Cover opening and closing protection circuit of food processor

Abstract

The utility model discloses a cover opening and closing protection circuit of a food processor. The cover opening and closing protection circuit comprises a power supply circuit, an IPM driving circuit, a main control circuit, a switching circuit and a signal converter, the IPM driving circuit and the main control circuit are connected with the power supply circuit; the switching circuit is connected with the power supply circuit and the IPM driving circuit and used for conducting or disconnecting according to the cover opening and closing state so as to control whether the power supply circuit supplies power to the IPM driving circuit or not; the signal converter is connected between the switching circuit and the main control circuit and is used for detecting the switching state of the switching circuit and sending a switching signal to the main control circuit according to the switching state; the main control circuit is connected with the IPM driving circuit, and the main control circuit is used for sending a control signal to the IPM driving circuit according to the switching signal; and the IPM driving circuit is used for being connected with a load, receiving the control signal sent by the main control circuit in a power-on state, and driving the load to work and stop.

Description

Technical Field

[0001] The utility model relates to the technical field of food processing, and particularly relates to an opening and closing cover protection circuit for a food processor. Background Art

[0002] At present, most food processors are provided with a cup body and a cup cover. The cup body and the cup cover are cooperatively connected to form a processing cavity for food processing. To ensure safe use, the food processor needs to detect whether the cup cover is closed before use, and perform corresponding operations according to whether the cover is closed or opened. For example, Chinese Utility Model Patent CN207940806U discloses a food processor, which includes an opening button and a main control unit. A switch button connected to the main control unit is arranged on the opening button, which is used to generate a signal change when performing a switch operation on the opening button. The main control unit controls the motor to stop running according to the signal change, so that when the lid is opened or during the opening process, the motor is already in a stopped state.

[0003] However, the above solution can only perform power-off protection by controlling the machine to pause when the user touches or presses the opening button. This method has problems that when the opening button fails or becomes insensitive after long-term use, the main control unit cannot receive signals in time and pause working, affecting user safety and experience.

[0004] Currently, there is also a method of connecting a magnetic control switch or a micro switch in series in an alternating current circuit, and protecting the circuit and components by turning on and off the alternating current during the opening and closing of the cover.

[0005] However, the above solutions also have many problems: (1) Connecting the switch in series in the strong electric circuit of the alternating current and directly controlling the on and off of the alternating current during the opening and closing of the cover will cause the circuit components to be damaged due to the impact of high voltage and large current; (2) When the switch is disconnected, the whole machine is powered off and cannot remember the current working state, resulting in a poor experience; (3) In case of switch damage or software failure, the whole machine cannot be powered off, posing a certain safety hazard.

[0006] Therefore, providing an opening and closing cover protection circuit for a food processor that can detect the opening and closing state of the cover, protect the components, and perform power-off protection in case of a failure has become a technical problem that needs to be solved urgently in this field. Summary of the Utility Model

[0007] Aiming at the deficiencies of the existing technology, the purpose of the utility model is to provide an opening and closing cover protection circuit for a food processor, which solves the problems that the switch connected in series in the strong electric circuit causes large current impact on the components, the whole machine cannot remember the working state when the switch is disconnected, and there is a safety hazard that the whole machine cannot be powered off in case of switch failure.

[0008] The above technical object of the present utility model is achieved by the following technical solutions:

[0009] An opening and closing cover protection circuit for a food processor, comprising a power supply circuit, an IPM drive circuit, a main control circuit, a switch circuit, and a signal converter; the IPM drive circuit and the main control circuit are connected to the power supply circuit; the switch circuit is connected to the power supply circuit and the IPM drive circuit, and is used to conduct or disconnect according to the opening and closing state of the cover, so as to control whether the power supply circuit supplies power to the IPM drive circuit; the signal converter is connected between the switch circuit and the main control circuit, and is used to detect the switch state of the switch circuit and send a switch signal to the main control circuit according to the switch state; the main control circuit is connected to the IPM drive circuit, and the main control circuit is used to send a control signal to the IPM drive circuit according to the switch signal; the IPM drive circuit is used to connect a load, and in the energized state, receive the control signal sent by the main control circuit, and drive the load to work and stop.

[0010] Further, the switch circuit includes: a magnetic control switch, the first end of the magnetic control switch is connected to the power supply circuit, and the second end of the magnetic control switch is respectively connected to the power input end of the IPM drive circuit and the signal input end of the signal converter.

[0011] Further, the signal converter includes: a triode, the base of the triode is connected to the second end of the magnetic control switch, and is used to detect the switch state of the magnetic control switch; the collector of the triode is connected to the main control circuit, and is used to send a switch signal to the main control circuit according to the switch state of the magnetic control switch; the emitter of the triode is grounded; a first resistor, one end of the first resistor is connected to the power supply circuit, and the other end is connected to the collector of the triode.

[0012] Further, the signal converter further includes: a zener diode, the first end of the zener diode is connected to the second end of the magnetic control switch, and the second end of the zener diode is connected to the base of the triode.

[0013] Further, the signal converter further includes: a second resistor, one end of the second resistor is connected to the second end of the zener diode, and the other end is connected to the base of the triode.

[0014] Further, the signal converter further includes: a third resistor, one end of the third resistor is connected to the base of the triode, and the other end is connected to the emitter of the triode.

[0015] Further, the triode is an NPN triode.

[0016] Further, the power supply circuit includes: an EMC circuit for connecting to an external power supply to eliminate current interference; a rectification module connected to the EMC circuit for converting the alternating current transmitted by the EMC circuit into direct current; and a power control module connected to the rectification module for generating different voltage values to supply power to the main control circuit, the IPM drive circuit, and the signal converter.

[0017] Further, the EMC circuit includes: a neutral line port, a live line port, and a first parallel branch, a second parallel branch, a third parallel branch, and a common mode inductor connected in parallel between the neutral line port and the live line port; the first parallel branch includes a varistor; the second parallel branch includes a first discharge resistor and a second discharge resistor connected in series for filtering out differential mode interference generated by the food processor; the third parallel branch includes a first X capacitor for filtering out common mode interference generated by the food processor.

[0018] Further, the power control module includes: a voltage transformation module connected to the output end of the rectification module for receiving the direct current transmitted by the rectification module and performing voltage transformation processing; a DC power supply module connected to the secondary winding of the voltage transformation module; a switching power supply module connected to the primary winding of the voltage transformation module; and a feedback module connected to the switching power supply module and the DC power supply module respectively; the DC power supply module sends a voltage signal to the feedback module, and the feedback module is used to output a feedback signal to the switching power supply module according to the value of the voltage signal, and the switching power supply module is used to adjust the output voltage of the voltage transformation module based on the feedback signal.

[0019] The beneficial effects of the embodiments of the present utility model are as follows:

[0020] 1. The present application provides a lid opening / closing protection circuit for a food processor. The lid opening / closing protection circuit includes a power supply circuit, an IPM drive circuit and a main control circuit connected to the power supply circuit, a switch circuit, and a signal converter. The switch circuit is connected between the power supply circuit and the IPM drive circuit, and the signal converter is connected between the switch circuit and the main control circuit. The signal converter sends a switch signal to the main control circuit according to the switch state of the switch circuit, and the main control circuit sends a control signal to the IPM drive circuit according to the switch signal, thereby driving the load to work and stop. The switch circuit is connected in series between the power supply circuit and the IPM drive circuit, that is, in the weak current loop, which can protect the components, so that other components will not be damaged by high voltage and large current impacts in the switch state of the switch circuit.

[0021] 2. By connecting the main control circuit and the IPM drive circuit to the power supply circuit in the present application, when the switch circuit is disconnected, the power supply circuit can still supply power to the main control circuit and the IPM drive circuit, enabling the whole machine to be powered on and remember the current working state, thus improving the user experience.

[0022] 3. In this application, a switch circuit is connected in series to the power supply circuit and the IPM drive circuit. When the switch circuit is closed, the power supply circuit provides electrical energy to the IPM drive circuit. When the switch circuit fails, since the power supply circuit, the IPM drive circuit, and the main control circuit are connected, the main control circuit and the IPM drive circuit can still be powered off by controlling the power supply circuit to cut off the power, protecting the circuit and improving the safety and stability of the opening / closing cover protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the following briefly introduces the drawings required for the embodiments of this application.

[0024] Figure 1 It is a schematic structural diagram of the opening / closing cover protection circuit of a food processor shown in an embodiment of this application;

[0025] Figure 2 It is a schematic circuit diagram of the opening / closing cover protection circuit of a food processor shown in an embodiment of this application;

[0026] Figure 3 It is a schematic circuit diagram of the switch circuit of the opening / closing cover protection circuit of a food processor shown in an embodiment of this application;

[0027] Figure 4 It is a schematic circuit diagram of the signal converter of the opening / closing cover protection circuit of a food processor shown in an embodiment of this application;

[0028] Figure 5 It is a schematic circuit diagram of the power supply circuit of the opening / closing cover protection circuit of a food processor shown in an embodiment of this application;

[0029] Figure 6 It is a schematic circuit diagram of the power control module of the opening / closing cover protection circuit of a food processor shown in an embodiment of this application.

[0030] Reference Numerals: 1 - power supply circuit; 11 - EMC circuit; 111 - neutral line port; 112 - live line port; 12 - rectification module; 13 - power control module; 131 - voltage transformation module; 132 - switching power supply module; 133 - feedback module; 134 - DC power supply module; 2 - IPM drive circuit; 3 - main control circuit; 4 - switch circuit; 41 - magnetic control switch; 5 - signal converter. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "inner" and "outer" is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present application. In addition, terms such as "first" and "second" are only used for differential description and cannot be construed as indicating or implying relative importance.

[0032] The purpose of the present utility model is to provide a lid opening / closing protection circuit for a food processor to solve the problems of large current impact on components caused by the switch being connected in series in the strong power circuit, the whole machine being unable to remember the working state when the switch is disconnected, and the potential safety hazard of being unable to cut off the power in case of switch failure.

[0033] The food processors with lid opening / closing safety requirements provided by the present application include a juice extractor, a blender, a soymilk maker, a blender with automatic cleaning, etc. An inlet tube is provided at the upper end of the juice collection chamber of the juice extractor, and a safety lid is provided at the upper end of the inlet tube. The lid opening / closing protection circuit of the present application can be applied to the above-mentioned juice extractor. The blender includes a main body and a cup body. A crushing knife driven by a motor is provided in the cup body, and a safety lid is provided at the upper end of the cup body. The lid opening / closing protection circuit of the present application can be applied to the above-mentioned blender.

[0034] Next, the technical solutions in the embodiments of the present application will be described with reference to the drawings in the embodiments of the present application.

[0035] See Figure 1 -4, a lid opening / closing protection circuit for a food processor includes a power supply circuit 1, an IPM drive circuit 2 connected to the power supply circuit 1, a main control circuit 3, a switch circuit 4, and a signal converter 5.

[0036] The power supply circuit 1 is connected to the IPM drive circuit 2 and the main control circuit 3 and is used to supply power to the IPM drive circuit 2 and the main control circuit 3.

[0037] The switch circuit 4 is connected to the power supply circuit 1 and the IPM drive circuit 2 and is used to conduct or disconnect according to the lid opening / closing state of the food processor to control whether the power supply circuit 1 supplies power to the IPM drive circuit 2.

[0038] The signal converter 5 is connected between the switch circuit 4 and the main control circuit 3 and is used to detect the switch state of the switch circuit 4 and send a switch signal to the main control circuit 3 according to the switch state.

[0039] Among them, the main control circuit 3 is connected to the IPM drive circuit 2. The main control circuit 3 is used to send a control signal to the IPM drive circuit 2 according to a switching signal. The IPM drive circuit 2 is used to connect to a load and, in the powered-on state, receive the control signal sent by the main control circuit 3, and then drive the load to work and stop.

[0040] When the switch circuit 4 is closed, the signal converter 5 sends the switching signal to the main control circuit 3. The main control circuit 3 judges that the food processor is in the lid-closed state according to the switching signal, and the main control circuit 3 sends a control signal to the IPM drive circuit 2. The IPM drive circuit 2 drives the load to work according to the control signal.

[0041] When the switch circuit 4 is open, the signal converter 5 sends the switching signal to the main control circuit 3. The main control circuit 3 receives the switching signal, judges that the food processor is in the lid-open state, and the main control circuit 3 does not send a control signal to the IPM drive circuit 2, and the load stops working.

[0042] In one embodiment, the above-mentioned switching signal can be a high-level signal and a low-level signal. When the switch circuit 4 is closed, the switching signal is a low-level signal. When the switch circuit 4 is open, the switching signal is a high-level signal.

[0043] In this application, by setting the above-mentioned lid-opening and lid-closing protection circuit, the above-mentioned switch circuit 4 is arranged in the power supply circuit 1 and the IPM drive circuit 2, and is conducted or disconnected according to the lid-opening and lid-closing state.

[0044] On the one hand, the power supply circuit 1 outputs a weak electrical signal, and the switch circuit 4 receives a weak electrical signal. Conducting or disconnecting during the lid-opening and lid-closing process can prevent other components in the circuit from being impacted by high voltage and large current, protect the components, and at the same time cooperate with the signal converter 5 to send a switching signal to the main control circuit 3 according to the on-off state of the switch circuit 4. The main control circuit 3 controls the operation of the IPM drive circuit 2 according to the switching signal, improving the accuracy of the lid-opening and lid-closing protection circuit.

[0045] On the other hand, both the power supply circuit 1 and the main control circuit 3 are connected to the IPM drive circuit 2. In the case where the switch circuit 4 is damaged or faulty, the IPM drive circuit 2 can also be powered off by controlling the power-off of the power supply circuit 1 to protect the circuit.

[0046] It should be noted that the IPM drive circuit 2 (also known as the intelligent power circuit) can convert the direct current of the power supply circuit 1 into three-phase current to adapt to the current demand of the load. Among them, the load is a brushless motor.

[0047] The switch circuit 4 includes a magnetic control switch 41 or a Hall detection switch, etc. (see Figure 3 ).

[0048] This application is described by taking the magnetic control switch 41 as an example. The first end of the magnetic control switch 41 is connected to the power supply circuit 1, and the second end of the magnetic control switch 41 is respectively connected to the power input end of the IPM drive circuit 2 and the signal input end of the signal converter 5. The current flowing out of the magnetic control switch 41 is divided into two paths and flows to the IPM drive circuit 2 and the signal converter 5 respectively.

[0049] The signal output end of the signal converter 5 is connected to the main control circuit 3, and is used to send a switch signal to the main control circuit 3. Specifically, the switch signal includes a low-level signal and a high-level signal. The main control circuit 3 is used to judge whether the food processor is in the lid-closed state or the lid-open state according to the low-level signal or the high-level signal.

[0050] Specifically, the signal converter 5 includes a triode Q1, a first resistor R10, a zener diode D4, a second resistor R11, and a third resistor R12 (see Figure 4 ).

[0051] The base of the triode Q1 is connected to the second end of the magnetic control switch 41 and is used to detect the switch state of the magnetic control switch 41. The collector of the triode Q1 is connected to the main control circuit 3 and is used to send a switch signal to the main control circuit 3 according to the switch state of the magnetic control switch 41. The emitter of the triode Q1 is grounded.

[0052] One end of the first resistor R10 is connected to the power supply circuit 1, and the other end is connected to the collector of the triode Q1, and is used to protect the safety of the circuit of the signal converter 5.

[0053] The zener diode D4 is connected between the triode Q1 and the magnetic control switch 41. Specifically, the first end of the zener diode D4 is connected to the second end of the magnetic control switch 41, and the second end of the zener diode D4 is connected to the base of the triode Q1, and is used to limit the change range of the base voltage, so as to achieve the effect of stabilizing the operating point of the triode Q1. At the same time, the zener diode D4 will block the excess voltage when overvoltage occurs, thereby protecting the triode Q1 from damage.

[0054] One end of the second resistor R11 is connected to the second end of the zener diode D4, and the other end of the second resistor R11 is connected to the base of the triode Q1, and is used to stabilize the operating state of the signal converter 5 and improve the anti-interference ability of the signal converter 5.

[0055] One end of the third resistor R12 is connected to the base of the triode Q1, and the other end of the third resistor R12 is connected to the emitter of the triode Q1, and is used to establish a current path, protect the triode Q1 from damage by excessive current, and can output a stable voltage to a certain extent.

[0056] In an embodiment, the above triode Q1 may be an NPN type triode.

[0057] The specific working process of the signal converter 5 is as follows:

[0058] When the magnetic control switch 41 is closed, both ends of the switch circuit 4 are conducting, the zener diode D4 connected to the switch circuit 4 conducts, the base of the triode Q1 receives a high level, so that the triode Q1 conducts. Due to the existence of the first resistor R10, the collector of the triode Q1 sends a low-level signal to the main control circuit 3. The main control circuit 3 receives the low-level signal and determines that the food processor is in the lid-closed state.

[0059] When the magnetic control switch 41 is open, both ends of the switch circuit 4 are disconnected, the zener diode D4 connected to the switch circuit 4 is cut off, the base of the triode Q1 receives a low level, so that the triode Q1 is turned off. Due to the existence of the first resistor R10, the collector of the triode Q1 sends a high-level signal to the main control circuit 3. The main control circuit 3 receives the high-level signal and determines that the food processor is in the lid-open state.

[0060] As can be seen from the above, whether the food processor is in the lid-open state or the lid-closed state, the main control circuit 3 will continuously obtain the signal sent by the switch circuit 4, and judge the low-level signal and high-level signal sent by the magnetic control switch 41 when it is closed and open according to the signal converter 5, and continuously obtain the lid-open state and lid-closed state of the food processor.

[0061] See Figure 5 , the power supply circuit 1 includes an EMC circuit 11, a rectification module 12, and a power control module 13.

[0062] The EMC circuit 11 is used to connect to an external power supply to eliminate current interference, and the output end of the EMC circuit 11 outputs alternating current. The rectification module 12 is connected to the EMC circuit 11 and is used to convert the alternating current transmitted by the EMC circuit 11 into direct current. The power control module 13 is connected to the rectification module 12 and is used to receive the direct current sent by the rectification module 12 for processing and generate different voltage values to supply power to the main control circuit 3, the IPM drive circuit 2, and the signal converter 5, so that the IPM drive circuit 2 can operate normally.

[0063] Among them, the above-mentioned EMC circuit 11 includes a neutral line port 111, a live line port 112, and a first parallel branch, a second parallel branch, a third parallel branch, and a common mode inductor L1 connected in parallel between the neutral line port 111 and the live line port 112.

[0064] The first parallel branch includes a varistor VDR1, and the second parallel branch includes a first discharge resistor R1 and a second discharge resistor R3 connected in series, which are used to filter out the differential mode interference generated by the food processor.

[0065] The third parallel branch includes a first X capacitor CX1, which is used to filter out the common mode interference generated by the food processor.

[0066] It should be noted that the EMC circuit 11 (Chinese name: electromagnetic compatibility circuit) may have a power connection terminal (not shown in the figure) for connecting to an external power supply to introduce the current of the external power supply into the rectification module 12 and the power control module 13. Among them, the EMC circuit 11 has a filtering function and can reduce the interference of the current flowing in from the external power supply to the load.

[0067] In this application, the EMC circuit 11 is connected to an external power supply to access the current, and is connected to the IPM drive circuit 2 through the rectification module 12 and the power control module 13. The current of the external power supply is transported to the load connected to the IPM drive circuit 2 through the EMC circuit 11 and the power connection terminal to drive the load to work.

[0068] See Figure 6 , the power control module 13 includes a voltage transformation module 131, a DC power supply module 134, a switching power supply module 132, and a feedback module 133.

[0069] The voltage transformation module 131 is connected to the output terminal of the rectification module 12 for receiving the direct current sent by the rectification module 12 and performing voltage transformation processing on it; the DC power supply module 134 is connected to the secondary winding of the voltage transformation module 131, the switching power supply module 132 is connected to the primary winding of the voltage transformation module 131, and the feedback module 133 is respectively connected to the switching power supply module 132 and the DC power supply module 134.

[0070] The DC power supply module 134 sends a voltage signal to the feedback module 133. When the value of the voltage signal is greater than or equal to a preset voltage threshold, the feedback module 133 outputs a feedback signal and sends the feedback signal to the switching power supply module 132. The switching power supply module 132 is used to adjust the output voltage of the voltage transformation module 131 according to the feedback signal.

[0071] Among them, in the case of using the IPM drive circuit 2, the preset voltage threshold can be set according to the specification.

[0072] By setting the voltage transformation module 131, the high-frequency voltage input by the rectification module 12 is transformed and output to the DC power supply module 134, and by setting the feedback module 133 between the DC power supply module 134 and the switching power supply module 132 to feedback and adjust the output voltage of the switching power supply module 132, the working stability of the switching power supply circuit is effectively reduced.

[0073] The following specifically introduces the working process of the opening and closing cover protection circuit of the food processor (see Figure 1 -4):

[0074] When the magnetic control switch 41 is closed, that is, when the cup cover of the food processor is buckled on the cup body and a closed processing cavity is formed, both ends of the switch circuit 4 are connected, and the electrical signal sent by the power supply circuit 1 flows out from the switch circuit 4 and flows into two flow paths respectively. A part of it flows into the IPM drive circuit 2 to supply power to the IPM drive circuit 2, facilitating the main control circuit 3 to control the operation of the IPM drive circuit 2, and the system works normally.

[0075] Another part flows into the signal converter 5 through the switch circuit 4. At this time, due to the input of the electrical signal, the zener diode D4 conducts, the base of the triode Q1 receives a high level, which makes the triode Q1 conduct. The collector of the triode Q1 sends a low-level signal to the main control circuit 3 connected to the output end of the signal converter 5. The main control circuit 3 judges that the food processor is in the lid-closed state according to the received low-level signal, and the main control circuit 3 sends a control circuit to the IPM drive circuit 2 to control the IPM drive circuit 2 to drive the load to work.

[0076] When the magnetic control switch 41 is disconnected, that is, when the cup cover of the food processor is separated from the cup body, both ends of the switch circuit 4 are disconnected, and the electrical signal of the power supply circuit 1 cannot flow through the switch circuit 4. On the one hand, the IPM drive circuit 2 connected to the switch circuit 4 does not receive an electrical signal, and at this time the IPM drive circuit 2 is not powered on.

[0077] On the other hand, the zener diode D4 of the signal converter 5 connected to the switch circuit 4 is in the cut-off state, the base of the triode Q1 receives a low level, which causes the triode Q1 to turn off. Since the collector of the triode Q1 is connected to the power supply circuit 1 through the first resistor R10, the collector of the triode Q1 sends a high-level signal to the main control circuit 3 at this time. The main control circuit 3 judges that the food processor is in the lid-open state according to the high-level signal, and the main control circuit 3 does not send a control signal to the IPM drive circuit 2, so as not to drive the load to work.

[0078] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "set" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0079] It should be noted that, without conflict, the features in the embodiments of the present application can be combined with each other.

[0080] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An opening and closing cover protection circuit for a food processor, characterized in that, The lid opening and closing protection circuit includes: A power supply circuit, an IPM drive circuit connected to the power supply circuit, and a main control circuit. The power supply circuit is used to supply power to the IPM drive circuit and the main control circuit; A switch circuit, connected to the power supply circuit and the IPM drive circuit, for conducting or disconnecting according to the lid opening and closing state to control whether the power supply circuit supplies power to the IPM drive circuit; A signal converter, connected between the switch circuit and the main control circuit, for detecting the switch state of the switch circuit and sending a switch signal to the main control circuit according to the switch state; The main control circuit is connected to the IPM drive circuit, and the main control circuit is used to send a control signal to the IPM drive circuit according to the switch signal; The IPM drive circuit is used to connect to a load, and in the powered-on state, receive the control signal sent by the main control circuit to drive the load to work and stop.

2. The opening and closing lid protection circuit of the food processor according to claim 1, characterized in that The switch circuit includes: A magnetic control switch, the first end of the magnetic control switch is connected to the power supply circuit, and the second end of the magnetic control switch is respectively connected to the power input end of the IPM drive circuit and the signal input end of the signal converter.

3. The opening and closing cover protection circuit of the food processor according to claim 2, characterized in that The signal converter includes: A triode, the base of the triode is connected to the second end of the magnetic control switch, for detecting the switch state of the magnetic control switch; The collector of the triode is connected to the main control circuit, for sending a switch signal to the main control circuit according to the switch state of the magnetic control switch; The emitter of the triode is grounded; A first resistor, one end of the first resistor is connected to the power supply circuit, and the other end is connected to the collector of the triode.

4. The opening and closing lid protection circuit of the food processor according to claim 3, characterized in that, The signal converter further includes: A zener diode, the first end of the zener diode is connected to the second end of the magnetic control switch, and the second end of the zener diode is connected to the base of the triode.

5. The opening and closing cover protection circuit of the food processor according to claim 4, characterized in that, The signal converter further includes: A second resistor, one end of the second resistor is connected to the second end of the zener diode, and the other end of the second resistor is connected to the base of the triode.

6. The opening and closing lid protection circuit of the food processor according to claim 4, characterized in that, The signal converter further includes: A third resistor, one end of the third resistor is connected to the base of the triode, and the other end of the third resistor is connected to the emitter of the triode.

7. The opening / closing cover protection circuit of the food processor according to claim 3, characterized in that, The triode is an NPN triode.

8. The opening and closing lid protection circuit of the food processor according to claim 1, characterized in that, The power supply circuit includes: An EMC circuit, which is used to connect to an external power supply to eliminate current interference; A rectification module, connected to the EMC circuit, for converting the alternating current transmitted by the EMC circuit into direct current; A power control module, connected to the rectification module, for generating different voltage values to supply power to the main control circuit, the IPM drive circuit, and the signal converter.

9. The opening and closing cover protection circuit of the food processor according to claim 8, characterized in that, The EMC circuit includes: A neutral line port, a live line port, and a first parallel branch, a second parallel branch, a third parallel branch, and a common mode inductor connected in parallel between the neutral line port and the live line port; The first parallel branch includes a varistor; The second parallel branch includes a first discharge resistor and a second discharge resistor connected in series, for filtering out the differential mode interference generated by the food processor; The third parallel branch includes a first X capacitor for filtering out the common-mode interference generated by the food processor.

10. The opening and closing lid protection circuit of the food processor according to claim 8, characterized in that, The power control module includes: A voltage transformation module connected to the output end of the rectification module for receiving the direct current sent by the rectification module and performing voltage transformation processing; A direct current power supply module connected to the secondary winding of the voltage transformation module; A switching power supply module connected to the primary winding of the voltage transformation module; A feedback module respectively connected to the switching power supply module and the direct current power supply module; The direct current power supply module sends a voltage signal to the feedback module. The feedback module is used to output a feedback signal to the switching power supply module according to the value of the voltage signal. The switching power supply module is used to adjust the output voltage of the voltage transformation module based on the feedback signal.

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