A motor overcurrent protection circuit
By designing a motor overcurrent protection circuit and employing components such as signal processing and amplification modules, the problem of inaccurate motor current measurement was solved, achieving accurate measurement and protection of motor current, and improving the stability and safety of motor operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU ANGUI ELECTRONICS CO LTD
- Filing Date
- 2025-02-14
- Publication Date
- 2026-06-26
AI Technical Summary
The change in current during motor operation leads to unstable operation, and the circuit impedance and contact resistance cause inaccurate current measurement with large errors, which can easily burn out the motor.
Design a motor overcurrent protection circuit, including a signal processing module, a signal amplification module, a motor control module, and a DC power supply. The motor voltage is collected by a sampling module, the signal is amplified by an amplification module, the gain is adjusted by a feedback module, the measurement accuracy is improved by a pull-down module, and the protection module prevents overvoltage, thereby achieving accurate current measurement and protection.
It enables accurate measurement of motor current, reduces errors, prevents motor damage, and improves the stability and safety of motor operation.
Smart Images
Figure CN224418429U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of motor control, specifically to a motor overcurrent protection circuit. Background Technology
[0002] In modern home furnishings, an increasing number of products utilize electrical components for control. For example, automatic curtains and automatic drying racks on balconies are controlled by motors, providing convenience for consumers. However, during operation, the motor current can fluctuate, leading to unstable operation. Furthermore, if the motor stalls, the current increases, potentially causing it to burn out. Therefore, it's essential to measure the motor current during use to detect faults and shut down the motor promptly, preventing damage. However, factors such as line impedance, lead resistance, and contact resistance can lead to inaccurate current measurements. These factors also weaken the current signal detected by the measuring equipment, resulting in significant errors during measurement. Utility Model Content
[0003] To address the shortcomings of existing technologies, this utility model provides a motor overcurrent protection circuit.
[0004] The objective of this utility model is achieved through the following solution:
[0005] A motor overcurrent protection circuit includes: a signal processing module, a signal amplification module, a motor control module, a motor, and a DC power supply. The signal processing module is electrically connected to the signal amplification module, the signal amplification module is electrically connected to the motor control module, the motor control module is electrically connected to the motor, and the DC power supply is electrically connected to the signal processing module, the signal amplification module, and the motor control module, respectively. The signal amplification module includes a sampling module, a first filtering module, an amplification module, a feedback module, a pull-down module, and a protection module. The sampling module is electrically connected to the first filtering module and the motor control module, respectively. The first filtering module is electrically connected to the amplification module. The amplification module is electrically connected to the feedback module, the pull-down module, the protection module, and the DC power supply, respectively. The feedback module is electrically connected to the pull-down module and the protection module, respectively. The protection module is electrically connected to the signal processing module.
[0006] In one embodiment, the sampling module includes a resistor R2, which has a terminal 1 and a terminal 2. Terminal 1 of resistor R2 is electrically connected to the first filtering module and the amplification module, respectively, and terminal 2 of resistor R2 is electrically connected to the motor control module.
[0007] In one embodiment, the first filtering module includes capacitor C3 and capacitor C5, which have terminal 1 and terminal 2. Terminal 1 of capacitor C3 is grounded, and terminal 2 of capacitor C3 is electrically connected to the DC power supply and the amplification module, respectively. Terminal 1 of capacitor C5 is grounded, and terminal 2 of capacitor C5 is electrically connected to the sampling module and the amplification module, respectively.
[0008] In one embodiment, the amplification module includes an operational amplifier (OPA) having terminals 3-7. Terminal 3 of the OPA is electrically connected to a DC power supply and a first filter module, terminal 4 of the OPA is grounded, terminal 5 of the OPA is electrically connected to a sampling module and a first filter module, terminal 6 of the OPA is electrically connected to a pull-down module, terminal 7 of the OPA is electrically connected to a protection module, and a feedback module is connected in parallel between terminals 6 and 7 of the OPA.
[0009] In one embodiment, the feedback module includes a capacitor C7 and a resistor R11, the pull-down module includes a resistor R14, and the protection module includes a resistor R3. Capacitor C7, resistors R11, R14, and R3 each have a terminal 1 and a terminal 2. Terminals 1 and 2 of capacitor C7 and resistor R11 are connected in parallel and electrically connected to the amplification module and terminal 2 of resistor R14. Terminal 1 of resistor R14 is grounded, and terminal 2 of resistor R14 is electrically connected to the amplification module. Terminal 1 of resistor R3 is electrically connected to the amplification module. Terminal 2 of resistor R3 is electrically connected to the signal processing module.
[0010] In one embodiment, the signal amplification module further includes a voltage regulator module, which is electrically connected to the protection module and the signal processing module, respectively.
[0011] In one embodiment, the voltage regulator module includes a capacitor C6 and a diode DZ1. The capacitor C6 and the diode DZ1 have a terminal 1 and a terminal 2, respectively. The terminals 1 and 2 of the capacitor C6 and the diode DZ1 are connected in parallel. The terminal 1 of the parallel connection of the capacitor C6 and the diode DZ1 is grounded, and the terminal 2 is electrically connected to the protection module and the signal processing module, respectively.
[0012] In one embodiment, the signal processing module includes a signal control chip and an indicator module. The signal control chip has multiple ports. The indicator module is electrically connected to port 10 of the signal control chip. Port 9 of the control chip is electrically connected to a DC power supply. Port 7 of the signal control chip is grounded.
[0013] In one embodiment, the signal processing module further includes a connection port, which has a grounded terminal 1 and a grounded terminal 2. Terminal 1 of the connection port is electrically connected to the signal control chip, and terminal 2 of the connection port is grounded.
[0014] In one embodiment, the motor control module includes a motor control chip, a current limiting module, a voltage limiting module, and a second filter module. The motor control chip has multiple ports. The input terminals IN1 and IN2 of the motor control chip are electrically connected to the current limiting module, and the output terminals OUT1 and OUT2 of the motor control chip are electrically connected to the motor, respectively. The ground terminal of the motor control chip is electrically connected to the sampling module and the current limiting module, respectively. The DC power supply of the motor control chip is electrically connected to the second filter module and the DC power supply, respectively. The current limiting module is grounded and electrically connected to the signal processing module. The voltage limiting module is grounded and electrically connected to the sampling module. The second filter module is grounded and electrically connected to the DC power supply.
[0015] Compared with the prior art, the present invention has at least the following advantages:
[0016] This utility model discloses a motor overcurrent protection circuit by setting up a sampling module, which calculates the current of the sampling module by measuring the voltage on the sampling module, and then obtains the current on the motor. At the same time, an amplification module is set up to amplify the signal output to the signal processing module, so as to prevent the signal received by the signal processing module from being too small, which would cause errors when the signal processing module reads the signal. Attached Figure Description
[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:
[0018] Figure 1 This is a circuit diagram of a motor overcurrent protection circuit according to the present invention;
[0019] Figure 2 for Figure 1 Circuit diagram of the signal amplification module;
[0020] Figure 3 for Figure 1 Circuit diagram of the signal processing module;
[0021] Figure 4 for Figure 1 Circuit diagram of the motor control module and the motor;
[0022] In the attached figures, the reference numerals are as follows: 1. Signal processing module; 11. Signal control chip; 12. Indicator module; 13. Connection port; 2. Signal amplification module; 21. Sampling module; 22. First filter module; 23. Amplification module; 24. Feedback module; 25. Pull-down module; 26. Protection module; 27. Voltage regulator module; 3. Motor control module; 31. Motor control chip; 32. Current limiting module; 33. Voltage limiting module; 34. Second filter module; 4. Motor. Detailed Implementation
[0023] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.
[0024] It should be noted that all directional indicators in this utility model embodiment, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indicator will also change accordingly.
[0025] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0026] To further understand the utility model's content, features, and effects, the following embodiments are provided, along with detailed descriptions in conjunction with the accompanying drawings:
[0027] like Figure 1 As shown, Figure 1This is a circuit diagram of a motor overcurrent protection circuit, including: a signal processing module 1, a signal amplification module 2, a motor control module 3, a motor 4, and a DC power supply. The signal processing module 1 is electrically connected to the signal amplification module 2, the signal amplification module 2 is electrically connected to the motor control module 3, and the motor control module 3 is electrically connected to the motor 4. The DC power supply is electrically connected to the signal processing module 1, the signal amplification module 2, and the motor control module 3, respectively. When the motor 4 is operating, the motor control module 3 acts as a start / stop switch for the motor 4 and simultaneously collects the voltage of the motor 4 during operation. When the motor control module 3 collects the voltage of the motor 4 at a certain operating moment, it sends the voltage signal to the signal amplification module 2 for amplification and output to the signal processing module 1. The signal processing module 1 processes the voltage signal and calculates the operating current of the motor 4 based on the voltage signal to determine if the current on the motor 4 is too high. When the current on the motor 4 is too high, the signal processing module 1 sends a control command to the motor control module 3, which then stops the motor 4. It should be noted that the power supply DC in this embodiment is a direct current power supply, which provides the operating voltage for the signal processing module 1, the signal amplification module 2, and the motor control module 3.
[0028] Specifically, such as Figure 1 and Figure 2 As shown, the signal amplification module 2 includes a sampling module 21, a first filtering module 22, an amplification module 23, a feedback module 24, a pull-down module 25, and a protection module 26. The sampling module 21 is electrically connected to the first filtering module 22 and the motor control module 3, respectively. The first filtering module 22 is electrically connected to the amplification module 23. The amplification module 23 is electrically connected to the feedback module 24, the pull-down module 25, the protection module 26, and the DC power supply, respectively. The feedback module 24 is electrically connected to the pull-down module 25 and the protection module 26, respectively. The protection module 26 is electrically connected to the signal processing module 1. The sampling module 21 is used to collect the voltage output from the motor control module 3 to the signal amplification module 2; the first filtering module 22 is used to reduce signal interference to the amplification module 23; the feedback module 24 can provide feedback adjustment to the amplification module 23 to reduce the gain and increase the stability of the signal input to the amplification module 23; the pull-down module 25 can form a differential input with the sampling module 21 to improve measurement accuracy; and the protection module 26 can prevent the voltage output from the amplification module to the signal processing module 1 from being too high, thereby protecting the signal processing module 1.
[0029] Specifically, refer to Figure 2The sampling module 21 includes a resistor R2, which has a terminal 1 and a terminal 2. Terminal 1 of resistor R2 is electrically connected to the first filtering module 22 and the amplification module 23, respectively, and terminal 2 of resistor R2 is electrically connected to the motor control module 3. Since terminal 2 of resistor R2 is electrically connected to the motor control module 3, the voltage signal from the motor control module 3 can be input to the amplification module 23 through resistor R2.
[0030] Specifically, refer to Figure 2 The first filtering module 22 includes capacitors C3 and C5, each having a terminal (terminal 1) and a terminal (terminal 2). Terminal 1 of capacitor C3 is grounded, and terminal 2 of capacitor C3 is electrically connected to the DC power supply and the amplification module 23. Terminal 1 of capacitor C5 is grounded, and terminal 2 of capacitor C5 is electrically connected to the sampling module 21 and the amplification module 23. Specifically, capacitor C3 filters the DC power supply input to the amplification module 23, and capacitor C5 filters the voltage noise input from the motor control module 3 to the amplification module 23, thereby preventing noise interference in the voltage input to the amplification module 23.
[0031] Specifically, refer to Figure 2 The amplification module 23 includes an operational amplifier (OPA) with terminals 3-7. Terminal 3 of the OPA is electrically connected to the power supply DC and the first filter module 22, terminal 4 of the OPA is grounded, terminal 5 of the OPA is electrically connected to the sampling module 21 and the first filter module 22, terminal 6 of the OPA is electrically connected to the pull-down module 25, and terminal 7 of the OPA is electrically connected to the protection module 26. Terminals 6 and 7 of the OPA are connected in parallel to a feedback module 24.
[0032] Specifically, refer to Figure 2 Feedback module 24 includes capacitor C7 and resistor R11, pull-down module 25 includes resistor R14, and protection module 26 includes resistor R3 (unlabeled). Capacitor C7, resistors R11, R14, and R3 each have terminals 1 and 2. Terminals 1 and 2 of capacitor C7 and resistor R11 are connected in parallel and electrically connected to terminal 2 of amplifier module 23 and resistor R14. Terminal 1 of resistor R14 is grounded, and terminal 2 of resistor R14 is electrically connected to amplifier module 23. Terminal 1 of resistor R3 is electrically connected to amplifier module 23. Terminal 2 of resistor R3 is electrically connected to signal processing module 1. Capacitor C7 and resistor R11 are connected in parallel to amplifier module 23 to provide phase compensation, prevent oscillation, and suppress noise. Simultaneously, terminal 1 of resistor R14 is grounded, ensuring a low potential on resistor R14.
[0033] It should be noted that in actual operation, the voltage signal across resistor R2 is input to the non-inverting input terminal 5 of the operational amplifier OPA. Simultaneously, the inverting input terminal 6 of the operational amplifier OPA is connected to a pull-down resistor R14. Since terminal 1 of resistor R14 is grounded, the potential across resistor R14 is low, forming a differential input at the input terminals of the operational amplifier OPA. This differential input, by measuring the difference between the signals at the non-inverting and inverting input terminals, has the ability to suppress common-mode noise and electromagnetic interference. Furthermore, during transmission, the electromagnetic interference experienced by the two input terminals is similar, thus ensuring signal integrity and accuracy. The operational amplifier OPA amplifies the difference signal between the non-inverting input terminal 5 and the inverting input terminal 6 internally, and then outputs the amplified voltage signal from the OPA's input terminal 7 to signal processing module 1 for processing.
[0034] Preferably, refer to Figure 2 The signal amplification module 2 also includes a voltage regulator module 27, which is electrically connected to the protection module 26 and the signal processing module 1, respectively. The voltage regulator module 27 prevents voltage fluctuations in the circuit, thereby avoiding interference with the voltage signal output by the operational amplifier (OPA).
[0035] Specifically, refer to Figure 2 The voltage regulator module 27 includes a capacitor C6 and a Zener diode DZ1. Capacitor C6 and diode DZ1 each have a terminal (terminal 1) and a terminal (terminal 2), which are connected in parallel. Terminal 1 of the parallel connection is grounded, and terminal 2 is electrically connected to the protection module 26 and the signal processing module 1, respectively. It should be noted that the Zener diode plays a role in stabilizing the voltage in the circuit. When the voltage in the circuit exceeds the breakdown voltage of the Zener diode DZ1, the Zener diode DZ1 will enter a reverse breakdown state, thereby limiting the voltage in the circuit and achieving voltage regulation. Simultaneously, the capacitor C6 connected in parallel with the Zener diode DZ1 can reduce voltage fluctuations in the circuit through filtering, thus stabilizing the circuit voltage.
[0036] Specifically, such as Figure 1 and Figure 3As shown, the signal processing module 1 includes a signal control chip 11 and an indicator module 12. The signal control chip 11 has multiple ports. The indicator module 12 is electrically connected to port 10 of the signal control chip 11. Port 9 of the signal control chip 11 is electrically connected to the power supply 5. Port 7 of the signal control chip 11 is grounded. Port 6 of the signal control chip 11 is electrically connected to the signal amplification module 2. Ports 19 and 20 of the signal control chip 11 are also electrically connected to the signal amplification module 2. The signal control chip 11 receives and processes the voltage signal transmitted by the operational amplifier (OPA) through port 6, and sends control signals to the motor control module 3 through ports 19 and 20 based on the processed voltage signal to control the motor 4 to stop. The indicator module 12 serves to prompt the user. It should be noted that the indicator module 12 includes a capacitor C24, a resistor R38, and an LED. Capacitor C24 and resistor R38 have terminals 1 and 2. Terminal 1 of capacitor C24 is electrically connected to terminal 1 of resistor R38 and terminal 10 of signal control chip 11, respectively, while terminal 2 of capacitor C24 is grounded. Terminal 1 of resistor R38 is electrically connected to signal control chip 11, and terminal 2 of resistor R38 is connected to the LED. Capacitor C24 acts as a voltage regulator to prevent LED flickering, while resistor R38 provides current limiting protection to prevent LED burnout. In this embodiment, the signal processing chip 11 uses a JG105 chip.
[0037] Preferably, refer to Figure 3 The signal processing module 1 also includes a connection port 13, which has two grounded terminals, terminal 1 and terminal 2. Terminal 1 of the connection port 13 is electrically connected to the signal control chip 11, and terminal 2 of the connection port 13 is grounded. The connection port 13 can be used to debug the signal processing module 1, and it can be connected to an external computer to debug the signal control chip 11.
[0038] Specifically, such as Figure 1 and Figure 4As shown, the motor control module 3 includes a motor control chip 31, a current limiting module 32, a voltage limiting module 33, and a second filter module 34. The motor control chip 31 has multiple ports. The input terminals IN1 and IN2 of the motor control chip 31 are electrically connected to the current limiting module 32, and the output terminals OUT1 and OUT2 of the motor control chip 31 are electrically connected to the motor 4, respectively. The ground terminal of the motor control chip 31 is electrically connected to the sampling module 21 and the current limiting module 33, respectively. The power interface VCC of the motor control chip 31 is electrically connected to the second filter module 34 and the DC power supply, respectively. The current limiting module 32 is grounded and electrically connected to the signal processing module 1; the voltage limiting module 33 is grounded and electrically connected to the sampling module 21; the second filter module 34 is grounded and electrically connected to the DC power supply. It should be noted that the current limiting module 32 prevents the input signal voltage from being too high and increases the signal impedance to reduce electromagnetic interference; the voltage limiting module 33 is grounded to pull down the potential and release static electricity to prevent the motor control chip 31 from being affected by static electricity; the second filter module can filter the voltage input to the motor control chip 31 to ensure the stable operation of the motor control chip 31. In this embodiment, the motor control chip 31 is a TMI8140.
[0039] Among them, reference Figure 4 The current limiting module 32 includes resistors R5, R6, R7, and R10, each with a terminal 1 and a terminal 2. Terminals 1 of resistors R5 and R10 are grounded, and terminals 2 of resistors R5 and R10 are electrically connected to the motor control chip 31. Terminals 1 of resistors R6 and R7 are electrically connected to terminals 19 and 20 of the signal control chip 11, and terminals 2 of resistors R6 and R7 are electrically connected to terminals 1 of resistors R5 and R10 and the motor control chip 31, respectively.
[0040] Among them, reference Figure 4 The voltage limiting module 33 includes resistors R12 and R13, which each have a terminal 1 and a terminal 2. Terminals 1 and 2 of resistors R12 and R13 are connected in parallel. Terminal 1 of the parallel connection is grounded, and terminal 2 is connected to the ground of the motor control chip.
[0041] Among them, reference Figure 4 The second filter 34 includes capacitor C1 and capacitor C2. Capacitor C1 and capacitor C2 have terminal 1 and terminal 2 respectively. Terminal 1 of capacitor C1 and terminal 1 of capacitor C2 are grounded respectively. Terminal 1 of capacitor C1 and terminal 2 of capacitor C2 are electrically connected to the VCC terminal of the power supply and motor control chip 31 respectively.
[0042] In summary, during operation, the output terminals OUT1 and OUT2 of the motor control chip 31 output drive signals to the motor 4, ultimately forming a circuit to ground. When the current of the motor 4 is too high, a voltage drop will occur in resistors R12 and R13, which are connected to ground. Since directly measuring the voltage drop across resistors R12 and R13 and the current in the motor 4 is difficult, a sampling resistor R2 is used to collect the voltage across R2 instead of measuring the voltage across resistors R12 and R13. Because resistor R2 is connected in series with the motor control chip 31, the current flowing through resistor R2 is the same as the current flowing through resistors R12 and R13. However, due to the voltage division effect of the resistors, the resistance of resistor R2 needs to be less than the resistance of resistors R12 and R13 to reduce the impact of the voltage division effect of resistor R2.
[0043] In this embodiment, the resistance of the sampling resistor R2 is 100Ω. The resistance values of resistors R12 and R13 are Since the resistance of sampling resistor R2 is less than that of resistors R12 and R13, the voltage division effect of resistor R2 can be ignored. Therefore, the voltage signal input to operational amplifier OPA through resistor R2 is equal to the voltage across resistors R12 and R13. The voltage signal is input to the non-inverting input of operational amplifier OPA through resistor R2, and forms a differential input with the grounding resistor R14 connected to the inverting input of operational amplifier OPA. The amplified voltage signal is input to the 6th pin of signal control chip 11 through pin 7 of operational amplifier OPA. Since the resistance of resistor R2 is constant, the current through resistor R2 can be calculated using Ohm's law, which is the current across resistors R12 and R13. Thus, the current across motor 4 can be obtained. At this time, when the signal control chip 11 determines that the current on the motor 4 is too high, it can send a PWM signal through the 19th and 20th terminals of the signal control chip 11 to the 11th and 12th terminals of the motor control chip 31, and then turn off the motor 4 by outputting commands through the OUT1 and OUT2 terminals of the motor control chip 31.
[0044] The above are merely embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.
Claims
1. A motor overcurrent protection circuit, characterized in that, include: The system comprises a signal processing module (1), a signal amplification module (2), a motor control module (3), a motor (4), and a DC power supply. The signal processing module (1) is electrically connected to the signal amplification module (2), the signal amplification module (2) is electrically connected to the motor control module (3), the motor control module (3) is electrically connected to the motor (4), and the DC power supply is electrically connected to the signal processing module (1), the signal amplification module (2), and the motor control module (3), respectively. The signal amplification module (2) includes a sampling module (21), a first filtering module (22), and an amplification module (23). The system includes a feedback module (24), a pull-down module (25), and a protection module (26). The sampling module (21) is electrically connected to the first filtering module (22) and the motor control module (3), respectively. The first filtering module (22) is electrically connected to the amplification module (23). The amplification module (23) is electrically connected to the feedback module (24), the pull-down module (25), the protection module (26), and the DC power supply, respectively. The feedback module (24) is electrically connected to the pull-down module (25) and the protection module (26), respectively. The protection module (26) is electrically connected to the signal processing module (1).
2. The motor overcurrent protection circuit according to claim 1, characterized in that, The sampling module (21) includes a resistor R2, which has a terminal 1 and a terminal 2. Terminal 1 of the resistor R2 is electrically connected to the first filter module (22) and the amplification module (23) respectively, and terminal 2 of the resistor R2 is electrically connected to the motor control module (3).
3. The motor overcurrent protection circuit according to claim 1, characterized in that, The first filtering module (22) includes capacitor C3 and capacitor C5. Capacitor C3 and capacitor C5 have terminal 1 and terminal 2. Terminal 1 of capacitor C3 is grounded, and terminal 2 of capacitor C3 is electrically connected to the power supply DC and the amplification module respectively. Terminal 1 of capacitor C5 is grounded, and terminal 2 of capacitor C5 is electrically connected to the sampling module (21) and the amplification module (23) respectively.
4. The motor overcurrent protection circuit according to claim 1, characterized in that, The amplification module (23) includes an operational amplifier (OPA) with terminals 3-7. Terminal 3 of the OPA is electrically connected to the power supply DC and the first filter module (22). Terminal 4 of the OPA is grounded. Terminal 5 of the OPA is electrically connected to the sampling module (21) and the first filter module (22). Terminal 6 of the OPA is electrically connected to the pull-down module (25). Terminal 7 of the OPA is electrically connected to the protection module (26). Terminals 6 and 7 of the OPA are connected in parallel to a feedback module (24).
5. The motor overcurrent protection circuit according to claim 1, characterized in that, The feedback module (24) includes a capacitor C7 and a resistor R11, the pull-down module (25) includes a resistor R14, and the protection module (26) includes a resistor R3. The capacitor C7, resistor R11, resistor R14 and resistor R3 each have a terminal 1 and a terminal 2. The terminals 1 and 2 of the capacitor C7 and resistor R11 are connected in parallel and electrically connected to the amplifier module (23) and the terminal 2 of the resistor R14. The terminal 1 of the resistor R14 is grounded, and the terminal 2 of the resistor R14 is electrically connected to the amplifier module (23). The terminal 1 of the resistor R3 is electrically connected to the amplifier module (23), and the terminal 2 of the resistor R3 is electrically connected to the signal processing module (1).
6. The motor overcurrent protection circuit according to claim 1, characterized in that, The signal amplification module (2) also includes a voltage regulator module (27), which is electrically connected to the protection module (26) and the signal processing module (1).
7. A motor overcurrent protection circuit according to claim 6, characterized in that, The voltage regulator module (27) includes a capacitor C6 and a diode DZ1. The capacitor C6 and the diode DZ1 have a terminal 1 and a terminal 2, respectively. The terminals 1 and 2 of the capacitor C6 and the diode DZ1 are connected in parallel. The terminal 1 of the parallel connection of the capacitor C6 and the diode DZ1 is grounded, and the terminal 2 is electrically connected to the protection module (26) and the signal processing module (1), respectively.
8. A motor overcurrent protection circuit according to claim 1, characterized in that, The signal processing module (1) includes a signal control chip (11) and an indicator module (12). The signal control chip (11) has multiple ports. The indicator module (12) is electrically connected to port 10 of the signal control chip (11). Terminal 9 of the control chip (11) is electrically connected to the DC power supply. Terminal 7 of the signal control chip (11) is grounded. Terminal 6 of the signal control chip (11) is electrically connected to the signal amplification module (2). Terminals 19 and 20 of the signal control chip (11) are electrically connected to the signal amplification module (2) respectively.
9. A motor overcurrent protection circuit according to claim 8, characterized in that, The signal processing module (1) further includes a connection port (13), which has a grounded terminal 1 and a grounded terminal 2. Terminal 1 of the connection port (13) is electrically connected to the signal control chip (11), and terminal 2 of the connection port (13) is grounded.
10. A motor overcurrent protection circuit according to claim 1, characterized in that, The motor control module (3) includes a motor control chip (31), a current limiting module (32), a voltage limiting module (33), and a second filter module (34). The motor control chip (31) has multiple ports. The input terminals IN1 and IN2 of the motor control chip (31) are electrically connected to the current limiting module (32). The output terminals OUT1 and OUT2 of the motor control chip are electrically connected to the motor (4) respectively. The ground terminal of the motor control chip (31) is electrically connected to the sampling module (21) and the current limiting module (32) respectively. The power supply DC of the motor control chip (31) is electrically connected to the second filter module (34) and the power supply DC respectively. The current limiting module (32) is grounded and electrically connected to the signal processing module (1). The voltage limiting module (33) is grounded and electrically connected to the sampling module (21). The second filter module (34) is grounded and electrically connected to the power supply DC.