Electronic lock
By employing a switching power supply and inductively coupled circuit design in the electronic lock, and using a clock signal to control the current intensity and frequency, efficient data transmission between the key and the lock cylinder is achieved, solving the problems of slow communication speed and high power consumption in existing technologies.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ISEO SERRATURE
- Filing Date
- 2024-11-06
- Publication Date
- 2026-06-19
AI Technical Summary
Existing electronic locks have low communication speeds and high power consumption, especially during data exchange between the key and the lock cylinder, where power needs to be significantly reduced to achieve signal separation, resulting in low efficiency.
The design employs a switching power supply and inductively coupled primary and secondary electronic circuits. A primary microcontroller generates a clock signal to control the current intensity and frequency, enabling synchronous or asynchronous data exchange. The resonant frequency is used to modify components and signal analysis devices for efficient data transmission.
It enables efficient two-way data exchange between the key and the lock cylinder, improves communication speed, reduces power consumption, and enhances system efficiency.
Smart Images
Figure CN122249842A_ABST
Abstract
Description
[0001] manual
[0002] The present invention relates to an electronic lock comprising a key and a lock cylinder equipped with a slot for inserting the key, and a method for bidirectional data transmission between the key and the lock cylinder when the key is inserted into the slot of the lock cylinder.
[0003] An electronic lock is known in which the key is characterized by a primary electronic circuit including a primary microcontroller and an independent power source (usually a battery), and the lock cylinder includes a secondary electronic circuit including a secondary microcontroller and a power storage device (usually a capacitor).
[0004] In such electronic locks, a system is typically provided for transferring electrical energy from a battery to a capacitor. This system usually consists of a switching power supply that facilitates energy transfer through inductive coupling, which occurs between the primary coil in the primary electronic circuit and the secondary coil in the secondary electronic circuit when the key is inserted into the lock cylinder slot.
[0005] Furthermore, in such electronic locks, data exchange between the key and the lock cylinder typically occurs with a transponder that has loose magnetic coupling. Data is transmitted to the lock cylinder by amplitude modulation (typically 100%) of the alternating magnetic field generated by the key, and data is asynchronously transmitted from the lock cylinder to the key by changing the q-factor (quality factor) of the circuit (typically by short-circuiting the secondary coil).
[0006] The advantages of this system include its simple circuitry and low sensitivity to the coupling coefficient between the primary and secondary coils.
[0007] The disadvantage is the low communication speed, which is due to the need to integrate the carrier signal to significantly separate the modulated frequency from the carrier frequency (usually by at least an order of magnitude), and for transmission, the power transmitted from the key to the lock cylinder needs to be reduced by an average of 50% when transmitted from the key to the lock cylinder and by 75% when transmitted from the lock cylinder to the key.
[0008] Therefore, the technical objective of this invention is to create an electronic lock of the aforementioned type that eliminates the technical defects observed in the known art.
[0009] As part of this technical task, one object of the present invention is to create an electronic lock of the aforementioned type that can transmit in both directions at higher speeds and with less power reduction.
[0010] According to the present invention, this technical objective and these and other objectives are achieved by providing an electronic lock system comprising: a key; a lock cylinder having a slot for inserting the key; a primary electronic circuit mounted on the key and including a primary microcontroller and a generator; a secondary electronic circuit mounted on the lock cylinder and including a secondary microcontroller; and a switching power supply for periodic power transfer from the key to the lock cylinder, wherein the switching power supply includes a primary coil inserted into the primary electronic circuit, a secondary coil inserted into the secondary electronic circuit and inductively coupled to the primary coil when the key is inserted into the slot, and the primary electronic circuit. The first electronic switch in the primary microcontroller is capable of switching between an enabled state and a disabled state to allow or prevent current from flowing through the primary coil. The primary microcontroller is configured to generate a switching frequency via a clock signal that defines the start time of each power transfer cycle, each power transfer cycle including the realization of a maximum value of the current intensity through the primary coil, and is configured to synchronously transmit a serial signal at the switching frequency or a divisor of the switching frequency for selecting the maximum value of the current intensity through the primary coil in each power transfer cycle for encoding data transmitted from the primary microcontroller to the secondary microcontroller.
[0011] In a preferred embodiment of the invention, the secondary electronic circuitry includes first signal analysis devices at the terminals of the secondary coil, these first analysis devices being configured to reconstruct the maximum current value passing through the primary coil during each energy transfer cycle when the first electronic switch is enabled.
[0012] In a preferred embodiment of the invention, the secondary electronic circuit includes a component for modifying the resonant frequency of an inductively coupled circuit formed by the primary and secondary electronic circuits, and a second electronic switch configured to include or exclude the resonant frequency modification component.
[0013] In a preferred embodiment of the invention, the secondary microcontroller is configured to transmit a serial switching signal to the second electronic switch.
[0014] In another preferred embodiment of the invention, the primary microcontroller includes a second signal analysis device at the terminals of the primary coil, the second analysis device being configured to identify the resonant frequency when the first electronic switch is disabled.
[0015] In a preferred embodiment of the invention, the secondary electronic circuit includes a third signal analysis device at the terminals of the secondary coil, the third analysis device being configured to reconstruct a clock synchronization signal when the first electronic switch is in an enabled state.
[0016] In a preferred embodiment of the invention, the secondary electronic circuit includes a storage capacitor for electrical energy supplied by the secondary coil, and the secondary microcontroller is configured to acquire and analyze the voltage across the storage capacitor, and is configured to synchronously transmit a switching signal for the second electronic switch at the frequency of a reconstructed clock whenever the voltage across the storage capacitor reaches a threshold.
[0017] In a preferred embodiment of the present invention, the switching power supply is a flyback type.
[0018] In electronic locks, power is transmitted using inductively coupled primary and secondary coils.
[0019] Data exchange can be performed synchronously or asynchronously, with the first method being preferred when speed is a critical factor.
[0020] In the case of synchronous data exchange, when the first electronic switch is in the enabled state, the synchronization signal (meaning the clock signal generated by the primary microcontroller) is reconstructed from the ineffective part of the voltage on the lock cylinder side.
[0021] The synchronization signal defines the moment when the signal across the primary coil contains information transmitted from the primary electronic circuitry, wherein the signal level changes to indicate a transmission as "one" or "zero" due to a change in the maximum current intensity flowing through the primary coil.
[0022] The synchronization signal reconstructed by the secondary microcontroller defines the timing at which the secondary electronic circuitry is modified by the resonant frequency modification component, such that the second analysis device can determine whether the resonant frequency modification component is inserted when the first electronic switch is disabled.
[0023] Other features of the invention are further defined in the following claims.
[0024] Other features and advantages of the invention will become more apparent from the description of preferred, but not exclusive, embodiments of the electronic lock, which are presented in the accompanying drawings for illustrative rather than limiting purposes, wherein:
[0025] Figure 1 The key and lock cylinder of the electronic lock are shown schematically;
[0026] Figure 2 The circuit diagram of the electronic lock is shown;
[0027] Figure 3 The method of data transmission from key to lock cylinder is illustrated schematically.
[0028] Referring to the accompanying drawings, the electronic lock includes a key 1 and a lock cylinder 2, which is equipped with a slot 3 for inserting the key 1.
[0029] The electronic lock also includes: a primary electronic circuit 4, which is mounted on the key 1; a secondary electronic circuit 5, which is mounted on the lock cylinder 2; and a switching power supply for the periodic transmission of electrical energy from the key 1 to the lock cylinder 2.
[0030] The primary electronic circuit 4 includes a primary microcontroller A, and similarly, the secondary electronic circuit 5 includes a secondary microcontroller B.
[0031] The switching power supply includes a primary coil L1 inserted into the primary electronic circuit 4, and a secondary coil L2 inserted into the secondary electronic circuit 5 and inductively coupled to the primary coil L1 when the key 1 is inserted into the slot 3 of the lock cylinder 2.
[0032] The switching power supply also includes an electronic switch M2 inserted into the primary electronic circuit 4, which can switch between an enabled state and an disabled state when current flows through the primary coil L1.
[0033] The primary coil L1 can be coupled to the blade of the key 1, and the secondary coil L2 can be coupled to the rotor of the lock cylinder 2 adjacent to the slot 3, such that when the key 1 is inserted into the slot 3, the primary coil L1 and the secondary coil L2 are aligned with parallel or nearly parallel axes.
[0034] The primary microcontroller A is programmed to perform periodic energy transfer from an independent power source 8 (typically a battery) located in the primary electronic circuit 4 to an energy storage device (typically a capacitor C5) located in the secondary electronic circuit 5.
[0035] Battery 8 via input port V CCA Power is supplied to all active components of the primary electronic circuit 4 (including the primary microcontroller A).
[0036] The primary microcontroller A has a digital serial output port (labeled "Clock Output A") through which it transmits a clock signal. The switching frequency determines the start of each power transfer cycle, which involves implementing the current I through the primary coil L1. L1 The maximum value I L1a I L1b .
[0037] The start of each energy transfer cycle corresponds to the moment when current begins to flow through the primary coil L1.
[0038] The primary microcontroller A also transmits signals synchronously from the digital serial output port (labeled "Serial Output A") at the switching frequency or a divisor of that switching frequency, thereby selecting the current I passing through the primary coil L1 during each power transfer cycle. L1 Maximum current value I L1aOr I L1b This is used to encode the data transmitted from the primary microcontroller A to the secondary microcontroller B.
[0039] In practice, during data transmission from the key to the lock cylinder, for each energy transfer cycle or cycle group, the primary microcontroller A operates at two different current values I at a time interval t1 defined by the clock signal. L1 a and I L1b Choose the maximum current intensity I between L1 .
[0040] Choose a lower value I L1b Corresponding to the transmission of "zero", a higher value I is selected. L1a This corresponds to the transmission of "one".
[0041] Switching power supplies can be flyback type.
[0042] In this configuration, the flyback circuit includes a trigger A1 and a voltage comparator U1, and the electronic switch M2 is formed by a MOSFET controlled by the trigger A1.
[0043] Voltage comparator U1 compares the voltage across resistor R14 through which the current flowing through the primary coil L1 passes with a reference voltage, so that when the voltage across resistor R14 exceeds the reference voltage, MOSFET M2 is switched from the on state to the off state.
[0044] The energy transfer cycle proceeds as follows.
[0045] The primary microcontroller A sends a clock signal to set trigger A1.
[0046] When set, trigger A1 sends a signal from its Q output, which causes MOSFET M2 to switch from the blocking state to the conducting state.
[0047] The current supplied by battery 8 flows sequentially through primary coil L1, MOSFET M2 and resistor R14.
[0048] Resistor R14 has one terminal grounded and another terminal connected to the inverting input of voltage comparator U1, while its non-inverting input is maintained at the maximum reference voltage, which is determined by the voltage present at the analog output port (labeled "Analog Output A") of primary microcontroller A and regulated by a voltage divider consisting of resistors R15, R16, R17 and capacitor filter C8.
[0049] As the current flowing through coil L1 gradually increases, the voltage across resistor R14 increases proportionally.
[0050] When the voltage at the inverting input of comparator U1 exceeds the maximum reference voltage at the non-inverting input of comparator U1, comparator U1 resets flip-flop A1 by sending a signal to the CLR input of flip-flop A1.
[0051] As a result of the reset, flip-flop A1 not only sends a signal from its Q output to switch MOSFET M2 from the on state to the off state, but also sends a signal from its Q output that is detected by the primary microcontroller A via the digital serial input port (labeled "Digital Input A").
[0052] When MOSFET M2 switches from the ON state to the OFF state, the current flow through the primary coil L1 stops, and the current begins to flow through the secondary coil L2.
[0053] The current flowing through the secondary coil L2 charges the capacitor C5 via the diode D6.
[0054] Essentially, when MOSFET M2 is in the on state, energy is stored in the magnetic field formed by the primary coil L1 and the secondary coil L2. Once MOSFET M2 switches from the on state to the off state, the energy stored in the magnetic field is transferred to capacitor C5 and then to the load R6.
[0055] The secondary electronic circuit 5 includes a first signal analysis device at the terminals of the secondary coil L2.
[0056] These first analysis devices are configured to reconstruct the current I passing through the primary coil L1 during each energy transfer cycle when the first electronic switch M2 is in the enabled state. L1 The maximum value I L1a Or I L1b .
[0057] The first analysis device includes a comparator U4, specifically a voltage comparator, connected to the secondary microcontroller B.
[0058] Comparator U4 captures the peak voltage across the secondary coil L2 and compares it with a reference voltage.
[0059] If the captured peak voltage exceeds the reference voltage, comparator U4 sends a "-" signal to the digital serial input port (labeled "Serial Input B") of the secondary microcontroller B. The "-" signal indicates the maximum current value I reached in the primary coil L1. L1a Conversely, if the captured peak voltage is lower than the reference voltage, comparator U4 sends a "zero" signal to the digital serial input port (labeled "Serial Input B") of the secondary microcontroller B. The "zero" signal indicates the current I reached in the primary coil L1. L1 Minimum current value IL1b .
[0060] In detail, resistors R20 and R21 form a voltage divider that regulates the input voltage to the operating voltage of comparator U3, which extracts the clock signal and sends it to microcontroller B via the "clock input B" port.
[0061] Resistors R22 and R23 form a voltage divider that regulates the input voltage to the operating voltage of comparator U4, which extracts the data signal and sends it to microcontroller B via the "serial input B" port.
[0062] The secondary electronic circuit 5 also includes a component C1 for modifying the resonant frequency of the inductively coupled circuit formed by the primary electronic circuit 4 and the secondary electronic circuit 5, and a second electronic switch M1 configured to include or exclude the component C1 for modifying the resonant frequency.
[0063] The second electronic switch M1 is composed of a second MOSFET. The secondary microcontroller B is configured to transmit switching signals for the second electronic switch M1 via a digital serial output port (labeled "serial output B").
[0064] The component C1 used to modify the resonant frequency consists of a capacitor placed in parallel with the secondary coil L2.
[0065] The primary microcontroller A includes a second signal analysis device at the terminal of the primary coil L1.
[0066] These second analysis devices are configured to detect the resonant frequency when the first electronic switch M2 is disabled. The second analysis device includes a comparator U2, specifically a voltage comparator, connected to the primary microcontroller A via a digital serial input port (labeled "Serial Input A").
[0067] The secondary electronic circuit 5 also includes a third signal analysis device at the terminals of the secondary coil L2.
[0068] These third analysis devices are configured to reconstruct the clock synchronization signal when the first electronic switch M2 is in the enabled state.
[0069] The third analysis device includes a comparator U3, specifically a voltage comparator, connected to the secondary microcontroller B.
[0070] Comparator U3 detects the zero-crossing of the voltage at the terminal of the secondary coil L2 and sends the data to the digital serial input port of the secondary microcontroller B (labeled "clock input B"), allowing the secondary microcontroller B to reconstruct the clock signal generated by the primary microcontroller A.
[0071] In detail, resistors R20 and R21 form a voltage divider that regulates the input voltage to the operating voltage of comparator U3, which extracts the clock signal and sends it to microcontroller B via the "clock input B" port.
[0072] The secondary microcontroller B is configured to acquire and analyze the voltage at the terminal of the storage capacitor C5, and whenever the voltage at the terminal of the storage capacitor C5 reaches a threshold voltage, transmit a switching signal for the second switch M1 synchronously at a reconstructed clock frequency via a digital serial output port (labeled "Serial Output B"). This threshold voltage is read by the secondary microcontroller B through an analog input port (labeled "Analog Input B").
[0073] Specifically, whenever the voltage at the terminal of storage capacitor C5 reaches the threshold voltage, the secondary microcontroller B engages capacitor C1.
[0074] In practice, the switching signal changes the state of MOSFET M1, which in turn excludes or includes capacitor C1 connected in parallel with the secondary coil L2.
[0075] When included, capacitor C1 changes the resonant frequency of the inductively coupled circuit through coils L1 and L2, and this also affects the signal at the terminals of the primary coil L1 when MOSFET M2 is disabled, because when enabled, the voltage supplied by battery 8 exists across the primary coil L1.
[0076] Therefore, when MOSFET M2 is disabled, the voltage across resistor R19, which is connected in series with the primary coil L1 and upstream of diode D4, is recorded. The average value of this voltage, obtained through capacitor C7, is taken at the midpoint of the voltage divider formed by resistors R11 and R12 and is transmitted to one input of comparator U2. The instantaneous value of this voltage, obtained through resistor R13, which is located upstream of diode D4 and connected in series with resistor R19, is transmitted to the other input.
[0077] When capacitor C1 is engaged, the voltage oscillates at a lower frequency, and therefore, the amplitude of the oscillation is reduced.
[0078] Comparator U2 determines whether the instantaneous value of the voltage is greater than or less than its average value. One case corresponds to excluding capacitor C1, while the other case corresponds to including the capacitor.
[0079] Comparator U2 then transmits the information to primary microcontroller A via the digital serial input port "Serial Input A".
[0080] In detail, resistors R9 and R10 and capacitor C6 form a low-pass filter that eliminates high-frequency and unwanted components of the signal. This filter can also be implemented in other ways, such as through DSP circuitry.
[0081] Therefore, electronic locks are able to perform efficient and effective two-way data exchange between the key and the lock cylinder.
[0082] As envisioned, the electronic lock can be modified and varied in many ways, all of which are within the scope of the inventive concept; furthermore, all details can be replaced by technically equivalent components.
[0083] In practice, the materials and dimensions used can vary depending on the needs and current technology.
Claims
1. An electronic lock system, the electronic lock system comprising: Key (1); A lock cylinder (2) having a slot (3) for inserting the key (1); a primary electronic circuit (4) mounted on the key (1) and including a primary microcontroller (A) and a power generator (8); a secondary electronic circuit (5) mounted on the lock cylinder (2) and including a secondary microcontroller (B); and a switching power supply for periodically transmitting electrical energy from the key (1) to the lock cylinder (2), wherein the switching power supply includes a primary coil (L1) inserted into the primary electronic circuit (4), a secondary coil (L2) inserted into the secondary electronic circuit (5) and inductively coupled to the primary coil (L1) when the key (1) is inserted into the slot (3), and a secondary coil (L2) inserted into the primary electronic circuit (4). 4) A first electronic switch (M2) capable of switching between a state where current is enabled through the primary coil (L1) and a state where current is disabled through the primary coil, characterized in that the primary microcontroller (A) is configured to generate a switching frequency by means of a clock signal defining the start time of each power transfer cycle, each power transfer cycle including realizing a maximum value of the intensity of the current through the primary coil (L1), and is configured to synchronously transmit a serial signal at the switching frequency or a divisor of the switching frequency, the serial signal being used to select the maximum value of the intensity of the current through the primary coil (L1) in each power transfer cycle for encoding data transmitted from the primary microcontroller (A) to the secondary microcontroller (B).
2. The electronic lock system according to the preceding claims, characterized in that... The first electronic switch (M2) is formed by the first MOSFET.
3. The electronic lock system according to any of the preceding claims, characterized in that... The secondary electronic circuit (5) includes a first means for analyzing the signal at the end of the secondary coil (L2), the first means being configured to reconstruct the current (I) passing through the primary coil (L1) in each energy transfer cycle when the first electronic switch (M2) is in the enabled state. L1 The maximum value of the intensity of ) (I) L1a , I L1b ).
4. The electronic lock system according to the preceding claim, characterized in that... The first analysis device includes a comparator (U4) connected to the secondary microcontroller (B).
5. The electronic lock system according to any of the preceding claims, characterized in that... The secondary electronic circuit (5) includes a component (C1) for modifying the resonant frequency of the inductively coupled circuit formed by the primary electronic circuit (4) and the secondary electronic circuit (5), and a second electronic switch (M1) configured to include or exclude the component (C1) for modifying the resonant frequency.
6. The electronic lock system according to the preceding claim, characterized in that... The second microcontroller (B) is configured to transmit a serial signal for switching the second electronic switch (M1).
7. The electronic lock system according to any one of claims 5 and 6, characterized in that... The component (C1) used to modify the resonant frequency is a capacitor.
8. The electronic lock system according to any one of claims 5 to 7, characterized in that... The second electronic switch (M1) is formed by the second MOSFET.
9. The electronic lock system according to any one of claims 5 to 8, characterized in that... The primary microcontroller (A) includes a second means for analyzing the signal at the end of the primary coil (L1), the second means being configured to identify the resonant frequency when the first electronic switch (M2) is in the disabled state.
10. The electronic lock system according to the preceding claim, characterized in that... The second analysis device includes a comparator (U2) connected to the primary microcontroller (A).
11. The electronic lock system according to any of the preceding claims, characterized in that... The secondary electronic circuit (5) includes a third means for analyzing the signal at the end of the secondary coil (L2), the third means being configured to reconstruct the clock synchronization signal when the first electronic switch (M2) is in the enabled state.
12. The electronic lock system according to the preceding claim, characterized in that... The third analysis device includes a comparator (U3) connected to the secondary microcontroller (B).
13. The electronic lock system according to any one of claims 9 to 12, characterized in that... The secondary electronic circuit (5) includes a capacitor (C5) for accumulating the electrical energy supplied by the secondary coil (L2), and the second microcontroller (B) is configured to acquire and analyze the voltage across the accumulation capacitor (C5), and is configured to synchronously transmit the switching signal of the second electronic switch (M1) at a reconstructed clock frequency whenever the voltage across the accumulation capacitor (C5) reaches a threshold.
14. The electronic lock system according to any of the preceding claims, characterized in that... The switching power supply is a flyback type.