Touch key identification anti-interference circuit and intelligent lock

Abstract

The embodiment of the utility model provides a touch key identification anti-interference circuit and an intelligent lock, and relates to the technical field of intelligent locks, the touch key identification anti-interference circuit comprises a voltage stabilizing module, a first resistor, a first capacitor module, a power amplifier module and a touch key identification module, the first resistor is used for filtering interference signals of the power amplifier module on the voltage stabilizing module, further filtering voltage interference on the touch key identification module, and eliminating mistaken identification of the touch key identification module on a touch event of a touch key caused by the interference signals. Compared with the prior art, the resistance-capacitance filter has the advantages that voltage interference of the power amplifier module on the voltage stabilizing module can be reduced, so that compared with a capacitance filter in the prior art, the resistance-capacitance filter has the advantages that the effect of filtering voltage interference signals of the power amplifier module is improved, and the problem that a touch key recognition module mistakenly recognizes a touch event of a touch key in the prior art is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of smart locks, and in particular to an anti-interference circuit for touch key recognition and a smart lock. Background Art

[0002] The internal structure of the smart lock includes a touch key recognition module, a power amplifier module, and a voltage stabilizing module electrically connected to a power source. The voltage stabilizing module supplies power to the touch key recognition module and the power amplifier module. The touch key recognition module is used to recognize the touch events of the touch keys of the smart lock, while the power amplifier module is used to control the volume of the speaker of the smart lock. However, since the power amplifier module causes voltage interference to the voltage stabilizing module, which in turn causes voltage interference to the touch key recognition module, the touch key recognition module misrecognizes the touch events of the touch keys.

[0003] In the prior art, in order to prevent the touch key recognition module from misrecognizing a touch event of a touch key, a capacitive filter is used to filter the voltage interference signal of the power amplifier module.

[0004] In the process of implementing the present application, the inventors found that there are at least the following problems in the prior art: due to the poor effect of using a capacitor filter to filter the voltage interference signal of the power amplifier module, the touch key recognition module misidentifies the touch event of the touch key. Utility Model Content

[0005] The utility model provides an anti-interference circuit for touch key recognition and a smart lock, so as to at least solve the problem in the prior art that the touch key recognition module misrecognizes the touch event of the touch key due to the poor effect of using a capacitor filter to filter the voltage interference signal of the power amplifier module.

[0006] In a first aspect, an embodiment of the utility model provides an anti-interference circuit for touch key recognition, comprising: a voltage stabilizing module, a first resistor, a first capacitor module, a power amplifier module, and a touch key recognition module;

[0007] The voltage stabilizing module is electrically connected to the touch key recognition module, and the voltage stabilizing module is also electrically connected to the first resistor. The voltage stabilizing module is used to be electrically connected to a power source to supply power to the touch key recognition module and the first resistor;

[0008] The first resistor is electrically connected to the first capacitor module and the power amplifier module respectively, and the first resistor and the first capacitor module form a resistor-capacitor filter for filtering out interference signals from the power amplifier module to the voltage stabilizing module;

[0009] The power amplifier module is used to control the volume of a speaker electrically connected to the power amplifier module;

[0010] The touch key recognition module is used to recognize a touch event of a touch key electrically connected to the touch key recognition module.

[0011] Optionally, the voltage stabilizing module includes a first voltage stabilizer and a second voltage stabilizer; the first voltage stabilizer is electrically connected to the first end of the first resistor, and the first voltage stabilizer is used to be electrically connected to the power supply to supply power to the first resistor; the second end of the first resistor is electrically connected to the first capacitor module and the power amplifier module, respectively; the second voltage stabilizer is electrically connected to the touch key recognition module, and the second voltage stabilizer is used to be electrically connected to the power supply to supply power to the touch key recognition module.

[0012] Optionally, the anti-interference circuit for touch key recognition also includes a second resistor and a second capacitor module; the second voltage regulator is electrically connected to the first end of the second resistor; and the second end of the second resistor is electrically connected to the second capacitor module and the touch key recognition module, respectively.

[0013] Optionally, the first voltage regulator and the second voltage regulator are both low voltage dropout linear regulators.

[0014] Optionally, the second capacitor module includes multiple capacitors, and the capacitance value of each capacitor in the second capacitor module is different; the second end of the second resistor is electrically connected to the first end of each capacitor in the second capacitor module, and the second end of each capacitor in the second capacitor module is grounded.

[0015] Optionally, the voltage stabilizing module includes a first voltage stabilizer; the first voltage stabilizer is electrically connected to the touch key identification module, and the first voltage stabilizer is also electrically connected to the first end of the first resistor, and the first voltage stabilizer is used to be electrically connected to the power supply to supply power to the touch key identification module and the first resistor; the second end of the first resistor is electrically connected to the first capacitor module and the power amplifier module respectively.

[0016] Optionally, the anti-interference circuit for touch key recognition also includes a second resistor and a second capacitor module; the first voltage regulator is electrically connected to the first end of the second resistor; and the second end of the second resistor is electrically connected to the second capacitor module and the touch key recognition module, respectively.

[0017] Optionally, the first capacitor module includes multiple capacitors, and the capacitance value of each capacitor in the first capacitor module is different; the second end of the first resistor is electrically connected to the first end of each capacitor in the first capacitor module, and the second end of each capacitor in the first capacitor module is grounded.

[0018] Optionally, the power source is a battery.

[0019] In a second aspect, an embodiment of the utility model provides a smart lock, comprising an anti-interference circuit for touch key recognition as described in the first aspect.

[0020] Compared with the prior art, the utility model has the following advantages:

[0021] The embodiment of the utility model provides an anti-interference circuit for touch key recognition, in which a resistor-capacitor filter is formed by a first resistor and a first capacitor module to filter out interference signals from a power amplifier module to a voltage stabilizing module, thereby filtering out voltage interference caused to the touch key recognition module, and eliminating misrecognition of touch events of touch keys by the touch key recognition module caused thereby. Due to the voltage-dividing effect of the first resistor on the interference voltage of the power amplifier module, the voltage interference of the power amplifier module to the voltage stabilizing module can be reduced. Therefore, compared with the capacitor filter in the prior art, the resistor-capacitor filter improves the effect of filtering the voltage interference signal of the power amplifier module. Compared with the method of filtering the voltage interference signal of the power amplifier module by using a capacitor filter in the prior art, the voltage interference caused to the touch key recognition module can be filtered out, thereby avoiding misrecognition of touch events of the touch keys by the touch key recognition module. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a structural schematic diagram of an anti-interference circuit for touch key recognition provided by an embodiment of the utility model;

[0024] Figure 2 This is a specific structural schematic diagram of an anti-interference circuit for touch key recognition provided by an embodiment of the utility model;

[0025] Figure 3 This is another specific structural schematic diagram of the anti-interference circuit for touch key recognition provided by an embodiment of the utility model.

[0026] Reference numerals:

[0027] 10 - voltage stabilizing module; 11 - first voltage stabilizer; 12 - second voltage stabilizer; 20 - power amplifier module; 30 - touch key identification module; 40 - speaker; 50 - touch key; 60 - power supply; R1 - first resistor; R2 - second resistor; C1 - first capacitor module; C2 - second capacitor module. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] Reference Figure 1 The embodiment of the utility model provides an anti-interference circuit for touch key recognition, including: a voltage stabilizing module 10, a first resistor R1, a first capacitor module C1, a power amplifier module 20, and a touch key recognition module 30; the voltage stabilizing module 10 is electrically connected to the touch key recognition module 30, and the voltage stabilizing module 10 is also electrically connected to the first resistor R1, and the voltage stabilizing module 10 is used to be electrically connected to a power supply 60 to supply power to the touch key recognition module 30 and the first resistor R1; the first resistor R1 is electrically connected to the first capacitor module C1 and the power amplifier module 20 respectively, and the first resistor R1 and the first capacitor module C1 form a resistor-capacitor filter, which is used to filter out the interference signal of the power amplifier module 20 to the voltage stabilizing module 10; the power amplifier module 20 is used to control the volume of a speaker 40 electrically connected to the power amplifier module 20; the touch key recognition module 30 is used to recognize the touch event of the touch key 50 electrically connected to the touch key recognition module 30.

[0030] It should be noted that the touch event is an event in which the touch key 50 is touched. After a touch event occurs on the touch key 50, the capacitance value of the touch key 50 increases, and the touch key recognition module 30 converts the capacitance value of the touch key 50 into a count value, and the count value is negatively correlated with the capacitance value of the touch key 50. If the capacitance value of the touch key 50 increases, the count value decreases, and the count value decreases by a comparison with a preset threshold value. If the count value decreases by a greater amount than the preset threshold value, the touch key recognition module 30 determines that a touch event occurs on the touch key 50; wherein, the count value decreases by a range of 20 to 30 when a touch event occurs on the touch key 50.

[0031] When the speaker 40 is broadcasting a voice, the current of the power amplifier module 20 driving the speaker 40 increases instantaneously. At this time, the output power of the voltage stabilizing module 10 remains unchanged, and the power amplifier module 20 generates a voltage interference signal that reduces the voltage, that is, an interference voltage signal that is opposite to the output voltage of the voltage stabilizing module 10. The voltage interference signal reduces the output voltage of the voltage stabilizing module 10. The output voltage of the voltage stabilizing module 10 is also the power supply voltage of the touch key recognition module 30. The power supply voltage of the touch key recognition module 30 is reduced, resulting in a decrease in the count value of the touch key recognition module 30. When the decrease in the count value is greater than or equal to the preset threshold (the preset threshold is set in the range of 10 to 20), the touch key recognition module 30 mistakenly determines that a touch event has occurred on the touch key 50, that is, the touch key recognition module 30 misidentifies the touch event of the touch key 50. The anti-interference circuit for touch key recognition provided by the embodiment of the utility model forms a resistor-capacitor filter through the first resistor R1 and the first capacitor module C1 to filter out the interference signal of the power amplifier module 20 to the voltage stabilizing module 10, so that when the speaker 40 broadcasts the voice, the decrease in the count value of the touch key recognition module 30 caused by the voltage interference signal of the power amplifier module 20 is less than the preset threshold value, so as to avoid the touch key recognition module 30 from misrecognizing the touch event of the touch key 50.

[0032] It should be noted that, when the speaker 40 broadcasts voice, the louder the volume of the speaker 40 is, the greater the instantaneous increase in the current of the power amplifier module 20 driving the speaker 40 is.

[0033] In particular, when the power amplifier module 20 controls the speaker 40 to broadcast the voice at the maximum volume, the current driven by the power amplifier module 20 to drive the speaker 40 increases to the maximum current instantaneously. At this time, the output power of the voltage regulator module 10 remains unchanged, and the power amplifier module 20 generates a maximum voltage interference signal that reduces the voltage, that is, a signal of an interference voltage that is opposite to the output voltage of the voltage regulator module 10. The maximum voltage interference signal reduces the output voltage of the voltage regulator module 10. The output voltage of the voltage regulator module 10 is also the power supply voltage of the touch key recognition module 30. Then, the power supply voltage of the touch key recognition module 30 is reduced, resulting in a decrease in the count value of the touch key recognition module 30. Compared with the case where the power amplifier module 20 controls the speaker 40 to broadcast the voice at a volume less than the maximum volume, when the power amplifier module 20 controls the speaker 40 to broadcast the voice at the maximum volume, the maximum voltage interference signal of the power amplifier module 20 causes the count value of the touch key recognition module 30 to decrease by a larger amount, thereby increasing the risk that the count value decreases by a value greater than or equal to the preset threshold, thereby increasing the risk that the touch key recognition module 30 erroneously determines that a touch event has occurred on the touch key 50.

[0034] When the power amplifier module 20 controls the speaker 40 to broadcast the voice at the maximum volume, after a certain period of time, the power of the power supply 60 (such as a battery) is greatly reduced, so that the output power of the voltage regulator module 10 is reduced, not only can it not provide the maximum current required for the maximum volume of the speaker 40, but also compared with the case where the power of the power supply 60 (such as a battery) is sufficient, when the power of the power supply 60 (such as a battery) is greatly reduced, the output power of the voltage regulator module 10 is reduced. Then, for the same increase in the current driven by the power amplifier module 20 to drive the speaker 40, the maximum voltage interference signal of the power amplifier module 20 causes the output voltage of the voltage regulator module 10 to decrease by a greater amount, that is, the power supply voltage of the touch key recognition module 30 is reduced by a greater amount, resulting in a greater decrease in the count value of the touch key recognition module 30, and thus the risk of the count value decrease being greater than or equal to the preset threshold value increases, which increases the risk of the touch key recognition module 30 erroneously judging that a touch event has occurred on the touch key 50.

[0035] The anti-interference circuit for touch key recognition provided by the embodiment of the utility model forms a resistor-capacitor filter through the first resistor R1 and the first capacitor module C1 to filter out the interference signal of the power amplifier module 20 to the voltage stabilizing module 10, which not only improves the interference suppression capability of the power supply 60, but also makes the count value of the touch key recognition module 30 reduced by the voltage interference signal of the power amplifier module 20 less than the preset threshold value when the power amplifier module 20 controls the speaker 40 to broadcast the voice at the maximum volume, especially when the power supply is low, so as to avoid the touch key recognition module 30 from misrecognizing the touch event of the touch key 50.

[0036] In addition, through the current compensation of the power amplifier module by the first capacitor module, when the power amplifier module 20 controls the speaker 40 to broadcast voice at the maximum volume, especially when the power supply is low, the maximum current required for the maximum volume of the speaker 40 is maintained, and under the condition that there is no obvious loss in the volume of the speaker 40, the decrease in the count value of the touch key recognition module 30 caused by the voltage interference signal of the power amplifier module 20 is less than the preset threshold, leaving sufficient recognition space for the count value reduction for real touch events, thereby meeting the requirements of loud voice broadcasting and high-sensitivity touch experience.

[0037] In some embodiments, the voltage stabilizing module 10 may be a low dropout linear regulator (LDO) or a combination of low dropout linear regulators, wherein the low dropout linear regulator is used to provide a stable DC voltage power supply, and has functions such as overcurrent protection, over-temperature protection, precision reference source, differential amplifier, delay device, etc., and these characteristics help to improve the stability and reliability of the circuit; the first capacitor module C1 is a module composed of multiple capacitors in parallel; the power amplifier module 20 is a power amplifier of the speaker 40; the resistor-capacitor filter is an R (resistance) C (capacitance) filter; the number of touch keys 50 is multiple, for example, 12 or 15, and the touch key recognition module may be a recognition module for identifying touch keys for inputting passwords; the power of the speaker 40 is not less than 0.5 watts (for example, 0.5 watts).

[0038] In summary, in the embodiment of the utility model, a resistor-capacitor filter is formed by the first resistor R1 and the first capacitor module C1 to filter out the interference signal of the power amplifier module 20 to the voltage stabilizing module 10, and then filter out the voltage interference caused to the touch key recognition module 30, thereby eliminating the misrecognition of the touch event of the touch key 50 by the touch key recognition module 30. Due to the voltage-dividing effect of the first resistor R1 on the interference voltage of the power amplifier module 20, the voltage interference of the power amplifier module 20 to the voltage stabilizing module 10 can be reduced. Therefore, compared with the capacitor filter in the prior art, the resistor-capacitor filter improves the effect of filtering the voltage interference signal of the power amplifier module. Compared with the method of using a capacitor filter to filter the voltage interference signal of the power amplifier module in the prior art, the voltage interference caused to the touch key recognition module can be filtered out, thereby avoiding the misrecognition of the touch event of the touch key by the touch key recognition module.

[0039] Optional, see Figure 2 The voltage stabilizing module 10 includes a first voltage stabilizer 11 and a second voltage stabilizer 12; the first voltage stabilizer 11 is electrically connected to the first end of the first resistor R1, and the first voltage stabilizer 11 is used to be electrically connected to the power supply 60 to supply power to the first resistor R1; the second end of the first resistor R1 is electrically connected to the first capacitor module C1 and the power amplifier module 20 respectively; the second voltage stabilizer 12 is electrically connected to the touch key recognition module 30, and the second voltage stabilizer 12 is used to be electrically connected to the power supply 60 to supply power to the touch key recognition module 30.

[0040] In some embodiments, the input end of the first voltage regulator 11 is electrically connected to the power supply 60, the output end of the first voltage regulator 11 is electrically connected to the first end of the first resistor R1, and the ground end of the first voltage regulator 11 is grounded; the input end of the power amplifier module 20 is electrically connected to the second end of the first resistor R1, the output end of the power amplifier module 20 is electrically connected to the speaker 40, and the ground end of the power amplifier module 20 is grounded; the input end of the second voltage regulator 12 is electrically connected to the power supply 60, the output end of the second voltage regulator 12 is electrically connected to the input end of the touch key recognition module 30, and the ground end of the second voltage regulator 12 is grounded; the output end of the touch key recognition module 30 is electrically connected to multiple touch keys 50, and the ground end of the touch key recognition module 30 is grounded.

[0041] In the embodiment of the utility model, when the speaker 40 broadcasts the voice, the voltage interference signal of the power amplifier module 20 reduces the output voltage of the first voltage regulator 11, thereby reducing the output voltage of the power supply 60. However, since the voltage interference signal of the power amplifier module 20 is consumed by the first voltage regulator 11, the reduction amount of the output voltage of the power supply 60 is less than the reduction amount of the output voltage of the first voltage regulator 11. When the output voltage of the power supply 60 is reduced, the output voltage of the second voltage regulator 12 is reduced. However, since the voltage interference signal of the power amplifier module 20 is consumed by the first voltage regulator 11 and the power supply 60 and the filtering function of the power supply 60, the reduction amount of the output voltage of the second voltage regulator 12 is less than the reduction amount of the output voltage of the power supply 60, and is less than the reduction amount of the output voltage of the first voltage regulator 11. The output voltage of the second voltage regulator 12 is also the power supply voltage of the touch key recognition module 30. Therefore, the reduction amount of the power supply voltage of the touch key recognition module 30 is less than the reduction amount of the output voltage of the power supply 60, and is less than the reduction amount of the output voltage of the first voltage regulator 11.

[0042] When a voltage stabilizer is used to power the touch key recognition module 30 and the power amplifier module 20 at the same time, when the speaker 40 broadcasts the voice, the voltage interference signal of the power amplifier module 20 causes the output voltage of the voltage stabilizer to decrease. The output voltage of the voltage stabilizer is also the power supply voltage of the touch key recognition module 30. Then, the amount of reduction in the power supply voltage of the touch key recognition module 30 is equal to the amount of reduction in the output voltage of the voltage stabilizer.

[0043] Therefore, compared with the embodiment in which one voltage regulator is used to power the touch key recognition module 30 and the power amplifier module 20 at the same time, the embodiment in which the first voltage regulator 11 is used to power the power amplifier module 20 and the second voltage regulator 12 is used to power the touch key recognition module 30 can further reduce the influence of the voltage interference signal of the power amplifier module 20 on the supply voltage of the touch key recognition module 30.

[0044] Optionally, the anti-interference circuit for touch key recognition also includes a second resistor R2 and a second capacitor module C2; ​​the second voltage regulator 12 is electrically connected to the first end of the second resistor R2; the second end of the second resistor R2 is electrically connected to the second capacitor module C2 and the touch key recognition module 30 respectively.

[0045] In an embodiment of the utility model, the second resistor R2 and the second capacitor module C2 form a resistor-capacitor filter, which can filter the voltage interference signal transmitted through the second regulator 12, and further reduce the influence of the voltage interference signal of the power amplifier module 20 on the supply voltage of the touch key recognition module 30.

[0046] Optionally, both the first voltage regulator 11 and the second voltage regulator 12 are low voltage dropout linear regulators.

[0047] It should be noted that the low voltage dropout linear regulator has good voltage stability and low voltage noise, which is beneficial to reducing voltage interference to the touch key recognition module 30 .

[0048] Optionally, the second capacitor module C2 includes multiple capacitors, and the capacitance value of each capacitor in the second capacitor module C2 is different; the second end of the second resistor R2 is electrically connected to the first end of each capacitor in the second capacitor module C2, and the second end of each capacitor in the second capacitor module C2 is grounded.

[0049] In some embodiments, the second capacitor module C2 includes two capacitors.

[0050] In the embodiment of the utility model, a plurality of capacitors with different capacitance values ​​are combined to form the second capacitor module C2, which can increase the frequency range of the interference signal to be filtered out, and is beneficial to reducing the voltage interference to the touch key recognition module 30.

[0051] Optional, see Figure 3 The voltage stabilizing module 10 includes a first voltage stabilizer 11; the first voltage stabilizer 11 is electrically connected to the touch key recognition module 30, and the first voltage stabilizer 11 is also electrically connected to the first end of the first resistor R1. The first voltage stabilizer 11 is used to be electrically connected to the power supply 60 to supply power to the touch key recognition module 30 and the first resistor R1; the second end of the first resistor R1 is electrically connected to the first capacitor module C1 and the power amplifier module 20 respectively.

[0052] In an embodiment of the utility model, the first voltage regulator 11 is used to simultaneously power the power amplifier module 20 and the touch key recognition module 30, which can reduce costs compared to the embodiment in which the first voltage regulator 11 is used to power the power amplifier module 20 and the second voltage regulator 12 is used to power the touch key recognition module 30.

[0053] Optionally, the anti-interference circuit for touch key recognition also includes a second resistor R2 and a second capacitor module C2; ​​the first voltage regulator 11 is electrically connected to the first end of the second resistor R2; the second end of the second resistor R2 is electrically connected to the second capacitor module C2 and the touch key recognition module 30 respectively.

[0054] In an embodiment of the utility model, the second resistor R2 and the second capacitor module C2 form a resistor-capacitor filter, which can filter the voltage interference signal transmitted through the first regulator 11, and further reduce the influence of the voltage interference signal of the power amplifier module 20 on the power supply voltage of the touch key recognition module 30.

[0055] Optionally, the first capacitor module C1 includes multiple capacitors, and the capacitance value of each capacitor in the first capacitor module C1 is different; the second end of the first resistor R1 is electrically connected to the first end of each capacitor in the first capacitor module C1, and the second end of each capacitor in the first capacitor module C1 is grounded.

[0056] In some embodiments, the first capacitor module C1 includes two capacitors.

[0057] In the embodiment of the utility model, a plurality of capacitors with different capacitance values ​​are combined to form the first capacitor module C1, which can increase the frequency range of the interference signal to be filtered out, and is beneficial to reducing the voltage interference to the touch key recognition module 30.

[0058] Optionally, the power source 60 is a battery.

[0059] In the embodiment of the utility model, a battery is used as the power source 60, so that the anti-interference circuit of the touch key recognition does not rely on the power supply of the power grid, thereby improving the power supply safety.

[0060] An experiment was conducted using the anti-interference circuit for touch key recognition provided by an embodiment of the utility model. The power supply 60 is a battery, the preset threshold is 10, the equivalent internal resistance of the speaker 40 is 8 ohms, the resistance value of the first resistor R1 is 3.3 ohms, the capacitance value of the first capacitor module C1 is not less than 44 microfarads (for example, 45 microfarads), the resistance value of the second resistor R2 is 15 ohms, and the capacitance value of the second capacitor module C2 is not less than 22 microfarads (for example, 23 microfarads). The test result shows that when the speaker 40 broadcasts the voice at the maximum volume, the voltage drop of the power supply 60 is less than 100 millivolts (for example, 99 millivolts), and the decrease in the count value of the touch key recognition module 30 (the decrease in the count value is 3 in some experimental results) is less than 5. Since the decrease in the count value of the touch key recognition module 30 is less than the preset threshold, the touch key recognition module 30 does not recognize the touch event of the touch key 50. In the case where the speaker 40 broadcasts the voice, the interference signal of the power amplifier module 20 does not cause the touch key recognition module 30 to misrecognize the touch event of the touch key 50.

[0061] In another experiment, an experiment was conducted using a solution of related technology, that is, a capacitor filter was used to filter the voltage interference signal of the power amplifier module. When the speaker was broadcasting voice at maximum volume, the current of the power amplifier module driving the speaker instantly increased to 400 mA (close to the output current upper limit of 500 mA of the power amplifier module), causing the power supply voltage to drop by approximately 500 mV, and the decrease in the count value of the touch key recognition module (the decrease in the count value was 11 in some experimental results) was greater than 10. Since the decrease in the count value of the touch key recognition module was greater than the preset threshold, the touch key recognition module mistakenly recognized the touch event of the touch key. Then, when the speaker was broadcasting voice, the interference signal of the power amplifier module caused the touch key recognition module to misrecognize the touch event of the touch key.

[0062] Therefore, from the experimental results, the anti-interference circuit for touch key recognition provided in the embodiment of the utility model avoids the misrecognition of the touch event of the touch key 50 by the touch key recognition module 30, while the solution of the related technology has the problem of misrecognition of the touch event of the touch key by the touch key recognition module. Compared with the related technology, the anti-interference circuit for touch key recognition provided in the embodiment of the utility model improves the effect of filtering the voltage interference signal of the power amplifier module.

[0063] In the related art, on the basis of capacitive filters respectively provided on one side of the power amplifier module and one side of the touch key recognition module, a controller loaded with software is added. When the interference signal of the power amplifier module causes the decrease in the count value of the touch key recognition module to be greater than a preset threshold, the touch key recognition module is corrected through the controller so that the touch key recognition module recognizes it as a non-touch event, so as to avoid the touch key recognition module from misidentifying the touch event of the touch key.

[0064] In the embodiment of the utility model, a resistor is added to one line of the power amplifier module and one line of the touch key recognition module respectively, so that one line of the power amplifier module and one line of the touch key recognition module are respectively provided with a first-level resistor-capacitor filter, thereby improving the effect of filtering the voltage interference signal of the power amplifier module, and effectively avoiding the touch key recognition module from misidentifying the touch event of the touch key. Compared with adding a controller loaded with software in the related art, the cost of adding two resistors is lower, thereby saving costs.

[0065] An embodiment of the utility model provides a smart lock, including the aforementioned anti-interference circuit for touch key recognition.

[0066] In some embodiments, the touch key recognition module 30 may be a main control chip in a smart lock with a touch key recognition function; in other embodiments, the touch key recognition module 30 may also be a dedicated chip for touch key recognition in a smart lock.

[0067] The specific implementation process of the anti-interference circuit for touch key recognition in the smart lock is similar to the implementation process of the anti-interference circuit for touch key recognition mentioned above, and will not be repeated here.

[0068] In summary, in the embodiment of the utility model, a resistor-capacitor filter is formed by the first resistor R1 and the first capacitor module C1 to filter out the interference signal of the power amplifier module 20 to the voltage stabilizing module 10, and then filter out the voltage interference caused to the touch key recognition module 30, thereby eliminating the misrecognition of the touch event of the touch key 50 by the touch key recognition module 30. Due to the voltage-dividing effect of the first resistor R1 on the interference voltage of the power amplifier module 20, the voltage interference of the power amplifier module 20 to the voltage stabilizing module 10 can be reduced. Therefore, compared with the capacitor filter in the prior art, the resistor-capacitor filter improves the effect of filtering the voltage interference signal of the power amplifier module. Compared with the method of using a capacitor filter to filter the voltage interference signal of the power amplifier module in the prior art, the voltage interference caused to the touch key recognition module can be filtered out, thereby avoiding the misrecognition of the touch event of the touch key by the touch key recognition module.

[0069] Finally, it should be noted that, in this article, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or terminal device.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0071] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An anti-interference circuit for touch key recognition, characterized in that: include: Voltage stabilizing module, first resistor, first capacitor module, power amplifier module, touch key recognition module; The voltage stabilizing module is electrically connected to the touch key recognition module, and the voltage stabilizing module is also electrically connected to the first resistor. The voltage stabilizing module is used to be electrically connected to a power source to supply power to the touch key recognition module and the first resistor; The first resistor is electrically connected to the first capacitor module and the power amplifier module respectively, and the first resistor and the first capacitor module form a resistor-capacitor filter for filtering out interference signals from the power amplifier module to the voltage stabilizing module; The power amplifier module is used to control the volume of a speaker electrically connected to the power amplifier module; The touch key recognition module is used to recognize a touch event of a touch key electrically connected to the touch key recognition module.

2. The anti-interference circuit for touch key recognition according to claim 1, characterized in that: The voltage stabilizing module includes a first voltage stabilizer and a second voltage stabilizer; The first voltage stabilizer is electrically connected to a first end of the first resistor, and the first voltage stabilizer is used to be electrically connected to the power supply to supply power to the first resistor; The second end of the first resistor is electrically connected to the first capacitor module and the power amplifier module respectively; The second voltage regulator is electrically connected to the touch key recognition module, and the second voltage regulator is used to be electrically connected to the power supply to supply power to the touch key recognition module.

3. The anti-interference circuit for touch key recognition according to claim 2, characterized in that: The anti-interference circuit for touch key recognition also includes a second resistor and a second capacitor module; The second voltage stabilizer is electrically connected to the first end of the second resistor; The second end of the second resistor is electrically connected to the second capacitor module and the touch key recognition module respectively.

4. The anti-interference circuit for touch key recognition according to claim 3, characterized in that: The first voltage regulator and the second voltage regulator are both low voltage dropout linear regulators.

5. The anti-interference circuit for touch key recognition according to claim 3, characterized in that: The second capacitor module includes a plurality of capacitors, and the capacitance value of each capacitor in the second capacitor module is different; The second end of the second resistor is electrically connected to the first end of each capacitor in the second capacitor module, and the second end of each capacitor in the second capacitor module is grounded.

6. The anti-interference circuit for touch key recognition according to claim 1, characterized in that: The voltage stabilization module includes a first voltage stabilizer; The first voltage stabilizer is electrically connected to the touch key recognition module, and the first voltage stabilizer is also electrically connected to the first end of the first resistor, and the first voltage stabilizer is used to be electrically connected to the power supply to supply power to the touch key recognition module and the first resistor; The second end of the first resistor is electrically connected to the first capacitor module and the power amplifier module respectively.

7. The anti-interference circuit for touch key recognition according to claim 6, characterized in that: The anti-interference circuit for touch key recognition also includes a second resistor and a second capacitor module; The first voltage stabilizer is electrically connected to a first end of the second resistor; The second end of the second resistor is electrically connected to the second capacitor module and the touch key recognition module respectively.

8. The anti-interference circuit for touch key recognition according to any one of claims 1 to 7, characterized in that: The first capacitor module includes a plurality of capacitors, and the capacitance value of each capacitor in the first capacitor module is different; The second end of the first resistor is electrically connected to the first end of each capacitor in the first capacitor module, and the second end of each capacitor in the first capacitor module is grounded.

9. The anti-interference circuit for touch key recognition according to any one of claims 1 to 7, characterized in that: The power source is a battery.

10. A smart lock, characterized in that: The invention comprises an anti-interference circuit for touch key recognition as claimed in any one of claims 1 to 9.

Images