A smart lock control circuit powered by induction

Abstract

This utility model belongs to the field of smart lock technology, specifically an inductively powered smart lock control circuit. It employs a low-power MCU chip and uses a low-frequency RFID circuit to emit an electromagnetic field to power the smart lock and establish secure authentication communication. After successful authentication, the MCU controls the motor drive circuit to unlock the lock. The circuit has a built-in supercapacitor for energy storage. It features an ESD-protected USB interface for wired charging and internal communication. The internal circuitry includes power management, status indication, and Hall effect detection, ensuring safety and reliability. It enables wired and wireless unlocking and charging of the electronic lock. In wireless mode, when the supercapacitor is fully charged, the unlocking speed is fast; when the charge is below a preset level, the unlocking speed can be appropriately reduced to ensure compatibility with different terminal devices.

Description

Technical Field

[0001] This utility model belongs to the field of smart lock technology, specifically a smart lock control circuit powered by induction. Background Technology

[0002] Currently, electronic locks typically rely on a terminal device to be brought close enough to obtain the energy needed for unlocking. To achieve rapid unlocking, existing technologies generally employ two methods: first, equipping the lock with a dedicated terminal device or connecting it to the lock body via a wired connection to quickly provide sufficient energy; second, using a wireless terminal, such as a mobile phone, for unlocking. However, different brands and models of mobile phones vary in their energy output performance, which can easily lead to delays or failures in the unlocking process, affecting the user experience.

[0003] Therefore, it is necessary to design the internal circuitry of electronic locks to enable them to achieve fast and stable energy acquisition and response even in wireless unlocking mode, and to have sufficient internal energy storage capacity so that they can work for a long time. Utility Model Content

[0004] Therefore, it is necessary to provide an inductively powered smart lock control circuit that can realize wired and wireless charging, and can intelligently manage the internal power supply. In wireless mode, if the power is sufficient, the lock can be unlocked quickly; if the power is insufficient, the unlocking speed can be slowed down to ensure compatibility with terminal devices.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0006] A smart lock control circuit powered by induction includes: an NFC identification module, a wireless charging module, a power control module, a power consumption control module, a motor control module, and a central processing module that are electrically connected.

[0007] The power control module is electrically connected to a supercapacitor;

[0008] The power control module is used to control the charging and discharging of the supercapacitor and to transmit the supercapacitor's power signal to the central processing module.

[0009] The NFC identification module is used to store the smart lock's identity ID information. When the terminal device triggers identification, it sends the identity ID information to the server for two-way verification. After successful verification, it obtains the key and generates an encryption command.

[0010] The wireless charging module receives AC signals from the terminal device through a charging antenna, and outputs DC voltage after rectification and voltage regulation to charge the supercapacitor.

[0011] The power consumption control module is signal-connected to the central processing module and controls the on / off of the power supply path from the supercapacitor to the central processing module according to the control instructions of the central processing module.

[0012] The motor control module receives the drive command from the central processing module and outputs the corresponding current to drive the micro motor to work.

[0013] The central processing module obtains the encryption command from the NFC identification module and compares the power signal with a preset threshold to determine the timing of the drive command issuance, so as to be compatible with different terminal devices.

[0014] Optionally, in one embodiment of this utility model, the supercapacitor is a lithium-ion supercapacitor to achieve rapid charging and discharging, long-term cyclic charging and discharging, and safe use.

[0015] Optionally, in one embodiment of this utility model, the NFC identification module includes a hardware encryption unit to improve security.

[0016] Optionally, in one embodiment of this utility model, the power consumption control module includes a logic circuit and a linear voltage regulator chip with a load switch and an enable terminal to realize the switching on and off of the power supply path of the battery.

[0017] Optionally, in one embodiment of this utility model, the wireless charging module is connected to a rectifier bridge, and also to a MOSFET and a transistor for voltage regulation control, so as to output a stable voltage and provide wireless charging for the internal circuit.

[0018] Optionally, in one embodiment of this utility model, the power control module is equipped with a battery protection circuit to realize intelligent management of internal power.

[0019] A sensor-powered smart padlock employs the aforementioned sensor-powered smart lock control circuit. The sensor-powered smart lock also includes a USB interface for wired charging and emergency unlocking. The USB interface is equipped with an electrostatic discharge protection diode to prevent damage to the internal circuitry from static electricity generated during plugging and unplugging.

[0020] Compared with the prior art, the control circuit of the inductively powered smart lock provided by this utility model has the following characteristics:

[0021] Employing a low-power chip as the central processing unit, it performs security authentication with the electronic lock via an NFC identification unit. After successful authentication, the central processing unit controls the motor drive circuit to unlock the lock. The internal circuitry features a power management system that supports charging the internal energy storage via a USB interface and also has wireless charging capabilities, enabling intelligent power switching. In wireless mode, when the battery is sufficiently charged, it can quickly draw power from the supercapacitor to unlock the lock without waiting for the terminal device to power it, thus improving the user experience. When the battery is low, the unlocking speed can be slowed down to ensure compatibility with different terminal devices. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a circuit diagram of the central processing module in Embodiment 1 of this utility model;

[0024] Figure 2 This is a circuit diagram of the NFC identification module in Embodiment 1 of this utility model;

[0025] Figure 3 This is a circuit diagram of the motor drive module of Embodiment 1 of this utility model;

[0026] Figure 4 This is a circuit diagram of the interface module of Embodiment 1 of this utility model;

[0027] Figure 5 This is a circuit diagram of the power consumption control module in Embodiment 1 of this utility model;

[0028] Figure 6 This is a circuit diagram of the wireless charging module according to Embodiment 1 of this utility model;

[0029] Figure 7 This is a circuit diagram of the power control module of Embodiment 1 of this utility model. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other. The technical solutions of the present invention will be further described below with reference to the accompanying drawings of the embodiments. The present invention is not limited to the specific embodiments described below.

[0031] It should be understood that the same or similar reference numerals in the accompanying drawings of the embodiments correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "front," "rear," "left," "right," "top," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms describing positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0032] To achieve ease of use and rapid unlocking of electronic locks, a control circuit for an inductively powered smart lock was designed, as follows: Example

[0033] like Figure 1-7 As shown, an inductively powered smart lock control circuit includes an electrically connected power control module, an NFC identification module, a wireless charging module, a motor control module, a power consumption control module, a central processing module, and an interface module.

[0034] The power control module includes a charging management chip IC1, a dual-channel load switch IC2, and a battery protection chip IC3. The charging management chip IC1 is responsible for controlling the safe charging of the internal circuit from an external power source, setting the charging current, and indicating the charging status. The dual-channel load switch IC2 acts as an electronic switch to control the on / off state of the circuit power supply. The battery protection chip IC3 monitors the remaining battery power and communicates with the central processing module. The power control module is connected to a lithium-ion supercapacitor as an internal power source to power the internal circuit. In one embodiment, the charging management chip can be a PST4056H, the battery protection chip can be a CM1006, and the dual-channel load switch can be an AND18205A.

[0035] The NFC identification module includes a card reader antenna and an NFC tag channel chip IC5. The NFC tag channel chip IC5 is used for radio frequency signal processing, data communication with the central processing unit, and control of the NFC switch. In one embodiment, the NFC tag channel chip can be an FM11NT082C-NTCZ.

[0036] The wireless charging module includes a charging antenna, which receives AC signals from the terminal device and converts them into DC voltage output to charge the internal supercapacitor.

[0037] The motor control module includes a motor driver chip IC7, which receives control signals from the central processing module and drives the micro motor to work. In one embodiment, the motor driver chip may be SA116.

[0038] The power consumption control module includes a linear voltage regulator IC4, which converts the input voltage into a lower, stable output voltage to power the internal circuitry. In one embodiment, the linear voltage regulator IC4 can be an MD52E30QC3, which has a load switching function.

[0039] The central processing module includes a microcontroller chip IC8 and a Hall switch IC6. The microcontroller chip IC8 is a low-power chip responsible for coordinating and controlling the operation of all other external chips and circuits. The Hall switch IC6 is used to convert signals into clean digital signals that IC8 can read. The central processing module obtains encryption instructions from the NFC identification module and compares the power signal with a preset threshold to determine the timing of the drive command issuance to ensure compatibility with different terminal devices. Specifically, when the remaining power of the supercapacitor is greater than the preset threshold, the drive command is immediately issued to control the motor to unlock; when the remaining power of the supercapacitor is less than the preset threshold, the issuance of the drive command to control the motor to unlock is delayed. In one embodiment, the microcontroller chip can be CH32X033F8P6, and the Hall switch can be HAL251.

[0040] like Figure 4 As shown, the interface module includes connectors CN1, CN2, CN3, CN4 and USB interface CN5. In this embodiment, USB interface CN5 is a type-C interface connected to an external power supply, connector CN1 is connected to the motor, connector CN2 is connected to the reset circuit, and connectors CN3 and CN4 are interfaces for the card reader antenna and the charging antenna.

[0041] In the above content, the models involving IC1-IC8 are only one example. IC1-IC8 can be components with the same function, such as MCU, MPU, DSP or CPLD.

[0042] like Figure 7As shown, specifically in the power control module, the voltage input terminal VCC of the charging management chip IC1 is electrically connected to the USB interface, the battery connection terminal BAT is electrically connected to the battery, and the voltage input terminal VCC of the Hall switch IC6 is electrically connected; the power supply terminal VDD of the battery protection chip IC3 is electrically connected to the battery, and the charge / discharge control terminals OC and OD are electrically connected to the two gates of the dual-channel load switch IC2, respectively. The constant current charging current setting terminal PROG of the charging management chip IC1 is connected to the battery connection terminal BAT, and a resistor R2 is connected in series on the connection line. The resistor R2 is used to set the magnitude of the constant current charging current. A filter is connected in parallel between this connection line and the voltage input terminal VCC. The supercapacitor is connected to the battery connection terminal BAT via a filter capacitor C1. The supercapacitor serves as the internal power supply battery. A filter capacitor C5 is connected in series between the battery connection terminal BAT and the constant current charging current setting terminal PROG. A decoupling capacitor C2 is connected between the power supply terminal VDD and the ground terminal VSS of the battery protection chip IC3. A current limiting resistor R1 is connected in series between the power supply terminal VDD of the battery protection chip IC3 and the battery connection terminal BAT of the charging management chip IC1. A resistor R3 is connected in series to ground at the current detection terminal CS of the battery protection chip IC3. The dual-channel load switch IC2 is used to switch between two sets of lines. The dual-channel load switch IC2 includes two independent switches G1 and G2.

[0043] like Figure 2 As shown, specifically in the NFC identification module, the RF output terminal of the card reader antenna is electrically connected to the analog input terminals IN1 and IN2 of the NFC tag channel chip IC5, respectively. The digital output terminal IRQ, clock signal ports SDA and SCL of the NFC tag channel chip IC5 are connected in parallel and electrically connected to the voltage input terminal VCC, and also electrically connected to the I / O pins PB10 and PB11 of the microcontroller chip IC8. The digital output terminal IRQ is also electrically connected to the I / O pin PB0 of the microcontroller chip IC8, and the voltage output terminal VOUT is electrically connected to the I / O pin PA6 of the microcontroller chip IC8. The CSN terminal is electrically connected to the I / O pin PC3 of the microcontroller chip IC8; the two RF output terminals ATN1 and ATN2 of the card reader antenna are connected in series with resonant capacitors C13 and C14, which together determine the resonant frequency of the circuit; the voltage input terminal VCC of the NFC tag channel chip IC6 is connected to a ferrite bead FB1 to suppress high-frequency noise interference, and is also connected to a decoupling capacitor C8 and grounded; the voltage output terminal VOUT of the NFC tag channel chip IC6 is connected in series with a current-limiting resistor R4, and also includes a ground bypass for the series decoupling capacitor C7; the clock signal ports SDA and SCL are connected to pull-up resistors R6 and R7, respectively.

[0044] like Figure 6As shown, specifically in the wireless charging module, diodes D5, D6, D7, and D8 are connected in parallel between the two input terminals RF1 and RF2 of the charging antenna to form a bridge rectifier circuit, which converts the AC power received by the antenna into unidirectional DC power. An electrolytic capacitor C15, C16, and C24 are connected in parallel in the output direction, and a protection diode ZD1 is connected in parallel between the output direction and ground. Isolation step-down diodes D4 and D9 are connected in series at the output terminals respectively.

[0045] like Figure 3 As shown, specifically, the motor control module is a dual operational amplifier. The output terminals OUTA and OUTB of the motor driver chip IC7 are connected to the positive and negative terminals of the motor, respectively, and a high-frequency decoupling capacitor C22 is connected between the two output terminals. The power supply terminal VDD is connected to a filter capacitor C21 and grounded. The power supply terminal VDD is also connected to the voltage output terminal VOUT of the linear regulator chip IC4. The input terminals INA and INB and the ground terminal GND are connected in series with a bias resistor R8, an isolation resistor R9, and a feedback resistor R10 and grounded, respectively. The output pins OUTA and OUTB output the drive current and are connected to the two terminals of the micro motor. The input terminals INA and INB and the ground terminal GND receive PWM signals or direction control signals from the microcontroller chip IC8. By inputting specific high and low level combinations to these pins, the rotation and stopping of the motor are determined.

[0046] like Figure 5 As shown, specifically, the power consumption control module is a power management circuit. The voltage input terminal VIN of the linear regulator chip IC4 is electrically connected to the supercapacitor. A filter capacitor C3 is connected in parallel between the voltage input terminal VIN and the ground terminal GND. The voltage output terminal VOUT outputs a 3.3V voltage and is connected in series with a filter capacitor C6 and grounded. The enable terminal EN is connected in parallel with a logic circuit. In this embodiment, the logic circuit includes three diodes D1, D2, and D3. Diode D3 is electrically connected to the USB interface CN5, diode D2 is connected to the I / O pin PA9 of the microcontroller chip IC8, and diode D1 is electrically connected to the voltage output terminal VOUT of the NFC tag channel chip IC5. When any one of the three signals is high, the enable terminal EN of the linear regulator chip IC4 will be pulled high, thereby outputting a voltage. By using different signals, the 3.3V power supply can be flexibly turned on and off to achieve intelligent power management.

[0047] like Figure 1As shown, specifically, decoupling capacitors C18 and C19 are connected in parallel to the power supply terminal VDD of microcontroller chip IC8; decoupling capacitor C17 and filter capacitor C20 are connected in parallel between the voltage input terminal VCC and the voltage output terminal OUT of Hall switch IC6; the voltage output terminal OUT is electrically connected to the I / O pin PB7 of microcontroller chip IC8; the I / O pin PA3 of microcontroller chip IC8 serves as the serial communication terminal RX; I / O pins PA18 and PA19 are connected to the USB interface and serve as the debug / download interface terminals SWDIO and SWCLK; a resistor R11 is connected in series with I / O pin PB1 to form a detection circuit; voltage divider resistors R12 and R13 are connected in parallel with I / O pin PA7 and electrically connected to the 3.3V voltage, with the other end of resistor R13 grounded.

[0048] Working principle:

[0049] The entire circuit is controlled by IC8. IC8 is responsible for processing all input signals, performing logical judgments, and finally outputting control signals to drive the motor and complete the opening and closing of the lock.

[0050] The internal power supply uses lithium-ion supercapacitors to maintain short-term circuit operation and data storage.

[0051] The circuit is equipped with a USB interface and a wireless charging module, supporting both wired and wireless charging methods, and is used for supercapacitor charging.

[0052] The circuit includes a charging management chip IC1, which manages the external power supply connected to the USB interface and safely charges the supercapacitor.

[0053] IC4 converts the unstable voltage of the supercapacitor into a stable lower voltage to power the logic circuitry of the entire circuit.

[0054] The alternating current sensed by the charging antenna is converted into a direct current voltage by a rectifier and filter circuit consisting of diodes D5-D8 and capacitor C25. After passing through the voltage regulator ZD1 and the filter capacitor, it is sent to IC1 to charge the supercapacitor.

[0055] The card reader antenna and matching capacitors C12-C14 form a resonant circuit for communication with standard-compliant terminal devices.

[0056] IC6 is a Hall switch used to detect the position of the latch and output a HALL signal. The HALL signal is sent to the main control MCU to detect the door's open / closed status and realize functions such as door not closed alarm and automatic locking.

[0057] IC8 reads the HALL signal from Hall sensor IC6 to determine the bolt position.

[0058] After IC8 obtains the encryption command, it sends control signals through OUTA and OUTB.

[0059] IC7 can directly drive a micro motor, receive signals from the main control MCU, and output sufficient current and voltage to control the motor.

[0060] By controlling the input logic of IC7, the MCU can change the voltage polarity across the motor, thereby controlling the motor's forward and reverse rotation.

[0061] The circuit is powered by a supercapacitor, and the voltage is provided after being regulated by IC4. The main control MCU, card reader chip, etc. are in a low-power "sleep" state.

[0062] When a user brings their terminal device close to the card reader area, the terminal device reads the smart lock's identity ID information through the card reader antenna and sends this information to the server for verification. Once verified, the server obtains the key and generates an encrypted command.

[0063] After receiving the encryption command, IC8 sends an unlocking signal to the motor driver chip IC7. During unlocking, IC7 drives the motor to rotate, which in turn retracts the bolt via a mechanical structure, completing the unlocking action.

[0064] After the unlocking action is completed, the MCU stops outputting drive signals, and the motor stops rotating. It waits for the next operation.

[0065] The electronic lock solution features wireless / wired dual-mode charging, RFID identification, lock body status detection, and IC8 intelligent control. The IC8 coordinates the power supply, sensing, authentication, and execution units to achieve secure and reliable locking and unlocking.

[0066] The inductive power supply smart lock control circuit of this solution has high security, based on two-way authentication, and cannot be cracked by simply copying signals.

[0067] The circuit includes charge / discharge management, on / off management, and multiple filtering functions, ensuring high reliability. The USB interface features ESD electrostatic protection, and the circuit also includes reverse power connection protection and signal filtering, effectively resisting external interference and ensuring stable operation.

[0068] Employing lithium-ion supercapacitors, the circuit meets the requirements of internal power supply scenarios. IC1 and IC3 enable intelligent charging, while IC4 automatically controls the power supply path to save power. The entire circuit can enter a "sleep state" when idle, maintaining an extremely long standby time solely on battery power. When an external device approaches, the internal battery powers rapid unlocking, enhancing the user experience. Example

[0069] This embodiment discloses an inductively powered smart padlock, which internally adopts the inductively powered smart lock control circuit described in Embodiment 1.

[0070] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A smart lock control circuit powered by induction, characterized in that, It includes an NFC identification module with electrical connections, a wireless charging module, a power control module, a power consumption control module, a motor control module, and a central processing module; The power control module is electrically connected to a supercapacitor; The power control module is used to control the charging and discharging of the supercapacitor and to transmit the supercapacitor's power signal to the central processing module. The NFC identification module is used to store the smart lock's identity ID information. When the terminal device triggers identification, it sends the identity ID information to the server for two-way verification. After successful verification, it obtains the key and generates an encryption command. The wireless charging module receives AC signals from the terminal device through a charging antenna, and outputs DC voltage after rectification and voltage regulation to charge the supercapacitor. The power consumption control module is signal-connected to the central processing module and controls the on / off of the power supply path from the supercapacitor to the central processing module according to the control instructions of the central processing module. The motor control module receives the drive command from the central processing module and outputs the corresponding current to drive the micro motor to work. The central processing module obtains the encryption command from the NFC identification module and compares the power signal with a preset threshold to determine the timing of the drive command issuance, so as to be compatible with different terminal devices.

2. An inductively powered smart lock control circuit according to claim 1, wherein, The supercapacitor is a lithium-ion supercapacitor, designed to enable rapid charging and discharging, long-term cyclic charging and discharging, and safe use.

3. The inductively powered smart lock control circuit of claim 1, wherein, The NFC identification module includes a hardware encryption unit to improve security.

4. The inductively powered smart lock control circuit of claim 1, wherein, The power consumption control module includes logic circuits and a linear voltage regulator chip with a load switch and an enable terminal to control the switching of the power supply path of the supercapacitor.

5. The inductively powered smart lock control circuit of claim 1, wherein, The wireless charging module is electrically connected to a rectifier bridge for voltage regulation control, so as to output a stable voltage and provide wireless charging for the internal circuit.

6. An inductively powered smart lock control circuit according to claim 1, wherein, The power control module is equipped with a battery protection circuit to achieve intelligent internal power management.

Images