A passive lock powered by NFC and its lock opening and closing control circuit

Abstract

This application discloses an NFC-powered passive lock and its locking / unlocking control circuit. The circuit includes a coil module, a communication module, an energy storage boost module, a motor drive module, and an MCU module. The coil module generates an induced electromotive force when an external NFC device approaches. The communication module is connected to the coil module. The energy storage boost module is connected to the coil module. The motor drive module is connected to the energy storage boost module. The MCU module is connected to the communication module, the energy storage boost module, and the motor drive module. This application utilizes the energy properties of NFC radio frequency technology to obtain an induced electromotive force when an external NFC device is attached to and communicating with the passive lock. The energy is then stored in the energy storage boost module, and finally, this accumulated energy is provided to the motor drive module to rotate the external motor, thus achieving the locking / unlocking function. With this setup, no power supply is needed inside the passive lock, effectively avoiding the inability to unlock due to a dead battery and improving the user experience.

Description

Technical Field

[0001] This application belongs to the field of lock technology, and in particular relates to a passive lock powered by NFC and its lock opening and closing control circuit. Background Technology

[0002] Near Field Communication (NFC) is a short-range wireless radio frequency transmission technology that allows devices (such as mobile phones) using NFC to exchange data via radio frequency when they are close to each other.

[0003] Some locks on the market also use NFC technology. Current NFC locks typically employ a combination of battery, main controller, and NFC transmitter. Since the NFC lock acts as a card reader, it needs to search for cards in real time, and even in sleep mode, the battery continues to be consumed. This means that when the battery in the NFC lock is depleted, it cannot be opened, requiring external power or mechanical unlocking, thus impacting the user experience.

[0004] Therefore, it is necessary to improve existing technologies to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a passive lock powered by NFC and its lock opening and closing control circuit, aiming to solve the technical problem that NFC locks in the prior art are prone to failure to unlock due to battery depletion.

[0006] To achieve the above objectives, one embodiment of this application provides a passive lock switch control circuit powered by NFC, comprising: a coil module, a communication module, an energy storage boost module, a motor drive module, and an MCU module; the coil module is used to generate an induced electromotive force when an external NFC device approaches; the communication module is connected to the coil module for communication with the external NFC device; the energy storage boost module is connected to the coil module; the motor drive module is connected to the energy storage boost module; the MCU module is connected to the communication module, the energy storage boost module, and the motor drive module, and is used to control the motor drive module to operate after the voltage of the energy storage boost module reaches a preset value.

[0007] In one possible embodiment, the energy storage boost module includes a rectifier unit, a switching unit, a boost unit, and an energy storage unit; the rectifier unit is connected to the coil module, the switching unit is connected to the rectifier unit and the MCU module, the boost unit is connected to the switching unit and the MCU module, and the energy storage unit is connected to the boost unit.

[0008] In one possible embodiment, the rectifier unit includes a rectifier bridge, the switching unit includes a first switching transistor and a second switching transistor, the boost unit includes a boost chip, and the energy storage unit includes an energy storage capacitor; the input terminal of the rectifier bridge is connected to the coil module, the source of the first switching transistor is connected to the output terminal of the rectifier bridge, the drain of the second switching transistor is connected to the gate of the first switching transistor, the gate of the second switching transistor is connected to the MCU module, the fifth pin of the boost chip is connected to the drain of the first switching transistor, the sixth pin of the boost chip is connected to the MCU module, and the energy storage capacitor is connected to the sixth pin of the boost chip.

[0009] In one possible embodiment, the communication module includes an NFC communication chip, which connects the coil module and the MCU module.

[0010] In one possible embodiment, the MCU module includes an MCU chip, with a first pin connected to both the third and fifth pins of the NFC communication chip, so that the MCU chip turns on when the voltage at the first pin reaches a second preset value, and controls the energy storage boost module to operate when the voltage at the first pin reaches a third preset value.

[0011] In one possible embodiment, the coil module includes a first coil group and a second coil group. The first coil group is connected to the communication module and generates a first induced electromotive force when an external NFC device is near. The second coil group is connected to the energy storage boost module and generates a second induced electromotive force when an external NFC device is near.

[0012] In one possible embodiment, the switch lock control circuit further includes a detection module connected to the MCU module. The detection module is used to detect changes in the position of the external latch and send the changes to the MCU module.

[0013] In one possible embodiment, the detection module includes a Hall sensor, the output of which is connected to the MCU module.

[0014] One embodiment of this application provides a passive lock powered by NFC, including a motor and a controller, wherein the controller is electrically connected to the motor and the controller is provided with the aforementioned switch control circuit.

[0015] The above-described one or more embodiments provided in this application have at least one of the following technical effects:

[0016] This application utilizes the energy properties of NFC radio frequency technology to acquire induced electromotive force when an external NFC device is attached to and communicating with a passive lock. This induced electromotive force is then stored through an energy storage boost module, and finally, this accumulated energy is supplied to the motor drive module to rotate the external motor, thus enabling the locking and unlocking function. With this setup, no power source is needed inside the passive lock, effectively preventing situations where the lock cannot be opened due to a dead battery, and improving the user experience. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the NFC-powered passive lock switch control circuit provided in this application embodiment;

[0019] The following are the labeling elements in the figure:

[0020] 110-Coil module; 120-Communication module; 130-Energy storage boost module; 131-Rectifier unit; 132-Switching unit; 133-Boost unit; 134-Energy storage unit; 140-Motor drive module; 150-MCU module; 160-Detection module. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the embodiments of this application, and should not be construed as limiting this application.

[0022] In the description of the embodiments of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In the embodiments of this application, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0025] Current NFC locks typically use a combination of battery, main controller, and NFC transmitter. As a card reader, the NFC lock needs to search for cards in real-time, and even in sleep mode, it continuously consumes battery power. Generally, current technology requires at least 20uA of power for real-time card searching in sleep mode, and around 1W of power to maintain device operation during card reading. This power supply method is problematic during power outages.

[0026] Or, if the battery is low, an external power supply or mechanical method is needed to unlock it; at the same time, in places where the usage frequency is very low but needs to be in operation for several years, it is necessary to replace the battery regularly or install a wired power supply, which brings high costs.

[0027] To address the above problems, in one embodiment of this application, such as Figure 1 As shown, a passive lock switch control circuit powered by NFC is provided, including a coil module 110, a communication module 120, an energy storage boost module 130, a motor drive module 140, and an MCU module 150. The MCU module 150 includes an MCU chip U4.

[0028] The coil module 110 is used to generate an induced electromotive force when an external NFC device is near. In this embodiment, the coil module 110 includes a first coil group and a second coil group. The first coil group includes coil LA and coil LB, and is connected to the communication module 120. The first coil group generates a first induced electromotive force when an external NFC device is near. The second coil group includes coil RF1 and coil RF2, and is connected to the energy storage boost module 130. The second coil group generates a second induced electromotive force when an external NFC device is near.

[0029] The communication module 120 is connected to the coil module 110 and is used for communication with external NFC devices. In this embodiment, the communication module 120 includes an NFC communication chip U2, which is connected to the coil module 110 and the MCU module 150.

[0030] Specifically, the first pin of the NFC communication chip U2 is connected to the coil LB, and the eighth pin of the NFC communication chip U2 is connected to the coil LA. When the coils LA and LB sense a 13.56MHz electromagnetic field emitted by an external NFC device, a weak first induced electromotive force is generated. The NFC communication chip U2 receives this first induced electromotive force and directly feeds it into its internal circuitry. The internal micro-rectifier bridge and voltage regulator circuit convert the AC power into DC power, supplying power to the internal logic circuits and memory. Simultaneously, it also supplies power to the MCU module 150, enabling it to conduct and achieve communication and information verification with the external NFC device.

[0031] The energy storage boost module 130 is connected to the coil module 110. The energy storage boost module 130 includes a rectifier unit 131, a switching unit 132, a boost unit 133, and an energy storage unit 134. The rectifier unit 131 is connected to the coil module 110, the switching unit 132 is connected to the rectifier unit 131 and the MCU module 150, the boost unit 133 is connected to the switching unit 132 and the MCU module 150, and the energy storage unit 134 is connected to the boost unit 133.

[0032] In this embodiment, the rectifier unit 131 includes a rectifier bridge, the switch unit 132 includes a first switch Q1 and a second switch Q3, the boost unit 133 includes a boost chip U3, and the energy storage unit 134 includes an energy storage capacitor C10. The rectifier bridge is composed of diodes D1, D2, D4, and D5. The input terminal of the rectifier bridge is connected to the coils RF1 and RF2 of the coil module 110. The second induced electromotive force is converted into DC current after passing through the rectifier bridge. The source of the first switch Q1 is connected to the output terminal of the rectifier bridge, the drain of the second switch Q3 is connected to the gate of the first switch Q1, the gate of the second switch Q3 is connected to the MCU module 150, the fifth pin of the boost chip U3 is connected to the drain of the first switch Q1, the sixth pin of the boost chip U3 is connected to the MCU module 150, and the energy storage capacitor C10 is connected to the sixth pin of the boost chip U3.

[0033] The motor drive module 140 is connected to the energy storage boost module 130. The motor drive module 140 includes a drive chip U1, the first pin of which is connected to the eighth pin of the MCU chip U4, and the third pin of which is connected to the ninth pin of the MCU chip U4.

[0034] The MCU module 150 is connected to the communication module 120, the energy storage boost module 130, and the motor drive module 140, and is used to control the motor drive module 140 to operate after the voltage of the energy storage boost module 130 reaches a preset value. In this embodiment, the first pin of the MCU chip U4 is connected to the third and fifth pins of the NFC communication chip U2, and the seventh pin of the MCU chip U4 is connected to the seventh pin of the boost chip U3. The MCU chip U4 is turned on when the voltage of its first pin reaches a second preset value. When the voltage of its first pin reaches a third preset value, the MCU chip U4 generates a boost PWM waveform to control the boost chip U3 to operate, thereby accumulating charge in the energy storage capacitor C10. The MCU chip U4 continuously monitors the charge on the energy storage capacitor C10. When the voltage of the energy storage capacitor C10 is greater than the first preset value, the MCU chip U4 controls the motor drive module 140 to operate, thereby causing the external motor to rotate.

[0035] In one embodiment of this application, the NFC-powered passive lock switch control circuit further includes a detection module 160, which is connected to the MCU module 150. The detection module 160 is used to detect changes in the position of the external latch and send them to the MCU module 150.

[0036] In this embodiment, the detection module 160 includes a Hall sensor U5, and the output terminal of the Hall sensor U5 is connected to the MCU module 150.

[0037] In one embodiment of this application, an NFC-powered passive lock is also provided, including a motor and a controller. The controller is electrically connected to the motor, and the controller is provided with the aforementioned lock / open control circuit to control the rotation of the motor and drive the external bolt to move, thereby realizing the lock / opening mechanism.

[0038] It should be noted that the chip provided in this application is only an example, and those skilled in the art can choose other chips as needed.

[0039] It should be noted that this application aims to protect the circuit structure. As for the program control part, those skilled in the art should select appropriate circuits and chips according to the chip models in this application or as needed and program them appropriately to realize the corresponding program control functions in this application. Therefore, some of them are mature and established technologies in the prior art and are not the focus of protection in this application. Therefore, this application will not elaborate on this control part.

[0040] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A passive lock switch control circuit powered by NFC, characterized in that, include: The system comprises a coil module, a communication module, an energy storage boost module, a motor drive module, and an MCU module. The coil module generates an induced electromotive force when an external NFC device approaches. The communication module is connected to the coil module and is used for communication with the external NFC device. The energy storage boost module is connected to the coil module. The motor drive module is connected to the energy storage boost module. The MCU module is connected to the communication module, the energy storage boost module, and the motor drive module, and is used to control the motor drive module to operate after the voltage of the energy storage boost module reaches a first preset value.

2. The NFC-powered passive lock switch control circuit according to claim 1, characterized in that, The energy storage boost module includes a rectifier unit, a switch unit, a boost unit, and an energy storage unit; the rectifier unit is connected to the coil module, the switch unit is connected to the rectifier unit and the MCU module, the boost unit is connected to the switch unit and the MCU module, and the energy storage unit is connected to the boost unit.

3. The NFC-powered passive lock switch control circuit according to claim 2, characterized in that, The rectifier unit includes a rectifier bridge, the switching unit includes a first switching transistor and a second switching transistor, the boost unit includes a boost chip, and the energy storage unit includes an energy storage capacitor. The input terminal of the rectifier bridge is connected to the coil module, the source of the first switching transistor is connected to the output terminal of the rectifier bridge, the drain of the second switching transistor is connected to the gate of the first switching transistor, the gate of the second switching transistor is connected to the MCU module, the fifth pin of the boost chip is connected to the drain of the first switching transistor, the sixth pin of the boost chip is connected to the MCU module, and the energy storage capacitor is connected to the sixth pin of the boost chip.

4. The NFC-powered passive lock switch control circuit according to claim 1, characterized in that, The communication module includes an NFC communication chip, which is connected to the coil module and the MCU module.

5. The NFC-powered passive lock switch control circuit according to claim 4, characterized in that, The MCU module includes an MCU chip. The first pin of the MCU chip is connected to both the third pin and the fifth pin of the NFC communication chip, so that the MCU chip is turned on when the voltage of the first pin reaches a second preset value, and controls the energy storage boost module to work when the voltage of the first pin reaches a third preset value.

6. A passive lock switch control circuit powered by NFC according to any one of claims 1-5, characterized in that, The coil module includes a first coil group and a second coil group. The first coil group is connected to the communication module and generates a first induced electromotive force when an external NFC device is near it. The second coil group is connected to the energy storage boost module and generates a second induced electromotive force when an external NFC device is near it.

7. A passive lock switch control circuit powered by NFC according to any one of claims 1-5, characterized in that, The switch lock control circuit also includes a detection module, which is connected to the MCU module. The detection module is used to detect changes in the position of the external lock tongue and send the information to the MCU module.

8. The NFC-powered passive lock switch control circuit according to claim 7, characterized in that, The detection module includes a Hall sensor, and the output of the Hall sensor is connected to the MCU module.

9. A passive lock powered by NFC, characterized in that, It includes a motor and a controller, the controller being electrically connected to the motor, and the controller being provided with a switch lock control circuit as described in any one of claims 1-8.

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