A lid opening safety food processor

Abstract

This utility model provides a food processor with safe opening mechanism, including a cup assembly. The cup assembly includes a cup body, a cup lid, and a pulverizing blade disposed within the cup body. The cup lid closes to the cup body. The pulverizing blade is driven by a variable frequency motor. When the cup lid closes to the cup body, a switch is closed. The switch simultaneously controls the conduction of a first branch and a second branch. A variable frequency motor drive module is used to supply power to the variable frequency motor drive module. A main control module receives a first control signal for the cup lid closing and outputs a drive signal to the variable frequency motor drive module. The main control module receives a second control signal for the cup lid opening and immediately stops outputting a drive signal to the variable frequency motor drive module. An energy storage module is disposed in the first branch and is used to discharge to maintain power supply to the variable frequency motor drive module after the switch is opened. The food processor achieves soft stop and hard power cut-off of the variable frequency motor through the first and second branches, providing dual protection to ensure the safety of opening the food processor.

Description

Technical Field

[0001] This utility model belongs to the field of food processing machines, and in particular relates to a food processing machine with safe lid opening driven by a variable frequency motor. Background Technology

[0002] Existing food processors with soy milk making capabilities include a cup assembly and a main unit. The cup assembly consists of a cup body and a grinding blade housed within it. The grinding blade is driven by a motor to rotate and process ingredients such as soybeans, black beans, grains, and fish to create beverages like soy milk, rice porridge, rice paste, and thick soup. Because the cup contains the grinding blade, if the user opens the lid while the machine is in operation, or if the lid is not closed when starting the food processor, an open lid signal is sent to the main control module. Based on this signal, the main control module either prevents the food processor from starting or uses software to stop the motor from rotating the grinding blade, thus preventing mechanical injury from the user's fingers touching the rotating blade's edge after the lid is opened. Regarding this safety requirement for opening the lid of a food processor, the national standard GB / T 4706.30-2024 stipulates that "for the stirrer, except for the lid, other detachable parts shall not be removed. During the test, a test fixture similar to Type B in GB / T 16842-2016 shall be used, but a circular baffle with a diameter of 125mm shall be used instead of a non-circular baffle, and the distance from the tip of the test fixture to the baffle shall be 100mm." For food processors that meet this requirement, combined with the requirements of national standard GB 4706.19-2008, and taking into account the safety protection of users when making hot drinks, the motor can be stopped by disconnecting the low-voltage control when the lid of the food processor is opened.

[0003] However, the newly revised national standard GB / T 4706.19-2024 has added stricter requirements for food processing machines, specifically soy milk makers. Clause 22.40 of the standard stipulates that "for soy milk makers, any switches used to control the motor should also disconnect those electronic circuits that, if they fail, would cause the machine to fail to meet the requirements of this document." In other words, for food processing machines with soy milk functions, the method of stopping the motor by disconnecting the low-voltage power supply when the lid is opened does not meet the requirements of the newly revised national standard. The motor must be stopped by disconnecting the power supply to the drive motor or directly disconnecting the high-voltage power supply after the lid is opened to meet the safety requirements for opening the lid in the new national standard. For traditional blenders driven by series-wound motors, connecting a high-voltage safety switch in series on the neutral line of the main circuit, and disconnecting the neutral line when the lid is opened, meets the requirements of the newly revised national standard GB / T 4706.19-2024 for disconnecting the high-voltage power supply when the lid is opened. However, the solution of disconnecting the neutral wire via a high-voltage switch when the lid is opened has problems. The high-voltage switch is large, while the triggering space in a food processor is very limited. Furthermore, due to the high voltage in the main circuit, disconnecting the neutral wire causes significant wear and tear on the overall circuit and components, especially the electrical sparks generated at the moment the switch opens and closes, affecting the reliability of the control circuit and the lifespan of critical components. This is especially true for food processors driven by three-phase brushless variable frequency motors. Currently, variable frequency motors in food processors offer multiple advantages such as low noise, stepless speed regulation, and stable crushing performance. However, compared to traditional food processors driven by series-wound motors, variable frequency motor-driven food processors have more complex control circuits and higher requirements for safety and reliability.

[0004] Therefore, if those skilled in the art want food processors to meet the safety requirement of stopping the variable frequency motor when the lid of a food processor with a soy milk function is opened in the latest revised national standard GB / T4706.19-2024, they have to return to the method mentioned in the background of this application of disconnecting the neutral wire by a safety switch to achieve the purpose of stopping the variable frequency motor by disconnecting the high voltage. At the same time, they have to sacrifice more hardware switch space, trigger reliability and power device wear and tear.

[0005] Furthermore, the applicant's prior utility model patent application, CN201822199225.0, discloses a food processor with rapid power-off capability, pointing out that existing variable frequency motor-driven food processors suffer from significant communication interference during motor operation and a prolonged residual voltage after power failure. In other words, those skilled in the art would not want a large residual voltage after power failure. Another utility model patent in the industry, CN202020497240.8, addresses the same issue. Brushless motors, due to the need for voltage stabilization and filtering, have filter capacitors connected in parallel across numerous motor terminals. However, after the food processor is powered off, these filter capacitors suffer from excessive residual charge and prolonged discharge time. Therefore, for food processors driven by variable frequency motors, those skilled in the art would prefer that the voltage stabilization and filtering module rapidly de-energize after the entire food processor is powered off, allowing the food processor to quickly return to a safe power level after normal shutdown. This would enable after-sales service personnel to quickly disassemble and inspect the machine, making after-sales service faster and safer. Both of the aforementioned prior art patents point to the need for the variable frequency motor to stop driving and the power supply of the variable frequency motor drive module to be de-energized as soon as possible after the food processing machine is shut down. In other words, those skilled in the art tend to increase the power-down rate of the voltage stabilization and filtering module so that it can be de-energized as soon as possible or the power-down time can be minimized.

[0006] There is also a utility model patent in the industry with patent number CN202020497240.8, which discloses a working circuit for a food processor. This patent states in its background section that the brushless motor is controlled by a brushless motor working circuit. Existing brushless motor working circuits typically use software logic to start and stop the brushless motor based on the opening and closing state of the lid. However, using software logic control poses certain safety risks. Therefore, this patent provides a brushless motor working circuit where the input of an isolating switch circuit is connected to the lid status signal CAP, and the output is connected to the motor drive signal enable terminal MotorEN of the first controller. When the lid opens from closed, the lid status signal CAP changes from low to high, and the motor drive signal enable terminal MotorEN of the first controller changes from high to low, thereby shutting down the motor drive signal inside the first controller, i.e., turning off the brushless motor M. When the cup lid changes from open to closed, the cup lid status signal CAP changes from high to low, and the motor drive signal enable terminal MotorEN of the first controller changes from low to high, thereby enabling the brushless motor drive signal of the first controller, which can start the brushless motor M. This scheme triggers the cup lid status signal to switch from low to high when the cup lid changes from closed to open, and the MCU controls the cessation of sending drive signals to the variable frequency motor drive circuit, thereby causing the variable frequency motor to stop driving. In addition, the patent also mentions in paragraph

[0045] of the specification that the cup lid status signal CAP output by the cup lid detection circuit can directly enable or deactivate the motor drive signal of the first controller (MCU1) through the isolation switch circuit, and the isolation switch circuit can act as a hard switch for the motor drive signal. However, in reality, this patent still controls the variable frequency motor to stop working through MCU software, which is essentially still a weak current control of the variable frequency motor to stop working. Therefore, the above scheme cannot meet the safety requirements of the newly revised national standard GB / T 4706.19-2024 regarding the reliable stopping of the variable frequency motor when the lid is opened. Based on this, if those skilled in the art want to meet the safety requirements for opening the lid in the national standard GB / T 4706.19-2024, they have to return to the method of disconnecting the neutral wire by a micro switch mentioned in the background of this application to meet the standard requirements.

[0007] Therefore, in food processing machines driven by variable frequency motors, how to reduce the space occupied by the lid opening trigger while ensuring the safety and reliability of the control circuit, the stable operation of power devices, low life loss, and meeting the safety requirements of the newly revised national standard GB / T4706.19-2024 for reliable stopping of the variable frequency motor when the lid is opened is an urgent technical problem to be solved. Utility Model Content

[0008] The purpose of this invention is to provide a food processing machine driven by a variable frequency motor that can safely and reliably stop driving the variable frequency motor when the cup lid is opened. Under the premise of meeting the safety requirements for opening the lid in the national standard GB / T 4706.19-2024, this invention solves the problems of large hardware space occupation, high wear and tear on the overall circuit and components caused by the cup lid triggering the high-voltage switch, especially the electric sparks that occur at the moment the switch is opened and closed, which affect the reliability of the control circuit and the service life of key components.

[0009] To solve the above-mentioned technical problems, this utility model provides a food processor with a safe opening mechanism, including a cup body assembly. The cup body assembly includes a cup body, a cup lid, and a pulverizing blade disposed within the cup body. The cup lid closes onto the cup body, and the pulverizing blade is driven by a variable frequency motor. The device also includes: When the cup lid is closed, the switch is activated, connecting the first and second branches. When the cup lid is opened, the switch is deactivated, disconnecting the first and second branches. The power module is connected to the first and second branches via a switch; The variable frequency motor drive module is connected to the first branch, and the power supply module is connected to the power supply terminal of the variable frequency motor drive module through the switch. The main control module is connected to the second branch and outputs a drive signal to the variable frequency motor drive module. The second branch is also equipped with a level conversion module connected to the power module through the switch. The level conversion module is connected to the control signal input terminal of the main control module and provides a control signal. An energy storage module is located in the first branch. The power supply module is connected to the energy storage module through the switch. The energy storage module is connected to the power supply terminal of the variable frequency motor drive module and discharges when the switch is opened, so that the power supply terminal of the brushless motor drive module is delayed and de-energized.

[0010] Furthermore, the energy storage module includes a first capacitor, and a first diode is connected between the switch and the first capacitor.

[0011] Furthermore, a passive energy storage module is located in the second branch. The passive energy storage module includes a second capacitor, and the capacitance value of the first capacitor is greater than the capacitance value of the second capacitor.

[0012] Furthermore, a passive energy storage module is located in the second branch; The first resistor is connected in parallel with the passive energy storage module. When the second branch is disconnected, the main control module accelerates the acquisition of the second control signal.

[0013] Furthermore, the capacitance value of the first capacitor is EC1, and the capacitance value of the second capacitor is EC2, where EC1 ≥ 10 * EC2.

[0014] Furthermore, a second diode is located in the second branch and electrically connected between the switch and the passive energy storage module.

[0015] Furthermore, the level conversion module includes a transient voltage suppression diode, an N-type transistor, a P-type transistor, a second resistor, a third resistor, and a fourth resistor. The negative terminal of the transient voltage suppression diode is connected to the second branch, and the positive terminal of the transient voltage suppression diode is connected to the base of the N-type transistor through the second resistor. The base of the N-type transistor is also grounded through the third resistor. The emitter of the N-type transistor is grounded, and the collector of the N-type transistor is coupled to the base of the P-type transistor. The emitter of the P-type transistor is connected to a first voltage terminal, and the collector is coupled to the control signal input terminal of the main control module. The collector of the P-type transistor is also grounded through the fourth resistor.

[0016] Furthermore, the positive terminal of the first diode is connected to the switch, the negative terminal of the first diode is connected to the positive terminal of the first capacitor and the power supply terminal of the variable frequency motor drive module, and the negative terminal of the first capacitor is grounded.

[0017] Furthermore, the positive terminal of the second diode is connected to the switch, the negative terminal of the second diode is connected to the positive terminal of the second capacitor and the input terminal of the level conversion module, and the negative terminal of the second capacitor is grounded.

[0018] Furthermore, a fifth resistor is provided between the collector of the P-type transistor and the control signal input terminal of the main control module. One end of the fifth resistor is connected to the collector of the P-type transistor, and the other end is grounded through a third capacitor.

[0019] The beneficial effects of this utility model are: 1. In the food processing machine industry, there is a core contradiction between the new national standard's stringent requirements for lid opening safety and existing technologies. One side of the contradiction lies in the mandatory requirement of the new standard: to ensure user safety, the motor must be stopped immediately and reliably when the lid is opened. This essentially requires a solution that disconnects high-voltage power, as low-voltage solutions relying on software control are at risk of failure. The other side of the contradiction lies in the "reverse teaching" of existing technologies. In the field of variable frequency motor drives, a basic and widely accepted reverse teaching is that the +15V power supply to the variable frequency motor drive module should never be directly disconnected during normal motor operation. Textbooks and chip manufacturers (such as Silan Microelectronics) explicitly warn that doing so will cause a voltage drop, causing the power devices (IGBTs) of the variable frequency motor drive module to enter the non-saturated operating region. This can result in damage to the devices, or even tube explosion, burning out the entire drive module, or even causing the machine to explode. Based on this, those skilled in the art are forced to choose the less desirable option of disconnecting the neutral wire by opening the lid. Therefore, it is urgent to solve the technical problems that need to be addressed, such as how to ensure the safe and reliable stopping of the motor drive when the lid is opened, while meeting the new national standard, and how to solve the problems caused by the lid triggering the high-voltage switch to open and close, which results in large hardware space occupation, high overall circuit and component losses, and especially the electric sparks that occur at the moment the switch is opened and closed, affecting the reliability of the control circuit and the service life of key components.

[0020] When the cup lid is opened, the food processing machine triggers the switch to disconnect and controls the first and second branches to disconnect. In terms of timing, the second branch's "software shutdown" (soft stop) precedes the first branch's "hardware shutdown" (hard power cut) of the variable frequency motor drive module. The disconnection action of the same switch, through the second and first branches, double-shuts down the variable frequency motor drive module, thereby reliably stopping the variable frequency motor and achieving the purpose of safety protection when the lid is opened. In the second branch, the main control module acquires the cover opening control signal and first stops outputting drive signals to the variable frequency drive module to control the variable frequency motor drive module to stop driving the variable frequency motor. In the first branch, the switch is opened, causing the power module to disconnect. Instead, the energy storage module discharges to the variable frequency motor drive module to maintain the voltage within the normal operating range, i.e., the saturation voltage range. After the variable frequency motor drive module is shut down by software in the first branch, the power supply to the variable frequency motor drive module is disconnected to achieve the subsequent hardware shutdown of the variable frequency motor drive module. Through the dual protection mechanism of hard shutdown and soft shutdown, from the perspective of user safety and avoiding mechanical hazards, it can fully meet the cover opening safety requirements in the newly revised national standard GB / T 4706.19-2024 (hereinafter referred to as the new national standard).

[0021] 2. The food processor includes a switch and a variable frequency motor drive module. When the cup lid is opened, the switch is turned off. The switch controls the first and second branches to disconnect, thereby cutting off the power supply to the variable frequency motor drive module when the cup lid is opened and the switch is triggered to disconnect. The main control module is located in the second branch. When the cup lid is closed and the switch is closed, the second branch is turned on. The main control module receives a first control signal indicating the cup lid is closed and outputs a drive signal to the variable frequency motor drive module, controlling the variable frequency motor to drive the pulverizer to process the food inside the cup. When the cup lid is opened, the switch is turned off, and the second branch is disconnected. The main control module receives a second control signal indicating the cup lid is open. Preferably, the I / O port of the main control module is used to receive either the first or second control signal. The switch can trigger the disconnection of the first and second branches simultaneously or not simultaneously, thus implementing different priorities for the disconnection sequence of the first and second branches at the mechanical control node where the switch is triggered to disconnect. For example, it is preferable that the second branch is disconnected first, followed by the first branch.

[0022] When the lid is opened, the I / O port switches from the first control signal to the second control signal. The main control module stops outputting drive signals to the variable frequency motor drive module, causing the variable frequency motor drive module to stop driving. Simultaneously, the switch synchronously disconnects the first branch, cutting off the power supply to the power module. The energy storage module located in the first branch discharges to maintain power supply to the variable frequency motor drive module, ensuring that the variable frequency motor drive module can normally turn off its switching transistor according to the main control module stopping outputting drive signals during the power supply maintenance period, so that the variable frequency motor actually stops driving under the control of the main control module. Moreover, during the period when the energy storage module loses power and maintains the variable frequency motor drive module's normal operating voltage range, it is sufficient to prioritize the main control module in terms of time to stop outputting drive signals to the variable frequency motor drive module and to prioritize the main control module in terms of time to control the variable frequency motor drive module to stop driving the variable frequency motor. At the same time, during the period when the energy storage module maintains the normal operating voltage range, the switching transistor of the variable frequency drive module switches from the on state to the off state, and then the energy storage module stops discharging to the variable frequency motor drive module.

[0023] In this way, while meeting the safety requirements for opening the lid of the new national standard, the driving of the variable frequency motor is normally shut off based on the working principle of the IGBT of the variable frequency motor drive module. This ensures user safety, effectively shutting off the hardware circuit of the variable frequency motor after opening the lid, and also ensures the stable and reliable switching of the control circuit of the entire food processor. This effectively avoids the power devices from being damaged by abnormal impacts, thus extending the service life of the variable frequency motor and control circuit of the food processor, and consequently extending the service life of the entire food processor.

[0024] 3. The power supply of the variable frequency motor drive module is generally a low-voltage circuit. Mechanical shutdown of the variable frequency motor can be achieved by controlling the disconnection of this low-voltage circuit. This can be accomplished by using a low-voltage switch in conjunction with the cup lid to turn the switch on and off. This results in a small hardware structure for the cup lid trigger switch, with only low-voltage leads required for electrical signal transmission. This minimizes the space occupied by the hardware switch and reduces the cost of hardware circuit connections. Even when upgrading existing food processing machines that use the main control module software to shut down the variable frequency motor when the cup lid is opened to meet the new national standard for lid opening safety, no major modifications to the hardware structure are needed. Only the drive board of the food processing machine needs to be upgraded. This further saves significant R&D time and product improvement costs associated with lid opening safety upgrades.

[0025] 4. The power module is connected to the first branch and the second branch via switches, which means that the voltage connected to the second branch is also the power supply voltage required by the variable frequency motor drive module. The I / O port of the main control module used to receive the control signal is generally a standardized 5V interface. Therefore, a level conversion module is also provided on the second branch. The power module converts the first control signal for the lid to be closed and the second control signal for the lid to be opened into the first control signal for the lid to be closed and the second control signal for the lid to be opened into the second branch, thereby quickly and accurately detecting the closed state of the lid relative to the cup body and the cup mouth, so as to respond quickly when the lid is opened, and control the variable frequency motor to reliably stop driving through a dual shutdown mechanism of soft shutdown and hard shutdown. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the food processing machine of this utility model.

[0028] Figure 2 This is a circuit control diagram of the food processing machine of this utility model.

[0029] Figure 3 This is another circuit control diagram of the food processing machine of this utility model.

[0030] Figure 4 This is another circuit control diagram of the food processing machine of this utility model.

[0031] Figure 5 This is a power-off diagram of the energy storage module and the passive energy storage module in the first and second branches of the food processing machine of this utility model.

[0032] Figure 6 This is a schematic diagram showing the switching between the first and second control signals of the main control module of the food processing machine of this utility model.

[0033] Figure 7 This is a circuit connection diagram for the safety protection circuit when the lid of the food processing machine of this utility model is opened.

[0034] The names of the components shown in the diagram are as follows: 100. Cup body assembly; 101. Cup body; 102. Cup lid; 103. Crusher; 200. Switch; 300. Variable frequency motor drive module; 400. Main control module; 500. Energy storage module; 600. Passive energy storage module; 700. Level conversion module; 800. Power supply module; 900. Main unit; 901. Variable frequency motor. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The food processing machine is driven by a variable frequency motor, which is driven by a variable frequency motor drive module. This drive module uses IGBTs as its core components to achieve its driving function. Pages 30-33 of the textbook *Power Electronics Technology and MATLAB Simulation* (Second Edition), a textbook for the "Twelfth Five-Year Plan" of ordinary higher education published by China Electric Power Press (ISBN 978-7-5123-6067-9), disclose the structure and working principle of the Insulated Gate Bipolar Transistor (IGBT), as well as its characteristics and main parameters. Based on the working principle and characteristics of IGBTs, the food processing machine generates a three-phase AC voltage by precisely controlling the PWM duty cycle of six IGBTs, thereby driving the variable frequency motor.

[0037] Based on the working principle and performance parameters of IGBTs, those skilled in the art fully understand that the power supply terminal of the IGBT drive module should be within the safe voltage range of the saturation region so that the variable frequency motor can normally drive the pulverizer to process food. That is, the current power supply voltage of the variable frequency motor drive module is within the normal operating voltage range. When the switching transistor of the variable frequency drive module is normally turned off, the current power supply voltage of the variable frequency motor drive module is normally within the cutoff voltage range.

[0038] A well-known domestic manufacturer of variable frequency motor drive modules, such as Hangzhou Silan Microelectronics Co., Ltd., has published an electronic manual for an intelligent power module (IPM, i.e., variable frequency motor drive module) on its official website. The specific model is SDM10C60TA2B1, and the URL is: https: / / www.silan.com.cn / index.php / product / details / 2501.html. The manual clearly states that the typical value of the control power supply voltage Vcc for this model is 15V, with a minimum of 13.5V and a maximum of 16.5V. This means the normal operating voltage range of the variable frequency motor drive module is between 13.5V and 16.5V, with a typical value of 15V. While the manual provides an optimal control power supply voltage Vcc value, in actual operation, the normal operating voltage range can be flexibly adjusted according to the actual operating conditions based on the actual characteristics of the IGBT, such as between 10V and 18V, with a typical value of 15V.

[0039] Based on the existing technologies described above, both textbooks and chip electronics manufacturers have explained and limited the operating voltage required for normal operation of variable frequency motor drive modules based on the IGBT working principle. They all clarify that the operating voltage of the variable frequency motor drive module should be maintained within the normal operating voltage range that allows the IGBT to be driven safely and reliably. In other words, the power supply voltage of the variable frequency motor drive module should be in the saturation region or in the cutoff region after normal shutdown. Whether based on textbooks or common knowledge in the field, it is clear that directly disconnecting the power supply to the variable frequency motor drive module is not allowed; that is, the power supply voltage of the variable frequency motor drive module should not be in the amplification region. Otherwise, it will directly lead to abnormal conduction of the switching transistor, such as short circuits in the upper and lower bridge arms of the IGBT or an uncontrollable "half-on, half-off" state of the switching transistor, directly causing a sudden increase in the temperature of the switching transistor, resulting in the risk of transistor failure or even machine failure.

[0040] In the food processing machine industry, there is a core contradiction between the new national standard's stringent requirements for lid opening safety and existing technologies. One side of the contradiction lies in the mandatory requirement of the new standard: to ensure user safety, the motor must be stopped immediately and reliably when the lid is opened. This essentially requires a solution that disconnects high-voltage power, as low-voltage solutions relying on software control are at risk of failure. The other side of the contradiction lies in the "reverse teaching" of existing technologies. In the field of variable frequency motor drives, a basic and widely accepted reverse teaching is that the +15V (i.e., the aforementioned typical value) power supply to the variable frequency motor drive module should never be directly disconnected during normal motor operation. Textbooks and chip manufacturers (such as Silan Microelectronics) explicitly warn that doing so will cause a voltage drop, causing the power devices (IGBTs) of the variable frequency motor drive module to enter the non-saturated operating region. This can result in damage to the devices, or even tube explosion, burning out the entire drive module, or even causing the machine to explode. Therefore, those skilled in the art are forced to choose the less desirable option of disconnecting the neutral wire by opening the lid. Therefore, it is urgent to solve the technical problems that need to be addressed, such as how to ensure the safe and reliable stopping of the motor drive when the lid is opened, while meeting the new national standard, and how to solve the problems caused by the lid triggering the high-voltage switch to open and close, which results in large hardware space occupation, high overall circuit and component losses, and especially the electric sparks that occur at the moment the switch is opened and closed, affecting the reliability of the control circuit and the service life of key components.

[0041] like Figures 1 to 7 As shown, this utility model provides a food processor with a safe opening mechanism, including a cup assembly 100. The cup assembly 100 includes a cup body 101, a cup lid 102, and a pulverizing blade 103 disposed within the cup body 101. The cup lid 102 covers the cup body 101, and the pulverizing blade 103 is driven by a variable frequency motor 901. It should be noted that the cup lid 102 can directly cover the cup body 101 in a contact manner, or indirectly cover the cup body in a non-contact manner, or multiple lids can be stacked on top of the cup body 101, one of which is the cup lid 102 in this embodiment. In other words, any movable or removable part in the food processor that can safely cover the opening of the cup can be considered as the cup lid 102 in this embodiment. Specifically, as shown... Figure 1 and Figure 2As shown, the food processing machine includes a switch 200, a variable frequency motor drive module 300, a main control module 400, and an energy storage module 500. One end of the switch 200 is electrically connected to the power supply module 800, and the other end is used to simultaneously lead out the first branch L1 and the second branch L2. When the cup lid 102 closes the cup body 101, the switch 200 closes, simultaneously controlling the first branch L1 and the second branch L2 to conduct. When the cup lid 102 opens, the switch 200 closes, simultaneously controlling the first branch L1 and the second branch L2 to disconnect. The variable frequency motor drive module 300 is located on the first branch L1. The power supply module 800 is connected to the power supply terminal of the variable frequency motor drive module 300 through the switch 200. Preferably, the variable frequency motor drive module 300 includes... Six IGBTs are connected via the first branch L1, enabling the power module 800 to supply power to the variable frequency motor drive module 300. When the first branch L1 is disconnected, the power supply to the variable frequency motor drive module 300 is cut off. The main control module 400 is located on the second branch L2. When the second branch L2 is connected, the main control module 400 acquires a first control signal and outputs a drive signal to the variable frequency motor drive module 300. When the second branch L2 is disconnected, the main control module 400 acquires a second control signal and immediately stops outputting drive signals to the variable frequency motor drive module 300. Consequently, the variable frequency motor stops driving the pulverizer 103 to rotate, achieving a safety protection when the lid is open. The control signal is preferably a high-level and a low-level signal. The closing and opening of the cup lid 102 is responded to by the on and off of the switch 200. The I / O port of the main control module 400 used to acquire the control signal switches from the first control signal to the second control signal. The energy storage module 500 is located in the first branch L1. After the switch 200 is turned off, the energy storage module 500 discharges to maintain power supply to the variable frequency motor drive module 300. When the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300, the current supply voltage of the energy storage module 500 to the variable frequency motor drive module 300 is within the normal operating voltage range of the variable frequency motor drive module 300. The variable frequency motor drive module 300 is in the saturation region when in normal driving state, that is, the normal operating voltage range. When it stops working, it is in the cutoff region. It is not allowed to be in the amplification region when in working state, as this region will cause the IGBT of the variable frequency motor drive module 300 to suddenly heat up and explode.

[0042] The energy storage module 500 discharges until it stops supplying power to the variable frequency motor drive module 300, after the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300 to control the brushless motor to stop driving. Thus, after the switch 200 disconnects the first branch L1 and the second branch L2, the main control module 400 preferentially stops outputting drive signals to the variable frequency motor drive module 300 via software control, i.e., a "soft stop". After the switch 200 is disconnected, especially during the "soft stop", the energy storage module 500 has sufficient charge to continue discharging to the power supply terminal of the variable frequency motor drive module 300 and maintain the current supply voltage at the power supply terminal within the normal operating voltage range of the variable frequency motor drive module 300, i.e., operating within the saturation voltage range. After the "soft stop" is safely completed, i.e., after the IGBTs and other power devices in the variable frequency motor drive module 300 safely enter the non-operating state, the power is continuously reduced from the saturation voltage range to the cutoff voltage range. Preferably, the energy storage capacitor has a safety margin, so that after the "soft stop" is safely completed, the power-off voltage is still within the normal operating voltage range, that is, higher than the critical value of the saturation region amplification region, so that both the "soft stop" and "hard power-off" of the dual-branch can be completed safely.

[0043] When the cup lid 102 is opened, the food processing machine triggers the switch 200 to disconnect, and simultaneously controls the first branch L1 and the second branch L2 to disconnect. In terms of timing, the second branch L2 "soft stops" before the first branch L1 "hard cuts off" the variable frequency motor drive module 300. The disconnection action of the same switch 200, through the second branch L2 and the first branch L1, double shuts off the variable frequency motor drive module 300, thereby reliably stopping the variable frequency motor 901 and achieving the purpose of safety protection when the lid is opened. In the second branch L2, the main control module 400 acquires the cover opening control signal and first stops outputting drive signals to the variable frequency motor drive module 300 to control the variable frequency motor drive module to stop driving the variable frequency motor. In the first branch L1, the switch 200 is opened, causing the power module 800 to be disconnected. Instead, the energy storage module 500 discharges to the variable frequency motor drive module 300 to maintain the voltage within the normal operating range, i.e., the saturation voltage range. After the variable frequency motor drive module 300 is softly stopped in the first branch L1, the power supply to the variable frequency motor drive module 300 is disconnected to achieve a hard power-off of the variable frequency motor drive module 300. Through the dual protection mechanism of hard power-off and soft stop, from the perspective of user safety and avoiding mechanical hazards, the cover opening safety requirements in the new national standard can be fully met.

[0044] Specifically, when the cup lid 102 is opened, the switch 200 is disconnected. The switch 200 simultaneously controls the first branch L1 and the second branch L2 to disconnect, which is equivalent to the first branch L1 and the second branch L2 being set in parallel. The two parallel branches are connected in series with the switch 200 so that the switch 200 can simultaneously control the on and off of the first branch L1 and the second branch L2. This achieves the goal of cutting off the power supply from the power module 800 to the variable frequency motor drive module 300 when the cup lid 102 is opened and the switch 200 is triggered to disconnect. The main control module 400 is located in the second branch L2. When the cup lid 102 closes the switch 200, the second branch L2 is turned on. The main control module 400 receives the first control signal of the cup lid 102 closing. The main control module 400 outputs a drive signal to the variable frequency motor drive module 300 to control the variable frequency motor to drive and drive the pulverizer 103 to process the food in the cup. When the cup lid 102 opens the cup mouth, the switch 200 is turned off, the second branch L2 is turned off, and the main control module 400 receives the second control signal of the cup lid 102 opening. Preferably, the I / O port of the main control module 400 is used to obtain the first control signal or the second control signal.

[0045] Such as 2 and Figure 7 As shown, when the closed cup lid 102 is opened, the I / O port of the main control module 400 switches from the first control signal to the second control signal. The main control module 400 immediately stops outputting drive signals to the variable frequency motor drive module 300, so that the variable frequency motor drive module 300 stops driving. At the same time, the switch 200 synchronously disconnects the first branch L1, the power supply of the power module 800 is cut off, and the energy storage module 500 set in the first branch L1 discharges to maintain power supply to the variable frequency motor drive module 300. This ensures that the variable frequency motor drive module 300 can normally turn off the switch tube of the variable frequency motor drive module 300 according to the main control module stopping the output of drive signals during the power supply maintenance period, so that the variable frequency motor actually stops driving under the control of the main control module 400. Furthermore, during the period when the energy storage module 500 loses power and maintains the variable frequency motor drive module 300 within its normal operating voltage range, it is sufficient to prioritize the main control module 400 in terms of time to stop outputting drive signals to the variable frequency motor drive module 300, and to prioritize the control module in terms of time to stop driving the variable frequency motor. At the same time, during the period when the energy storage module 500 maintains its normal operating voltage range, the switching transistor of the variable frequency motor drive module 300 switches from the on state to the off state, and then the energy storage module 500 stops discharging to the variable frequency motor drive module 300.

[0046] In this way, while meeting the safety requirements for opening the lid of the new national standard, the drive of the variable frequency motor drive module 300 is normally shut off based on the working principle of the IGBT of the variable frequency motor drive module 300. This ensures user safety, effectively shutting off the hardware circuit of the variable frequency motor after opening the lid, and also ensures the stable and reliable switching of the control circuit of the entire food processing machine. It effectively avoids the power devices from being damaged by abnormal impacts, thereby extending the service life of the variable frequency motor and control circuit of the food processing machine, and thus extending the service life of the entire food processing machine.

[0047] Because the power supply of the variable frequency motor drive module 300 uses a low-voltage circuit, the mechanical shutdown of the variable frequency motor can be achieved by controlling the disconnection of the low-voltage circuit. This can be achieved by using a low-voltage switch 200 in conjunction with the cup lid 102 to turn the switch 200 on and off. This results in a small hardware structure for the cup lid 102 trigger switch 200, where the low-voltage leads are sufficient for electrical signal transmission. This minimizes the space occupied by the hardware switch 200 and reduces the cost of hardware circuit connections. Even when upgrading the opening safety of an existing food processing machine that uses the main control module 400 to soft-stop the variable frequency motor when the cup lid 102 is opened to meet the new national standard for opening safety, no major modifications to the hardware structure are required. Only the drive board of the food processing machine needs to be upgraded. This further saves significant R&D time and product improvement costs associated with meeting the new national standard for opening safety upgrades.

[0048] like Figure 3 and Figure 5As shown, the supply voltage of the variable frequency motor drive module 300 is higher than the voltage of the control signal. The power supply module 800 is connected to the first branch L1 and the second branch L2 via the switch 200, directly supplying power to the variable frequency motor drive module 300, and converting it into a control signal for the main control module 400 via the level conversion module 700. Specifically, the power supply module 800 is connected to the first branch L1 and the second branch L2 via the switch 200, which means that the voltage connected to the second branch L2 is also the supply voltage required by the variable frequency motor drive module 300, preferably a typical value of 15V. The I / O port of the main control module 400 used to receive the control signal is generally a standardized 5V interface. Therefore, a level conversion module 700 is also provided on the second branch L2. The power supply module 800 converts the voltage of the cup lid 102 closing into the main control module 400 via the level conversion module 700 on the second branch L2. In this embodiment, the first control signal and the second control signal for opening the lid 102 are preferably both high-level signals. The high-level signal is maintained when the lid is closed, while the second control signal is low-level and switches to low-level when the lid is open. The main control module uses its I / O port for receiving control signals to identify and switch signals, thereby quickly and accurately detecting the lid 102's position relative to the cup body's opening. This allows for a rapid response when the lid 102 is opened, and a dual shutdown mechanism of soft stop and hard power-off ensures reliable stopping of the variable frequency motor. It is understood that with reasonable circuit improvements, the first control signal can also be low-level, and the second control signal high-level, meaning the low-level signal is maintained when the lid is closed and switches to high-level when the lid is open.

[0049] like Figure 5 As shown, in this preferred embodiment, the energy storage module 500 includes a first capacitor C1. A first diode D1 is connected between the switch 200 and the first capacitor C1. The positive terminal of the first diode D1 is connected to the switch 200, and the negative terminal of the first diode D1 is connected to the positive terminal of the first capacitor C1 and the power supply terminal of the variable frequency motor drive module 300. The positive terminal of the first capacitor C1 is connected to both the negative terminal of the first diode D1 and the power supply terminal of the variable frequency motor drive module 300. The negative terminal of the first capacitor C1 is grounded. When the switch 200 is open, the voltage at the positive terminal of the first diode D1 is less than the voltage at the negative terminal, and the first diode D1 is in the off state.

[0050] In another implementation, such as Figures 4 to 6As shown, a passive energy storage module 600 can also be provided. This module is primarily used for voltage regulation and filtering of the first control signal from the main control module 400. However, after the switch 200 is opened, the passive energy storage module 600 requires a power-down process, which to some extent affects the main control module 400's response to receiving the second control signal. Therefore, as another preferred embodiment, the passive energy storage module 600 is located in the second branch L2, and the first resistor R1 is connected in parallel with the passive energy storage module 600 to accelerate its discharge. When the second branch L2 is open, it accelerates the main control module 400's acquisition of the second control signal. When the cup lid 102 is opened and the switch 200 is opened, the I / O port of the main control module 400 switches from a high-level signal to a low-level signal. The main control module quickly responds to the lid-opening control signal and immediately stops outputting drive signals to the variable frequency motor drive module 300. Preferably, the passive energy storage module 600 includes a second capacitor C2, and the capacitance value of the first capacitor C1 is greater than the capacitance value of the second capacitor C2. The capacitance value of the first capacitor C1 is EC1, and preferably the capacitance value of the second capacitor C2 is EC2, where EC1 ≥ 10 * EC2. When EC2 is de-energized, the variable frequency motor drive module soft-stops through the second branch. During the soft-stop cycle, the energy storage module 600 continuously discharges and maintains a voltage range within which the variable frequency motor drive module operates normally, i.e., within the saturation region. After the soft-stop is completed, i.e., the variable frequency motor drive module stops driving the variable frequency motor, the energy storage module 600 continues to de-energize and eventually reaches the cutoff voltage. The second branch L2 also includes a second diode D2, which is electrically connected between the switch 200 and the passive energy storage module 600. Specifically, the positive terminal of the second diode D2 is connected to the switch 200, and the negative terminal of the second diode D2 is connected to the positive terminal of the second capacitor C2 and the first resistor. When the switch 200 is open, the second diode D2 is in the cutoff state.

[0051] Preferably, the second branch L2 is equipped with the passive energy storage module 600 and the level conversion module 700. The passive energy storage module 600 is electrically connected between the switch 200 and the level conversion module 700. Preferably, the level conversion module 700 is used to convert the 15V voltage of the power supply module 800 into the 5V voltage of the main control module I / O port. Figure 5As shown, the level conversion module 700 includes a transient voltage suppression diode D3, an N-type transistor Q1, a P-type transistor Q2, a second resistor R2, a third resistor R3, and a fourth resistor R4. The cathode of the transient voltage suppression diode D3 is connected to the second branch L2, and the anode of the transient voltage suppression diode D3 is connected to the base of the N-type transistor Q1 through the second resistor R2. The base of the N-type transistor Q1 is also grounded through the third resistor R3. The emitter of the N-type transistor Q1 is grounded, and the collector of the N-type transistor Q1 is coupled to the base of the P-type transistor Q2 (a resistor can be provided between them). The emitter of the P-type transistor Q2 is connected to the first voltage terminal VCC, and the collector is coupled to the detection terminal I / O of the main control module 400 (a resistor can be provided between the collector and the detection terminal). The collector of the P-type transistor Q2 is also grounded through the fourth resistor R4. A fifth resistor is provided between the collector of the P-type transistor Q2 and the I / O port of the main control module 400. One end of the fifth resistor is connected to the collector of the P-type transistor, and the other end is grounded through a third capacitor.

[0052] Specifically, such as Figures 2 to 7As shown, this embodiment optimizes the circuit of the food processor and provides a preferred cup lid 102 opening and closing protection circuit for the food processor. Specifically, it includes a power module 800, a switch 200, a level conversion module 700, a variable frequency motor drive module 300, and a main control module 400. The main control module 400 outputs a drive signal to the variable frequency motor drive module 300. The switch 200 is configured to connect the power supply terminal VCC of the power module 800 and the input terminal of the level conversion module 700 when the cup lid 102 is closed, and disconnect the power supply terminal VCC of the power module 800 and the input terminal K of the level conversion module 700 when the cup lid 102 is open. The level conversion module 700 is configured to respond to the voltage signal at its input terminal K by outputting a detection level signal to the detection terminal I / O of the main control module 400 when the lid 102 is opened. This causes the main control module 400 to stop outputting drive signals to the variable frequency motor drive module 300, thereby stopping the variable frequency motor. When the lid 102 is opened, the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300 earlier than the de-energization time of the power supply terminal VCC of the variable frequency motor drive module 300. Furthermore, when the main control module 400 stops outputting drive signals, the voltage at the power supply terminal VCC of the variable frequency motor drive module 300 is within the normal operating voltage range of the variable frequency motor drive module 300. It should be noted that the "normal operating voltage range" refers to a voltage interval within which the power devices (e.g., IGBTs or MOSFETs) of the variable frequency motor drive module 300 can operate stably and reliably without entering dangerous half-voltage or amplification states. From the broadest perspective, the lower limit of this range is the critical point at which a power device transitions from the saturation region to the amplification region. As long as the voltage does not fall below this critical point, the power device can operate normally. This critical point is the minimum safe voltage to prevent damage to the device. To improve system stability and reliability, a safer "preferred range" is usually chosen. This range lies above the lower critical point, ensuring that the power device operates efficiently and safely under any operating conditions. Understandably, when a food processing machine directly uses a manufacturer-specific model of variable frequency motor drive module to drive a variable frequency motor, the "normal operating voltage range" is generally marked in the manufacturer's instruction manual. As mentioned earlier, the control power supply voltage Vcc of the variable frequency motor drive module is marked in the instruction manual as a typical value of 15V, a minimum value of 13.5V, and a maximum value of 16.5V. Therefore, the "normal operating voltage range" of the variable frequency motor drive module can be understood to be between 13.5V and 16.5V.

[0053] In the cup lid 102 opening and closing protection circuit of the food processor, when the cup lid 102 is opened, the motor can be stopped by two independent mechanisms (soft stop and hard power cut-off), instead of relying solely on a single high-voltage switch 200, as detailed below: At the soft-stop level, this disclosure introduces a level conversion module 700, which sends a detection level signal to the main control module 400 when the cup lid 102 is opened, triggering a "soft stop". Upon receiving the aforementioned detection level signal indicating the cup lid 102 is open, i.e., the second control signal, the main control module 400 immediately stops outputting drive signals to the variable frequency motor drive module 300, effectively transmitting a stop command to the variable frequency motor, causing it to stop rotating. The moment the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300 is earlier than the moment the power supply terminal VCC of the variable frequency motor drive module 300 is de-energized. Therefore, during the "soft stop" process, the power supply terminal VCC of the variable frequency motor drive module 300 is not de-energized; that is, the software-controlled stop process occurs before the physical power de-energization of the variable frequency motor drive module 300. Furthermore, when the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300, the voltage at the power supply terminal of the variable frequency motor drive module 300 remains within its normal operating voltage range. This ensures that the power supply voltage of the variable frequency motor drive module 300 remains in the saturation region when the main control module 400 stops outputting drive signals, preventing damage to power devices due to voltage drops below the critical point. This achieves safe motor shutdown while protecting core components. The power supply to the variable frequency motor drive module 300 is gradually disconnected only after the main control module 400 stops outputting drive signals, providing valuable buffer time for power devices such as IGBTs. This allows the IGBTs to safely complete the transition from the on to the off state with sufficient power support, without entering the dangerous amplification region or half-voltage state due to a sudden voltage drop. Therefore, voltage drops will not impact power devices such as IGBTs, solving the problem of potential IGBT damage or module burnout caused by directly disconnecting the +15V power supply to the variable frequency motor drive module 300 in existing technologies.

[0054] At the level of physical power cut-off, the food processing machine directly disconnects the power supply terminals of the power module 800 and the variable frequency motor drive module 300 when the cup lid 102 is opened via the switch 200, thus achieving the cut-off of high voltage without relying on software control. This fundamentally eliminates the risk of the variable frequency motor failing to stop due to software failure, thereby meeting the requirements of the new national standard.

[0055] In summary, the food processor employs both soft-stop and hard-shutdown mechanisms upon lid opening, with the physical switch 200 ultimately cutting off the high-voltage power, ensuring the safety requirements of the new national standards. Simultaneously, the timing design of soft-stop followed by hard-shutdown completely eliminates the risk of IGBT tube explosion and module burnout, guaranteeing long-term product reliability and significantly improving the food processor's lifespan and stability. Furthermore, the food processor integrates both soft-stop and hard-shutdown mechanisms; even if the software control malfunctions under extreme conditions, the hardware switch 200 can still disconnect the power supply, providing a solid safety barrier. This also avoids the risk of the motor failing to stop due to software malfunctions when using a low-voltage switch 200 (such as a reed switch or Hall effect sensor) alone.

[0056] In an optional embodiment of this example, the protection circuit includes an energy storage module 500. When the cup lid 102 is opened, the energy storage module 500 discharges to supply power to the power supply terminal of the variable frequency motor drive module 300. The function of the energy storage module 500 is to provide a brief, continuous power supply to the variable frequency motor drive module 300 after the switch 200 is opened, thereby achieving delayed shutdown. In practical applications, when the cup lid 102 is opened, the switch 200 begins to open due to a physical or electromagnetic mechanism (e.g., the separation of a magnet from a reed switch). The switch 200 immediately sends a signal to the level conversion module 700, informing it that the cup lid 102 has been opened. The level conversion module 700 quickly transmits this signal to the main control module 400. Upon receiving the signal, the main control module 400 immediately stops outputting drive signals to the variable frequency motor drive module 300. At this time, the variable frequency motor begins to enter a soft-stop state. The energy storage module 500 begins to discharge at the instant the switch 200 is opened. This discharge process provides a brief power supply to the variable frequency motor drive module 300, ensuring that after the main control module 400 stops the drive signal, the variable frequency motor drive module 300 still has sufficient power to complete its internal shutdown process, thus achieving delayed mechanical shutdown. The discharge characteristics of the energy storage module 500 determine that the voltage will not drop sharply like the instantaneous disconnection of switch 200. It provides a brief, stable voltage drop process. This stable voltage drop provides valuable buffer time for power devices such as IGBTs. During this short period, the power supply voltage of the variable frequency motor drive module 300 remains within the normal operating range, allowing the IGBT devices to safely complete the transition from the on state to the off state with sufficient power support, without entering the dangerous amplification region or half-voltage state due to a sudden voltage drop. Only when the energy storage module 500 is depleted will the power supply to the variable frequency motor drive module 300 be completely cut off. At this time, the motor has completely stopped driving, and the power devices such as IGBTs are in a safe state and will not be damaged by the voltage drop. This disclosure introduces an energy storage module 500 to ensure that the power supply voltage of the variable frequency motor drive module 300 remains in the saturation region when the main control module 400 stops the drive signal, thereby avoiding damage to power devices due to voltage drops below the critical point. This achieves the protection of core components while safely stopping the motor.

[0057] In an optional embodiment, the energy storage module 500 discharges until it stops supplying power to the variable frequency motor drive module 300, after the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300 to control the variable frequency motor to stop driving. That is, after the cup lid 102 is opened, the main control module 400 immediately stops outputting drive signals to the variable frequency motor drive module 300. This is equivalent to issuing a "soft stop" command to the motor. During this stage, the variable frequency motor drive module 300 still has power to ensure that power devices such as IGBTs can safely enter a non-operating state. After the main control module 400 stops sending drive signals, the energy storage module 500 begins to discharge. Its function is to briefly provide power to the variable frequency motor drive module 300 after the physical switch 200 is opened. This power supply process ensures that the power supply voltage does not drop to a dangerous area instantly, providing the necessary buffer time for the internal shutdown process of the drive module. Only when the energy storage module 500 is exhausted and can no longer maintain power supply will the power supply to the variable frequency motor drive module 300 be completely cut off. At this point, since the motor has stopped driving, power devices such as IGBTs are in a safe state, and the final voltage drop will not cause any damage to the devices.

[0058] In an optional embodiment, the output terminal of the power module 800 is electrically connected to the switch 200; the switch 200 is coupled to the power terminal VCC of the variable frequency motor drive module 300 and the energy storage module 500 through the first branch L1, and to the input terminal of the level conversion module 700 through the second branch L2; the switch 200 is used to disconnect the power module 800 from the first branch L1 and the second branch L2 when the cup lid 102 is opened, and to connect the power module 800 from the first branch L1 and the second branch L2 when the cup lid 102 is closed.

[0059] The switch 200 acts as the "master gate" of the circuit, controlling two different branches to power on and off the variable frequency motor drive module 300 and the level conversion module 700. When switch 200 is on, the power module 800 can supply power to the power supply terminal of the variable frequency motor drive module 300 and the energy storage module 500 through the first branch L1. This allows the variable frequency motor drive module 300 to operate normally, while the energy storage module 500 is charged and kept fully charged, preparing for subsequent power outage buffering. The power module 800 can provide a signal to the input terminal of the level conversion module 700 through the second branch L2. This signal indicates that the lid 102 is closed, and the main control module 400 can normally output a drive signal to the variable frequency motor drive module 300. When switch 200 is off, it immediately disconnects the power module 800 from the two branches: after switch 200 is off, the connection between the power module 800 and the variable frequency motor drive module 300 and the energy storage module 500 is cut off. At this time, the energy storage module 500 begins to discharge, continuing to provide a brief power supply to the variable frequency motor drive module 300 to achieve a "soft stop" buffer effect. This design ensures that when the cup lid 102 is opened, the main control module 400 can receive the signal and stop driving immediately, while the energy storage module 500 takes over the power supply, providing the buffer time required for the safe shutdown of the variable frequency motor drive module 300.

[0060] In an optional embodiment, the positive terminal of the energy storage module 500 is connected to the first branch L1 and the power supply terminal VCC of the variable frequency motor drive module 300; the protection circuit also includes a passive energy storage module 600, the positive terminal of which is connected to the second branch L2 and the input terminal of the level conversion module 700; the negative terminals of both the energy storage module 500 and the passive energy storage module 600 are grounded. The capacity of the energy storage module 500 is greater than the capacity of the passive energy storage module 600. Optionally, both the energy storage module 500 and the passive energy storage module 600 are electrolytic capacitors; for example, the energy storage module 500 is represented by a first electrolytic capacitor EC1, and the passive energy storage module 600 is represented by a second electrolytic capacitor EC2.

[0061] After switch 200 is opened, energy storage module 500 provides continuous power to variable frequency motor drive module 300. Since variable frequency motor drive module 300 requires a certain amount of energy during the turn-off process to maintain the safe state of power devices such as IGBTs, the capacity of energy storage module 500 is designed to be larger to ensure sufficient energy to complete the "soft stop" process. After switch 200 is opened, passive energy storage module 600 provides a cleaner and more stable DC power supply to level conversion module 700, and can also provide short-term power to level conversion module 700 to ensure its accuracy and reliability when detecting signals. The main function of this module is to ensure that level conversion module 700 has sufficient power to send the final turn-off signal to main control module 400 at the moment switch 200 is opened. Because level conversion module 700 itself has very low power consumption, it requires far less energy than the motor drive module; therefore, the capacity of passive energy storage module 600 can be designed to be smaller.

[0062] In this embodiment, the discharge time of the energy storage module 500 and the passive energy storage module 600 can be precisely controlled by the capacity difference between them. The passive energy storage module 600, with its smaller capacity, discharges rapidly, ensuring that the main control module 400 receives the shutdown signal immediately. The energy storage module 500, with its larger capacity, provides a longer buffer time, ensuring that the variable frequency motor drive module 300 has sufficient power to safely shut down. This allows for the reasonable allocation of the energy storage module 500's capacity based on the actual power consumption requirements of different modules. This ensures the reliability of critical functions (such as the safe shutdown of the variable frequency motor) while avoiding unnecessary cost waste. The dual-power supply design decouples the signal transmission and motor power supply buffer functions, resulting in higher system stability when dealing with the instantaneous disconnection of switch 200.

[0063] Furthermore, considering that there is typically some ripple voltage and high-frequency noise at the output of the power module 800, the passive energy storage module 600, connected to the input of the level conversion module 700, acts as a filter, absorbing these voltage fluctuations and noise. This provides the level conversion module 700 with a cleaner and more stable DC power supply, ensuring its accuracy and reliability when detecting signals. When the power supply voltage experiences a momentary drop for some reason, the passive energy storage module 600 will discharge to maintain voltage stability, preventing the level conversion module 700 from malfunctioning or failing due to insufficient power supply.

[0064] In this optional embodiment, the capacity of the energy storage module 500 is EC1, and the capacity of the passive energy storage module 600 is EC2, where EC1 ≥ 10 * EC2. The main task of the energy storage module 500 is to provide a shutdown buffer for the variable frequency motor drive module 300. After the motor stops driving, the variable frequency motor drive module 300 still needs to maintain power supply for a period of time to ensure that the power devices (such as IGBTs) can safely complete the internal shutdown process. Since the power of the variable frequency motor drive module 300 is relatively large, it requires more energy, so the capacity of the energy storage module 500 needs to be large enough. The main task of the passive energy storage module 600 is to filter and provide signal transmission buffer for the level conversion module 700. The power consumption of the level conversion module 700 is very small; it only needs to provide power for a very short time at the moment the switch 200 is opened to ensure that the shutdown signal can be received by the main control module 400. Therefore, the capacity of the passive energy storage module 600 can be very small. Preferably, the energy required by the energy storage module 500 is at least ten times that required by the passive energy storage module 600. This precise capacity design ensures that the timeliness of signal transmission and the safety of power shutdown are simultaneously met throughout the entire safety protection process. The significant capacity difference achieves perfect timing for "fast signal transmission" and "slow power disconnection." The passive energy storage module 600 discharges rapidly, ensuring that the main control module 400 receives the signal immediately; the energy storage module 500 discharges slowly, ensuring that the drive module has sufficient time to safely shut down. This precise capacity design avoids unnecessary waste. There is no need to configure a large-capacity capacitor for the low-power level conversion module 700, thus saving cost and PCB space. This quantitative design ensures that the shutdown signal and drive module shutdown process can be reliably completed even under different external environments, further improving the stability and safety of the entire circuit.

[0065] For example, C1 = 470 μF and C2 = 4.7 μF. However, this disclosure is not limited thereto.

[0066] In an optional embodiment, the protection circuit further includes a first resistor R1 connected in parallel with the passive energy storage module 600. When the cup lid 102 is opened and the switch 200 is turned off, the charging of the passive energy storage module 600 by the power module 800 is cut off. At this time, the passive energy storage module 600 will discharge rapidly through this parallel resistor. The discharge time of the capacitor is determined by its capacity and the resistance in the circuit. By connecting a resistor with an appropriate resistance value in parallel, the discharge speed of the passive energy storage module 600 can be precisely controlled. This ensures that at the moment the switch 200 is turned off, the passive energy storage module 600 can quickly release the stored electrical energy to the level conversion module 700, enabling it to immediately send a shutdown signal to the main control module 400, thereby ensuring the rapid triggering of the shutdown signal and achieving a more timely "soft stop" of the motor. This disclosure further enhances the reliability of the entire safety protection circuit by connecting a resistor in parallel with the passive energy storage module 600. It ensures that the opening action can be converted into an electrical signal as quickly as possible and transmitted to the main control module 400, so that the core step of "the main control module 400 stops outputting drive signals to the variable frequency motor drive module 300" can be completed as early as possible before the actual power is cut off, providing more sufficient safety buffer time for the motor and power devices.

[0067] In an optional embodiment of this invention, the protection circuit further includes a first diode D1 and a second diode D2; the anode of the first diode D1 is connected to the first branch L1, and the cathode of the first diode D1 is connected to the anode of the energy storage module 500 and the power supply terminal VCC of the variable frequency motor drive module 300; the anode of the second diode D2 is connected to the second branch L2, and the cathode of the second diode D2 is connected to the anode of the passive energy storage module 600 and the input terminal K of the level conversion module 700.

[0068] The first diode D1 and the second diode D2 primarily function as unidirectional conductors, ensuring that current can only flow from the power module 800 to the energy storage module 500 and not in the reverse direction. When the lid 102 is closed, current can flow from the power module 800 through the first branch L1 and the first diode D1 to charge the energy storage module 500 and power the motor drive module. When the lid 102 is open and the switch 200 is off, the power supply to the power module 800 is cut off. At this time, the unidirectional conduction characteristic of the first diode D1 prevents current from flowing back from the energy storage module 500 to the switch 200, ensuring that all the electrical energy in the energy storage module 500 is used to provide buffer power to the variable frequency motor drive module 300, achieving efficient energy utilization. Similarly, the second diode D2 ensures that current can only flow from the power module 800 to the passive energy storage module 600 and the level conversion module 700. When switch 200 is turned off, it prevents current from flowing back, ensuring that passive energy storage module 600 can stably discharge to level conversion module 700 through its parallel resistor to provide a timely shutdown signal.

[0069] The unidirectional conduction characteristic of the two diodes effectively prevents the charge of the energy storage module 500 from flowing back to the power module 800 or the first branch L1 and the second branch L2 after the switch 200 is turned off, thus avoiding energy loss. This design isolates the power module 800 from the energy storage module 500 and its downstream circuits. This not only protects the power module 800 itself but also allows the energy storage module 500 to discharge more stably and controllably.

[0070] In an optional embodiment, the level conversion module 700 includes a transient voltage suppression diode D3, an N-type transistor Q1, a P-type transistor Q2, a second resistor R2, a third resistor R3, and a fourth resistor R4. The cathode of the transient voltage suppression diode D3 is connected to the second branch L2, and the anode of the transient voltage suppression diode D3 is connected to the base of the N-type transistor Q1 through the second resistor R2. The base of the N-type transistor Q1 is also grounded through the third resistor R3. The emitter of the N-type transistor Q1 is grounded, and the collector of the N-type transistor Q1 is coupled to the base of the P-type transistor Q2 (a resistor may be provided between them). The emitter of the P-type transistor Q2 is connected to the first voltage terminal VCC, and the collector is coupled to the detection terminal I / O of the main control module 400 (a resistor may be provided between the collector and the detection terminal). The collector of the P-type transistor Q2 is also grounded through the fourth resistor R4.

[0071] A transient voltage suppressor diode D3, also known as a TVS diode, is introduced. The cathode of this TVS diode is connected to the second branch L2, and the anode is connected to the base of the N-type transistor Q1. When an abnormally high transient voltage (such as static electricity or a surge) occurs on the second branch L2, the TVS diode will quickly conduct, clamping the high voltage to a safe level, thereby protecting the downstream N-type transistor Q1 and the entire circuit from damage.

[0072] With the lid 102 closed, switch 200 is on. The 15V voltage from switch 200 is supplied to the power supply terminal of the variable frequency motor drive module 300 through the first branch L1, and to the TVS diode through the second branch L2. When the voltage across the TVS diode is higher than its breakdown voltage, the diode is in a breakdown state; when the voltage across the TVS diode is lower than its breakdown voltage, the diode is in an open circuit state. When switch 200 is on, the voltage drop between the anode and cathode of the TVS diode is 15V. Ideally, the TVS diode should be in a breakdown state; therefore, its breakdown voltage is lower than 15V. When the TVS diode breaks down, the voltage at the anode of the TVS diode provides current to the base of the N-type transistor Q1 through the second resistor R2. The N-type transistor Q1 conducts, and its collector becomes low. This low level pulls down the base of the P-type transistor Q2, causing Q2 to conduct. At this time, the collector of the P-type transistor Q2 (connected to the detection terminal of the main control module 400) is pulled up to the voltage of the first voltage terminal (high level in this example), and outputs a normal state signal, i.e., a high level signal, to the main control module 400.

[0073] With the lid 102 open, switch 200 is disconnected, the second branch L2 is de-energized, and the current to the base of N-type transistor Q1 is cut off. The third resistor R3 pulls the base potential down to ground, causing N-type transistor Q1 to turn off. The collector voltage of the N-type transistor increases, which in turn increases the base voltage of P-type transistor Q2, causing P-type transistor Q2 to turn off. At this time, the collector of P-type transistor Q2 is grounded through the fourth resistor R4, outputting a low-level detection signal to the main control module 400.

[0074] In the level conversion module 700, the TVS diode provides robust transient voltage protection, enhancing the circuit's reliability in complex electromagnetic environments. The switching of two transistors ensures that the detection signal output to the main control module 400 is a clear high or low level, avoiding unstable intermediate voltage states and ensuring accurate judgment by the main control module 400. Under normal operating conditions, the current in the circuit, through precise resistor design, can be kept at a low level, thereby reducing the overall power consumption of the module.

[0075] Optionally, the resistance of the second resistor R2 is A2, and the resistance of the third resistor R3 is A3, where A3 ≥ P * A2, and P ≥ 5. In this embodiment, the second resistor R2 is located between the TVS diode and the base of the N-type transistor, and its function is to limit current. When the second branch L2 is energized, the second resistor R2 limits the current flowing to the base of the N-type transistor, preventing excessive base current from damaging the transistor. The third resistor R3 is connected between the base of the N-type transistor and ground, and its function is to act as a pull-down resistor. When the second branch L2 is de-energized, the third resistor R3 quickly pulls the base voltage of the transistor down to ground level, ensuring that the N-type transistor is reliably cut off. This disclosure sets A3 ≥ P * A2, P ≥ 5, meaning that the resistance value A3 of the pull-down resistor (third resistor R3) is much larger than the resistance value A2 of the current-limiting resistor (second resistor R2). When the second branch L2 is de-energized, the resistance of the third resistor R3 is large enough to quickly pull the base voltage of the N-type transistor down to zero, thus completely cutting it off. This ensures that the base voltage of the P-type transistor Q2 can reliably rise, thereby cutting off Q2 and ultimately outputting a low-level signal. The large resistance of the third resistor R3, in conjunction with the collector resistor of the N-type transistor Q1, enables rapid signal level switching. When the N-type transistor Q1 is conducting, the current flowing through the second resistor R2 and the third resistor R3 can be precisely controlled at a low level, thereby reducing the static power consumption of the entire level conversion module 700.

[0076] Optionally, the reverse breakdown voltage of the transient voltage suppression diode D3 is U1, 10V≤U1≤14V, and the output voltage of the power module 800 is 15V.

[0077] In this embodiment, the output voltage of the power module 800 is 15V, which is higher than the reverse breakdown voltage (U1) of the TVS diode. This means that under normal operating conditions, the TVS diode is in the reverse cutoff state. At this time, the current can flow normally through the second resistor R2 to the base of the N-type transistor Q1, enabling the level conversion module 700 to operate normally. When a transient high voltage (such as electrostatic discharge or surge) higher than 15V occurs in the second branch L2, the TVS diode will quickly enter the reverse breakdown state. Since its breakdown voltage U1 (10V-14V) is lower than the 15V of the power module 800, the TVS diode will clamp the voltage within a safe range. This effectively prevents high-voltage pulses from damaging sensitive components such as the downstream N-type transistor Q1. This parameter configuration perfectly balances the normal function and protection function of the circuit. Under normal conditions, the TVS diode does not affect signal transmission; while in case of an abnormality, it can quickly activate protection to ensure the reliability of the level conversion module 700. This design further improves the stability and durability of the entire safety protection circuit in harsh electromagnetic environments.

[0078] When the voltage across a TVS diode is higher than its breakdown voltage, the TVS diode is in a breakdown state; when the voltage across it is lower than its breakdown voltage, it is in an open-circuit state. Based on this characteristic, when switch 200 is turned on, the voltage drop across the anode and cathode of the TVS diode is 15V. At this point, it is desirable for the TVS diode to be in a breakdown state. Therefore, the recommended reverse breakdown voltage for the TVS diode can be lower than 14V. However, to allow for a certain soft-stop time, a breakdown voltage above 10V is desirable. This is because when a high-power switching transistor turns on below 8V, it will not be able to turn on effectively, causing most of the energy to accumulate in the PN junction, leading to heat generation and ultimately device damage. Therefore, the reverse breakdown voltage of the TVS diode is between 10V and 14V, and 12V can be selected specifically. Please refer to [reference needed]. Figure 5 , Figure 5 This is a timing diagram showing the voltage changes of the first electrolytic capacitor EC1, the second electrolytic capacitor EC2, and the input terminals of the variable frequency motor drive module 300 when switch 200 changes from on to off. When switch 200 changes from on to off, the voltage across the second electrolytic capacitor EC2 drops from 15V. Between 15V and 12V, the TVS diode is in the on state. At this time, the voltage is divided by the second resistor R2 and the fourth resistor R4, providing voltage to the base of the N-type transistor Q1. Generally, when the resistance of the third resistor R3 is greater than five times the resistance of the second resistor R2, the N-type transistor Q1 is in a saturated state, and the collector of the N-type transistor Q1 is in a low-level state. This low level pulls down the base of the P-type transistor Q2, turning on the P-type transistor Q2. At this time, the collector of P-type transistor Q2 (connected to the detection terminal of the main control module 400) is pulled high to the voltage of the first voltage terminal VCC (high level in this embodiment), outputting a normal state signal to the main control module 400, that is, the level of the detection terminal I / O of the main control module 400 is a high-level detection signal. When the voltage on EC2 continues to drop from 12V, the TVS transistor is in the off state. At this time, the voltage divider between the second resistor R2 and the third resistor R3 provides 0V to the base of the transistor, which can make the N-type transistor Q1 in the off state. The collector voltage of the N-type transistor increases, which will increase the base voltage of the P-type transistor, causing the P-type transistor Q2 to be cut off. At this time, the collector of P-type transistor Q2 is grounded through the fourth resistor R4, outputting a low-level detection signal to the main control module 400, and the level of the detection terminal I / O of the main control module 400 is a low-level detection signal. Thus, through the above circuit, the final feedback is that when switch 200 is turned on, the detection terminal I / O of the main control module 400 is at a high level; when switch 200 is turned off, the detection terminal I / O of the main control module 400 is at a low level. Therefore, through the above circuit, the 15V switching of the power supply module 800 is converted into a 5V level change, which is then provided to the main control module 400 for detection.

[0079] In an optional embodiment, the switch 200 includes a first switch 200S1, which is a low-voltage switch 200, such as a reed switch or a Hall element. Traditional low-voltage switch 200 solutions typically rely on software to detect state changes and control the motor. If the software malfunctions, the motor may fail to stop, posing a serious safety hazard and thus failing to meet the stringent requirements of the new national standard. While this disclosure also uses a low-voltage switch 200, its function is drastically different from traditional solutions. In this embodiment, the low-voltage switch 200 (first switch 200S1) not only acts as a signal trigger but also directly as a physical switch 200 to disconnect the power supply. When the cup lid 102 is opened, the low-voltage switch 200 (such as a reed switch) immediately disconnects. After the low-voltage switch 200 disconnects, the power supply to the power module 800 is cut off. At this time, the energy storage module 500 begins to discharge, continuing to supply power to the motor drive module. During this brief power supply buffer period, the main control module 400 receives the lid-opening signal and immediately stops outputting drive signals, causing the variable frequency motor to enter a safe shutdown state. The power supply to the variable frequency motor drive module 300 is completely cut off only after the energy storage module 500 has finished discharging. This design relies entirely on the cooperation of the low-voltage switch 200 and the energy storage module 500, eliminating the need for an additional bulky and costly high-voltage switch 200, greatly simplifying the product's structural design and reducing manufacturing costs. Furthermore, the low-voltage switch 200 is compact and easily integrated into the product's compact structure. Although a low-voltage switch 200 is used in this disclosure, it still achieves a "soft stop first, hard disconnect" safety sequence through the buffering effect of the energy storage module 500, effectively protecting critical power devices such as IGBTs and complying with the requirements of the new national standard. Optionally, the first switch 200S1 in this disclosure is a 15V low-voltage switch 200, and the current on the switch 200 is very small, less than 0.1A, effectively meeting the requirements for small-size installation.

[0080] In this preferred embodiment, the food processing machine includes a main unit 900 and a cup assembly 100. The cup assembly 100 is detachably connected to the main unit 900. The variable frequency motor 901 is disposed inside the main unit and transmits torque through a contact or non-contact transmission structure.

[0081] Understandably, the food processing machine can also be an integrated structure of a variable frequency cup machine. The cup body assembly 100 includes a cup body 101 and a cup base located below the cup body. The variable frequency motor is located inside the cup base. The upper end of the rotor shaft of the variable frequency motor is connected to the crushing blade 103, and the crushing blade 103 is directly driven to rotate through the shaft of the variable frequency motor. The cup lid 102 is provided with a trigger part, and the cup lid 102 conducts or disconnects the switch 200 through the trigger part.

[0082] Understandably, the food processing machine can also be a single, non-detachable structure where the cup body and the main unit are integrated, with the variable frequency motor installed below the cup body.

[0083] Understandably, the food processing machine can also be a hands-free blender. The cup body includes a lid 102, which triggers the switch 200 inside the main unit to turn on or off. Alternatively, the main unit can be located in a receiving cavity and an installation port that accommodate the cup body assembly 100. The cup body assembly 100 is inserted into the receiving cavity through the installation port, and an outer lid is hinged to one side of the installation port. The cup body assembly 100 can also include a cup body and an inner lid that fits onto the cup body's opening. The outer lid is equivalent to the lid 102, and the switch 200 is triggered by the outer lid's triggering part.

[0084] Understandably, the food processing machine may also have other structural forms in which the cup lid 102 is movable or removable.

[0085] Understandably, the location of the switch is not limited; it can be placed on the cup body, the main unit, or other locations. The cup lid can directly trigger the switch, or it can be triggered indirectly through a linkage or other structure or medium.

[0086] It is understandable that the switch 200 can be turned off without simultaneously connecting the first branch L1 and the second branch L2, or simultaneously disconnecting the first branch L1 and the second branch L2. Preferably, when the cup lid 102 is opened and the switch 200 is turned off, the switch 200 disconnects the second branch L2 first, and then disconnects the first branch L1. Disconnecting the second branch L2 first allows the main control module 400 to immediately stop outputting drive signals to the variable frequency motor drive module 300 based on the lid opening level signal of the I / O port, thereby giving priority to controlling the soft stop of the variable frequency motor drive module 300 in terms of timing. After the switch 200 disconnects the second branch L2, the energy storage module 500 supplies power to the power supply terminal of the variable frequency motor drive module 300 to maintain it within the normal operating voltage range until the soft stop is completed, after which the energy storage module 500 continues to be powered off. This is equivalent to further optimizing the timing of soft stop and hard power-off. When the cup lid is opened, switch 200 first disconnects the second branch L2, then disconnects the first branch L1. The energy storage module 500 discharges, temporarily maintaining power supply to the power supply terminal of the variable frequency motor drive module and delaying power-off relative to the second branch L2. This allows the main control module 400 to enjoy dual priority timing, prioritizing a safe soft stop, followed by a reliable hard power-off of the first branch L1, thus fully ensuring user safety. The switch 200 can also be configured as a single-pole double-throw switch with trigger timing priority, or the switch can include a main switch and multiple sub-switches with timing characteristics that are linked to the main switch, thereby achieving different disconnection sequences.

[0087] Of course, the switch 200 can also be a conventional single-pole double-throw switch. The switch 200 can be activated to simultaneously turn on or simultaneously turn off the first branch L1 and the second branch L2. In this way, the power module 800 can supply power to the first branch L1 and the second branch L2 simultaneously with the same power module, or it can supply power to different power modules. For example, the first power module supplies power to the first branch L1 and the second power module supplies power to the second branch L2. The advantage is that different power modules can be configured to provide different power supply voltages, thereby more quickly meeting the power supply needs of the first branch L1 and the second branch L2, and further simplifying the circuit and electrical components in the second branch L2.

[0088] In addition to the preferred embodiments described above, the technical solutions protected by this utility model are not limited to the above embodiments. It should be noted that the combination of multiple technical solutions in any one embodiment, as well as the combination of technical solutions in any one embodiment with technical solutions in one or more other embodiments, are within the protection scope of this utility model. Although this utility model has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of this utility model are within the scope of protection claimed by this utility model.

Claims

1. A food processor with a safe opening mechanism, comprising a cup assembly, the cup assembly including a cup body, a cup lid, and a pulverizing blade disposed within the cup body, the cup lid closing onto the cup body, the pulverizing blade being driven by a variable frequency motor, characterized in that, include: When the cup lid is closed, the switch is activated, connecting the first and second branches. When the cup lid is opened, the switch is deactivated, disconnecting the first and second branches. The power module is connected to the first and second branches via a switch; The variable frequency motor drive module is connected to the first branch, and the power supply module is connected to the power supply terminal of the variable frequency motor drive module through the switch. The main control module is connected to the second branch and outputs a drive signal to the variable frequency motor drive module. The second branch is also equipped with a level conversion module connected to the power module through the switch. The level conversion module is connected to the control signal input terminal of the main control module and provides a control signal. An energy storage module is located in the first branch. The power supply module is connected to the energy storage module through the switch. The energy storage module is connected to the power supply terminal of the variable frequency motor drive module and discharges when the switch is opened, so that the power supply terminal of the brushless motor drive module is delayed and de-energized.

2. The food processing machine according to claim 1, characterized in that, The energy storage module includes a first capacitor, and a first diode is connected between the switch and the first capacitor.

3. The food processing machine according to claim 2, characterized in that, A passive energy storage module is located in the second branch. The passive energy storage module includes a second capacitor, and the capacitance value of the first capacitor is greater than the capacitance value of the second capacitor.

4. The food processing machine according to claim 2, characterized in that, The passive energy storage module is located in the second branch. The first resistor is connected in parallel with the passive energy storage module. When the second branch is disconnected, the main control module accelerates the acquisition of the second control signal.

5. The food processing machine according to claim 3, characterized in that, The capacitance value of the first capacitor is EC1, and the capacitance value of the second capacitor is EC2, where EC1 ≥ 10 * EC2.

6. The food processing machine according to claim 3, characterized in that, The second diode is located in the second branch and is electrically connected between the switch and the passive energy storage module.

7. The food processing machine according to claim 1, characterized in that, The level conversion module includes a transient voltage suppression diode, an N-type transistor, a P-type transistor, a second resistor, a third resistor, and a fourth resistor. The negative terminal of the transient voltage suppression diode is connected to the second branch, and the positive terminal of the transient voltage suppression diode is connected to the base of the N-type transistor through the second resistor. The base of the N-type transistor is also grounded through the third resistor. The emitter of the N-type transistor is grounded, and the collector of the N-type transistor is coupled to the base of the P-type transistor. The emitter of the P-type transistor is connected to a first voltage terminal, and the collector is coupled to the control signal input terminal of the main control module. The collector of the P-type transistor is also grounded through the fourth resistor.

8. The food processing machine according to claim 2, characterized in that, The positive terminal of the first diode is connected to the switch, the negative terminal of the first diode is connected to the positive terminal of the first capacitor and the power supply terminal of the variable frequency motor drive module, and the negative terminal of the first capacitor is grounded.

9. The food processing machine according to claim 6, characterized in that, The positive terminal of the second diode is connected to the switch, the negative terminal of the second diode is connected to the positive terminal of the second capacitor and the input terminal of the level conversion module, and the negative terminal of the second capacitor is grounded.

10. The food processing machine according to claim 7, characterized in that, A fifth resistor is provided between the collector of the P-type transistor and the control signal input terminal of the main control module. One end of the fifth resistor is connected to the collector of the P-type transistor, and the other end is grounded through a third capacitor.

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