Electronic cigarette microphone detection circuit and method

Abstract

The present invention discloses an electronic cigarette microphone detection circuit and method, relating to the field of electronic cigarettes, which includes an oscillation circuit, a counting circuit, a comparison output circuit, and an external selection circuit; the oscillation circuit generates an oscillation frequency when the device is powered on, the counting circuit is connected to the oscillation circuit and is used to detect the working frequency of the oscillation circuit; the counting circuit includes a counting group and a latching group, the latching group is used to set a reference oscillation frequency, and the counting group is used to detect a periodic oscillation frequency; the external selection circuit is connected to the counting circuit and the comparison output circuit and is used to set the detection accuracy; the comparison output circuit includes an adder and a comparator group and is used to output the oscillation frequency difference of the circuit and the smoking state of the electronic cigarette microphone. The present invention uses the most basic logic devices to form a detection circuit, can realize the detection of the electronic cigarette microphone without using a control chip and an algorithm, and can automatically adjust and update the detection accuracy of the circuit.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic cigarettes, and particularly to an electronic cigarette microphone detection circuit and method. Background Art

[0002] An electronic cigarette device is an electronic product that imitates cigarettes and supplies nicotine, tar, etc. as vapor through means such as electronic atomization. In products such as electronic cigarettes or atomizers, the capacitance change of an electronic cigarette microphone is usually used to represent the strength and direction of the puffing airflow. Then, the capacitance can be converted into a digital signal carrying frequency information, and the digital signal is processed to obtain the capacitance and its change amount, so as to obtain the strength and direction of the puffing current.

[0003] In the related art, the detection circuit all adopts relatively complex arithmetic circuits, such as multipliers, dividers, control chips, and other logic circuit devices, which ultimately leads to an overly large circuit structure and affects the spatial layout of electronic cigarette products. In addition, the detection accuracy in the related art is detected by clock circuit technology, which requires an additional built-in capacitor, and the fixed reference frequency will lead to a decrease in detection accuracy or even misjudgment, and the detection accuracy is not high. Summary of the Invention

[0004] The embodiments of the present application provide an electronic cigarette microphone detection circuit and method, which solve the problems of complex detection circuit, large occupied space, and low detection accuracy in the related art;

[0005] On the one hand, the present application provides an electronic cigarette microphone detection circuit, including an oscillation circuit, a counting circuit, a comparison output circuit, and an external selection circuit;

[0006] The oscillation circuit generates an oscillation frequency when the device is powered on. The counting circuit is connected to the oscillation circuit and is used to detect the working frequency of the oscillation circuit. Among them, the capacitance value and the generated oscillation frequency of the oscillation circuit are different in the smoking state and the non-smoking state;

[0007] The counting circuit includes a counting group and a latching group. The latching group is used to set the reference oscillation frequency, and the counting group is used to detect the periodic oscillation frequency;

[0008] The external selection circuit is connected to the counting circuit and the comparison output circuit and is used to set the detection accuracy. The comparison output circuit includes an adder and a comparator group and is used to output the oscillation frequency difference of the circuit and the smoking state of the electronic cigarette microphone.

[0009] On the other hand, the present application provides an electronic cigarette microphone detection method, and the method includes:

[0010] When the device is powered on, initialize the counting group and the latching group in the counting circuit;

[0011] The oscillation frequency of the oscillation circuit is detected by the counting circuit to determine the reference oscillation frequency and the periodic oscillation frequency within each period; wherein, the oscillation circuit is an RC oscillation circuit and is connected with a microphone sensor, and the capacitance value and the generated oscillation frequency of the oscillation circuit are different in the smoking state and the non-smoking state;

[0012] Receive the adjustment instruction input by the external selection circuit and set the detection threshold of the reference oscillation frequency; wherein, the adjustment instruction is used for the register group to shift the binary reference oscillation frequency to obtain the detection threshold;

[0013] Calculate the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency through the adder and the comparator group in the comparison output circuit, and output the comparison result through the oscillation frequency difference and the detection threshold, and judge the smoking state of the electronic cigarette microphone according to the output result.

[0014] The beneficial effects brought by the technical solution provided by the embodiment of the present application at least include: using the oscillation circuit as the starting oscillation unit, then detecting the periodic oscillation frequency within each period through the counting group, and at the same time determining the reference oscillation frequency through the latching group. This method does not require an internal clock circuit, but calculates the frequency through the circuit itself and the electronic cigarette microphone, which can reduce the occupied volume of the circuit; the comparison output circuit only uses an adder and a comparator group, without introducing additional multipliers and dividers, etc., which further simplifies the complexity of the circuit; and the external selection circuit can adjust the detection accuracy according to the actual situation and output the judgment result according to the accuracy. Compared with the prior art method of processing through a clock circuit and a logic chip, the complexity of the circuit can be greatly reduced, the space layout can be reduced, and the detection accuracy and speed can be improved. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the electronic cigarette microphone detection circuit provided by the embodiment of the present application;

[0016] Figure 2 is a schematic structural diagram of the electronic cigarette microphone detection circuit provided by another embodiment of the present application;

[0017] Figure 3 is a flowchart of the electronic cigarette microphone detection method provided by the embodiment of the present application;

[0018] Figure 4 is a logic diagram of the electronic cigarette microphone detection method provided by the embodiment of the present application;

[0019] Figure 5 is a timing diagram of the electronic cigarette microphone detection circuit provided by the embodiment of the present application. Detailed Embodiment

[0020] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0021] The term "multiple" as used herein refers to two or more than two. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0022] Figure 1 It is a schematic diagram of the structure of the electronic cigarette microphone detection circuit provided in the embodiment of the present application. Specifically, it includes an oscillation circuit, a counting circuit, a comparison output circuit and an external selection circuit. The oscillation circuit or oscillation module is connected to the electronic cigarette microphone sensor, and the electronic cigarette microphone obtains the change in capacitance through the slight change in gas flow. The oscillation circuit or oscillation module can emit a regular oscillation frequency when the electronic device is operating normally. This solution uses an RC oscillation circuit as an oscillation starting module. When the microphone sensor is connected to the module, the airflow disturbance generated by the user during use can be changed into an oscillation frequency change at any time.

[0023] The counting circuit is connected to the oscillation circuit, including a counting group and a latch group. The counting group is composed of a number of counts, and the specific number is determined by the value of the periodic oscillation. The latch group includes a number of latches, which are used to set the reference oscillation frequency. Under ideal conditions, the reference oscillation frequency is the periodic oscillation frequency detected when there is no airflow disturbance. In the latch state, comparison and subsequent calculation can be performed.

[0024] The comparison output circuit includes an adder and a comparator group, which are used to output the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency, and judge whether smoking is on or off according to the frequency difference. The comparator group may include several comparators, and the high and low level values ​​of the output results thereof indicate smoking or not smoking. Since the detection circuit is constructed using basic logic devices, it has a high degree of integration, does not occupy space, and does not require MCU chips and other storage chips to participate in the operation. The use of the RC oscillation circuit can directly generate oscillations based on passive devices or replace the traditional crystal oscillator circuit, so there is no need for additional built-in capacitors, further reducing the space occupied by the circuit. At the same time, in order to improve the detection accuracy of the circuit, an external selection circuit is also provided. The external selection circuit is composed of registers, which connect the counting circuit and the comparison output circuit. Because the counter counts a high value, directly judging smoking or not smoking by the difference will produce a large error. In actual use, a small finger touch or airflow disturbance will cause the frequency value to change. If the atomization circuit is directly started according to the difference, it will affect the user's experience.

[0025] The external selection circuit can set the detection accuracy, set the detection threshold according to the accuracy, that is, compare the detection threshold with the value output by the adder, and make a judgment according to the result. The detection accuracy of the register can be set before leaving the factory, or the detection accuracy can be adjusted at any time through an external button to meet the needs of different user scenarios.

[0026] Figure 2 It is a schematic structural diagram of an electronic cigarette microphone detection circuit provided by another embodiment of the present application. The counter periodically records the value of the oscillation circuit according to the setting, that is, the value is not unique. The latch group locks a certain fixed value as the reference oscillation frequency through a latch. This value is set according to the count value of the first detection period when the device is powered on and initialized each time. During subsequent detections, it will be further adjusted according to the result output by the comparator group. The result output by the latch group is fixed. After the counter outputs through an inverter, it is input to the adder together with the reference oscillation frequency value, that is, the difference between the real-time detected periodic oscillation frequency and the reference oscillation frequency is calculated, and the output is the oscillation frequency difference.

[0027] The comparator group includes a comparator and a secondary comparator. The output results of the two-stage comparator are used to judge the suction state of the current electronic cigarette. The external selection circuit includes several register groups, and the register groups process the reference data of the latch group according to the setting. In some solutions, a multiplier or a divider is used for judgment in this part, but the multiplier and the divider are larger in volume than the register and the adder. And the accuracy cannot be adjusted.

[0028] In this solution, the reference frequency value of the register component is represented in binary, and the division operation is realized by shifting the high bit to the right. In this application, an example is given where two registers respectively output a detection value. The first register shifts the value to the right by 1 bit to represent division by 2, shifts by 5 bits to represent division by 32, and shifts by 7 bits to represent division by 128. The number of bits by which different registers shift the binary value is determined by an external input. Schematically, the adjustment instruction SW_REF[13:0] means that the binary reference oscillation frequency does not move, SW_REF[13:5] means shifting to the right by 5 bits, and the reference oscillation frequency value is divided by 32; SW_REF[13:7] means division by 128. The output of the register after shifting to the right is the selection of a certain number of bits by the internal selector of the register group for output. The output of the first register in this solution is the first detection threshold, and the output of the second register is the second detection threshold, and the first detection threshold is greater than the second detection threshold.

[0029] The purpose of the two-stage comparison of the comparator group is to judge the magnitude relationship between the oscillation frequency difference and the first detection threshold and the second detection threshold. In this solution, the output of the adder is used as the negative pole of the first-stage comparator, and the second detection threshold is used as the positive pole; the output of the first-stage comparator is input to the negative pole of the second-stage comparator, and the first detection threshold is input to the positive pole of the second-stage comparator as an example.

[0030] When the output is 00, it indicates the smoking state; when the output is 11, it indicates non-smoking; when the output is 01, the latch group is cleared and the reference frequency value is re-obtained. The purpose of re-obtaining the reference value is to eliminate the interference of accidental touch. For example, the contact between the microphone, finger and object affects the capacitance value.

[0031] In summary, this circuit structure uses an oscillation circuit as the starting unit, then uses a counting group to detect the periodic oscillation frequency in each period, and at the same time uses a latch group to determine the reference oscillation frequency. This method does not require an internal clock circuit, but calculates the frequency through the circuit itself and the electronic cigarette microphone, which can reduce the occupied volume of the circuit; the comparison output circuit only uses an adder and a comparator group, without introducing additional multipliers and dividers, etc., which further simplifies the complexity of the circuit; and the external selection circuit can adjust the detection accuracy according to the actual situation and output a judgment result according to the accuracy. Compared with the method of processing through a clock circuit and a logic chip in the prior art, it can greatly reduce the complexity of the circuit, reduce the space layout, and improve the detection accuracy and speed.

[0032] Figure 3 It is a flowchart of the method for detecting an electronic cigarette microphone provided by an embodiment of the present application, including the following steps:

[0033] Step 301: Power on the device and initialize the counting group and latch group in the counting circuit.

[0034] Step 302: Detect the oscillation frequency of the oscillation circuit through the counting circuit to determine the reference oscillation frequency and the periodic oscillation frequency in each period.

[0035] In the first detection period after initialization, calculate the first oscillation period of the oscillation circuit through the counting group in the counting circuit. Then read the first oscillation period through the latch group and determine it as the reference oscillation frequency. The reference oscillation frequency here is determined in the first stable period after initialization, and the subsequent reference oscillation frequency will be determined by the detection output result.

[0036] Step 303: Receive the adjustment instruction input by the external selection circuit and set the detection threshold of the reference oscillation frequency.

[0037] The adjustment instructions input externally are executed by the register bank, and the process can be set before leaving the factory or adjusted manually by the user. The external selection circuit is connected with a detection accuracy control button. When the user manually inputs an adjustment instruction, the register bank updates the stored first instruction and second instruction, and respectively shifts the high bits of the reference oscillation frequency represented in binary to the right by the target number of bits according to the updated first instruction and second instruction to obtain the first detection threshold and the second detection threshold. For example, the first instruction is set to SW_REF[13:5], and the second instruction is set to SW_REF[13:7]. This step only requires an external button to complete the update of the register.

[0038] Step 304, calculate the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency through the adder and comparator group in the comparison output circuit, and output the comparison result through the oscillation frequency difference and the detection threshold, and judge the smoking state of the electronic cigarette microphone head according to the output result.

[0039] For each period, after the counting group detects the frequency value, the periodic oscillation frequency is inverted through an inverter, and after inversion, the reference oscillation frequency and the inverted periodic oscillation frequency are summed through an adder to obtain the oscillation frequency difference.

[0040] This solution inputs the first detection threshold and the oscillation frequency difference into a first-level comparator in the comparator group, and inputs the second detection threshold and the output of the first-level comparator into a second-level comparator in the comparator group. In this way, the comparator will only produce three results: greater than the first threshold, less than the second threshold, and between the two. The situation between the two mainly aims at the cases of accidental touch, the microphone head getting wet and damaged resulting in a change in capacitance value. For example, when sweat or saliva adheres to the microphone head, its frequency value in the non-smoking state will also change, so it is necessary to feedback the result to clear the register group and reset the reference oscillation frequency. At the same time, in different scenarios, the capacitance value may also change due to humidity or wind influence. At this time, the detection accuracy can be adjusted externally to reduce the probability of misjudgment.

[0041] Reference Figure 4 and Figure 5 , when determining the adjustment accuracy (1 / 32 and 1 / 128) and the reference oscillation frequency (4095), detect the difference between the count value and the reference value. In the second period, the count value becomes smaller to 4000, and the frequency difference is 95, that is, between the first detection threshold (128) and the second detection threshold (32), and the output result is 01. This change indicates that the capacitance value of the microphone head has changed. For example, getting wet or sweating causes the reference value to shift. At this time, it is necessary to calibrate the reference value in time to ensure the accuracy of the judgment.

[0042] In summary, the present solution connects the latch group and the comparator group to form a negative feedback mechanism of the circuit. When the reference frequency value changes, the register group is cleared and initialized in a timely manner, and the periodic oscillation frequency of the counter group is used as the reference oscillation frequency again, ensuring that the detection accuracy of the circuit structure can be updated in real time. Moreover, the external selection circuit performs shift selection through the register group and directly uses the most primitive logic devices to complete the functions of the multiplier and the divider, which can not only improve the processing speed, but also reduce the volume and complexity of the circuit structure. In addition, the adjustment instructions input externally can directly change the shift quantity of the register group, and thus can automatically adjust the first detection threshold and the second detection threshold to adapt to various usage scenarios and improve the user experience.

[0043] The preferred embodiments of the present invention have been described above; it should be understood that the present invention is not limited to the above specific embodiments, and the devices and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art can make many possible changes and modifications without departing from the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes, which does not affect the essence of the present invention; therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the protection of the technical solution of the present invention.

Claims

1. An electronic cigarette microphone detection circuit, characterized in that, It includes an oscillation circuit, a counting circuit, a comparison output circuit, and an external selection circuit; The oscillation circuit generates an oscillation frequency when the device is powered on. The counting circuit is connected to the oscillation circuit and is used to detect the operating frequency of the oscillation circuit. Among them, the capacitance value and the generated oscillation frequency of the oscillation circuit are different in the smoking state and the non-smoking state; The counting circuit includes a counting group and a latching group. The latching group contains a latch, which is initialized according to the output result fed back by the comparison output circuit to set a reference oscillation frequency. The counting group contains several counters, which count according to a detection period and determine the periodic oscillation frequency of the oscillation circuit, and send it to the comparison output circuit; The comparison output circuit includes an adder and a comparator group. The output of the adder and the external selection circuit are connected to the input of the comparator group, which is used to output the oscillation frequency difference of the circuit and determine the smoking state of the e-cigarette microphone head according to the comparator group; The external selection circuit is connected to the counting circuit and the comparison output circuit. It includes a register group. The input of the register group is connected to the output of the latching group, and the output is connected to the input of the comparator group, which is used to set the detection accuracy of the e-cigarette microphone head; The comparator group includes a first-level comparator and a second-level comparator. The output of the adder and the first output of the register group are connected to the input of the first-level comparator. The output of the first-level comparator and the second output of the register group are connected to the input of the second-level comparator. The output of the comparator group is connected to the latch; 2. The electronic cigarette microphone detection circuit according to claim 1, characterized in that, The oscillation circuit is an RC oscillation circuit and is connected to the microphone sensor of the e-cigarette microphone head; 3. The electronic cigarette microphone detection circuit according to claim 2, characterized in that, The output of the counting group is connected to an inverter. The inverter and the output of the latching group are connected to the input of the adder in the comparison output circuit; 4. An electronic cigarette microphone detection method, characterized in that, The method is used for the e-cigarette microphone head detection circuit according to any one of claims 1-3. The method includes: When the device is powered on, initialize the counting group and the latching group in the counting circuit; Detect the oscillation frequency of the oscillation circuit through the counting circuit to determine the reference oscillation frequency and the periodic oscillation frequency in each period. Among them, the oscillation circuit is an RC oscillation circuit and is connected to a microphone sensor. The capacitance value and the generated oscillation frequency of the oscillation circuit are different in the smoking state and the non-smoking state; Receive the adjustment instruction input by the external selection circuit and set the detection threshold of the reference oscillation frequency. Among them, the adjustment instruction is used for the register group to shift the binary reference oscillation frequency to obtain the detection threshold. When the first instruction in the adjustment instruction is obtained, shift the reference oscillation frequency by one level according to the first instruction to obtain the first detection threshold. When the second instruction in the adjustment instruction is obtained, shift the reference oscillation frequency by two levels according to the second instruction to obtain the second detection threshold. The second detection threshold is less than the first detection threshold; Calculate the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency by comparing the adder and comparator group in the output circuit, and output a comparison result based on the oscillation frequency difference and the detection threshold, and determine the smoking state of the e-cigarette microphone according to the output result; Among them, when the oscillation frequency difference is greater than the first detection threshold and the second detection threshold, the output result is determined to be the smoking state; when the oscillation frequency difference is less than the first detection threshold and the second detection threshold, the output result is determined to be the non-smoking state; when the oscillation frequency difference is less than the first detection threshold and greater than the second detection threshold, trigger the latch in the latch group to be initialized, determine the periodic oscillation frequency collected by the counting group in the next cycle as the reference oscillation frequency, and latch it.

5. The method according to claim 4, wherein The oscillation frequency detection of the oscillation circuit by the counting circuit to determine the reference oscillation frequency and the periodic oscillation frequency in each period includes: In the first detection period of initialization, calculate the first oscillation period of the oscillation circuit by the counting group in the counting circuit; Read the first oscillation period through the latch group and latch it as the reference oscillation frequency.

6. The method according to claim 5, wherein The calculation of the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency by comparing the adder and comparator group in the comparison output circuit, and the output of the comparison result through the oscillation frequency difference and the detection threshold; includes: Invert the periodic oscillation frequency detected by the counting group through an inverter; Sum the reference oscillation frequency and the inverted periodic oscillation frequency through the adder to obtain the oscillation frequency difference; Input the first detection threshold and the oscillation frequency difference into a first-level comparator in the comparator group, and input the second detection threshold and the output of the first-level comparator into a second-level comparator in the comparator group.

7. The method according to any one of claims 4 to 6, characterized in that, The external selection circuit is connected with a detection precision control button. When the user manually inputs an adjustment instruction, the register group updates the stored first instruction and second instruction, and respectively shifts the high bits of the binary representation of the reference oscillation frequency to the right by the target number of bits according to the updated first instruction and second instruction to obtain the first detection threshold and the second detection threshold.

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