the motor.

[0020] As described above, the present invention has the following beneficial effects: By setting a fast switching circuit, the fast switching circuit includes a first capacitor branch, a first N-MOS transistor, a first resistor branch, a second resistor branch, a third resistor branch, a fourth resistor branch, a second N-MOS transistor, and a first diode. The input terminal of the first capacitor branch is electrically connected to the positive electrode of the battery pack. The first terminal of the first resistor branch and the third terminal of the second resistor branch are electrically connected to the input terminal of the first capacitor branch. The first drain of the first N-MOS transistor is electrically connected to the second terminal of the first resistor branch. The first gate of the first N-MOS transistor and the fifth terminal of the third resistor branch are electrically connected to the fourth terminal of the second resistor branch. The first N-MOS transistor... The first source of the S-MOSFET, the sixth terminal of the third resistor branch, and the second drain of the second N-MOS transistor are electrically connected to the output terminal of the first capacitor branch. The seventh terminal of the fourth resistor branch, the second gate of the second N-MOS transistor, and the fifth terminal are electrically connected. The second source of the second N-MOS transistor is electrically connected to the eighth terminal of the fourth resistor branch. The eighth terminal is electrically connected to the positive terminal of the electronic switch and the MCU_SW port. The positive terminal of the first diode is electrically connected to the output terminal of the first capacitor branch, and the negative terminal is electrically connected to the fifth terminal. When the electronic switch is closed, the positive electrode of the battery pack and the electronic switch are turned on. After being turned on, the leakage current flowing from the battery pack into the electronic switch is limited, thereby ensuring the usable power of the battery pack. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0022] Figure 1 A block diagram of a low-power switching circuit provided in the embodiments of this specification;

[0023] Figure 2 This is a circuit diagram of a low-power switching circuit provided in the embodiments of this specification. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] Example 1:

[0027] like Figure 1 as well as Figure 2 As shown in the figure, this specification provides a low-power switching circuit, including a high-voltage switch, an electronic switch S1, a fast-switching circuit 1, and an electronic switch detection circuit 2. One end of the fast-switching circuit 1 is electrically connected to the positive electrode of the battery pack via the high-voltage switch. The other end of the fast-switching circuit 1, the positive electrode of the electronic switch S1, is electrically connected to one end of the electronic switch detection circuit 2. The other end of the electronic switch detection circuit 2 is electrically connected to the MCU_SW port of the MCU. The MCU can detect whether the electronic switch S1 is closed through the MCU_SW port and the electronic switch detection circuit 2.

[0028] The fast switching circuit 1 includes a first capacitor branch 11 and a first N-MOS transistor 12 (i.e., Figure 2 Q3), the first resistor branch, the second resistor branch, the third resistor branch, the fourth resistor branch, and the second N-MOS transistor 13 (i.e. Figure 2 Q4) and the first diode D6. Among them, Figure 2 In the diagram, the first resistor branch is represented by resistor R7, the second resistor branch by resistor R8, the third resistor branch by resistor R9, and the fourth resistor branch by resistor R10. The following explanations will directly use R7, R8, R9, and R10 as examples.

[0029] The input terminal of the first capacitor branch 11 is electrically connected to the positive electrode of the battery pack. The first terminal of the first resistor branch R7 and the third terminal of the second resistor branch R8 are electrically connected to the input terminal of the first capacitor branch 11. The first drain of the first N-MOS transistor 12 is electrically connected to the second terminal of the first resistor branch R7. The first gate of the first N-MOS transistor 12, the fifth terminal of the third resistor branch R9, and the fourth terminal of the second resistor branch R8 are electrically connected. The first source of the first N-MOS transistor 12, the sixth terminal of the third resistor branch R9, and the second N-MOS transistor 12 are also electrically connected. The second drain of MOSFET 13 is electrically connected to the output terminal of the first capacitor branch 11. The seventh terminal of the fourth resistor branch R10, the second gate of the second N-MOSFET 13, and the fifth terminal of the third resistor branch R9 are electrically connected. The second source of the second N-MOSFET 13 is electrically connected to the eighth terminal of the fourth resistor branch R10. The eighth terminal is electrically connected to the positive terminal of the electronic switch S1 and the MCU_SW port. The positive terminal of the first diode D6 is electrically connected to the output terminal of the first capacitor branch 11, and the negative terminal is electrically connected to the fifth terminal of the third resistor branch R9.

[0030] In practical applications, multiple diodes for isolation are used in low-power switching circuits, for example, Figure 2 Diodes D3, D4, and D5 in the diagram.

[0031] The fast-switching circuit 1 is used to conduct the first current branch when the electronic switch S1 is closed and the first capacitor branch 11 is not fully charged. The first current branch includes: the first capacitor branch 11, the first diode D6, the fourth resistor branch R10, the diode D4, and the electronic switch S1. It also conducts the second current branch, which includes: the first capacitor branch 11, the second N-MOS transistor 13, the diode D4, and the electronic switch S1. Finally, it conducts the third current branch, which includes: the second resistor branch R8, the fourth resistor branch R10, the diode D4, and the electronic switch S1. The fast-switching circuit 1 is also used to conduct only the third current branch when the electronic switch S1 is closed and the first capacitor branch 11 is fully charged. This limits the leakage current flowing from the battery pack into the electronic switch S1, ensuring a small leakage current between the battery pack and the branch containing the electronic switch S1, thereby ensuring the usable power of the battery pack.

[0032] The aforementioned low-power switching circuit, by setting the aforementioned fast switching circuit 1, can conduct the positive electrode of the battery pack and the electronic switch S1 when the electronic switch S1 is closed, and after conduction, it limits the leakage current flowing from the battery pack into the electronic switch S1, thereby ensuring the usable power of the battery pack.

[0033] In another embodiment of this application, the fast switching circuit 1 is also used to disconnect the positive electrode of the battery pack and the electronic switch S1 when the electronic switch S1 is turned off, and to quickly discharge the first capacitor branch 11 through the first resistor branch R7, the second resistor branch R8, the third resistor branch R9 and the first N-MOS transistor 12 to ensure the response speed of the electronic switch S1.

[0034] In detail, when electronic switch S1 is open, since the cathode of diode D4 is floating, the second N-MOS transistor 13, diodes D3 and D6, and the fourth resistor branch R10 are inactive. Only the first capacitor branch 11, the first resistor branch R7, the second resistor branch R8, the third resistor branch R9, and the first N-MOS transistor 12 are active. The capacitor in the first capacitor branch 11 is rapidly discharged through the first resistor branch R7, the second resistor branch R8, and the third resistor branch R9, realizing the power-down acceleration function. This ensures that when electronic switch S1 is closed again, the low-power fast switching circuit can quickly enter the working state to ensure the response speed of weak current output.

[0035] Specifically, each resistor branch consists of at least two resistor units connected in series. Each first resistor unit can be a single resistor or a combination of more than one resistor connected in series, parallel, or in a mixed manner. The multiple resistors can be the same or different.

[0036] In one embodiment of this application, as Figure 2 As shown, the electronic switch detection circuit 2 includes a second capacitor branch C5. One end of the second capacitor branch C5 is electrically connected to the positive terminal of the electronic switch S1, and the other end of the second capacitor branch C5 is grounded. The second capacitor branch is used to ensure that when the high-voltage switch and the electronic switch S1 are closed, the MCU_SW port is at a high level while the second capacitor branch C5 is charging. When the MCU detects that the MCU_SW port is at a high level, it determines that the high-voltage switch and the electronic switch S1 are closed.

[0037] like Figure 1 , Figure 2As shown, the aforementioned low-power switching circuit also includes: a control circuit 3, an MCU self-locking circuit 4, and a low-power output module 5. The control circuit 3 includes a switching transistor 31 and a fifth resistor branch 32; the input terminal of the first capacitor branch 11 is electrically connected to the positive electrode of the battery pack through the fifth resistor branch 32 and the high-power switch; the fifth resistor branch 32 is composed of at least two first resistor units connected in series, one end of the fifth resistor branch 32 is used to be electrically connected to the positive electrode of the battery pack through the high-power switch, and the other end of the fifth resistor branch 32 is electrically connected to the input terminal of the fast switching circuit 1; the current inflow terminal of the switching transistor 31 is electrically connected to the end of the fifth resistor branch 32 near the positive electrode of the battery pack, the first control terminal of the switching transistor 31 is electrically connected to the connection point between any two adjacent first resistor units in the fifth resistor branch 32, and the current outflow terminal of the switching transistor 31 is used to be electrically connected to the low-power output module 5.

[0038] The fast switching circuit 1 is also used to turn on the switching transistor 31 when the electronic switch S1 is closed, so that the MCU self-locking circuit 4 can run and the low voltage output module 5 can output voltage.

[0039] The fast switching circuit 1 is also used to turn off the switching transistor 31 when the electronic switch S1 is open, so as to disconnect the MCU self-locking circuit 4 and stop the low voltage output module 5 from outputting voltage.

[0040] Specifically, the low-voltage output module 5 includes a DC-DC circuit and a voltage regulator unit electrically connected to the back end of the DC-DC circuit. When the switching transistor 31 is turned on, the battery pack supplies power from point P and outputs a low-voltage voltage VCC through the DC-DC circuit and the voltage regulator unit to the power input terminal of the MCU.

[0041] Specifically, the fifth resistor branch 32 is composed of at least two first resistor units connected in series. Each first resistor unit can be a single resistor, or it can be composed of more than one resistor connected in series, parallel, or in a mixed manner. The multiple resistors can be the same or different. In this embodiment, the fifth resistor branch 32 is described using two first resistor units, resistor R1 and resistor R3.

[0042] Specifically, the reason why the signal type output by the MCU_LOCK port is a PWM signal is: when the MCU pin corresponding to the MCU_LOCK port fails, it can ensure that the switching transistor 31 will not turn on abnormally, thus avoiding the problem of static power consumption of the battery pack.

[0043] Specifically, the switching transistor 31 is a P-MOS transistor or a PNP transistor.

[0044] It should be noted that most of the switching devices controlled by the MCU are PNP transistors. Using transistors has the following drawbacks: First, the on-state voltage drop of a transistor is relatively large when it is turned on; second, because transistors have different operating states, namely saturation, amplification, and high impedance, when using transistors as switching devices at the power input of the low-voltage section while ensuring static power consumption, the response speed of the potential signal in the low-voltage section will be different, resulting in a deviation in the environmental information collected by the MCU at the moment of power-on of the low-power switching circuit.

[0045] When a P-MOS transistor is used as the switching transistor for the power input control terminal of the low-voltage section in switching transistor 31, although it also exists in different states under different conditions, namely the cutoff region, the variable resistance region, and the saturation region, the duration of its variable resistance region is relatively short, on the order of nanoseconds; at the same time, when it is in the variable resistance region, its impedance value is also on the order of milliohms. Therefore, the operating state of the P-MOS transistor can be divided into two types: the on state and the off state.

[0046] Therefore, this application sets a switching transistor 31 in the control circuit 3. The switching transistor 31 uses a P-MOS transistor Q1, so that when the electronic switch S1 is closed, the switching transistor 31 can be turned on quickly, which speeds up the low-power output of the battery pack and the response speed of the MCU, while ensuring the timeliness of the signal detected by the MCU. At the same time, when the electronic switch S1 fails to press the button, it can be ensured that the P-MOS transistor Q1 cannot be turned on, reducing the energy loss of the battery pack by the low-power switching circuit.

[0047] like Figure 2 As shown, the MCU self-locking circuit 4 includes resistor R2, NPN transistor Q2, resistor R4, resistor R5, capacitor C2, diode D1, resistor R6, diode D2, and capacitor C1. Resistor R2 is electrically connected to the first control terminal of switch 31, and the other end is electrically connected to the collector of NPN transistor Q2. Resistor R4 is electrically connected between the base and emitter of NPN transistor Q2. The emitter of NPN transistor Q2 is grounded. One end of capacitor C2 is electrically connected to the emitter of NPN transistor Q2, and the other end is electrically connected to resistor R2. One end of resistor R5 is electrically connected, and the other end of resistor R5 is electrically connected to the base of NPN transistor Q2. The anode of diode D1 is electrically connected to the emitter of NPN transistor Q2. The cathode of diode D1 is electrically connected to one end of capacitor C1. The other end of capacitor C1 is electrically connected to the MCU_LOCK port of the MCU. The connection point between capacitor C2 and resistor R5 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the cathode of diode D2. The anode of diode D2 is electrically connected to the cathode of diode D1.

[0048] In some other implementations, the NPN transistor Q2 can also be replaced by an N-MOS transistor. Specifically, the MCU self-locking circuit 4 includes a resistor R2, an N-MOS transistor Q2, a resistor R4, a resistor R5, a capacitor C2, a diode D1, a resistor R6, a diode D2, and a capacitor C1. Resistor R2 is electrically connected to the first control terminal of the switching transistor 31, and the other end is electrically connected to the drain of the N-MOS transistor Q2. Resistor R4 is electrically connected between the gate and source of the N-MOS transistor Q2. The source of the N-MOS transistor Q2 is grounded. One end of capacitor C2 is electrically connected to the source of the N-MOS transistor Q2, and the other end is... One end of resistor R5 is electrically connected to the gate of N-MOS transistor Q2. The anode of diode D1 is electrically connected to the source of N-MOS transistor Q2. The cathode of diode D1 is electrically connected to one end of capacitor C1. The other end of capacitor C1 is electrically connected to the MCU_LOCK port of the MCU. The connection point between capacitor C2 and resistor R5 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the cathode of diode D2. The anode of diode D2 is electrically connected to the cathode of diode D1.

[0049] The MCU self-locking circuit 4 is used to turn on the switching transistor 31 before the high-voltage switch and electronic switch S1 are closed and the first capacitor branch 11 is fully charged. This ensures that when the MCU_SW port detects a high level, the MCU controls the MCU_LOCK port to output a signal, thereby keeping the switching transistor 31 continuously on and ensuring the response speed of the low-voltage output. The positive terminal of the battery pack is electrically connected to the high-voltage switch. Figure 2 Point P in the diagram is the negative terminal of the battery pack connected to... Figure 2 The battery pack has a high-voltage switch at its rear end, and the battery pack is configured to output voltage when the high-voltage switch is closed. Electronic switch S1 is a low-voltage switch.

[0050] When the MCU_LOCK outputs a PWM signal, a high level causes capacitor C1 to charge, resulting in a high level between resistors R6 and R5, and C2 charging. This causes a high level at the connection between Q2 and R5, turning Q2 on, which in turn turns on switch 31. A low level causes the energy from C2 to flow through resistors D1, D2, and R6, resulting in a high level at the connection between Q2 and R5, turning on Q2, and thus turning on switch 31. This allows the MCU to control the MCU_LOCK port to output a PWM signal, which in turn... Figure 2 C2 in the middle is periodically charged to complete Figure 2 The continuous conduction of Q2 ensures the normal operation of the MCU self-locking circuit 4, thereby ensuring that the switching transistor 31 remains in a continuously conducting state. This allows the output voltage from the drain of the switching transistor 31 to the low-voltage output module 54, ensuring the response speed of the low-voltage output.

[0051] Specifically, the resistance value of the second resistor branch R8 is greater than the resistance value of the fourth resistor branch R10. This is to reduce leakage current and ensure discharge speed.

[0052] Specifically, the resistance value of the second resistor branch R8 is greater than the resistance value of the first resistor branch R7. This is to ensure that the first N-MOS transistor 12 can work normally.

[0053] Specifically, the low-voltage output module 5 includes a voltage regulator unit. When the switching transistor 31 is turned on, the voltage of the battery pack is output to the voltage regulator unit of the low-voltage output module 5 after passing through the switching transistor 31, and then output to the load.

[0054] Specifically, under the condition that the high-voltage switch is closed, that is, the battery pack voltage is input from point P for power supply, when the electronic switch S1 is closed, the low-voltage part located at the rear end of the switch tube 31 is connected to the battery pack through the fast switching circuit 1 and the fifth resistor branch 32. The voltage between the two resistor units of the fifth resistor branch 32 makes the source and gate of the P-MOS transistor Q1 conduct, thereby putting the P-MOS transistor Q1Q1 in the conducting state.

[0055] When electronic switch S1 is closed, the battery pack charges the capacitor in the first capacitor branch 11, thereby turning on the first capacitor branch 11 and instantaneously connecting the low-voltage section located behind the switching transistor 31 with the battery pack. After the capacitor in the first capacitor branch 11 is fully charged, the branch containing the first capacitor branch 11 is in an open state, and there is no conduction between the source and gate of the P-MOS transistor Q1. Therefore, the P-MOS transistor Q1 cannot be turned on. Before the capacitor in the first capacitor branch 11 is fully charged, the MCU_LOCK outputs a PWM signal to ensure that the switching transistor 31 is turned on, thereby continuously supplying power to the low-voltage section.

[0056] Therefore, during the charging process of the capacitor in the first capacitor branch 11 by the battery pack, that is, at the instant when the weak current part located at the rear end of the switching transistor 31 is connected to the battery pack, the power supply input terminal of the MCU, which is electrically connected to the drain of the P-MOS transistor Q1, outputs a voltage to the MCU to wake up the MCU. At this time, the MCU_SW port detects a high level and determines that the electronic switch S1 is closed, thereby controlling the MCU_LOCK port to output a PWM signal. The output PWM signal... Figure 2 C2 in the middle is periodically charged to complete Figure 2 The continuous conduction of Q2 ensures the normal operation of the MCU self-locking circuit 4, thereby guaranteeing that the P-MOS transistor Q1 remains in a continuously conducting state. This allows the drain voltage of the P-MOS transistor Q1 to be output to the low-voltage output module 5, ensuring the response speed of the low-voltage output.

[0057] It should be noted that by setting the first capacitor branch 11, when the electronic switch S1 is closed, the capacitor in the first capacitor branch 11 is in the charging process. The voltage between the two resistor units in the fifth resistor branch 32 can quickly turn on the P-MOS transistor Q1, supplying power to the MCU. This ensures that the MCU_LOCK port quickly outputs a PWM signal, thereby completing the continuous power supply of the battery pack to the low-power output module 5 and realizing the power-on acceleration function. On the other hand, when the electronic switch S1 is opened, the capacitor in the first capacitor branch 11 can be quickly discharged through the resistors in other resistor branches (first resistor branch R7, second resistor branch R8, and third resistor branch R9), realizing the power-down acceleration function. This ensures that when the electronic switch S1 is closed again, the low-power fast switching circuit can quickly enter the working state, thus ensuring the response speed of the low-power output.

[0058] Example 2:

[0059] This specification also provides an electric device with a motor, including the low-power switching circuit of embodiment 1. The motor is electrically connected to the MCU, which controls the operation of the motor. The motor is typically a brushless motor powered by a battery pack and equipped with a high-voltage switch. The electric device can be a garden tool such as a lawnmower.

[0060] By incorporating the low-power switching circuit of this application into the electric device, the rapid start-stop function of the motor of the electric device can be satisfied, while also achieving a smaller leakage current and reducing energy loss to the battery pack.

[0061] While the present invention has been described through preferred embodiments, it is not limited to the embodiments described herein, and various changes and modifications are made without departing from the scope of the invention.

[0062] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0063] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A low-power switching circuit, characterized in that, The system includes a high-voltage switch, an electronic switch, an electronic switch detection circuit, and a fast-switching circuit. One end of the fast-switching circuit is electrically connected to the positive electrode of the battery pack via the high-voltage switch. The other end of the fast-switching circuit, the positive electrode of the electronic switch, and one end of the electronic switch detection circuit are electrically connected. The other end of the electronic switch detection circuit is electrically connected to the MCU_SW port of the MCU. The MCU can detect whether the electronic switch is closed through the MCU_SW port and the electronic switch detection circuit. The fast switching circuit includes a first capacitor branch, a first N-MOS transistor, a first resistor branch, a second resistor branch, a third resistor branch, a fourth resistor branch, a second N-MOS transistor, and a first diode. The input terminal of the first capacitor branch is electrically connected to the positive electrode of the battery pack. The first terminal of the first resistor branch and the third terminal of the second resistor branch are electrically connected to the input terminal of the first capacitor branch. The first drain of the first N-MOS transistor is electrically connected to the second terminal of the first resistor branch. The first gate of the first N-MOS transistor and the fifth terminal of the third resistor branch are electrically connected to the first diode of the second resistor branch. The four terminals are electrically connected as follows: the first source of the first N-MOS transistor, the sixth terminal of the third resistor branch, and the second drain of the second N-MOS transistor are electrically connected to the output terminal of the first capacitor branch; the seventh terminal of the fourth resistor branch, the second gate of the second N-MOS transistor, and the fifth terminal are electrically connected; the second source of the second N-MOS transistor is electrically connected to the eighth terminal of the fourth resistor branch; the eighth terminal is electrically connected to the positive terminal of the electronic switch and the MCU_SW port; the positive terminal of the first diode is electrically connected to the output terminal of the first capacitor branch, and the negative terminal is electrically connected to the fifth terminal. The resistance value of the second resistor branch is greater than the resistance value of the fourth resistor branch, and the resistance value of the second resistor branch is greater than the resistance value of the first resistor branch. The fast switching circuit is used to conduct a first current branch, a second current branch, and a third current branch when the electronic switch is closed and the first capacitor branch is not fully charged. The first current branch includes a first capacitor branch, a first diode, a fourth resistor branch, and an electronic switch. The second current branch includes a first capacitor branch, a second N-MOS transistor, and an electronic switch. The third current branch includes a second resistor branch, a fourth resistor branch, and an electronic switch. When the first capacitor branch is fully charged, only the third current branch is conducted, so that when the electronic switch is closed, the positive electrode of the battery pack and the electronic switch are connected, and after being connected, the leakage current flowing from the battery pack into the electronic switch is limited.

2. The low-power switching circuit according to claim 1, characterized in that, The fast switching circuit is also used to disconnect the positive electrode of the battery pack and the electronic switch when the electronic switch is turned off, and to quickly discharge the first capacitor branch through the first resistor branch, the second resistor branch, the third resistor branch and the first N-MOS transistor to ensure the response speed of the electronic switch.

3. The low-power switching circuit according to claim 1, characterized in that, Also includes: The system includes a control circuit, an MCU self-locking circuit, and a low-voltage output module. The control circuit includes a switching transistor and a fifth resistor branch. The input terminal of the first capacitor branch is electrically connected to the positive electrode of the battery pack through the fifth resistor branch and the high-voltage switch. The fifth resistor branch is formed by connecting at least two first resistor units in series. One end of the fifth resistor branch is electrically connected to the positive electrode of the battery pack through the high-voltage switch, and the other end of the fifth resistor branch is electrically connected to the input terminal of the fast switching circuit. The current inflow terminal of the switching transistor is electrically connected to the end of the fifth resistor branch near the positive electrode of the battery pack. The first control terminal of the switching transistor is electrically connected to the connection point between any two adjacent first resistor units in the fifth resistor branch. The current outflow terminal of the switching transistor is electrically connected to the low-voltage output module. The fast switching circuit is also used to turn on the switching transistor when the electronic switch is closed, so that the MCU self-locking circuit can operate and the low voltage output module can output voltage. The fast switching circuit is also used to turn off the switching transistor when the electronic switch is turned off, so as to disconnect the MCU self-locking circuit and stop the low voltage output module from outputting voltage.

4. The low-power switching circuit according to claim 1, characterized in that, The electronic switch detection circuit includes a second capacitor branch, one end of which is electrically connected to the positive terminal of the electronic switch, and the other end of which is grounded.

5. The low-power switching circuit according to claim 3, characterized in that, The MCU self-locking circuit includes resistor R2, NPN transistor Q2, resistor R4, resistor R5, capacitor C2, diode D1, resistor R6, diode D2, and capacitor C1. Resistor R2 is electrically connected to the first control terminal of the switching transistor, and its other end is electrically connected to the collector of NPN transistor Q2. Resistor R4 is electrically connected between the base and emitter of NPN transistor Q2. The emitter of NPN transistor Q2 is grounded. One end of capacitor C2 is electrically connected to the emitter of NPN transistor Q2, and its other end is electrically connected to one end of resistor R5. The other end of resistor R5 is electrically connected to the base of NPN transistor Q2. The anode of diode D1 is electrically connected to the emitter of NPN transistor Q2. The cathode of diode D1 is electrically connected to one end of capacitor C1. The other end of capacitor C1 is electrically connected to the MCU_LOCK port of the MCU. The connection point between capacitor C2 and resistor R5 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the cathode of diode D2. The anode of diode D2 is electrically connected to the cathode of diode D1.

6. The low-power switching circuit according to claim 3, characterized in that, The MCU self-locking circuit includes resistor R2, N-MOS transistor Q2, resistor R4, resistor R5, capacitor C2, diode D1, resistor R6, diode D2, and capacitor C1. Resistor R2 is electrically connected to the first control terminal of the switching transistor, and its other end is electrically connected to the drain of the N-MOS transistor Q2. Resistor R4 is electrically connected between the gate and source of the N-MOS transistor Q2. The source of the N-MOS transistor Q2 is grounded. One end of capacitor C2 is electrically connected to the source of the N-MOS transistor Q2, and its other end is electrically connected to one end of resistor R5. The other end of resistor R5 is electrically connected to the gate of N-MOS transistor Q2. The anode of diode D1 is electrically connected to the source of N-MOS transistor Q2. The cathode of diode D1 is electrically connected to one end of capacitor C1. The other end of capacitor C1 is electrically connected to the MCU_LOCK port of the MCU. The connection point between capacitor C2 and resistor R5 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to the cathode of diode D2. The anode of diode D2 is electrically connected to the cathode of diode D1.

7. The low-power switching circuit according to claim 3, characterized in that, The switching transistor is a P-MOS transistor or a PNP transistor.

8. An electric device having a motor, characterized in that, Includes a low-power switching circuit as described in any one of claims 1-7, wherein the motor is electrically connected to the MCU, and the MCU is used to control the operation of the motor.

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