Pre-charge circuit based on motor control and electric garden equipment

Abstract

This invention provides a pre-charging circuit based on motor control and an electric garden device. The pre-charging circuit includes a current limiting module, a discharge module, a voltage detection module, an electrolytic capacitor C1, a main MOSFET Q1, and an MCU. When there is a large-capacity electrolytic capacitor between the positive input terminal P+ of the motor and ground (GND), the pre-charging circuit can prevent arcing between the battery pack terminals and the tool terminals or between the switch contacts when the lithium battery pack is inserted or when power is applied. This effectively protects the contact parts, prevents the terminals from melting, and improves the tool's lifespan and user experience. The circuit self-test module (discharge module and voltage detection module) ensures stable and reliable operation of the pre-charging circuit. When an abnormality occurs, it can promptly report an error, preventing the tool from starting.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to pre-charging circuits and electric garden equipment based on motor control. Background Technology

[0002] To absorb the reverse current from the motor and prevent it from impacting other components, an electrolytic capacitor C1 is required between the motor's positive input terminal P+ and ground (GND). The capacitance of C1 is typically large, ranging from several hundred to several thousand microfarads. Due to its functional requirements, C1 cannot be removed. This causes arcing between terminals in circuits controlled by signal switches when a lithium battery pack is inserted or when power is applied. Prolonged use can lead to terminal melting, damaging contact components and reducing tool lifespan.

[0003] In addition, in circuits controlled by the main switch, arcing will also occur the moment the switch is closed, causing the internal terminals of the switch to melt, thereby reducing the tool's lifespan. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a pre-charging circuit and electric garden equipment based on motor control, which can prevent arcing between the battery pack terminals and tool terminals or between switch contacts when a lithium battery pack is inserted or when the device is powered on, thereby effectively protecting the contact parts, preventing the terminals from melting, and thus improving the tool's service life and user experience.

[0005] In a first aspect, embodiments of the present invention provide a pre-charging circuit based on motor control, the pre-charging circuit including a current limiting module, a discharge module, a voltage detection module, an electrolytic capacitor C1, a main MOSFET Q1, and an MCU; The discharge module, the voltage detection module, and the electrolytic capacitor C1 are respectively connected to the current limiting module. The discharge module and the voltage detection module are respectively connected to the electrolytic capacitor C1. The electrolytic capacitor C1 is connected to the main MOSFET Q1. The discharge module, the voltage detection module, and the main MOSFET Q1 are respectively connected to the MCU. The voltage detection module is used to detect the voltage point of the electrolytic capacitor C1 as a first voltage at a first time when the switch module is closed, and to detect the voltage point of the electrolytic capacitor C1 as a second voltage at a second time. The MCU is configured to determine that the main MOSFET Q1 is normal when the second voltage is greater than the first voltage and the first difference between the second voltage and the first voltage is greater than a first judgment setting value; and to start the discharge module to discharge when the first difference is less than or equal to the first judgment setting value. If the voltage of the electrolytic capacitor C1 is detected to be the third voltage at the third time, and the second voltage is greater than the third voltage, and the second difference between the second voltage and the third voltage is greater than the second judgment set value, the main MOSFET Q1 is determined to be normal; after a preset charging time, if the voltage of the electrolytic capacitor C1 is detected to be the fourth voltage, and the fourth voltage is greater than the third judgment set value, the main MOSFET Q1 is turned on. When the second difference is less than or equal to the second judgment setting value, it is determined that the main MOSFET Q1 is abnormal or the pre-charge circuit is malfunctioning.

[0006] Furthermore, the discharge module includes a transistor Q3 and a discharge current-limiting resistor; The discharge module is used to receive a first control signal sent by the MCU; when the first control signal is set to a high level, the transistor Q3 is turned on, and the voltage of the electrolytic capacitor C1 is discharged to ground through the discharge current limiting resistor.

[0007] Furthermore, the pre-charging circuit also includes a driving module and a current limiting device; The current limiting device is used to cut off the large current of the pre-charging circuit when the drive module is damaged, causing the voltage point of the electrolytic capacitor C1 to short-circuit to ground.

[0008] Furthermore, the current limiting module includes resistors R2, R3, and R4, which are connected in parallel.

[0009] Furthermore, the discharge module also includes resistors R8 and R10, and the discharge current limiting resistor includes resistors R6 and R7. One end of the resistor R8 is input to the first control signal sent by the MCU. The other end of the resistor R8 is connected to one end of the resistor R10 and the base of the transistor Q3. The other end of the resistor R10 is connected to the emitter of the transistor Q3 and then grounded. The collector of the transistor Q3 is connected to the parallel resistors R6 and R7.

[0010] Furthermore, the voltage detection module includes a resistor R5, a switching transistor Q2, a resistor R9, and a capacitor C2; One end of the resistor R5 is connected to the current limiting module and the electrolytic capacitor C1 respectively. The other end of the resistor R5 is connected to the drain of the switching transistor Q2. The gate of the switching transistor Q2 is connected to the second control signal sent by the MCU. The source of the switching transistor Q2 is connected to one end of the resistor R9. The other end of the resistor R9 is grounded. The capacitor C2 is connected in parallel with the resistor R9.

[0011] Furthermore, the pre-charging circuit also includes a power supply, diode D1, and diode D2; The positive terminal of the power supply is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the current limiting device. The switching module is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the current limiting device, and the switching module is also connected to the power supply.

[0012] Furthermore, the gate of the main MOSFET Q1 is connected to the third control signal sent by the MCU, the drain of the main MOSFET Q1 is connected to the anode of the diode D1, and the source of the main MOSFET Q1 is connected to the drive module.

[0013] Furthermore, the first time is shorter than the second time, and the second time is shorter than the third time.

[0014] Secondly, embodiments of the present invention provide an electric garden device, including a pre-charging circuit based on motor control as described above.

[0015] This invention provides a pre-charging circuit based on motor control and an electric garden device. The pre-charging circuit includes a current limiting module, a discharge module, a voltage detection module, an electrolytic capacitor C1, a main MOSFET Q1, and an MCU. The discharge module, voltage detection module, and electrolytic capacitor C1 are connected to the current limiting module, the discharge module and voltage detection module are connected to the electrolytic capacitor C1, the electrolytic capacitor C1 is connected to the main MOSFET Q1, and the discharge module, voltage detection module, and main MOSFET Q1 are connected to the MCU. The voltage detection module is used to detect the voltage point of the electrolytic capacitor C1 as a first voltage at a first time when the switch module is closed, and to detect the voltage point of the electrolytic capacitor C1 as a second voltage at a second time. The MCU is used to determine the main MOSFET Q1 when the second voltage is greater than the first voltage and the first difference between the second voltage and the first voltage is greater than a first judgment set value. T-tube Q1 is normal; when the first difference is less than or equal to the first judgment setting value, the discharge module is started to discharge; at the third time, the voltage point of electrolytic capacitor C1 is detected as the third voltage. When the second voltage is greater than the third voltage, and the second difference between the second voltage and the third voltage is greater than the second judgment setting value, the main MOSFET Q1 is determined to be normal; after the preset charging time, the voltage point of electrolytic capacitor C1 is detected as the fourth voltage. When the fourth voltage is greater than the third judgment setting value, the main MOSFET Q1 is turned on; when the second difference is less than or equal to the second judgment setting value, the main MOSFET Q1 is determined to be abnormal or the pre-charge circuit is malfunctioning; when the lithium battery pack is inserted or the power is turned on, it can prevent arcing between the battery pack terminals and the tool terminals or between the switch contacts, thereby effectively protecting the contact parts, avoiding terminal melting, and thus improving the tool's service life and user experience.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of a pre-charging circuit based on motor control provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of another pre-charging circuit based on motor control provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of a pre-charging circuit structure based on motor control provided in Embodiment 2 of the present invention.

[0020] icon: 1-Current limiting module; 2-Discharge module; 3-Voltage detection module; 4-Drive module; 5-MCU. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions 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, 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.

[0022] To facilitate understanding of this embodiment, the embodiments of the present invention will be described in detail below.

[0023] Example 1: Figure 1 This is a schematic diagram of a pre-charging circuit based on motor control provided in Embodiment 1 of the present invention.

[0024] Reference Figure 1 The pre-charging circuit includes a current limiting module 1, a discharge module 2, a voltage detection module 3, an electrolytic capacitor C1, a main MOSFET Q1, and an MCU5. Discharge module 2, voltage detection module 3 and electrolytic capacitor C1 are respectively connected to current limiting module 1, discharge module 2 and voltage detection module 3 are respectively connected to electrolytic capacitor C1, electrolytic capacitor C1 is connected to main MOSFET Q1, and discharge module 2, voltage detection module 3 and main MOSFET Q1 are respectively connected to MCU5. The voltage detection module 3 is used to detect the voltage point of the electrolytic capacitor C1 as a first voltage at the first time when the switch module is closed, and to detect the voltage point of the electrolytic capacitor C1 as a second voltage at the second time. Here, under normal circumstances, when the power is connected, the electrolytic capacitor C1 is charged through diode D1, current limiting device R1, and current limiting module 1. The current limiting module 1 can adjust the charging current.

[0025] When the switch module is closed, the voltage detection module 3 detects the voltage at the P+ point of the electrolytic capacitor C1 at the first time as the first voltage, and after a certain delay (the second time), it detects the voltage at the P+ point again as the second voltage. MCU5 is used to determine that the main MOSFET Q1 is normal and the pre-charge circuit is working normally when the second voltage is greater than the first voltage and the first difference between the second voltage and the first voltage is greater than the first judgment setting value; when the first difference is less than or equal to the first judgment setting value, the discharge module 2 is started to discharge. Here, the MCU5 sends a first control signal to the discharge module 2 to start the discharge module 2 to discharge; after discharging for a period of time, which can be set between 10ms and 500ms, for example, discharging for 10ms, 80ms, 200ms, 350ms, 500ms, etc., the voltage of point P+ is detected again at the third time.

[0026] The voltage of electrolytic capacitor C1 is detected as the third voltage at the third time. When the second voltage is greater than the third voltage and the second difference between the second and third voltages is greater than the second judgment set value, the main MOSFET Q1 is determined to be normal and the pre-charge circuit is working normally. After the preset charging time, the voltage of electrolytic capacitor C1 is detected as the fourth voltage. When the fourth voltage is greater than the third judgment set value, the main MOSFET Q1 is turned on. The preset time can be set to within 1.5 seconds.

[0027] Here, when the fourth voltage is greater than the third judgment setting value, the MCU sends a third control signal to the main MOSFET Q1 to turn on the main MOSFET Q1; When the second difference is less than or equal to the second judgment setting value, it is determined that the main MOSFET Q1 is abnormal or the pre-charge circuit is malfunctioning. Here, the first time is less than the second time, and the second time is less than the third time. The first, second, and third times are relative to the closing time of the switching module, representing the chronological order of time. It should be noted that the first and second judgment setting values ​​are approximately between 1V and 5V, for example, 2V and 2.5V respectively. The difference between the third judgment setting value and the power supply voltage is between 3V and 10V (power supply voltage). For example, if the power supply voltage is 63V, then the third judgment value can be between 53V and 60V, such as 55V.

[0028] Furthermore, the discharge module 2 includes a transistor Q3 and a discharge current-limiting resistor; The discharge module 2 is used to receive the first control signal sent by the MCU5. When the first control signal is set to a high level, the transistor Q3 is turned on, and the voltage of the electrolytic capacitor C1 is discharged to ground through the discharge current limiting resistor.

[0029] In this application, when there is a large-capacity electrolytic capacitor between the positive input terminal P+ of the motor and ground (GND), this pre-charging circuit can prevent arcing between the battery pack terminals and the tool terminals or between the switch contacts when the lithium battery pack is inserted or when the power is turned on, thereby effectively protecting the contact parts, avoiding terminal melting, improving the tool's service life and user experience.

[0030] The circuit self-test module (discharge module 2 and voltage detection module 3) is designed to ensure stable and reliable operation of the pre-charge circuit. When an abnormality occurs, it can promptly report an error, preventing the tool from starting.

[0031] Furthermore, refer to Figure 2 The pre-charging circuit also includes a drive module 4 and a current limiting device R1; The current limiting device R1 is used to cut off the large current of the pre-charge circuit when the drive module 4 is damaged, causing the voltage point of the electrolytic capacitor C1 to short-circuit to ground.

[0032] In the prior art, when the tool is in use and the drive module is damaged, causing a short circuit from P+ to ground (GND), if the power supply is not removed, the pre-charge circuit will continue to draw a large current. The circuit will operate under overpower conditions, continuously generate heat, and there is a risk of smoke and fire, endangering property and life safety.

[0033] Specifically, in this application, the current-limiting device R1 is a PTC device (positive temperature coefficient thermistor). Its resistance increases dramatically with temperature, and when the temperature exceeds its Curie temperature, its resistance increases by several orders of magnitude within a very small temperature range (e.g., from a few ohms to tens of kiloohms or even megaohms). At this point, the extremely high resistance limits the fault current to a very small, almost negligible "leakage current" level (e.g., from tens of milliamperes to a few microamperes), thereby limiting the current in the pre-charging circuit, preventing continuous heating and circuit burnout, and even avoiding a larger safety accident.

[0034] Example 2: Figure 3 This is a schematic diagram of a pre-charging circuit structure based on motor control provided in Embodiment 2 of the present invention.

[0035] Reference Figure 3 The pre-charging circuit includes a current limiting module 1, a discharge module 2, a voltage detection module 3, an electrolytic capacitor C1, and a main MOSFET Q1. The main MOSFET Q1 controls the main circuit (overcurrent) to turn on and off. The pre-charging circuit also includes a drive module 4. The current limiting module 1 includes resistors R2, R3, and R4, which are connected in parallel. Each individual resistor can have a resistance of 2 kiloohms, but the resistance is not limited to 2 kiloohms, and the number of resistors connected in parallel is not limited to three.

[0036] The discharge module 2 also includes resistors R8 and R10, and discharge current limiting resistors include resistors R6 and R7; wherein, the resistance value of a single resistor can be 1 kΩ, but the resistance value is not limited to 1 kΩ, and the number of parallel resistors is not limited to 2. One end of resistor R8 is input to the first control signal sent by the MCU. The other end of resistor R8 is connected to one end of resistor R10 and the base of transistor Q3. The other end of resistor R10 is connected to the emitter of transistor Q3 and then grounded. The collector of transistor Q3 is connected to resistors R6 and R7 in parallel.

[0037] The voltage detection module 3 includes a voltage divider resistor R5, a resistor R9, a switching transistor Q2, and a capacitor C2; among them, capacitor C2 is a filter capacitor; the capacitance value of electrolytic capacitor C1 is generally in the range of several hundred microfarads to several thousand microfarads. One end of resistor R5 is connected to the current limiting module and electrolytic capacitor C1 respectively. The other end of resistor R5 is connected to the drain of switching transistor Q2. The gate of switching transistor Q2 is connected to the second control signal sent by MCU. The source of switching transistor Q2 is connected to one end of resistor R9. The other end of resistor R9 is grounded. Capacitor C2 is connected in parallel with resistor R9.

[0038] The pre-charging circuit also includes a power supply, diode D1, and diode D2, wherein diodes D1 and D2 are reverse protection diodes; The positive terminal of the power supply is connected to the anode of diode D1, and the cathode of diode D1 is connected to the current limiting device. The switching module is connected to the anode of diode D2, the cathode of diode D2 is connected to the current limiting device, and the switching module is also connected to the power supply.

[0039] The gate of the main MOSFET Q1 is connected to the third control signal sent by the MCU, the drain of the main MOSFET Q1 is connected to the anode of the diode D1, and the source of the main MOSFET Q1 is connected to the drive module 4.

[0040] This invention provides an electric garden device, including a pre-charging circuit based on motor control as described above.

[0041] The computer program product provided in this embodiment of the invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation details, please refer to the method embodiments, which will not be repeated here.

[0042] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0043] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0044] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A pre-charge circuit based on motor control, characterized by, The pre-charging circuit includes a current limiting module, a discharge module, a voltage detection module, an electrolytic capacitor C1, a main MOSFET Q1, and an MCU; The discharge module, the voltage detection module, and the electrolytic capacitor C1 are respectively connected to the current limiting module. The discharge module and the voltage detection module are respectively connected to the electrolytic capacitor C1. The electrolytic capacitor C1 is connected to the main MOSFET Q1. The discharge module, the voltage detection module, and the main MOSFET Q1 are respectively connected to the MCU. The voltage detection module is used to detect the voltage point of the electrolytic capacitor C1 as a first voltage at a first time when the switch module is closed, and to detect the voltage point of the electrolytic capacitor C1 as a second voltage at a second time. The MCU is configured to determine that the main MOSFET Q1 is normal when the second voltage is greater than the first voltage and the first difference between the second voltage and the first voltage is greater than a first judgment setting value; and to start the discharge module to discharge when the first difference is less than or equal to the first judgment setting value. If the voltage point of the electrolytic capacitor C1 is detected to be the third voltage at the third time, and the second voltage is greater than the third voltage, and the second difference between the second voltage and the third voltage is greater than the second judgment set value, then the main MOSFET Q1 is determined to be normal. After a preset charging time, the voltage point of the electrolytic capacitor C1 is detected to be the fourth voltage. When the fourth voltage is greater than the third judgment setting value, the main MOSFET Q1 is turned on. When the second difference is less than or equal to the second judgment setting value, it is determined that the main MOSFET Q1 is abnormal or the pre-charge circuit is malfunctioning.

2. The pre-charge circuit based on motor control according to claim 1, characterized in that, The discharge module includes a transistor Q3 and a discharge current-limiting resistor; The discharge module is used to receive a first control signal sent by the MCU; when the first control signal is set to a high level, the transistor Q3 is turned on, and the voltage of the electrolytic capacitor C1 is discharged to ground through the discharge current limiting resistor.

3. The pre-charge circuit based on motor control according to claim 1, wherein, The pre-charging circuit also includes a driving module and a current limiting device; The current limiting device is used to cut off the large current of the pre-charging circuit when the drive module is damaged, causing the voltage point of the electrolytic capacitor C1 to short-circuit to ground.

4. The pre-charge circuit based on motor control according to claim 1, wherein, The current limiting module includes resistors R2, R3, and R4, which are connected in parallel.

5. The pre-charge circuit based on motor control according to claim 2, wherein, The discharge module also includes resistors R8 and R10, and the discharge current limiting resistor includes resistors R6 and R7; One end of the resistor R8 is input to the first control signal sent by the MCU. The other end of the resistor R8 is connected to one end of the resistor R10 and the base of the transistor Q3. The other end of the resistor R10 is connected to the emitter of the transistor Q3 and then grounded. The collector of the transistor Q3 is connected to the parallel resistors R6 and R7.

6. The pre-charge circuit based on motor control according to claim 1, wherein, The voltage detection module includes resistor R5, switching transistor Q2, resistor R9, and capacitor C2; One end of the resistor R5 is connected to the current limiting module and the electrolytic capacitor C1 respectively. The other end of the resistor R5 is connected to the drain of the switching transistor Q2. The gate of the switching transistor Q2 is connected to the second control signal sent by the MCU. The source of the switching transistor Q2 is connected to one end of the resistor R9. The other end of the resistor R9 is grounded. The capacitor C2 is connected in parallel with the resistor R9.

7. The pre-charge circuit based on motor control according to claim 1, wherein, The pre-charging circuit also includes a power supply, diode D1, and diode D2; The positive terminal of the power supply is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the current limiting device. The switching module is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the current limiting device, and the switching module is also connected to the power supply.

8. The pre-charge circuit based on motor control according to claim 7, wherein, The gate of the main MOSFET Q1 is connected to the third control signal sent by the MCU, the drain of the main MOSFET Q1 is connected to the anode of the diode D1, and the source of the main MOSFET Q1 is connected to the drive module.

9. The pre-charge circuit based on motor control according to claim 1, wherein, The first time is less than the second time, and the second time is less than the third time.

10. An electric garden device, characterized in that Includes the motor-controlled pre-charging circuit as described in any one of claims 1 to 9.

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