CN115153108A - Electronic cigarette microphone detection circuit and method - Google Patents

Abstract

The invention discloses an electronic cigarette microphone detection circuit and method, which relate to the field of electronic cigarettes and comprise an oscillating circuit, a counting circuit, a comparison output circuit and an external selection circuit; the counting circuit is connected with the oscillating circuit and is used for detecting the working frequency of the oscillating circuit; the counting circuit comprises a counting group and a latch group, wherein the latch group is used for setting reference oscillation frequency, and the counting group is used for detecting periodic oscillation frequency; the external selection circuit is connected with the counting circuit and the comparison output circuit and is used for setting the detection precision; the comparison output circuit comprises an adder and a comparator group and is used for outputting the oscillation frequency difference of the circuit and the smoking state of the electronic cigarette microphone. The invention adopts the most basic logic devices to form the detection circuit, can realize the detection of the electronic cigarette microphone without adopting a control chip and an algorithm, and can automatically adjust and update the detection precision of the circuit.

Description

Electronic cigarette microphone head detection circuit and method

technical field

The embodiments of the present application relate to the field of electronic cigarettes, and in particular, to an electronic cigarette microphone head detection circuit and method.

Background technique

Electronic cigarette equipment is an electronic product that imitates cigarettes. Through electronic atomization and other means, nicotine and tar are converted into vapor and then supplied for smoking. In products such as electronic cigarettes or atomizers, the change in the capacitance of the electronic cigarette head is usually used to indicate the strength and direction of the blowing air flow, then the capacitance can be converted into a digital signal carrying frequency information, and then the The digital signal is processed to obtain the capacitance and its variation, so as to obtain the strength and direction of the blowing and absorbing current.

In the related art, the detection circuits all use relatively complex arithmetic circuits, such as multipliers, dividers, control chips, and other logic circuit devices, which eventually lead to an excessively large circuit structure and affect the spatial layout of electronic cigarette products; in addition, related technologies The detection accuracy in the device is detected by the clock circuit technology, which requires additional built-in capacitors, and the fixed reference frequency will lead to a decrease in the detection accuracy or even misjudgment, and the detection accuracy is not high.

SUMMARY OF THE INVENTION

The embodiments of the present application provide an electronic cigarette microphone head detection circuit and method, which solve the problems in the related art that the detection circuit is complex, occupies space, and has low detection accuracy;

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

The oscillating circuit generates an oscillating frequency when the device is powered on, and the counting circuit is connected to the oscillating circuit for detecting the operating frequency of the oscillating circuit; wherein the capacitance value of the oscillating circuit in the smoking state and the non-smoking state and the resulting oscillation frequency is not the same;

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;

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 electronic cigarette holder. Smoking status of the head.

On the other hand, the present application provides a method for detecting an electronic cigarette microphone head, the method comprising:

When the device is powered on, the counting group and latch group in the counting circuit are initialized;

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

Receive an adjustment instruction input from an external selection circuit, and set a 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;

Calculate the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency by comparing the adder and the comparator group in the output circuit, and output the comparison result through the oscillation frequency difference and the detection threshold, and judge the electronic device according to the output result. The smoking status of the cigarette end.

The beneficial effects brought by the technical solutions provided by the embodiments of the present application at least include: using an oscillation circuit as a starting unit, then detecting the periodic oscillation frequency in each cycle through a counting group, and determining a reference oscillation frequency through a latch group, this method does not require The built-in clock circuit, but the frequency calculation is performed by the circuit itself and the electronic cigarette microphone head, which can reduce the occupied volume of the circuit; the comparison output circuit only uses an adder and a comparator group, and there is no need to introduce additional multipliers and dividers. The complexity of the circuit is further simplified; 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 way of processing through a clock circuit and a logic chip in the prior art, 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 drawings

1 is a schematic structural diagram of an electronic cigarette microphone head detection circuit provided by an embodiment of the present application;

2 is a schematic structural diagram of an electronic cigarette microphone head detection circuit provided by another embodiment of the present application;

3 is a flowchart of a method for detecting an electronic cigarette microphone head provided by an embodiment of the present application;

4 is a logic diagram of a method for detecting an electronic cigarette microphone head provided by an embodiment of the present application;

FIG. 5 is a timing diagram of the electronic cigarette microphone head detection circuit provided by the embodiment of the present application.

Detailed ways

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

As used herein, "plurality" refers to two or more. "And/or", which describes the association relationship of the associated objects, means that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects are an "or" relationship.

FIG. 1 is a schematic structural diagram of a detection circuit for an electronic cigarette microphone head provided by an embodiment of the present application. Specifically, it includes an oscillator circuit, a counting circuit, a comparison output circuit and an external selection circuit. The oscillating circuit or the oscillating module is connected to the sensor of the electronic cigarette microphone head, and the electronic cigarette microphone head obtains the change of the capacitance through the slight change of the gas flow. The oscillating circuit or oscillating module can emit a regular oscillating frequency during normal operation of the electronic device. This solution uses an RC oscillator circuit as the starting module. When the microphone head sensor is connected to the module, the airflow disturbance generated by the user can be changed into the oscillation frequency change at any time.

The counting circuit is connected with the oscillating circuit, and includes a counting group and a latching group. The count group consists of several counts, and the specific number is determined according to the size of the periodic oscillation value. The latch group includes several latches for setting the reference oscillation frequency. In an ideal state, the reference oscillation frequency is the periodic oscillation frequency detected when there is no airflow disturbance. In the latched state, comparison and subsequent calculations can be performed.

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 to smoke or not according to the frequency difference. The comparator group may include several comparators, and the high and low level values of their output results indicate smoking or non-smoking. Since it is a detection circuit formed by using basic logic devices, it has a high degree of integration, does not occupy space, and does not require MCU chips and other memory chips to participate in operations. Using the RC oscillator circuit can directly generate oscillation based on passive devices or replace the traditional crystal oscillator circuit, so there is no need for additional built-in capacitors, which further reduces the occupied space of the circuit. At the same time, in order to improve the detection accuracy of this circuit, an external selection circuit is also set. The external selection circuit consists of registers, which are connected to the counting circuit and the comparison output circuit. Because the value counted by the counter is high, judging smoking or non-smoking directly by the difference will cause a large error. In the actual use process, a small finger touch or airflow disturbance will cause the frequency value to change. If you start directly based on the difference value The atomizing circuit will affect the user's experience.

The external selection circuit can set the detection precision, and set the detection threshold according to the precision, that is, compare the detection threshold with the value output by the adder, and judge 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.

FIG. 2 is a schematic structural diagram of a detection circuit for an electronic cigarette microphone head 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 uses the latch to lock a fixed value as the reference oscillation frequency. This value is set according to the count value of the first detection cycle when the device is powered on and initialized, and further adjusted according to the output result of the comparator group in the subsequent detection process. The output result of the latch group is fixed. After the counter is output through the inverter, it is input to the adder with the reference oscillation frequency value, that is, the difference between the real-time detection period oscillation frequency and the reference oscillation frequency is calculated, and the output is the oscillation. frequency difference.

The comparator group includes a comparator and a two-stage comparator, and the output result of the two-stage comparator is used to judge the current suction state of the 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 settings. In some schemes, multipliers or dividers are used in this section, but multipliers and dividers are larger than registers and adders. And the accuracy cannot be adjusted.

The reference frequency value of the register component in this scheme is represented as binary, and the division operation is realized by moving the high order right. In this application, two registers respectively output a detection value as an example for description. The first register shifts the entire value to the right by 1 bit for division by 2, 5 bits for division by 32, and 7 bits for division by 128. The number of bits shifted for binary values in different registers is determined by the external input. Illustratively, the adjustment command SW_REF[13:0] indicates that the binary reference oscillation frequency does not move, SW_REF[13:5] indicates that it is shifted to the right by 5 bits, and the reference oscillation frequency value is divided by 32; SW_REF[13:7] indicates that it is divided by 128. The right shift output of the register is to select a certain number of bits to output for the internal selector of the register group. In this solution, the output of the first register is the first detection threshold, the output of the second register is the second detection threshold, and the first detection threshold is greater than the second detection threshold.

The purpose of the two-stage comparison of the comparator group is to determine the magnitude relationship between the oscillation frequency difference and the first detection threshold and the second detection threshold. In this scheme, the adder outputs the negative pole of the first-level comparator, and the second detection threshold outputs the positive pole; the output of the first-level comparator is input to the negative pole of the second-level comparator, and the first detection threshold value is input to the positive pole of the second-level comparator as an example.

When the output is 00, it means that it is in the smoking state; when the output is 11, it means that it is not smoking; when the output is 01, the latch group is cleared to 0, and the reference frequency value is re-acquired. The purpose of re-acquiring the reference value is to eliminate the interference of false touches, for example, the contact between the microphone head and fingers and objects affects the capacitance value.

In summary, the circuit structure uses the oscillator circuit as the starting unit, and then detects the periodic oscillation frequency in each cycle through the counting group, and determines the reference oscillation frequency through the latch group. This method does not require a built-in clock circuit, but uses a circuit The frequency calculation is performed by itself and the electronic cigarette microphone, which can reduce the occupied volume of the circuit; the comparison output circuit only uses the adder and the comparator group, and there is no need to introduce additional multipliers and dividers, which further simplifies the complexity of the circuit; 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 way of processing through a clock circuit and a logic chip in the prior art, the complexity of the circuit can be greatly reduced, the space layout can be reduced, and the detection accuracy and speed can be improved.

3 is a flowchart of a method for detecting an electronic cigarette microphone head provided by an embodiment of the present application, comprising the following steps:

Step 301, the device is powered on, and the counting group and the latch group in the counting circuit are initialized.

In step 302, the oscillation frequency is detected on the oscillation circuit by the counting circuit, and the reference oscillation frequency and the periodic oscillation frequency in each cycle are determined.

In the first detection period after initialization, the first oscillation period of the oscillation circuit is calculated by the counting group in the counting circuit. Then, the first oscillation period is read through the latch group and determined as the reference oscillation frequency. The reference oscillation frequency here is determined in the first cycle when the circuit is stable after initialization, and the reference oscillation frequency thereafter will be determined by the detection output result.

Step 303: Receive an adjustment instruction input from an external selection circuit, and set a detection threshold of the reference oscillation frequency.

The adjustment command input from the outside is executed by the register group, and the process can be set before the factory, or the user can adjust it manually. The external selection circuit is connected with the detection precision control button. When the user manually inputs the adjustment instruction, the register group updates the stored first instruction and the second instruction, and oscillates the binary representation of the reference according to the updated first instruction and the second instruction. The high order of the frequency is shifted to the right by the target number of bits to obtain the first detection threshold and the second detection threshold. For example, the first command is set to SW_REF[13:5], and the second command is set to SW_REF[13:7]. This step only needs an external key to complete the update of the register.

Step 304: Calculate the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency by comparing the adder and the comparator group in the output circuit, and output the comparison result through the oscillation frequency difference and the detection threshold, and judge the smoking of the electronic cigarette tip according to the output result. state.

For each cycle, after the frequency value is detected by the counting group, the periodic oscillation frequency is inverted by the inverter, and after the inversion, the reference oscillation frequency and the inverted periodic oscillation frequency are summed by the adder to obtain the oscillation frequency. Difference.

In this solution, the first detection threshold and the difference of the oscillation frequency are input into the first-level comparator in the comparator group, and the second detection threshold and the output of the first-level comparator are input into the second-level comparator in the comparator group. The comparator thus produces only three results, greater than the first threshold, less than the second threshold, and in between. The situation between the two is mainly for the accidental touch and the situation that the capacitance value changes due to water or damage to the microphone head. For example, when sweat or saliva is attached to the microphone head, its frequency value will also change when it is not smoking, 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 the influence of humidity or wind. At this time, the detection accuracy can be adjusted through external control to reduce the probability of misjudgment.

4 and 5, in the case of determining the adjustment accuracy (1/32 and 1/128) and the reference oscillation frequency (4095), the difference between the count value and the reference value is detected, and in the second cycle, the count The value is reduced to 4000, the frequency difference is 95, that is, it is located 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 has changed, for example Water or sweat will cause the reference value to shift. At this time, it is necessary to calibrate the reference value in time to ensure the accuracy of judgment.

In summary, this scheme 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 time, and the periodic oscillation frequency of the counting group is re-used as The reference oscillation frequency ensures that the detection accuracy of the circuit structure can be updated in real time, and the external selection circuit performs shift selection through the register group, and directly uses the most primitive logic device to complete the functions of the multiplier and divider, which can not only improve the processing speed, but also The volume and complexity of the circuit structure are reduced, and the adjustment command input from the outside can directly change the shift number of the register group, and then the first detection threshold and the second detection threshold can be automatically adjusted to adapt to various usage scenarios and improve user usage. experience.

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-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood as being 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 solutions of the present invention, or modify them to equivalent examples of equivalent changes, which does not affect the essence of the present invention; The content of the technical solution of the present invention, and any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. An electronic cigarette microphone detection circuit is characterized by comprising an oscillating circuit, a counting circuit, a comparison output circuit and an external selection circuit;

the counting circuit is connected with the oscillating circuit and is used for detecting the working frequency of the oscillating circuit; wherein, the capacitance value of the oscillating circuit and the generated oscillating frequency are different under the smoking state and the non-smoking state;

the counting circuit comprises a counting group and a latch group, wherein the latch group is used for setting a reference oscillation frequency, and the counting group is used for detecting a periodic oscillation frequency;

the external selection circuit is connected with the counting circuit and the comparison output circuit and is used for setting detection precision; the comparison output circuit comprises an adder and a comparator group and is used for outputting the oscillation frequency difference of the circuit and the smoking state of the electronic cigarette microphone.

2. The electronic cigarette microphone according to claim 1, wherein the oscillating circuit is an RC oscillating circuit and is connected with a microphone sensor of the electronic cigarette microphone;

the RC oscillating circuit is respectively connected with the counting group and the latching group; the counter group comprises a plurality of counters, and the counters count and determine the periodic oscillation frequency of the RC oscillation circuit according to the detection period; the latch group comprises a latch and is initialized according to an output result fed back by the comparison output circuit.

3. The electronic cigarette microphone detection circuit of claim 2, wherein the counter array output is connected with an inverter; the outputs of the inverter and the latch set are connected to the inputs of the adder in the comparison output circuit; the output of the adder and the external selection circuit are connected to the inputs of the comparator bank.

4. The electronic cigarette microphone detection circuit of claim 3, wherein the external selection circuit comprises a register set, an input of the register set is connected to an output of the latch set, and an output of the register set is connected to an input of the comparator set.

5. The electronic cigarette microphone detection circuit of claim 4, wherein the set of comparators comprises a first-level comparator and a second-level comparator; the adder and the first output of the register group are connected with the input of the first-stage comparator, and the output of the first-stage comparator and the second output of the register group are connected with the input of the second-stage comparator; the outputs of the set of comparators are connected to the latch.

6. An electronic cigarette microphone detection method is characterized by comprising the following steps:

the equipment is powered on, and a counting group and a latching group in a counting circuit are initialized;

detecting the oscillation frequency of the oscillation circuit through the counting circuit, and determining a reference oscillation frequency and a periodic oscillation frequency in each period; the smoking state and the non-smoking state are different in capacitance value of the oscillating circuit and generated oscillating frequency;

receiving an adjusting instruction input by an external selection circuit, and setting a detection threshold value of the reference oscillation frequency; the adjusting instruction is used for shifting the reference oscillation frequency of the binary system by the register group to obtain the detection threshold value;

and calculating the oscillation frequency difference between the reference oscillation frequency and the periodic oscillation frequency by comparing an adder and a comparator group in an output circuit, outputting a comparison result by the oscillation frequency difference and the detection threshold value, and judging the smoking state of the electronic cigarette microphone according to the output result.

7. The method according to claim 6, wherein the detecting oscillation frequency of the oscillation circuit by the counting circuit, and determining the reference oscillation frequency and the periodic oscillation frequency in each period comprises:

calculating a first oscillation period of the oscillation circuit through a counting group in the counting circuit in an initialized first detection period;

reading the first oscillation period through the latch group and determining the first oscillation period as the reference oscillation frequency latch;

the receiving of the adjustment instruction input by the external selection circuit and the setting of the detection threshold of the reference oscillation frequency include:

acquiring a first instruction in the adjusting instruction, and performing primary shift on the reference oscillation frequency according to the first instruction to acquire a first detection threshold; acquiring a second instruction in the adjusting instructions, and performing secondary displacement on the reference oscillation frequency according to the second instruction to obtain a second detection threshold; the second detection threshold is less than the first detection threshold.

8. The method according to claim 7, wherein the oscillating frequency difference of the reference oscillating frequency and the periodic oscillating frequency is calculated by an adder and a comparator set in a comparison output circuit, and the smoking state of the electronic cigarette head is judged by the oscillating frequency difference and the detection threshold; the method comprises the following steps:

inverting the periodic oscillation frequency detected by the count group through an inverter;

summing the reference oscillation frequency and the inverted periodic oscillation frequency through the adder to obtain the oscillation frequency difference;

inputting the first detection threshold and the oscillating frequency difference into a first-stage comparator of the comparator set, and inputting the second detection threshold and an output of the first-stage comparator into a second-stage comparator of the comparator set;

when the oscillation frequency difference is larger than the first detection threshold and the second detection threshold, outputting a result and judging that the smoking state is achieved; and when the oscillation frequency difference is smaller than the first detection threshold and the second detection threshold, outputting a result and judging that the smoking is not in a smoking state.

9. The method according to claim 8, wherein when the oscillating frequency difference is smaller than the first detection threshold and larger than the second detection threshold, a latch in the latch group is triggered to initialize, and the periodic oscillating frequency acquired by the counter group in the next period is determined as the reference oscillating frequency and latched.

10. The method according to any one of claims 6 to 9, wherein the external selection circuit is connected with a detection accuracy control button, and when a user manually inputs an adjustment instruction, the register group updates the stored first instruction and second instruction, and shifts the upper bits of the reference oscillation frequency represented in binary to a target number of bits rightward according to the updated first instruction and second instruction, respectively, to obtain the first detection threshold and the second detection threshold.

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