A positive and negative rotation driving circuit with motor stall detection

Abstract

This utility model discloses a forward and reverse drive circuit with motor stall detection, including a switching power supply module, a motor drive module, a detection module, and a forward and reverse control module. The power input terminal of the motor drive module is connected to the power output terminal of the switching power supply module, and the power output terminal of the motor drive module is electrically connected to the motor. The detection module is used to collect the voltage signal of the switching power supply module. The control signal input terminal of the forward and reverse control module is connected to the output terminal of the detection module, and the control signal output terminal of the forward and reverse control module is connected to the switching signal terminal of the motor drive module. The forward and reverse control module determines whether the voltage signal exceeds a preset threshold. If so, it outputs a reverse signal to control the motor to reverse. When the motor encounters a foreign object and stalls during operation, the forward and reverse control module controls the motor to reverse operation based on the voltage signal collected by the detection module. If the voltage signal exceeds the preset threshold, the forward and reverse control module controls the motor to reverse, avoiding serious malfunctions such as motor damage or even burnout due to prolonged stalling.

Description

[Technical Field] This utility model relates to the field of motor drive circuit technology, and in particular to a forward and reverse drive circuit with motor stall detection. [Background Technology] To obtain juice from fresh fruits and vegetables, there are already very mature juicers available. Compared to existing juicers that use high-speed blades to crush the pulp of fruits and vegetables, the recently popular slow juicers are more popular with most consumers because they greatly reduce the damage to the fiber cells and nutritional value of fresh fruits and vegetables, and can preserve the flavor of fruits and vegetables to the greatest extent. Moreover, slow juicers generally have a simple structure and are operated manually, making them more suitable for carrying in the field.

[0003] Currently, the motor drive circuits of existing juicers do not have a stall protection mechanism. During use, if hard fruits are put in, the motor is prone to stalling due to high resistance. If the motor stalls for a long time, it will cause damage to the motor and may even cause a fire risk in severe cases. [Utility Model Content] To address the technical problem that current juicer motor drive circuits lack a stall protection mechanism, leading to prolonged motor stalling and damage, this invention proposes a forward and reverse drive circuit with motor stall detection.

[0005] To achieve the above objectives, this utility model is implemented by the following technical solution: A forward and reverse drive circuit with motor stall detection includes: A switching power supply module, wherein the switching power supply module is used to provide a stable operating voltage for the system; A motor drive module, wherein the power input terminal of the motor drive module is connected to the power output terminal of the switching power supply module, and the power output terminal of the motor drive module is electrically connected to the motor. A detection module, the input terminal of which is connected to the power output terminal of the switching power supply module, is used to acquire the voltage signal of the switching power supply module; The forward and reverse rotation control module has its control signal input terminal connected to the output terminal of the detection module and its control signal output terminal connected to the switching signal terminal of the motor drive module. The forward and reverse rotation control module determines whether the voltage signal exceeds a preset threshold. If so, it outputs a reverse signal to control the motor to reverse.

[0006] By adopting the above technical solution, the detection module will monitor the current status of the switching power supply module in real time and convert the current signal into a voltage signal. When the motor encounters a foreign object and becomes stalled during operation, the output current of the switching power supply module will increase sharply. That is, when the voltage signal received by the forward and reverse control module exceeds the preset threshold, the motor will be controlled to run in reverse. This helps the motor to quickly get out of the stall state and avoid serious faults such as motor damage or even burnout caused by prolonged stalling, thereby extending the service life of the motor and improving the reliability of motor operation.

[0007] As described above, in a forward / reverse drive circuit with motor stall detection, the switching power supply module includes: A filtering unit, wherein the input terminal of the filtering unit is connected to the mains power supply, and the first output terminal of the filtering unit is connected to the power input terminal of the motor drive module, and the filtering unit is used to filter out common-mode interference from the mains power grid; A non-isolated power supply unit, the input terminal of which is connected to the second output terminal of the filter unit, is used to step down the mains power to a stable DC voltage.

[0008] As described above, a forward and reverse drive circuit with motor stall detection includes a filtering unit comprising a common-mode filter L2, a varistor ZR1, and a fuse F1. The live wire of the mains power is connected to the second input terminal of the common-mode filter L2, and the second output terminal of the common-mode filter L2 is connected to the input terminal of the non-isolated power supply unit. The neutral wire of the mains power is connected to one end of the fuse F1, and the varistor ZR1 is connected between the live wire of the mains power and the other end of the fuse F1. The other end of the fuse F1 is also connected to the first input terminal of the common-mode filter L2, and the first output terminal of the common-mode filter L2 is connected to the power input terminal of the motor drive module.

[0009] As described above, a forward and reverse drive circuit with motor stall detection includes a non-isolated power supply unit comprising a non-isolated power chip U1, an inductor L1, a resistor R1, a resistor RJ1, and a diode D1. The second output terminal of the filter unit is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the input terminal of the non-isolated power chip U1. The output terminal of the non-isolated power chip U1 is connected to one end of the inductor L1, and the other end of the inductor L1 outputs a 5V DC voltage. The other end of the inductor L1 is also connected to the positive terminal of the diode D1, and the negative terminal of the diode D1 is connected to the power supply terminal of the non-isolated power chip U1. The resistor RJ1 is connected between the ground terminal of the non-isolated power chip U1 and ground.

[0010] As described above, a forward and reverse drive circuit with motor stall detection includes a detection module comprising a capacitor C4, resistors R2, R3, R11, and R12. The first output terminal of the filter unit is connected to the common point of resistors R2 and R3. The other common point of resistors R2 and R3 is connected to one end of resistor R12. The other end of resistor R12 is connected to ground via capacitor C4. The other end of resistor R12 is also connected to one end of resistor R11. The other end of resistor R11 is connected to the control signal input terminal of the forward and reverse control module.

[0011] As described above, a forward / reverse drive circuit with motor stall detection includes a motor drive module comprising a silicon controlled rectifier (SCR) 1, a rectifier bridge (DB1), relays RLY1 and RLY2, a capacitor (MC1), and a resistor (R5). The first output terminal of the filter unit is connected to the main electrode T1 of the SCR1. The first output terminal of the filter unit is also connected to one end of the capacitor (MC1). The other end of the capacitor (MC1) is connected to one end of the resistor (R5). The other end of the resistor (R5) is connected to the first AC input terminal of the rectifier bridge (DB1). The main electrode T2 of the SCR1 is connected to the first AC input terminal of the rectifier bridge (DB1). The second AC input terminal of the rectifier bridge (DB1) is connected to the mains power. The positive output terminal of the rectifier bridge (DB1) is connected to the normally closed terminal of the relay (RLY1). The common terminal of the relay (RLY1) is connected to the positive terminal of the motor. The first coil terminal of the relay (RLY1) is connected to the output terminal of the non-isolated unit. The second coil terminal of the relay (RLY1) is connected to the control signal output terminal of the forward / reverse control module. The negative output terminal of the rectifier bridge DB1 is connected to the normally closed terminal of the relay RLY2, the common terminal of the relay RLY2 is connected to the negative terminal of the motor, the first coil terminal of the relay RLY2 is connected to the output terminal of the non-isolated unit, and the second coil terminal of the relay RLY1 is connected to the control signal output terminal of the forward and reverse control module.

[0012] As described above, a forward and reverse drive circuit with motor stall detection includes a forward and reverse control module comprising: The main control unit has its control signal input terminal connected to the output terminal of the detection module. When the received voltage signal exceeds a preset voltage value, the main control unit outputs a reversal signal. When the received voltage signal exceeds a preset threshold multiple times consecutively, the main control unit outputs a stop signal. A switching control unit is provided, wherein the control signal input terminal of the switching control unit is connected to the first control signal output terminal of the main control unit, and the control signal output terminal of the switching control unit is connected to the switching signal terminal of the motor drive module. The switching control unit is used to control the motor to reverse when it receives the reverse signal. The motor control unit has its control signal input terminal connected to the second control signal output terminal of the main control unit, and its control signal output terminal connected to the controlled terminal of the motor drive module. When the motor control unit receives the stop signal, it controls the motor to stop running.

[0013] As described above, a forward / reverse drive circuit with motor stall detection includes a switching control unit comprising a transistor Q2, a diode D2, a diode D3, and a resistor R14. The first control signal output terminal of the main control unit is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the base of the transistor Q2. The emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the output terminal of the non-isolated unit, the collector of the transistor Q2 is also connected to the anode of the diode D3, the cathode of the diode D3 is connected to the output terminal of the non-isolated unit, and the collector of the transistor Q2 is also connected to the switching signal terminal of the motor drive module.

[0014] As described above, a forward and reverse drive circuit with motor stall detection includes a motor control unit comprising a transistor Q1, resistors R9, R10, and R13. The second control signal output terminal of the main control unit is connected to one end of resistor R13, and the other end of resistor R13 is connected to the base of transistor Q1. The emitter of transistor Q1 is grounded, and resistors R9 and R10 are connected in parallel between the collector of transistor Q1 and the controlled terminal of the motor drive module.

[0015] As described above, in a forward and reverse drive circuit with motor stall detection, the forward and reverse control module further includes: An alarm notification unit is provided, wherein the alarm notification terminal of the alarm notification unit is connected to the alarm notification terminal of the main control unit, and the alarm notification unit is used to provide an alarm notification when the main control unit outputs the stop signal.

[0016] Compared with the prior art, the forward and reverse drive circuit with motor stall detection proposed in this utility model has the following advantages: 1. The forward and reverse drive circuit proposed in this utility model monitors the current state of the switching power supply module in real time through a detection module and converts the current signal into a voltage signal. When the motor encounters a foreign object and becomes stalled during operation, the output current of the switching power supply module will increase sharply. That is, when the voltage signal received by the forward and reverse control module exceeds the preset threshold, the motor is controlled to run in reverse. This helps the motor to quickly get out of the stall state and avoid serious faults such as motor damage or even burnout caused by prolonged stalling, thereby extending the service life of the motor and improving the reliability of motor operation.

[0017] 2. The forward and reverse rotation control module proposed in this utility model includes a main control unit, a switching control unit, and a motor control unit. When the motor stalls, the main control unit outputs a reverse signal, and the switching control unit controls the motor to run in reverse, which helps the motor to quickly release the stall state. Secondly, when the main control unit detects that the motor is stalled multiple times in a row, it outputs a stop signal, and the motor control unit controls the motor to stop running, so as to prevent the motor from being damaged due to continuous abnormal operation. [Attached Image Description] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0019] Figure 1 This is a block diagram illustrating the circuit principle structure of this utility model; Figure 2 This is a partial circuit diagram of the motor drive module, detection module, and forward / reverse control module of this utility model; Figure 3 This is a schematic diagram of the main control unit of this utility model. Figure 4 This is a circuit diagram of the alarm notification unit of this utility model; Figure 5 This is a circuit diagram of the startup module of this utility model.

Detailed Implementation Methods

[0021] The forward and reverse drive circuit proposed in this specification is applied to household appliances, including but not limited to juicers, blenders, and other household appliances that require motor operation. This specification mainly uses juicers as an example to illustrate the implementation scenario. Other household appliances can be implemented by referring to this scenario, and this application will not elaborate further.

[0022] Specific embodiments, combined with Figures 1 to 5 As shown, further illustrating the technical solution of this utility model, a forward and reverse rotation drive circuit with motor stall detection includes a switching power supply module 100, a motor drive module 200, a detection module 300, and a forward and reverse rotation control module 400. The switching power supply module 100 provides a stable operating voltage for the system. The power input terminal of the motor drive module 200 is connected to the power output terminal of the switching power supply module 100, and the power output terminal of the motor drive module 200 is electrically connected to the motor. The input terminal of the detection module 300 is connected to the power output terminal of the switching power supply module 100, and the detection module 300 is used to collect the current signal of the switching power supply module 100. The control signal input terminal of the forward and reverse rotation control module 400 is connected to the output terminal of the detection module 300, and the control signal output terminal of the forward and reverse rotation control module 400 is connected to the switching signal terminal of the motor drive module 200. The forward and reverse rotation control module 400 determines whether the voltage signal exceeds a preset threshold; if so, it outputs a reverse signal to control the motor to reverse.

[0023] In this embodiment, the detection module monitors the current status of the switching power supply module in real time and converts the current signal into a voltage signal. When the motor encounters a foreign object and becomes stalled during operation, the output current of the switching power supply module will increase sharply. When the voltage signal received by the forward and reverse control module exceeds the preset threshold, the motor is controlled to run in reverse. This helps the motor to quickly release the stalled state and avoid serious faults such as motor damage or even burnout caused by prolonged stalling, thereby extending the service life of the motor and improving the reliability of motor operation.

[0024] Furthermore, as a preferred embodiment of this solution and not a limitation, the switching power supply module 100 includes a filtering unit 110 and a non-isolated power supply unit 120. The input terminal of the filtering unit 110 is connected to the mains power, and the first output terminal of the filtering unit 110 is connected to the power input terminal of the motor drive module 200. The filtering unit 110 is used to filter out common-mode interference from the mains power grid. The input terminal of the non-isolated power supply unit 120 is connected to the second output terminal of the filtering unit 110. The non-isolated power supply unit 120 is used to step down the mains power to a stable DC voltage.

[0025] The DC voltage is 5V DC voltage.

[0026] In a preferred embodiment, the filtering unit 110 includes a common-mode filter L2, a varistor ZR1, and a fuse F1. The live wire of the mains power is connected to the second input terminal (pin 3) of the common-mode filter L2, the second output terminal (pin 4) of the common-mode filter L2 is connected to the input terminal of the non-isolated power supply unit 120, the neutral wire of the mains power is connected to one end of the fuse F1, the varistor ZR1 is connected between the live wire of the mains power and the other end of the fuse F1, the other end of the fuse F1 is also connected to the first input terminal (pin 2) of the common-mode filter L2, and the first output terminal (pin 1) of the common-mode filter L2 is connected to the power input terminal of the motor drive module 200.

[0027] In this embodiment, the common-mode filter L2 can eliminate common-mode interference by using the principle of electromagnetic induction during the power supply process of the mains power grid or when other factors generate common-mode interference. This provides a more stable power supply for the non-isolated power supply unit and other subsequent circuit modules, avoiding problems such as circuit malfunction and signal distortion caused by grid noise, and improving the stability and reliability of the entire system. Secondly, when the mains voltage rises abnormally, the resistance of the varistor ZR1 will drop rapidly, keeping the voltage within a safe range, thus protecting the subsequent circuits from damage caused by the abnormal rise in mains voltage. As an overcurrent protection element, the fuse F1 will melt and cut off the circuit when an overcurrent occurs in the circuit, thereby preventing overcurrent from causing equipment damage or fire and other safety accidents.

[0028] In a preferred embodiment, the non-isolated power supply unit 120 includes a non-isolated power chip U1, an inductor L1, a resistor R1, a resistor RJ1, and a diode D1. The second output terminal of the filter unit 110 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the input terminal (i.e., L terminal) of the non-isolated power chip U1. The output terminal (i.e., ICG terminal) of the non-isolated power chip U1 is connected to one end of the inductor L1. The other end of the inductor L1 outputs a 5V DC voltage. The other end of the inductor L1 is also connected to the positive terminal of the diode D1. The negative terminal of the diode D1 is connected to the power supply terminal (i.e., VDD terminal) of the non-isolated power chip U1. The ground terminal (i.e., GND terminal) of the non-isolated power chip U1 is connected to ground via the resistor RJ1.

[0029] Alternatively, the non-isolated power supply chip U1 is preferably model OB2233L.

[0030] In this embodiment, the non-isolated power chip U1 integrates a step-down AC-DC circuit, which can convert the common-mode filtered mains power into a stable 5V DC voltage output, providing a suitable operating voltage for the subsequent control circuit to ensure the stable operation of the control system. The inductor L1 connected to the output terminal (i.e., ICG terminal) of the non-isolated power chip U1 can smooth the output current and reduce voltage ripple, so that the output voltage is not affected by voltage fluctuations and load changes. At the same time, the inductor L1 and the diode D1 form a freewheeling circuit to prevent the back electromotive force in the inductor L1 from damaging the non-isolated power chip U1.

[0031] Furthermore, as a preferred embodiment of this solution and not a limitation, the motor drive module 200 includes a silicon controlled rectifier (SCR) 1, a rectifier bridge DB1, relays RLY1 and RLY2, a capacitor MC1, and a resistor R5. The first output terminal of the filter unit 110 is connected to the main electrode T1 of the SCR 1. The first output terminal of the filter unit 110 is also connected to one end of the capacitor MC1. The other end of the capacitor MC1 is connected to one end of the resistor R5. The other end of the resistor R5 is connected to the first AC input terminal (i.e., AC2 terminal) of the rectifier bridge DB1. The main electrode T2 of the SCR 1... The first AC input terminal of the rectifier bridge DB1 is connected to the first AC input terminal, the second AC input terminal (i.e., AC1 terminal) of the rectifier bridge DB1 is connected to the mains power, the positive output terminal (i.e., DC+ terminal) of the rectifier bridge DB1 is connected to the normally closed terminal (i.e., pin 5) of the relay RLY1, the common terminal (i.e., pin 3) of the relay RLY1 is connected to the positive terminal of the motor (i.e., MOTO1), the first coil terminal (i.e., pin 1) of the relay RLY1 is connected to the output terminal of the non-isolated unit 120, and the second coil terminal (i.e., pin 2) of the relay RLY1 is connected to the control signal output terminal of the forward and reverse control module 400. The negative output terminal (i.e., DC- terminal) of the rectifier bridge DB1 is connected to the normally closed terminal (i.e., pin 5) of the relay RLY2, the common terminal (i.e., pin 3) of the relay RLY2 is connected to the negative terminal of the motor (i.e., MOTO1), the first coil terminal (i.e., pin 1) of the relay RLY2 is connected to the output terminal of the non-isolated unit 120, and the second coil terminal (i.e., pin 2) of the relay RLY1 is connected to the control signal output terminal of the forward and reverse control module 400.

[0032] Specifically, after the mains power is filtered by the filter unit 110 to eliminate common-mode interference, it enters the main electrode T1 of the SCR1 through the first output terminal of the filter unit 110, and flows from the main electrode T1 to the main electrode T2, providing a current path for the main circuit and realizing the drive control of the motor. After receiving the current from the main circuit, the rectifier bridge DB1 rectifies the AC power to convert it into DC power. The rectified DC power is output from the positive output terminal (i.e., DC+ terminal) and the negative output terminal (i.e., DC- terminal) of the rectifier bridge DB1, providing DC power for the subsequent relays RLY1 and RLY2 and the motor drive. Relays RLY1 and RLY2 are used to control the forward and reverse rotation of the motor. During normal motor operation, the normally closed terminals (pin 5) and common terminals (pin 3) of relays RLY1 and RLY2 are closed, and the motor rotates forward. When the motor stalls, the control signal output terminal of the forward / reverse control module 400 outputs a control signal. At this time, the second coil terminals (pin 2) of relays RLY1 and RLY2 receive the control signal and become closed, causing the contacts of relays RLY1 and RLY2 to switch. Specifically, the normally open terminals (pin 4) and common terminals (pin 3) of relays RLY1 and RLY2 become closed, and the motor rotates in reverse.

[0033] In this embodiment, the motor drive module, through the coordinated operation of the silicon controlled rectifier (SCR1), relays RLY1 and RLY2, can control the start, stop, and forward / reverse rotation of the motor, thereby meeting the requirements of different application scenarios for the motor's operating state. Secondly, by adjusting the conduction angle of the SCR1, the input voltage of the motor can be adjusted to achieve stepless speed regulation of the motor, meeting the requirements of motor speed under different loads and operating conditions. At the same time, by using the contact switching of relays RLY1 and RLY2, the forward and reverse rotation of the motor can be controlled quickly and accurately, thereby rapidly switching the motor's operating state when the motor is stalled, improving the flexibility and rapid response capability of the motor drive.

[0034] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the detection module 300 includes a capacitor C4, a resistor 2, a resistor R3, a resistor R11, and a resistor R12. The first output terminal of the filter unit 110 is connected to the common point of the resistors R2 and R3. The other common point of the resistors R2 and R3 is connected to one end of the resistor R12. The other end of the resistor R12 is connected to ground via the capacitor C4. The other end of the resistor R12 is also connected to one end of the resistor R11. The other end of the resistor R11 is connected to the control signal input terminal (i.e., the MD_AD terminal) of the forward / reverse control module 400.

[0035] In this embodiment, when the motor encounters a foreign object and stalls during operation, the output current of the switching power supply module will increase sharply. At this time, resistors R2 and R3 will convert the output current of the switching power supply module into a voltage signal, and resistors R2 and R3 form a voltage divider circuit to divide the voltage signal, so that the input voltage entering the detection module 300 and the motor drive module 200 is reduced to a suitable level range. Secondly, the RC low-pass filter circuit formed by resistor R12 and capacitor C4 will filter out high-frequency ripple and noise in the acquired signal, providing a stable acquisition signal for the forward and reverse control module 400. This allows the forward and reverse control module 400 to quickly control the motor to reverse when the motor stalls, enabling the motor to quickly get out of the stall state.

[0036] Furthermore, as a preferred embodiment of this solution and not a limitation, the forward / reverse control module 400 includes a main control unit 410, a switching control unit 420, and a motor control unit 430. The control signal input terminal of the main control unit 410 is connected to the output terminal of the detection module 300. When the received voltage signal exceeds a preset threshold, the main control unit 410 outputs a reverse signal. When the received voltage signal exceeds the preset threshold multiple times consecutively, the main control unit 410 outputs a stop signal. The control signal input terminal of the switching control unit 420 is connected to the first control signal output terminal of the main control unit 410. The control signal output terminal of the switching control unit 420 is connected to the switching signal terminal of the motor drive module 200. The switching control unit 420 is used to control the motor to reverse when it receives the reverse signal. The control signal input terminal of the motor control unit 430 is connected to the second control signal output terminal of the main control unit 410. The control signal output terminal of the motor control unit 430 is connected to the controlled terminal of the motor drive module 200. When the motor control unit 430 receives the stop signal, it controls the motor to stop running.

[0037] Specifically, when the voltage signal received by the main control unit 410 exceeds the preset threshold, it will output a reversal signal and control the motor to reverse through the switching control unit 420. After the motor reverses for 3 seconds, the switching control unit 420 will control the motor to run forward again. At this time, if the detection module 300 still detects that the motor is in a stalled state (i.e., the collected voltage signal still exceeds the preset threshold), it will control the motor to reverse again. This cycle continues. If the motor is detected to be in a stalled state for 3 consecutive times, the main control unit 410 will output a stop signal and control the motor to stop running through the motor control unit 430 to prevent the motor from being damaged due to continuous abnormal operation.

[0038] The preset threshold can be set to approximately 1.5 times the voltage signal under normal motor operation. It should be understood that the preset threshold, as well as the time interval for switching the motor from reverse to forward rotation and the number of continuous detections, are only provided as a preferred implementation method and are not specifically limited. The specific settings can be adjusted according to the actual situation.

[0039] In a preferred embodiment, the main control unit 410 includes a main control chip MCU, preferably of model FY80F493QW.

[0040] In this embodiment, the main control chip FY80F493QW has high computing speed and accuracy, and can quickly and accurately process the voltage signal of the detection module to realize real-time monitoring and rapid response of the motor's operating status. Thus, when the motor stalls, it can quickly control the motor to run in reverse, and even when the motor is detected to be stalled multiple times in a row, it can promptly control the motor to stop running to prevent the motor from being damaged due to continuous abnormal operation.

[0041] In a preferred embodiment, the switching control unit 420 includes a transistor Q2, a diode D2, a diode D3, and a resistor R14. The first control signal output terminal (i.e., the MD_FZ terminal) of the main control unit 410 is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the base of the transistor Q2. The emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the output terminal of the non-isolated unit 120, the collector of the transistor Q2 is also connected to the anode of the diode D3, the cathode of the diode D3 is connected to the output terminal of the non-isolated unit 120, and the collector of the transistor Q2 is also connected to the switching signal terminal (i.e., the second coil terminal of relays RLY1 and RLY2) of the motor drive module 200.

[0042] Specifically, after the base of transistor Q2 receives the inverting signal (high-level signal) output from the first control signal output terminal (i.e., MD_FZ terminal) of the main control unit 410, it conducts. At this time, the second coil terminals (i.e., pin 2) of relays RLY1 and RLY2 also conduct, causing the contacts of relays RLY1 and RLY2 to switch. That is, at this time, the normally open terminals (i.e., pin 4) and the common terminal (i.e., pin 3) of relays RLY1 and RLY2 are connected, and the motor runs in reverse.

[0043] Three seconds after the motor reverses, the first control signal output terminal of the main control unit 410 stops outputting the reverse signal, the transistor Q2 is cut off, and at the same time the second coil terminals (i.e., pin 2) of relays RLY1 and RLY2 are also cut off. At this time, the normally closed terminals (i.e., pin 5) and the common terminal (i.e., pin 3) of relays RLY1 and RLY2 are connected, and the motor runs in the forward direction.

[0044] In this embodiment, the switching of contacts of relays RLY1 and RLY2 is controlled by the conduction state of transistor Q2, thereby controlling the forward and reverse rotation of the motor, which has a simple circuit structure. Secondly, the setting of diodes D2 and D3 effectively prevents the reverse electromotive force generated when the relay coil is de-energized from damaging transistor Q2 and other circuit components, thereby improving the reliability and stability of the motor drive circuit.

[0045] In a preferred embodiment, the motor control unit 430 includes a transistor Q1, resistors R9, R10, and R13. The second control signal output terminal (i.e., the MD_EN terminal) of the main control unit 410 is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to the base of the transistor Q1. The emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 is connected to the controlled terminal (i.e., the control terminal G of the silicon controlled rectifier SCR1) of the motor drive module 200 by the resistors R9 and R10 connected in parallel.

[0046] In this embodiment, after the base of transistor Q1 receives the stop signal (low-level signal) output from the second control signal output terminal (i.e., MD_EN terminal) of the main control unit 410, it is turned off. At this time, the control electrode G of the thyristor SCR1 will also change from the on state to the off state, thereby cutting off the main circuit of the motor drive module and causing the motor to stop running, so as to prevent the motor from being damaged due to continuous abnormal operation.

[0047] Furthermore, as a preferred embodiment of this solution and not a limitation, the forward and reverse control module 400 also includes an alarm prompting unit 440. The input terminal of the alarm prompting unit 440 is connected to the alarm prompting terminal of the main control unit 410, and the output terminal of the alarm prompting unit 440 is electrically connected to a buzzer. The alarm prompting unit 440 is used to provide an alarm prompt when the main control unit 410 outputs the stop signal.

[0048] In a preferred embodiment, the alarm notification unit 440 includes a buzzer BUZ and a resistor R27. The output terminal of the non-isolated power supply unit 120 is connected to the power supply terminal of the buzzer BUZ. The alarm notification terminal (i.e., the BUZZ terminal) of the main control unit 410 is connected to one end of the resistor R27, and the other end of the resistor R27 is connected to the alarm notification terminal of the buzzer BUZ.

[0049] In this embodiment, when the second control signal output terminal of the main control unit 410 outputs a stop signal, the alarm prompt terminal (i.e., the BUZZ terminal) of the main control unit 410 will also output an alarm prompt signal at the same time. After receiving the alarm prompt signal, the alarm prompt terminal of the buzzer BUZ will emit an audible alarm to remind the user that the motor has stalled, so as to facilitate the user to quickly check and repair it.

[0050] Furthermore, as a preferred embodiment of this solution and not a limitation, it also includes a start module 500, which is connected to the start terminal of the main control unit 410, and is used to output the forward rotation signal / reverse rotation signal of the motor.

[0051] In a preferred embodiment, the start module 500 includes a push-button switch wiring port CN2, a resistor R23, and a resistor R24. The first output terminal (i.e., port 1) of the push-button switch wiring port CN2 is connected to one end of the resistor R23, and the other end of the resistor R23 is connected to the forward start terminal (i.e., forward rotation terminal) of the main control unit 410. The third output terminal (i.e., port 3) of the push-button switch wiring port CN2 is connected to one end of the resistor R24, and the other end of the resistor R24 ​​is connected to the reverse start terminal (i.e., reverse rotation terminal) of the main control unit 410. The second output terminal (i.e., port 2) of the push-button switch wiring port CN2 is grounded.

[0052] In this embodiment, the motor supports both forward and reverse starting, which can meet the application requirements under different working conditions or different process requirements. Secondly, the forward and reverse function also makes it easier for commissioning personnel to check and adjust the movement direction and transmission system of the equipment, quickly identify and solve problems that may occur during installation, and ensure the normal operation of the equipment.

[0053] The working principle of this embodiment is as follows: This invention proposes a forward and reverse drive circuit with motor stall detection. When the motor encounters a foreign object and stalls, it can control the motor to run in reverse. If the motor is repeatedly detected to be in a stall state, it can promptly stop the motor to prevent damage caused by continuous abnormal operation. The specific implementation principle is as follows: When the motor stalls, the output current of the switching power supply module 100 increases sharply. Resistors R2 and R3 in the detection module 300 convert the output current of the switching power supply module 100 into a voltage signal. When the voltage signal collected by the detection module 300 exceeds a preset threshold, the forward / reverse control module 400 outputs a reverse signal (high-level signal) at the first control signal output terminal (MD_FZ terminal) of the main control unit 410. Upon receiving the reverse signal, the base of transistor Q2 conducts, and the second coil terminals (pin 2) of relays RLY1 and RLY2... When transistor Q2 is turned on, it will also turn on. At this time, the normally open terminals (pin 4) and common terminals (pin 3) of relays RLY1 and RLY2 will be turned on, and the motor will run in reverse. After the motor reverses for 3 seconds, the first control signal output terminal of the main control unit 410 will stop outputting the reverse signal, transistor Q2 will be turned off, and the second coil terminals (pin 2) of relays RLY1 and RLY2 will also be turned off. At this time, the normally closed terminals (pin 5) and common terminals (pin 3) of relays RLY1 and RLY2 will be turned on, and the motor will run in forward rotation. If the motor is detected to be in a stalled state for three consecutive times (i.e., the current signal collected still exceeds the preset threshold), the second control signal output terminal of the main control unit 410 outputs a stop signal (low level signal). After receiving the stop signal, the base of transistor Q1 is cut off, and the control electrode G of the thyristor SCR1 will also change from the on state to the off state, thereby cutting off the main circuit of the motor drive module and stopping the motor from running, so as to prevent the motor from being damaged due to continuous abnormal operation. At the same time, the alarm prompt terminal (i.e. BUZZ terminal) of the main control unit 410 outputs an alarm prompt signal. After receiving the alarm prompt signal, the alarm prompt terminal of the buzzer BUZ emits an audible alarm to alert the user that the motor has stalled, so as to facilitate the user to quickly check and repair it.

[0054] Those skilled in the art should understand that the above description is one embodiment provided in conjunction with specific content, and does not imply that the specific implementation of this utility model is limited to these descriptions. Furthermore, due to differences in industry naming conventions, it is not limited to the above names or English names. Any methods or structures similar to or identical to those of this utility model, or any technical deductions or substitutions made based on the concept of this utility model, should be considered within the scope of protection of this utility model.

Claims

1. A forward and reverse drive circuit with motor stall detection, characterized in that, include: A switching power supply module, wherein the switching power supply module is used to provide a stable operating voltage for the system; A motor drive module, wherein the power input terminal of the motor drive module is connected to the power output terminal of the switching power supply module, and the power output terminal of the motor drive module is electrically connected to the motor. A detection module, the input terminal of which is connected to the power output terminal of the switching power supply module, is used to acquire the voltage signal of the switching power supply module; The forward and reverse rotation control module has its control signal input terminal connected to the output terminal of the detection module and its control signal output terminal connected to the switching signal terminal of the motor drive module. The forward and reverse rotation control module determines whether the voltage signal exceeds a preset threshold. If so, it outputs a reverse signal to control the motor to reverse.

2. The forward and reverse drive circuit with motor stall detection according to claim 1, characterized in that, The switching power supply module includes: A filtering unit, wherein the input terminal of the filtering unit is connected to the mains power supply, and the first output terminal of the filtering unit is connected to the power input terminal of the motor drive module, and the filtering unit is used to filter out common-mode interference from the mains power grid; A non-isolated power supply unit, the input terminal of which is connected to the second output terminal of the filter unit, is used to step down the mains power to a stable DC voltage.

3. A forward and reverse drive circuit with motor stall detection according to claim 2, characterized in that, The filtering unit includes a common-mode filter L2, a varistor ZR1, and a fuse F1. The live wire of the mains power is connected to the second input terminal of the common-mode filter L2, and the second output terminal of the common-mode filter L2 is connected to the input terminal of the non-isolated power supply unit. The neutral wire of the mains power is connected to one end of the fuse F1, and the varistor ZR1 is connected between the live wire of the mains power and the other end of the fuse F1. The other end of the fuse F1 is also connected to the first input terminal of the common-mode filter L2, and the first output terminal of the common-mode filter L2 is connected to the power input terminal of the motor drive module.

4. A forward and reverse drive circuit with motor stall detection according to claim 2, characterized in that, The non-isolated power supply unit includes a non-isolated power chip U1, an inductor L1, a resistor R1, a resistor RJ1, and a diode D1. The second output terminal of the filter unit is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the input terminal of the non-isolated power chip U1. The output terminal of the non-isolated power chip U1 is connected to one end of the inductor L1, and the other end of the inductor L1 outputs a 5V DC voltage. The other end of the inductor L1 is also connected to the positive terminal of the diode D1, and the negative terminal of the diode D1 is connected to the power supply terminal of the non-isolated power chip U1. The resistor RJ1 is connected between the ground terminal of the non-isolated power chip U1 and ground.

5. A forward and reverse drive circuit with motor stall detection according to claim 2, characterized in that, The detection module includes a capacitor C4, resistors R2, R3, R11, and R12. The first output terminal of the filter unit is connected to the common point of resistors R2 and R3. The other common point of resistors R2 and R3 is connected to one end of resistor R12. The other end of resistor R12 is connected to ground via capacitor C4. The other end of resistor R12 is also connected to one end of resistor R11. The other end of resistor R11 is connected to the control signal input terminal of the forward / reverse control module.

6. A forward and reverse drive circuit with motor stall detection according to claim 2, characterized in that, The motor drive module includes a silicon controlled rectifier (SCR) 1, a rectifier bridge (DB1), relays RLY1 and RLY2, a capacitor (MC1), and a resistor (R5). The first output terminal of the filter unit is connected to the main electrode T1 of the SCR1. The first output terminal of the filter unit is also connected to one end of the capacitor (MC1). The other end of the capacitor (MC1) is connected to one end of the resistor (R5). The other end of the resistor (R5) is connected to the first AC input terminal of the rectifier bridge (DB1). The main electrode T2 of the SCR1 is connected to the first AC input terminal of the rectifier bridge (DB1). The second AC input terminal of the rectifier bridge (DB1) is connected to the mains power. The positive output terminal of the rectifier bridge (DB1) is connected to the normally closed terminal of the relay (RLY1). The common terminal of the relay (RLY1) is connected to the positive terminal of the motor. The first coil terminal of the relay (RLY1) is connected to the output terminal of the non-isolated unit. The second coil terminal of the relay (RLY1) is connected to the control signal output terminal of the forward / reverse control module. The negative output terminal of the rectifier bridge DB1 is connected to the normally closed terminal of the relay RLY2, the common terminal of the relay RLY2 is connected to the negative terminal of the motor, the first coil terminal of the relay RLY2 is connected to the output terminal of the non-isolated unit, and the second coil terminal of the relay RLY1 is connected to the control signal output terminal of the forward and reverse control module.

7. A forward and reverse drive circuit with motor stall detection according to claim 2, characterized in that, The forward / reverse control module includes: The main control unit has its control signal input terminal connected to the output terminal of the detection module. When the received voltage signal exceeds a preset voltage value, the main control unit outputs a reversal signal. When the received voltage signal exceeds a preset threshold multiple times consecutively, the main control unit outputs a stop signal. A switching control unit is provided, wherein the control signal input terminal of the switching control unit is connected to the first control signal output terminal of the main control unit, and the control signal output terminal of the switching control unit is connected to the switching signal terminal of the motor drive module. The switching control unit is used to control the motor to reverse when it receives the reverse signal. The motor control unit has its control signal input terminal connected to the second control signal output terminal of the main control unit, and its control signal output terminal connected to the controlled terminal of the motor drive module. When the motor control unit receives the stop signal, it controls the motor to stop running.

8. A forward and reverse drive circuit with motor stall detection according to claim 7, characterized in that, The switching control unit includes transistor Q2, diode D2, diode D3, and resistor R14. The first control signal output terminal of the main control unit is connected to one end of resistor R14, and the other end of resistor R14 is connected to the base of transistor Q2. The emitter of transistor Q2 is grounded, the collector of transistor Q2 is connected to the anode of diode D2, the cathode of diode D2 is connected to the output terminal of the non-isolated unit, the collector of transistor Q2 is also connected to the anode of diode D3, the cathode of diode D3 is connected to the output terminal of the non-isolated unit, and the collector of transistor Q2 is also connected to the switching signal terminal of the motor drive module.

9. A forward and reverse drive circuit with motor stall detection according to claim 7, characterized in that, The motor control unit includes a transistor Q1, resistors R9, R10, and R13. The second control signal output terminal of the main control unit is connected to one end of resistor R13, and the other end of resistor R13 is connected to the base of transistor Q1. The emitter of transistor Q1 is grounded, and resistors R9 and R10 are connected in parallel between the collector of transistor Q1 and the controlled terminal of the motor drive module.

10. A forward and reverse drive circuit with motor stall detection according to claim 7, characterized in that, The forward / reverse control module also includes: An alarm notification unit is provided, wherein the alarm notification terminal of the alarm notification unit is connected to the alarm notification terminal of the main control unit, and the alarm notification unit is used to provide an alarm notification when the main control unit outputs the stop signal.

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