Signal detection circuit, signal detection system and cooking equipment

Abstract

The utility model discloses a signal detection circuit, a signal detection system and cooking equipment. Relates to the technical field of signal detection, and the signal detection circuit comprises a sampling circuit 101 which comprises a first resistor R1, a second resistor R2 and a third resistor R3 which are connected in series, the second resistor R2 is a temperature sensor arranged in target equipment, the third resistor R3 is connected with a switching device K in parallel, and the on-off state of the switching device K is determined by the equipment state of the target equipment; and the first chip 102 supplies power to the sampling circuit 101 and collects the voltage of a sampling point on a line between the first resistor R1 and the second resistor R2 to obtain a sampling signal value, and the sampling signal value is used for representing the temperature and the equipment state of the target equipment. By means of the electric pressure cooker, the problems that a thermistor in a temperature detection module arranged on a cooker cover of a split type electric pressure cooker in the prior art can only sense a temperature signal and cannot sense an upper pressure signal, and the pressure state in the cooker is difficult to detect are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of signal detection, in particular to a signal detection circuit, a signal detection system and cooking equipment. Background Art

[0002] The electric pressure cooker has the function of cooking food quickly and is an indispensable cooking tool in the modern kitchen. Electric pressure cookers include combined electric pressure cookers and split electric pressure cookers. The lid of the split electric pressure cooker can be removed for easy cleaning and has a wide range of applications.

[0003] The split-type electric pressure cooker in the related art can detect the temperature signal through the temperature detection module on the lid of the electric pressure cooker and transmit it to the control module of the main body of the electric pressure cooker through wireless transmission. The temperature detection module is provided with a thermistor. The thermistor can only sense the temperature signal and cannot sense the pressure signal of the cooking device. If the pressure signal of the cooking device is to be detected, the detection chip needs to be redesigned, and the chip design is difficult and costly.

[0004] Currently, no effective solution has been proposed to the problem that the thermistor in the temperature detection module installed on the lid of the split electric pressure cooker in the related art can only sense temperature signals but cannot sense pressure signals, making it difficult to detect the pressure state inside the pot. Utility Model Content

[0005] The utility model provides a signal detection circuit, a signal detection system and cooking equipment to solve the problems in related technologies.

[0006] According to one aspect of the present invention, a signal detection circuit is provided. The signal detection circuit includes: a sampling circuit comprising a first resistor, a second resistor, and a third resistor connected in series, wherein the second resistor is a temperature sensor disposed within a target device, and the third resistor is connected in parallel with a switch device, the on / off state of which is determined by the device state of the target device; a first chip, which supplies power to the sampling circuit via a first power port and collects the voltage at a sampling point on the line between the first resistor and the second resistor via a signal line to obtain a sampled signal value. This solves the problem in the related art that the thermistor in the temperature detection module disposed on the lid of a split-type electric pressure cooker can only sense temperature signals but not pressure signals, making it difficult to detect the pressure state within the cooker. In the sampling circuit, the resistor connected in series with the temperature sensor is connected in parallel with a switch device, the on / off state of which is determined by the device state. The sampled signal values ​​collected from the sampling points can simultaneously represent both the device temperature and the device state, thereby achieving the effect of the detection circuit simultaneously detecting both the temperature and pressure state within the electric pressure cooker.

[0007] Optionally, the resistance range of the second resistor is 0.1KΩ-100KΩ, and the resistance range of the third resistor is 10KΩ-100KΩ. By setting the resistance of the third resistor based on the temperature-dependent resistance of the second resistor, the device state and temperature can be accurately determined based on the sampled signal value.

[0008] Optionally, a bias resistor is connected in series between the first resistor and the second resistor. The bias resistor has a resistance range of 0 kΩ to 30 kΩ, and the first resistor has a resistance range of 2 kΩ to 30 kΩ. The resistance of the first resistor is set according to the resistance of the bias resistor of the first chip, so that the configuration of the sampling circuit can meet the operating requirements of the first chip.

[0009] Optionally, the signal detection circuit also includes: a first wireless power supply circuit, including a first coupling coil connected in parallel at both ends of the second power port and the third power port of the first chip, and a first capacitor connected in parallel with the first coupling coil, wherein the first coupling coil is used to obtain electrical energy and charge the first capacitor, and the first capacitor is used to discharge the electrical energy to the second wireless power supply circuit; a second wireless power supply circuit, including a second capacitor connected in series between the fourth power port and the ground line of the first chip, and a fourth resistor connected in parallel with the second capacitor, wherein the first capacitor charges the second capacitor through the fourth resistor, and the second capacitor supplies power to the first chip through the fourth resistor. The signal detection circuit can be a wireless module that is charged by wireless charging, so that the signal detection circuit can be suitable for signal detection of a split target device.

[0010] According to another aspect of the present invention, a signal detection system is provided. The signal detection system includes: the aforementioned signal detection circuit, configured to collect sampled signal values ​​and transmit the sampled signal values ​​to a signal processing circuit; and a signal processing circuit, wirelessly communicating with the signal detection circuit and configured to power the signal detection circuit. In the sampling circuit of the signal detection circuit, a resistor connected in series with the temperature sensor is connected in parallel to a switching device. The on / off state of the switching device is determined by the device state. The sampled signal values ​​collected from the sampling points can simultaneously represent both the device temperature and the device state. The signal processing circuit powers the sampling circuit, thereby enabling the detection circuit to simultaneously detect both the temperature and pressure state within the electric pressure cooker.

[0011] Optionally, the signal processing circuit includes: an RF gain circuit, connected to the second chip, including a second coupling coil, for controlling the oscillation of the second coupling coil to charge the signal detection circuit and receive a sampling signal; and a detection circuit, connected to the second chip, for performing detection processing on the sampling signal and transmitting the processed signal to the second chip. Through the coordination of the RF gain circuit, the detection circuit, and the second chip, the signal processing circuit supplies power to the signal detection circuit, obtains the sampling signal value detected by the signal detection circuit, and further determines the device temperature and device status based on the sampling signal value.

[0012] According to another aspect of the present invention, a cooking device is provided. The cooking device comprises: the aforementioned signal detection system; a pot; and a pot lid disposed on top of the pot, the pot lid being used to seal the pot. The signal detection circuit in the signal detection system is disposed on the pot lid, and the signal processing circuit in the signal detection system is disposed on the pot body; and a microcontroller unit, communicatively connected to the signal processing circuit and configured to receive the output of the signal processing circuit and control the operation of the pot body. The sampled signal values ​​collected by the signal detection circuit disposed on the pot lid can reflect the device temperature and pressure status. The signal processing circuit disposed on the pot body obtains the sampled signal values ​​via wireless transmission, thereby achieving the effect of simultaneously detecting the temperature and pressure status within the electric pressure cooker pot by the detection circuit, thereby improving the cooking quality and efficiency of the cooking device.

[0013] Optionally, a stopper lever is provided on the pot lid, and the open / closed state of the stopper lever is used to determine the on / off state of the switch device. The on / off state of the switch device is associated with the open / closed state of the stopper lever in the cooking device. The open / closed state of the stopper lever reflects the pressure state of the cooking device, thereby allowing the on / off state of the switch device to reflect the pressure state of the cooking device.

[0014] Optionally, the anti-opening rod is connected to a trigger member, the switch device is an induction switch, and the trigger member is used to trigger the induction switch on and off. When the cooking device is in a non-pressurized state, the anti-opening rod, when opened, drives the trigger member away from the induction switch. If the induction switch does not sense the trigger member, it is in an off state. When the cooking device is in a pressurized state, the anti-opening rod, when closed, drives the trigger member toward the induction switch. If the induction switch senses the trigger member, it is in a closed state. The trigger member and the induction switch cooperate to accurately detect the pressure state in the pot.

[0015] Optionally, the trigger member is a magnet, and the induction switch is a magnetic control switch. When the cooking device is in a non-pressurized state, the anti-opening lever, when opened, drives the magnet away from the magnetic control switch. If the magnetic control switch cannot detect the magnet, it is in an open state. When the cooking device is in a pressurized state, the anti-opening lever, when closed, drives the magnet toward the magnetic control switch. If the magnetic control switch detects the magnet, it is in a closed state. The pressure state in the pot can be accurately detected by the cooperation of the magnet and the magnetic control switch.

[0016] In the present invention, a sampling circuit in a signal detection circuit includes a first resistor, a second resistor, and a third resistor connected in series. The second resistor is a temperature sensor disposed within a target device. The third resistor is connected in parallel to a switch device, the on / off state of which is determined by the device state of the target device. A first chip in the signal detection circuit supplies power to the sampling circuit via a first power port, and the voltage at a sampling point on the line between the first resistor and the second resistor is collected via a signal line to obtain a sampled signal value. This solves the problem in the related art that the thermistor in the temperature detection module disposed on the lid of a split-type electric pressure cooker can only sense temperature signals but not pressure signals, making it difficult to detect the pressure state within the cooker. In the sampling circuit, the resistor connected in series with the temperature sensor is connected in parallel to a switch device, the on / off state of which is determined by the device state. The sampled signal value collected from the sampling point can simultaneously represent both the device temperature and the device state, thereby achieving the effect of the detection circuit simultaneously detecting both the temperature and pressure state within the electric pressure cooker. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 is a schematic diagram of a signal detection circuit according to an embodiment of the present utility model;

[0019] Figure 2 is a schematic diagram of an optional signal detection circuit according to an embodiment of the present utility model;

[0020] Figure 3 is a schematic diagram of a signal detection system according to an embodiment of the present utility model;

[0021] Figure 4 is a schematic diagram of an optional radio frequency gain circuit according to an embodiment of the present utility model;

[0022] Figure 5 is a schematic diagram of an optional detection circuit according to an embodiment of the present utility model;

[0023] Figure 6 is a schematic diagram of an optional second chip according to an embodiment of the present utility model;

[0024] Figure 7 is a schematic diagram of a cooking device according to an embodiment of the present invention;

[0025] Among them, 10, signal detection circuit; 11, signal processing circuit; 101, sampling circuit; 102, first chip; 103, first wireless power supply circuit; 104, second wireless power supply circuit; 21, pot body; 22, pot lid; 30, micro control unit; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; REF, bias resistor; C1, first capacitor; C2, second capacitor; K, switching device; L1, first coupling coil; L2, second coupling coil. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate for the embodiments of the present invention described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatuses.

[0029] According to an embodiment of the present utility model, a signal detection circuit is provided.

[0030] Figure 1 Schematic diagram of a signal detection circuit according to an embodiment of the present invention. Figure 1 As shown, the signal detection circuit includes the following parts:

[0031] The sampling circuit 101 includes a first resistor R1, a second resistor R2, and a third resistor R3 connected in series. The second resistor R2 is a temperature sensor set inside the target device. The third resistor R3 is connected in parallel with a switch device K. The on / off state of the switch device K is determined by the device state of the target device.

[0032] It should be noted that the target device can be a cooking device, such as an electric pressure cooker, and the device state can be either unpressurized or pressurized. The unpressurized state means the pressure inside the cooker is close to or equal to ambient pressure, while the pressurized state means the pressure inside the cooker is higher than ambient pressure. The on / off state of the switch device K is associated with the device state of the target device. Depending on the device state, the on / off state of the switch device K varies. For example, if the electric pressure cooker is unpressurized, the switch device K is open; if the electric pressure cooker is pressurized, the switch device K is closed.

[0033] Among them, one end of the sampling circuit 101 and the first power port of the first chip 102 ( Figure 1 The other end of the sampling circuit 101 is grounded, and the first chip 102 supplies power to the sampling circuit 101. When the switch device K is in the off state, the first resistor R1, the second resistor R2, and the third resistor R3 divide the voltage. When the switch device K is in the on state, the third resistor R3 is short-circuited, and the first resistor R1 and the second resistor R2 divide the voltage.

[0034] The first chip 102 supplies power to the sampling circuit 101 through the first power port, collects the voltage of a sampling point on the line between the first resistor R1 and the second resistor R2 through the signal line, and obtains a sampling signal value.

[0035] The signal line of the first chip 102 is connected from the pin VREFL to the sampling point. The voltage at the sampling point is the voltage relative to ground at the sampling point. The first resistor R1 can be connected to the first power port, and the third resistor R3 can be connected to the ground line. When the switch device K is in the open state, the first resistor R1, the second resistor R2, and the third resistor R3 divide the voltage. The voltage at the sampling point is the total divided voltage value of the second resistor R2 and the third resistor R3. The sampling signal value is a digitized voltage value. It can be the total divided voltage value of the second resistor R2 and the third resistor R3, or the inverse of the total divided voltage value of the second resistor R2 and the third resistor R3, that is, the divided voltage value of the first resistor R1. When the switch device K is in the closed state, the first resistor R1 and the second resistor R2 divide the voltage. The voltage at the sampling point is the divided voltage value of the second resistor R2. The sampling signal value can be the divided voltage value of the second resistor R2, or the inverse of the divided voltage value of the second resistor R2, that is, the divided voltage value of the first resistor R1.

[0036] The temperature sensor can be a thermistor. On the one hand, regardless of whether the switch device K is in the open or closed state, the thermistor's resistance and voltage divider value will change with the temperature inside the target device. The voltage value from the sampling point to ground will also change with temperature, and the sampled signal value will also change with temperature. Therefore, the sampled signal value can be used to represent the temperature of the target device. On the other hand, the thermistor's voltage divider value changes differently with temperature when the switch device K is in the open or closed state. The voltage value from the sampling point to ground also changes differently with temperature, and the sampled signal value also changes differently with temperature. Therefore, the sampled signal value can be used to represent the device status of the target device.

[0037] It should be noted that in the related art, two parallel detection circuits are provided to measure the temperature and pressure status of the cooking device separately. On the one hand, when the temperature or pressure status changes, the two detection signals change simultaneously, which will generate crosstalk and affect the accuracy of temperature and pressure status detection. On the other hand, it is necessary to sample the sampling signals of two signal detection points and process the two signals separately in the chip to determine the temperature and pressure status of the cooking device, which requires the design of two signal acquisition channels and signal processing programs in the chip. In contrast, in the present invention, a switch device K is provided in parallel with the voltage divider resistor in the sampling circuit 101. The collected sampling signal value can accurately represent the device temperature and device status simultaneously, and the device temperature and device status can be collected at a low cost without changing the chip design of the sampling circuit 101.

[0038] The signal detection circuit provided by the present invention comprises a sampling circuit 101 comprising a first resistor R1, a second resistor R2, and a third resistor R3 connected in series. The second resistor R2 is a temperature sensor provided within the target device. The third resistor R3 is connected in parallel to a switch device K, the on / off state of which is determined by the device status of the target device. A first chip 102 supplies power to the sampling circuit 101 via a first power port and collects the voltage at a sampling point on the line between the first resistor R1 and the second resistor R2 via a signal line to obtain a sampled signal value. This solves the problem in the related art that the thermistor in the temperature detection module provided on the lid of a split-type electric pressure cooker can only sense the temperature signal but not the pressure signal, making it difficult to detect the pressure state within the cooker. In the sampling circuit 101, the resistor connected in series with the temperature sensor is connected in parallel to a switch device, the on / off state of which is determined by the device status. The sampled signal value collected from the sampling point can simultaneously represent the device temperature and device status, thereby achieving the effect of the detection circuit simultaneously detecting the temperature and pressure state within the electric pressure cooker.

[0039] Optionally, in the signal detection circuit provided in the embodiment of the present invention, the resistance range of the second resistor R2 is 0.1KΩ-100KΩ, and the resistance range of the third resistor R3 is 10KΩ-100KΩ.

[0040] The second resistor R2 may be an NTC (Negative Temperature Coefficient) thermistor, and the resistance range of the NTC thermistor may be 0.1 KΩ-100 KΩ, which can meet the detection accuracy requirements in different temperature detection scenarios.

[0041] For example, if the target device is an electric pressure cooker and the third resistor R3 and the second resistor R2 have the same resistance level (for example, the second resistor R2 has a resistance of 50 kΩ and the third resistor R3 has a resistance range of 10 kΩ-100 kΩ), a larger resistance of the third resistor R3 can reduce the temperature uncertainty range in the event of a reed switch short-circuit failure. For example, if the second resistor R2 is an NTC thermistor with a resistance of 100 kΩ, and the third resistor R3 has a resistance of 30 kΩ, the temperature uncertainty range can be controlled below 50°C. If the third resistor R3 has a resistance of 50 kΩ, the temperature uncertainty range can be controlled below 40°C. Furthermore, the third resistor R3 should not be too large. If the third resistor R3 is too large, the voltage divider of the first resistor R1 will be too small, resulting in low resolution of the high-temperature data after the reed switch fails due to an open circuit.

[0042] Through this embodiment, the resistance of the third resistor R3 is set according to the characteristic that the resistance of the second resistor R2 changes with temperature, so as to achieve the purpose of accurately determining the device status and temperature according to the sampling signal value.

[0043] Optionally, in the signal detection circuit provided in an embodiment of the present invention, a bias resistor REF is connected in series between the first resistor R1 and the second resistor R2, the resistance range of the bias resistor REF is 0KΩ-30KΩ, and the resistance range of the first resistor R1 is 2KΩ-30KΩ.

[0044] The sampling circuit 101 may further include resistors in series with the first resistor R1, the second resistor R2, and the third resistor R3. Considering the half-bias characteristic of the first chip 102 (meaning that the voltage applied to the first chip 102 or its internal components is half of its normal operating voltage), a bias resistor REF may be connected in series with the first resistor R1 and the second resistor R2. The resistance of the first resistor R1 should be similar to that of the bias resistor REF. For example, if the bias resistor REF has a resistance of 21K, the second resistor R2 can be 20KΩ. In addition, the first resistor R1, the second resistor R2 and the third resistor R3 are used for voltage division, and the second resistor R2 and the third resistor R3 need to match the resistance of the first resistor R1. The resistance values ​​of the three can be set within the same order of magnitude (for example, the resistance value of the first resistor R1 is 1KΩ, and the resistance value range of the second resistor R2 and the third resistor R3 is 1KΩ-10KΩ). When the resistance values ​​of the three are within the same order of magnitude, the resistance value of the first resistor R1 should not be too large or too small. If the resistance value of the first resistor R1 is too small, inaccurate measurement of the high temperature section will result. If the resistance value of the first resistor R1 is too small, inaccurate measurement of the low temperature section will result.

[0045] According to this embodiment, the resistance of the first resistor R1 is set according to the resistance of the bias resistor REF of the first chip 102 , so that the configuration of the sampling circuit 101 can meet the working requirements of the first chip 102 .

[0046] The signal detection circuit can be a wireless module, which is charged by wireless charging. Optionally, in the signal detection circuit provided in an embodiment of the present invention, the signal detection circuit also includes: a first wireless power supply circuit 103, including a first coupling coil L1 connected in parallel at both ends of the second power port and the third power port of the first chip 102, and a first capacitor C1 connected in parallel with the first coupling coil L1, wherein the first coupling coil L1 is used to obtain electrical energy and charge the first capacitor C1, and the first capacitor C1 is used to discharge the electrical energy to the second wireless power supply circuit 104; the second wireless power supply circuit 104 includes a second capacitor C2 connected in series between the fourth power port and the ground line of the first chip 102, and a fourth resistor R4 connected in parallel with the second capacitor C2, wherein the first capacitor C1 charges the second capacitor C2 through the fourth resistor R4, and the second capacitor C2 supplies power to the first chip 102 through the fourth resistor R4.

[0047] Figure 2 is a schematic diagram of an optional signal detection circuit according to an embodiment of the present utility model, such as Figure 2As shown, the second power port of the first chip 102 is the interface indicated by the RF1 pin, the third power port of the first chip 102 is the interface indicated by the RF2 pin, and the first coupling coil L1 can be a radio frequency coil. When the signal processing circuit provided with a power supply generates an electromagnetic field through the radio frequency coil, the first coupling coil L1 generates a current through this electromagnetic field and charges the first capacitor C1. The radio frequency coil of the signal processing circuit provided with a power supply continuously oscillates, and the first capacitor C1 intermittently charges energy to the second capacitor C2 through the circuit within the first chip 102. When the first capacitor C1 charges the second capacitor C2, the fourth resistor R4 acts as a charging resistor. When the first capacitor C1 stops charging the second capacitor C2, the second capacitor C2 supplies power to the first chip 102, and the fourth resistor R4 acts as a discharge resistor. When the first chip 102 receives power, it powers up and supplies power to the sampling circuit 101.

[0048] In this embodiment, the signal detection circuit may be a wireless module that is charged by wireless charging, so that the signal detection circuit can be applicable to signal detection of a split target device.

[0049] The embodiment of the present utility model also provides a signal detection system.

[0050] Figure 3 Schematic diagram of a signal detection system according to an embodiment of the present invention. Figure 3 As shown, the device includes:

[0051] The signal detection circuit 10 in any of the above embodiments is configured to be provided on a target device, and is configured to collect sampled signal values ​​and send the sampled signal values ​​to the signal processing circuit 11 .

[0052] It should be noted that the target device can be a cooking device, for example, an electric pressure cooker. The signal detection circuit 10 is set on the electric pressure cooker to sample the sampling signal value that represents the temperature and device status of the electric pressure cooker. The signal detection circuit 10 can be a wireless module that sends the sampling signal value to the signal processing circuit 11 via wireless transmission.

[0053] The signal processing circuit 11 communicates wirelessly with the signal detection circuit 10 and is used to supply power to the signal detection circuit 10 .

[0054] On the one hand, the signal processing circuit 11 generates an electromagnetic field through the second coupling coil L2 and powers the signal detection circuit 10 by electromagnetic induction. On the other hand, the second coupling coil L2 of the signal processing circuit 11 and the coupling coil L1 of the signal detection circuit 10 communicate through an agreed preset resonant frequency. The coupling coil L1 of the signal detection circuit 10 sends the sampling signal value according to the preset resonant frequency, and the signal processing circuit 11 receives the sampling signal value sent by the signal detection circuit 10 according to the preset resonant frequency.

[0055] It should be noted that, since the sampled signal value represents the temperature and device status of the target device, the signal processing circuit 11 can determine the temperature and device status of the target device based on the sampled signal value.

[0056] The signal processing circuit 11 pre-stores first relationship data between a preset sampling signal value and a preset device state. For example, the first relationship data may be: when the preset sampling signal value is less than a preset signal threshold, it corresponds to a first device state; when the preset sampling signal value is greater than or equal to the preset signal threshold, it corresponds to a second device state. Therefore, the device state can be determined based on the acquired sampling signal value and the pre-stored first relationship data.

[0057] The signal processing circuit 11 also pre-stores second relationship data between preset sampling signal values ​​and preset temperature values ​​under different device states. The second relationship data may include a first curve and a second curve. The first curve represents the relationship between the preset sampling signal value and the preset temperature value under the first device state, and the second curve represents the relationship between the preset sampling signal value and the preset temperature value under the second device state. The device state can be determined based on the acquired sampling signal value and the pre-stored first relationship data, and then the temperature value corresponding to the sampling signal value is queried on the curve corresponding to the corresponding device state, which is the temperature of the target device.

[0058] In an optional embodiment, the target device is a cooking device, the first device state is an unpressurized state, and the second device state is a pressurized state. When the cooking device is in the unpressurized state, the switch device K in the signal detection circuit 10 is open, and the first resistor R1, the second resistor R2, and the third resistor R3 participate in voltage division. The first curve is the inverse of the voltage value of the second resistor R2 and the third resistor R3 to ground, that is, the voltage division value of the first resistor R1. The first curve is a relationship curve between the voltage division value of the first resistor R1 and the temperature of the cooking device. When the cooking device is in the pressurized state, the switch device K in the signal detection circuit 10 is closed, and the first resistor R1 and the second resistor R2 participate in voltage division. The first curve is the inverse of the voltage value of the second resistor R2 to ground, that is, the voltage division value of the first resistor R1. The second curve is a relationship curve between the voltage division value of the first resistor R1 and the temperature of the cooking device. The preset signal threshold is set to the sampling signal value corresponding to any temperature value greater than the boiling point in the first curve, for example, it can be the sampling signal value corresponding to any temperature value between 130°C and 150°C, thereby avoiding inaccurate temperature measurement when the switching device K fails.

[0059] The signal detection system provided by the embodiment of the present invention is configured to be set on a target device through a signal detection circuit 10 in any one of the above embodiments, and is configured to collect sampling signal values ​​and send the sampling signal values ​​to a signal processing circuit 11; the signal processing circuit 11 wirelessly communicates with the signal detection circuit 10 and is configured to power the signal detection circuit 10, thereby solving the problem in the related art that the thermistor in the temperature detection module provided on the lid of a split-type electric pressure cooker can only sense temperature signals but cannot sense pressure signals, making it difficult to detect the pressure state inside the pot. In the sampling circuit 101 of the signal detection circuit 10, a resistor connected in series with the temperature sensor is connected in parallel with a switching device, and the open and closed state of the switching device is determined by the device state. The sampling signal value collected from the sampling point can simultaneously represent the device temperature and the device state. The signal processing circuit 11 powers the sampling circuit, thereby achieving the effect of the detection circuit simultaneously detecting the temperature and pressure state inside the electric pressure cooker.

[0060] Optionally, in the signal detection system provided in an embodiment of the present invention, the signal processing circuit 11 includes: a radio frequency gain circuit, connected to the second chip, including a second coupling coil L2, used to control the oscillation of the second coupling coil L2 to charge the signal detection circuit 10 and receive the sampling signal; a detection circuit, connected to the second chip, used to perform detection processing on the sampling signal and send the processed signal to the second chip.

[0061] Figure 4 is a schematic diagram of an optional radio frequency gain circuit according to an embodiment of the present utility model, such as Figure 4As shown, the second coupling coil L2 is composed of a coil L21 and a coil L22. The coils L21 and L22 are used to transmit an oscillation signal and transfer energy to the first coupling coil L1 in the sampling circuit 101 through the coil RF. The coils L21 and L22 are also used to receive the sampled signal value transmitted by the first coupling coil L1. The Signal terminal is used to connect to the detection circuit to transfer the sampled signal value to the detection circuit.

[0062] Figure 5 is a schematic diagram of an optional detection circuit according to an embodiment of the present utility model, such as Figure 5 As shown, the Signal terminal of the detection circuit is used to connect to the RF gain circuit, receive the sampled signal value, perform detection processing on the sampled signal value, and then send it to the second chip through the RFR terminal.

[0063] Figure 6 is a schematic diagram of an optional second chip according to an embodiment of the present utility model, such as Figure 6 As shown, the RFR pin of the second chip is connected to the RFR terminal of the detection circuit to receive the sampled signal value after detection processing; the RFP pin and RFN pin of the second chip are respectively connected to the RFP terminal and RFN terminal of the RF gain circuit to control the RF gain circuit; the LED pin of the second chip is connected to the LED indicator light, the CN1 pin is used to debug the chip, the IDA pin is used to burn the program, the ICK pin is used for input and output signals, and capacitors C4 and C5 are filter capacitors for the second chip. The second chip can determine the device state of the target device based on the relationship between the pre-stored preset sampled signal value and the preset device state, and determine the temperature of the target device based on the relationship between the pre-stored preset sampled signal value and the preset temperature value under different device states.

[0064] Through the cooperation of the RF gain circuit, the detection circuit and the second chip, the signal processing circuit 11 supplies power to the signal detection circuit 10, obtains the sampling signal value detected by the signal detection circuit 10, and further determines the device temperature and device status based on the sampling signal value.

[0065] An embodiment of the present utility model also provides a cooking device.

[0066] Figure 7 Schematic diagram of a cooking device according to an embodiment of the present invention. Figure 7 As shown, the cooking device includes:

[0067] The signal detection system according to any one of the above embodiments.

[0068] A pot body 21 and a pot cover 22 arranged on the top of the pot body 21, the pot cover 22 is used to seal the pot body 21, wherein the signal detection circuit 10 in the signal detection system is arranged on the pot cover 22, and the signal processing circuit 11 in the signal detection system is arranged on the pot body 21.

[0069] It should be noted that the cooking device in this embodiment can be a split electric pressure cooker, the pot body 21 and the pot lid 22 are detachable, and the signal detection circuit 10 is arranged on the pot lid 22. In order to make the pot lid 22 light, the signal detection circuit 10 does not have a power supply or charger. The signal detection circuit 10 is a wireless module. When the lid is closed, the pot body 21 and the pot lid 22 are in contact, and the signal detection circuit 10 is within the sensing range of the signal processing circuit 11. The signal processing circuit 11 powers the signal detection circuit 10 by wireless charging. The signal detection circuit 10 transmits the detected sampling signal value to the signal processing circuit 11 by wireless transmission, and the signal processing circuit 11 processes the sampling signal value into temperature and device status.

[0070] The micro control unit 30 is in communication with the signal processing circuit 11 and is used to receive the output result of the signal processing circuit 11 and control the operation of the pot body 21.

[0071] Specifically, during the operation of the cooking device, the microcontroller unit 30 continuously calls the temperature and device status collected by the signal processing circuit 11 to obtain the real-time temperature and real-time pressure status inside the cooking device. On the one hand, it determines which stage of the cooking program to enter based on the temperature. On the other hand, when the pressure state in the pot jumps to the unpressurized state during the exhaust stage, a lid-opening signal can be output to solve the problem of long waiting time for users to exhaust. On the other hand, when the pressure state in the pot jumps to the unpressurized state during the exhaust stage, the corresponding temperature is the boiling point, and the boiling point can be accurately detected, so that the cooking temperature can be controlled according to the accurate boiling point when cooking porridge or soup, ensuring sufficient cooking while avoiding overflowing the pot.

[0072] The cooking device provided by the present invention comprises a signal detection system according to any of the above embodiments; a pot body 21; and a pot lid 22 disposed on top of the pot body 21, the pot lid 22 being used to seal the pot body 21. The signal detection circuit 10 in the signal detection system is disposed on the pot lid 22, and the signal processing circuit 11 in the signal detection system is disposed on the pot body 21; and a microcontroller unit 30, which is in communication with the signal processing circuit 11 and is configured to receive the output of the signal processing circuit 11 and control the operation of the pot body 21. The present invention solves the problem in the related art that the thermistor in the temperature detection module disposed on the pot lid of a split-type electric pressure cooker can only sense temperature signals but not pressure signals, making it difficult to detect the pressure state within the pot. The sampled signal value collected by the signal detection circuit 10 disposed on the pot lid 22 can reflect the device temperature and pressure state. The signal processing circuit 11 disposed on the pot body 21 obtains the sampled signal value via wireless transmission, thereby achieving the effect of simultaneously detecting the temperature and pressure state within the electric pressure cooker by the detection circuit, thereby improving the cooking quality and efficiency of the cooking device.

[0073] Optionally, in the cooking device provided in the embodiment of the present invention, a stopper rod is provided on the pot cover 22, and the open and closed state of the stopper rod is used to determine the on and off state of the switch device K.

[0074] It should be noted that the anti-opening lever is located at the edge of the electric pressure cooker's lid 22. When the pressure inside the electric pressure cooker rises to an upward pressure state, the anti-opening lever is pushed to the closed position by the internal pressure, locking the lid 22 and preventing it from accidentally opening when the pressure is too high. When the anti-opening lever is open, the pot is in a non-pressurized state, and the switch device K can be in the open state. When the anti-opening lever is closed, the pot is in an upward pressure state, and the switch device K can be in the closed state, thereby establishing a correlation between the on-off state of the switch device K and the open-close state of the anti-opening lever.

[0075] Through this embodiment, the on-off state of the switch device K is associated with the open-close state of the anti-opening rod in the cooking device. The open-close state of the anti-opening rod reflects the pressure state of the cooking device, so that the on-off state of the switch device K reflects the pressure state of the cooking device.

[0076] Optionally, in the cooking device provided in the embodiment of the present invention, the anti-opening rod is connected to a trigger member, the switch device K is an induction switch, and the trigger member is used to trigger the on and off of the induction switch.

[0077] Specifically, when the cooking device is in a non-pressurized state, the anti-opening rod drives the trigger part away from the sensing switch when it is opened, and the sensing switch is in an open state if it cannot sense the trigger part. When the cooking device is in a pressurized state, the anti-opening rod drives the trigger part close to the sensing switch when it is closed, and the sensing switch is in a closed state if it senses the trigger part. The pressure state in the pot can be accurately detected through the cooperation of the trigger part and the sensing switch.

[0078] Optionally, in the cooking device provided in the embodiment of the present invention, the triggering member is a magnet, and the induction switch is a magnetically controlled switch.

[0079] Specifically, the cooking device can be an electric pressure cooker, and the magnetic control switch can be a reed switch, a Hall element, etc. For example, the magnetic control switch is a reed switch, and the pot is in a non-pressurized state. When the anti-opening rod is opened, it drives the magnet away from the reed switch. If the reed switch cannot detect the magnet, it is in a disconnected state. When the pot is in a pressurized state, when the anti-opening rod is closed, it drives the magnet close to the reed switch. If the reed switch detects the magnet, it is in a closed state. The pressure state in the pot can be accurately detected by the cooperation of the magnet and the reed switch.

[0080] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0081] The above are merely examples of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the claims of the present invention.

Claims

1. A signal detection circuit, characterized in that: include: A sampling circuit (101) comprises a first resistor (R1), a second resistor (R2), and a third resistor (R3) connected in series, wherein the second resistor (R2) is a temperature sensor provided inside a target device, and the third resistor (R3) is connected in parallel with a switch device (K), wherein the on / off state of the switch device (K) is determined by the device state of the target device; The first chip (102) supplies power to the sampling circuit (101) through a first power port, collects the voltage of a sampling point on the line between the first resistor (R1) and the second resistor (R2) through a signal line, and obtains a sampling signal value.

2. The signal detection circuit according to claim 1, wherein: The resistance range of the second resistor (R2) is 0.1KΩ-100KΩ, and the resistance range of the third resistor (R3) is 10KΩ-100KΩ.

3. The signal detection circuit according to claim 2, wherein: A bias resistor (REF) is connected in series between the first resistor (R1) and the second resistor (R2), the resistance range of the bias resistor (REF) is 0KΩ-30KΩ, and the resistance range of the first resistor (R1) is 2KΩ-30KΩ.

4. The signal detection circuit according to claim 1, wherein: The signal detection circuit further includes: A first wireless power supply circuit (103) comprises a first coupling coil (L1) connected in parallel to both ends of the second power port and the third power port of the first chip (102), and a first capacitor (C1) connected in parallel to the first coupling coil (L1), wherein the first coupling coil (L1) is used to obtain electric energy and charge the first capacitor (C1), and the first capacitor (C1) is used to discharge the electric energy to the second wireless power supply circuit (104); The second wireless power supply circuit (104) comprises a second capacitor (C2) connected in series between a fourth power port of the first chip (102) and a ground line, and a fourth resistor (R4) connected in parallel with the second capacitor (C2), wherein the first capacitor (C1) charges the second capacitor (C2) through the fourth resistor (R4), and the second capacitor (C2) supplies power to the first chip (102) through the fourth resistor (R4).

5. A signal detection system, characterized in that: include: The signal detection circuit (10) according to any one of claims 1 to 4, configured to collect sampled signal values ​​and send the sampled signal values ​​to a signal processing circuit (11); The signal processing circuit (11) is in wireless communication with the signal detection circuit (10) and is used to supply power to the signal detection circuit (10).

6. The signal detection system according to claim 5, characterized in that: The signal processing circuit (11) comprises: A radio frequency gain circuit is connected to the second chip and includes a second coupling coil (L2) for controlling the oscillation of the second coupling coil (L2) to charge the signal detection circuit (10) and receive the sampling signal; The detection circuit is connected to the second chip and is used to perform detection processing on the sampling signal and send the processed signal to the second chip.

7. A cooking device, characterized in that: include: The signal detection system according to any one of claims 5 to 6; A pot body (21), and a pot cover (22) arranged on the top of the pot body (21), wherein the pot cover (22) is used to seal the pot body (21), wherein the signal detection circuit (10) in the signal detection system is arranged on the pot cover (22), and the signal processing circuit (11) in the signal detection system is arranged on the pot body (21); A micro control unit (30) is communicatively connected to the signal processing circuit (11) and is used to receive an output result of the signal processing circuit (11) and control the operation of the pot body (21).

8. The cooking device according to claim 7, characterized in that The pot cover (22) is provided with a stopper rod, and the open and closed state of the stopper rod is used to determine the on and off state of the switch device (K).

9. The cooking device according to claim 8, characterized in that The anti-opening rod is connected to a triggering member, and the switch device (K) is an induction switch, and the triggering member is used to trigger the on and off of the induction switch.

10. The cooking device according to claim 9, characterized in that The triggering member is a magnet, and the induction switch is a magnetically controlled switch.

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