Circuit structure of sensor, intelligent sensor and safety door switch

Abstract

The utility model provides a circuit structure of a sensor, an intelligent sensor and a safety door switch. A wireless transceiver chip; the reference voltage switching circuit module is electrically connected with the wireless transceiver chip and is used for providing reference voltage; the LC resonance circuit is electrically connected with the wireless transceiver chip; and the microprocessor is electrically connected with the antenna, the wireless transceiver chip and the reference voltage switching circuit module. Compared with the prior art, the resonant frequency of the LC resonant circuit electrically connected with the wireless transceiver chip and the carrier frequency of the antenna can be conveniently adjusted, so that the modulation depth of the sensor is conveniently adjusted.

Description

Technical Field

[0001] The utility model relates to a sensor, in particular to a sensor, an intelligent sensor and a safety door switch. Background Art

[0002] In the prior art, RFID technology usually refers to radio frequency technology, which mainly relies on the principle of magnetic field or electromagnetic field to achieve two-way communication between devices through wireless radio frequency, thereby realizing the function of exchanging data. In traditional door switches, the modulation depth of the sensor reader is usually fixed, the automatic coordination effect is poor, and the stable recognition effect is poor at the critical distance where data can be exchanged with the sensor, which makes it difficult to meet the demand for stability in the process sensor industry.

[0003] Therefore, how to provide a circuit structure of a sensor and how to conveniently adjust the resonant frequency of the LC resonant circuit electrically connected to the wireless transceiver chip and the carrier frequency of the antenna so as to facilitate adjustment of the modulation depth of the sensor are technical problems that need to be urgently solved in the present invention. Utility Model Content

[0004] The purpose of the utility model is to provide a sensor, a safety door switch and a control method thereof, so as to solve the technical problem of conveniently adjusting the resonant frequency of the LC resonant circuit electrically connected to the wireless transceiver chip and the carrier frequency of the antenna, thereby facilitating the adjustment of the modulation depth of the sensor.

[0005] In order to achieve the above object, the utility model proposes a circuit structure of a sensor, which includes:

[0006] antenna;

[0007] Wireless transceiver chip;

[0008] A reference voltage switching circuit module electrically connected to the wireless transceiver chip and used to provide a reference voltage;

[0009] An LC resonant circuit electrically connected to the wireless transceiver chip;

[0010] A microprocessor electrically connected to the antenna, the wireless transceiver chip, and the reference voltage switching circuit module.

[0011] Further preferably, the reference voltage switching circuit module is used to output more than two reference voltages, wherein the reference voltages at least include: a first reference voltage greater than a common voltage, and at least one second reference voltage less than a common voltage. The common voltage is the voltage used to power the wireless transceiver chip when the reference voltage switching circuit module switches from the reference voltage regulating circuit to the common voltage circuit or turns off the reference voltage switching circuit module.

[0012] Further preferably,

[0013] The reference voltage switching circuit module includes: a switching circuit switch for adjusting the reference voltage; wherein one end of the switching circuit switch is electrically connected to the first signal output end of the microprocessor, and the other end is electrically connected to the wireless transceiver chip; the switching circuit switch is used to connect the wireless transceiver chip to the corresponding reference voltage adjustment circuit according to the received first signal;

[0014] One input end of the switching circuit switch is also electrically connected to the second signal output end of the microprocessor, and the other end is electrically connected to the wireless transceiver chip; the switching circuit switch is used to enable the wireless transceiver chip to conduct the circuit connecting the common voltage circuit and the normal voltage protection circuit according to the received second signal; wherein the wireless transceiver chip is electrically connected between the normal voltage protection circuit and the reference voltage adjustment circuit; the output voltage of the common voltage circuit is the same as that of the normal voltage protection circuit.

[0015] Further preferably, the reference voltage regulation circuit also includes: a first regulation resistor having one end electrically connected to the first output end of the switching circuit switch and the other end electrically connected to the wireless transceiver chip, and a second regulation resistor having one end electrically connected to the second output end of the switching circuit switch and the other end electrically connected to the wireless transceiver chip.

[0016] Further preferably, the resistance value of the first adjusting resistor is greater than the resistance value of the second adjusting resistor; wherein the resistance value of the first adjusting resistor is 19KΩ; and the resistance value of the second adjusting resistor is 683Ω.

[0017] Further preferably, it also includes: a storage chip electrically connected to the microprocessor, for storing the identification number matched by the sensor and the trigger for data interaction.

[0018] Further preferably, it also includes: an output control circuit electrically connected to the microprocessor and used to drive an external load, and a power supply electrically connected to the output control circuit and the microprocessor, wherein the output control circuit includes: a first protection resistor, a first transistor and a first grounding resistor electrically connected to the external load in sequence, and a second protection resistor connected in parallel with the series circuit formed by the first protection resistor and the first transistor; wherein the collector of the first transistor is connected to the signal output end of the microprocessor, the base is connected to the first protection resistor, and the emitter is connected to the first grounding resistor.

[0019] Further preferably, the output control circuit also includes: a detection circuit connected in parallel with the first grounding resistor; wherein the detection circuit includes: a third protection resistor and a circuit protection capacitor connected in series, and a second transistor connected in parallel with the circuit protection capacitor, and the collector of the second transistor is electrically connected to the microprocessor; wherein the collector of the second transistor is grounded through the second grounding resistor, the base is connected to the third protection resistor, and the emitter is connected to the circuit protection capacitor.

[0020] Further preferably, the resistance value of the first grounding resistor is 2.2Ω; the resistance of the first protection resistor is 1KΩ; the resistance of the second protection resistor is 10KΩ; the resistance of the third protection resistor is 1KΩ; the resistance of the second grounding resistor is 10KΩ; and the capacitance value of the circuit protection capacitor is 100N.

[0021] The present application also provides an intelligent sensor, including: the circuit structure of the above-mentioned sensor.

[0022] The present application also provides a safety door switch, comprising: the above-mentioned smart sensor.

[0023] Further preferably, the smart sensor is an RFID sensor.

[0024] Compared with the prior art, the sensor, safety door switch and control method thereof provided in the present application conveniently adjust the resonant frequency of the LC resonant circuit electrically connected to the wireless transceiver chip and the carrier frequency of the antenna, thereby facilitating adjustment of the modulation depth of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a circuit module block diagram of a sensor in one embodiment of the utility model;

[0026] Figure 2 This is a schematic diagram of the circuit structure of a reference voltage switching circuit module in one embodiment of the utility model;

[0027] Figure 3 This is a schematic diagram of the circuit structure of an output control circuit in one embodiment of the utility model;

[0028] Figure 4 This is a control flow chart of a control method for a safety door switch in one embodiment of the utility model;

[0029] Figure 5 This is a specific flow chart of step S30 in an embodiment of the present utility model;

[0030] Figure 6 A control flow chart of a control method for a safety door switch preferably used in the second embodiment of the present utility model;

[0031] Figure 7 This is a specific flow chart of S1 in the second embodiment of the present utility model. DETAILED DESCRIPTION

[0032] The sensor of the present invention will be described in more detail below in conjunction with a schematic diagram, wherein a preferred embodiment of the present invention is shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the beneficial effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art, and not as a limitation to the present invention.

[0033] Embodiment 1

[0034] This embodiment provides a circuit structure of a sensor, such as Figures 1 to 4 As shown, it is mainly composed of an antenna for receiving radio frequency signals and sending carrier signals, a wireless transceiver chip, a reference voltage switching circuit module electrically connected to the wireless transceiver chip and used to provide and adjust the reference voltage, an LC resonant circuit electrically connected to the wireless transceiver chip (not shown in the figure), and a microprocessor.

[0035] The microprocessor is electrically connected to the antenna, the wireless transceiver chip, and the reference voltage switching circuit module. The wireless transceiver chip is preferably an RFID chip.

[0036] In addition, the microprocessor is used to control the reference voltage switching circuit module to start after sensing and identifying the trigger, and adjust the reference voltage used to power the wireless transceiver chip to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby adaptively adjusting the distance range for data interaction with the trigger.

[0037] From the above content, it can be known that: this embodiment can change the power supply voltage of the wireless transceiver chip by starting or shutting down the reference voltage switching circuit module, and by starting the reference voltage switching circuit module, that is, by providing a corresponding reference voltage, provide different power supply voltages to the wireless transceiver chip, thereby realizing the adjustment of the LC resonant circuit and the antenna voltage matched with the wireless transceiver chip, so as to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, so that the electromagnetic field generated by the antenna and the trigger for data interaction changes, generates different magnetic fields, and then changes the distance for data exchange.

[0038] The specific working principle is as follows:

[0039] When the trigger approaches the working area of ​​the sensor and is activated by the radio frequency signal transmitted by the antenna, the antenna then sends a carrier signal with an identification code signal, so that the wireless transceiver chip converts the received carrier signal into a corresponding induced voltage signal, and the trigger recognizes the trigger. Then, the reference voltage switching circuit module can be started to provide the wireless transceiver chip with a corresponding power supply voltage, i.e., a reference voltage, and adjust the corresponding reference voltage, thereby realizing the adjustment of the LC resonant circuit and the antenna voltage that match the wireless transceiver chip.

[0040] Therefore, through the above steps, the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna can be further adjusted, so that the electromagnetic field generated by the antenna and the trigger for data interaction changes, and different magnetic fields are generated, so that when the trigger reaches a range matching the magnetic field, the coil of the trigger obtains a stable voltage, and continues to achieve stable data exchange at different distance points. For example, by adjusting the carrier frequency to 125KHZ, electromagnetic induction can be directly generated with the coil of the electronic tag in the trigger, and then data exchange can be performed stably. In other words, when the trigger is close to the sensor, the modulation depth can be increased to achieve near-point triggering, and when the trigger is far away from the sensor, the modulation depth can be reduced to achieve far-point disconnection, thereby adaptively adjusting the distance range for data interaction with the trigger, thereby improving the stability of the sensor output signal, and effectively avoiding the technical problem of the sensor acting as a driving switch being frequently turned on and off when the trigger is close to the critical distance of the sensor, so as to increase its service life.

[0041] In addition, when the sensor in this embodiment can be applied to load equipment such as a safety door switch or used as a sensor switch, the above structure can effectively prevent the sensor from frequently starting and stopping the load equipment when the trigger is close to the critical distance of the sensor.

[0042] Specifically, the reference voltage switching circuit module includes: a switching circuit switch for adjusting the reference voltage. The switching circuit switch is connected to the first signal output terminal of the microprocessor, such as Figure 1The first signal input terminal IN1 shown in is electrically connected, and the other end is electrically connected to the wireless transceiver chip. The switching circuit switch is used to send a first signal to the switching circuit switch after the microprocessor detects an induced voltage, that is, the voltage signal corresponding to the carrier signal received by the antenna detected above is greater than the corresponding preset value, so that the switching circuit switch is connected to the corresponding reference voltage adjustment circuit according to the received first signal. Wherein, when the reference voltage switching circuit module is turned on, the microprocessor starts the switching circuit switch to connect the corresponding reference voltage adjustment circuit, thereby selecting R20 and R21 as different reference resistors, and then obtaining different reference voltages Vmodu, and providing them to the wireless transceiver chip, so that the LC resonant circuit matched with the wireless transceiver chip will be affected by the reference voltage and generate different magnetic fields.

[0043] Further preferably, one end of the switching circuit switch is Figure 2 The COM terminal shown is connected to the second signal output terminal of the microprocessor, such as Figure 1 The second signal input terminal IN2 shown in the figure is electrically connected, and the other end is electrically connected to the wireless transceiver chip, and is connected to the voltage signal path between the reference voltage adjustment circuit and the normal voltage protection circuit. The reference voltage adjustment circuit can be turned on and off by the voltage path. When the microprocessor receives the induced voltage, that is, the voltage signal corresponding to the carrier signal received by the antenna detected above is less than the corresponding preset value, a second signal is sent to the second signal input terminal IN2 of the switching circuit switch set in the reference voltage switching circuit module to make the circuit between the common voltage circuit and the normal voltage protection circuit conductive, for example, Figure 2 The reference voltage regulating circuit in the reference voltage switching circuit module is electrically connected to the digital logic voltage DVDD as shown in , thereby closing the reference voltage regulating circuit in the reference voltage switching circuit module. Wherein, the resistance value of the resistor R11 corresponding to the normal voltage protection circuit is preferably 100KΩ. And, the normal voltage protection circuit also includes: a protection capacitor C13 connected in parallel with the resistor R11, wherein C13 is preferably 220N. The VCC end of the switching circuit switch is electrically connected to the digital logic voltage DVDD, and at the same time, the VCC end and the GND end of the switching circuit switch are connected in parallel with the protection capacitor C19, and the capacitance value of the protection capacitor C19 is 100N. And, the second signal in this embodiment is preferably a high-level signal. When the second signal output end of the microprocessor sends a high-level signal to the second output end (NC end), the switching circuit switch conducts the circuit loop between the common voltage circuit and the normal voltage protection circuit. When the second signal output end of the microprocessor sends a low-level signal to the second output end (NC end), the switching circuit switch closes the circuit loop between the common voltage circuit and the normal voltage protection circuit.

[0044] In addition, it is worth mentioning that the output voltages of the common voltage circuit and the normal voltage protection circuit are preferably common voltages, and are preferably digital logic voltages DVDD with a voltage magnitude of 3.3V.

[0045] Here, it is worth mentioning that the switching circuit switch in this embodiment is preferably an analog switch, and its model may preferably be sgm3001.

[0046] Further preferably, the voltage input terminal of the wireless transceiver chip is electrically connected between the normal voltage protection circuit and the reference voltage adjustment circuit to obtain a reference voltage or a common voltage.

[0047] Further preferably, the reference voltage regulating circuit at least comprises: one end connected to the first output end of the switching circuit switch, that is, Figure 2 The NO end is electrically connected to the NO end shown in the figure, and the other end is electrically connected to the first regulating resistor R21 of the wireless transceiver chip, and to the second output end of the switching circuit switch, that is, Figure 2 The NC end shown in the figure is electrically connected, and the other end is electrically connected to the wireless transceiver chip. The resistance of the first regulating resistor R21 is greater than the resistance of the second regulating resistor R20, and the resistance of the first regulating resistor R21 is 19KΩ. The resistance of the second regulating resistor R20 is 68KΩ. Wherein, the microprocessor can output voltage signals of different voltages through the first signal output end of the microprocessor, such as high-level signals and low-level signals, to respectively realize the conduction of the first output end (NO end) and the second output end (NC end), so that the reference voltage regulating circuit provides different reference voltages, thereby realizing different modulation depths. For example, when the trigger is relatively close to the sensor, a high-level signal is output through the second signal output end to turn on the NO end, thereby increasing the reference voltage, so as to increase the modulation depth, and realize a closer near-point triggering compared to the triggering distance under the normal pressure state, and when the trigger is relatively far away from the sensor, the modulation depth is reduced, and the triggering distance under the normal pressure state is compared to the triggering distance, and the farther-away far-point disconnection is realized. Furthermore, it is worth mentioning that the induced voltage signal corresponding to the high level signal in this embodiment is greater than the induced voltage signal corresponding to the low level signal.

[0048] In addition, it is worth mentioning that the reference voltage adjustment circuit in this embodiment is not limited to the above-mentioned two-way adjustment circuit with different outputs and different reference voltages, and can also achieve the output of reference voltages of different voltage sizes by setting a variety of different size adjustment resistors.

[0049] Further preferably, the sensor also includes: a storage chip electrically connected to the microprocessor, for storing the identification number matched by the sensor and the trigger for data interaction; wherein the microprocessor is used to control the reference voltage switching circuit module to start after determining that the trigger matches the identification number, and adjust the carrier frequency so that the trigger is affected by the electromagnetic field of the antenna at different preset distances to generate a stable voltage for triggering data interaction. Here, it is worth mentioning that the trigger in this embodiment is mainly composed of an electronic tag chip and a matching coil. After the trigger enters the electromagnetic field provided by the sensor, the matching coil of the trigger will obtain a voltage through electromagnetic induction. When the voltage amplitude reaches the minimum voltage required for the electronic tag to start, the electronic tag can interact with the wireless transceiver chip for data, and the identification number stored in the above storage chip can preferably be the electronic tag ID identification number.

[0050] Further preferably, in order to facilitate the sensor to drive an external load, such as a safety door switch, the sensor also includes: an output control circuit electrically connected to the microprocessor and used to drive the external load, and a power supply electrically connected to the output control circuit and the microprocessor, wherein the output control circuit includes: a first protection resistor R14, a first transistor T1 and a first grounding resistor R16 electrically connected to the external load in sequence, and a second protection resistor R17 connected in parallel with the series circuit formed by the first protection resistor R14 and the first transistor T1; wherein the collector of the first transistor T1 is connected to the signal output terminal out1 of the microprocessor, the base is connected to the first protection resistor R14, and the emitter is connected to the grounding resistor R16. Wherein, the grounding resistor R16 is connected to the ground GND, and the resistance value is 2.2Ω. The resistance of the first protection resistor R14 is preferably 1KΩ. The resistance of the second protection resistor R17 is preferably 10KΩ.

[0051] Further preferably, in order to enable the sensor to output a load start signal or stop signal to an external load through an output control circuit, and also to monitor the current in the load circuit, the output control circuit further includes: a detection circuit connected in parallel with the grounding resistor R16; wherein the detection circuit includes: a third protection resistor R15 and a circuit protection capacitor C14 connected in series, and a second triode T2 connected in parallel with the circuit protection capacitor C14, and the collector of the second triode T2 is electrically connected to the microprocessor; wherein the collector of the second triode T2 is grounded through the second grounding resistor R13, the base is connected to the third protection resistor R15, and the emitter is connected to the circuit protection capacitor C1. The resistance of the third protection resistor R15 is preferably 1KΩ. The resistance of the second grounding resistor R13 is preferably 10KΩ. The capacitance value of the circuit protection capacitor C14 is 2.2N.

[0052] When connected to an external load, such as Figure 4When the output terminal out for electrically connecting the load shown in the figure, the first protection resistor R14, the first transistor T1 and the first grounding resistor R16 electrically connected in sequence, and the second protection resistor R17 connected in parallel with the series circuit formed by the first protection resistor R14 and the first transistor T1, etc. are connected to the power supply to form a load loop, if the current in the load loop is too large, the emitter of the second transistor T2 will generate a falling edge level, so that the microprocessor receives the falling edge level through the base of the second transistor T2, thereby controlling its signal output terminal to stop transmitting the output signal, thereby stopping driving the load.

[0053] In addition, the above-mentioned sensor also includes: a power conversion module electrically connected to the microprocessor and to the external power supply, so as to realize the regulated power supply to the microprocessor in the sensor, as well as the wireless transceiver chip, the output control circuit, the reference voltage adjustment circuit, the LC resonant circuit and the antenna.

[0054] In addition, it is worth mentioning that the digital logic voltage DVDD in the above output control circuit is preferably 3.3V.

[0055] Embodiment 2

[0056] This embodiment further provides a safety door switch, comprising: the sensor in any one of the above-mentioned embodiments.

[0057] Embodiment 3

[0058] This embodiment also provides a method for controlling a safety door switch, which is executed by the sensor in the above-mentioned embodiment 2. Figure 3 As shown, it includes the following steps:

[0059] Step S10: Obtaining the identification code of the trigger;

[0060] Step S20: determining whether the identification code matches the preset identification number;

[0061] Step S30: If the match is successful, the reference voltage switching circuit module is controlled to start and the reference voltage used to power the wireless transceiver chip is adjusted to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby adaptively adjusting the distance range for data interaction with the trigger.

[0062] Through the above steps, after the microprocessor senses and identifies the trigger, it can control the reference voltage switching circuit module to start up and adjust the reference voltage used to power the wireless transceiver chip by means of identity pairing identification, so as to adjust the LC resonant circuit and the antenna voltage, so as to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby changing the electromagnetic field for data exchange between the antenna and the trigger, and generating different magnetic fields, so that when the trigger reaches a range matching the magnetic field, the coil of the trigger obtains a stable voltage, and continues to realize stable data exchange at different distance points. For example, adjusting the carrier frequency to 125KHZ can directly generate an electromagnetic field with the coil of the electronic tag in the trigger. Induction, and then stably exchange data, that is to say, when the trigger is close to the sensor, the modulation depth is increased to achieve near-point triggering, and when the trigger is far away from the sensor, the modulation depth is reduced to achieve far-point disconnection, so as to adaptively adjust the distance range for data interaction with the trigger, thereby improving the stability of the sensor output signal, and effectively avoiding the technical problem of the sensor being frequently turned on and off as a driving switch when the trigger is close to the critical distance of the sensor, so as to increase its service life, especially when the sensor is applied to load equipment such as safety door switches, through the above method, it can be effectively avoided that when the trigger is close to the critical distance of the sensor, the sensor frequently starts and stops the load equipment, and the door switch authority is managed to improve the security level.

[0063] Further preferably, if the matching is successful, the reference voltage switching circuit module is controlled to start, and the reference voltage used to power the wireless transceiver chip is adjusted to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, such as Figure 4 As shown, step S30 includes the following steps:

[0064] Step S301: determining whether the induced voltage is greater than a first preset value;

[0065] Step S302: If yes, the reference voltage switching circuit module is controlled to start and switch the reference voltage regulating circuit to increase the reference voltage, thereby increasing the modulation depth, and reacquiring the induced voltage. Specifically, when the microprocessor of the sensor receives the induced voltage and determines that the induced voltage is greater than the corresponding first preset value, a high-level first signal is sent to the switching circuit switch, so that according to the received high-level first signal, the corresponding reference voltage regulating circuit is turned on, so as to increase the reference voltage while realizing the opening of the reference voltage regulating circuit, so as to increase the modulation depth, thereby realizing a closer proximity triggering than the triggering distance under the normal pressure state.

[0066] Step S303: If not, determining whether the induced voltage is greater than a second preset value, wherein the second preset value is less than the first preset value;

[0067] Step S304: If yes, the reference voltage switching circuit module is controlled to start and switch the reference voltage regulating circuit to reduce the reference voltage, thereby reducing the modulation depth, and reacquiring the induced voltage. Specifically, when the microprocessor of the sensor receives the induced voltage and determines that the induced voltage is less than the first preset value but greater than the second preset value, a low-level first signal is sent to the switching circuit switch, so that according to the received first signal, the corresponding reference voltage regulating circuit is turned on and connected, so that according to the received high-level first signal, the corresponding reference voltage regulating circuit is turned on and connected, so that while realizing the opening of the reference voltage regulating circuit, the reference voltage is reduced to reduce the modulation depth, thereby realizing a longer-distance far-point triggering compared to the triggering distance under the normal pressure state.

[0068] Step S305: If not, then turn off the reference voltage switching circuit module. Specifically, when the sensor's microprocessor receives the induced voltage and determines that the induced voltage is less than the corresponding second preset value, it sends a second signal to the switching circuit switch, so that according to the received second signal, the corresponding common voltage circuit and the normal voltage protection circuit are connected to achieve the closure of the reference voltage switching circuit module. In addition, it is explained here that turning off the reference voltage switching circuit module in this embodiment also refers to the state in which the reference voltage adjustment circuit is switched to the common voltage circuit in the above-mentioned reference voltage switching circuit module.

[0069] Through the above method, different modulation depths can be obtained, and the distance range for data interaction with the trigger can be adaptively adjusted, thereby improving the stability of the sensor output signal and effectively avoiding the sensor from frequently starting and stopping as a driving switch when the trigger is close to the critical distance of the sensor.

[0070] Here, it should be noted that, in this embodiment, the first preset value is preferably 0.8V, and the second preset value is preferably 1.5V, and this is only taken as an example for explanation without any specific limitation.

[0071] In addition, as a preferred method, in the step of obtaining the identification code of the trigger, such as Figure 5 As shown, the following steps are included before step S10:

[0072] Step S1: obtaining an induced voltage signal matching the trigger;

[0073] Step S2: Send a query command to the trigger according to the induced voltage signal, wherein after receiving the query command, the trigger generates a random code according to a preset algorithm and sends the random code to the sensor; wherein the preset algorithm may preferably be a random generation algorithm. wherein the random code may preferably be a random number, such as a natural number greater than 0.

[0074] Step S3: Generate an encryption code according to the received random code and preset rules; wherein the preset rules may preferably be a random generation algorithm. wherein the preset rules may preferably be a random generation algorithm, and the encryption code may preferably be a random value, such as a natural number greater than 0.

[0075] Step S4: Calculate the key digital number according to the random code, the encryption code and the preset key algorithm;

[0076] Step S5: Send the key digital number to the trigger, wherein the trigger decodes the key digital number according to a preset decryption algorithm and the random code to obtain a decryption code, and binds the decryption code and the identification code and sends it to the sensor.

[0077] Step S6: Determine whether the obtained decryption code matches the encryption code;

[0078] Step S7: If the matching is successful, unbind and obtain the identification code, otherwise re-acquire the induced voltage signal until multiple matching fails and exit.

[0079] Through the above steps, before the sensor and the trigger are matched and identified, interactive authentication can be performed based on the voltage signal generated on the sensor due to the impedance effect when the trigger is close to the sensor body, so as to avoid the technical problem of premature activation of the identification code matching due to large fluctuations caused by frequent approach or distance between the user and the sensor when using the trigger. In addition, by generating corresponding random codes and encryption codes for encryption and decryption by the trigger and the sensor respectively, it can be ensured that the trigger and the sensor are uniquely matched and authenticated by electromagnetic induction in the absence of an identification code, so as to avoid premature matching of the trigger due to mistaken approach to the sensor, thereby causing the sensor to start prematurely and fail to trigger the corresponding operation instruction, etc. In addition, encryption can be maintained during the matching process through the key algorithm and the decryption algorithm, so as to better avoid information leakage and security risks.

[0080] In addition, it is worth mentioning that the key algorithm and the decryption algorithm in this embodiment can preferably be the same set of algorithms and are inverse operations of each other, such as DESL, AES, HIGHT, and XXTEA algorithms.

[0081] In addition, the above steps can avoid the situation where the trigger matches other sensors that are arranged nearby.

[0082] like Figure 7 As shown, the step of obtaining the induced voltage signal matching the trigger, i.e., step S1, includes the following steps:

[0083] Step S11: when there are multiple induced voltage signals acquired within the set time and rule, the average voltage value of the induced voltage corresponding to each induced voltage signal is calculated. Specifically, the set time and rule may be: setting the period of the induced voltage signal to 50 ms, and detecting at least five periods of the induced voltage signal;

[0084] Step S12: determining whether the average voltage value is greater than a preset average voltage value;

[0085] Step S13: If yes, the average voltage value is used as the induced voltage;

[0086] Step S14: If not, continue to judge until exiting after a preset time, wherein the preset time may preferably be 2 seconds or the like.

[0087] By obtaining the induced voltage signal multiple times and calculating the average value, the interference caused by the instability of the generated voltage signal can be reduced.

[0088] The above are only preferred embodiments of the present invention and do not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, may make any equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which shall be deemed as the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A circuit structure of a sensor, characterized in that: include: antenna; Wireless transceiver chip; A reference voltage switching circuit module electrically connected to the wireless transceiver chip and used to provide a reference voltage; An LC resonant circuit electrically connected to the wireless transceiver chip; A microprocessor electrically connected to the antenna, the wireless transceiver chip, and the reference voltage switching circuit module.

2. The circuit structure of the sensor according to claim 1, characterized in that: The reference voltage switching circuit module is used to output more than two reference voltages, wherein the reference voltages include at least: a first reference voltage greater than a commonly used voltage, and at least one second reference voltage less than a commonly used voltage; the commonly used voltage is the voltage used to power the wireless transceiver chip when the reference voltage switching circuit module switches from the reference voltage adjustment circuit to the commonly used voltage circuit or turns off the reference voltage switching circuit module.

3. The circuit structure of the sensor according to claim 1, characterized in that: The reference voltage switching circuit module includes: a switching circuit switch for adjusting the reference voltage; wherein one end of the switching circuit switch is electrically connected to the first signal output end of the microprocessor, and the other end is electrically connected to the wireless transceiver chip; the switching circuit switch is used to connect the wireless transceiver chip to the corresponding reference voltage adjustment circuit according to the received first signal; One input end of the switching circuit switch is also electrically connected to the second signal output end of the microprocessor, and the other end is electrically connected to the wireless transceiver chip; the switching circuit switch is used to enable the wireless transceiver chip to conduct the circuit connecting the common voltage circuit and the normal voltage protection circuit according to the received second signal; wherein the wireless transceiver chip is electrically connected between the normal voltage protection circuit and the reference voltage adjustment circuit; the output voltage of the common voltage circuit is the same as that of the normal voltage protection circuit.

4. The circuit structure of the sensor according to claim 3, characterized in that: The reference voltage regulation circuit also includes: a first regulation resistor having one end electrically connected to the first output end of the switching circuit switch and the other end electrically connected to the wireless transceiver chip, and a second regulation resistor having the other end electrically connected to the second output end of the switching circuit switch and the other end electrically connected to the wireless transceiver chip.

5. The circuit structure of the sensor according to claim 4, characterized in that: The resistance value of the first regulating resistor is greater than the resistance value of the second regulating resistor; wherein the resistance value of the first regulating resistor is 19KΩ; and the resistance value of the second regulating resistor is 683Ω.

6. The circuit structure of the sensor according to claim 1, characterized in that: Also includes: The storage chip electrically connected to the microprocessor is used to store the identification number matched by the sensor and the trigger for data interaction.

7. The circuit structure of the sensor according to claim 1, characterized in that: Also includes: An output control circuit electrically connected to the microprocessor and used to drive an external load, and a power supply electrically connected to the output control circuit and the microprocessor, wherein the output control circuit includes: a first protection resistor, a first transistor and a first grounding resistor electrically connected to the external load in sequence, and a second protection resistor connected in parallel with the series circuit formed by the first protection resistor and the first transistor; wherein the collector of the first transistor is connected to the signal output end of the microprocessor, the base is connected to the first protection resistor, and the emitter is connected to the first grounding resistor.

8. The circuit structure of the sensor according to claim 7, characterized in that: The output control circuit also includes: a detection circuit connected in parallel with the first grounding resistor; wherein the detection circuit includes: a third protection resistor and a circuit protection capacitor connected in series, and a second transistor connected in parallel with the circuit protection capacitor, and the collector of the second transistor is electrically connected to the microprocessor; wherein the collector of the second transistor is grounded through the second grounding resistor, the base is connected to the third protection resistor, and the emitter is connected to the circuit protection capacitor.

9. The circuit structure of the sensor according to claim 8, characterized in that: The resistance value of the first grounding resistor is 2.2Ω; the resistance of the first protection resistor is 1KΩ; the resistance of the second protection resistor is 10KΩ; the resistance of the third protection resistor is 1KΩ; the resistance of the second grounding resistor is 10KΩ; and the capacitance value of the circuit protection capacitor is 100N.

10. An intelligent sensor, characterized in that: include: The circuit structure of the sensor as described in any one of claims 1 to 9 above; wherein the smart sensor is an RFID sensor.

11. A safety door switch, characterized in that: include: The smart sensor as claimed in claim 10.

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