Electronic cigarette chip sensitivity self-calibration method

Abstract

An electronic cigarette chip sensitivity self-calibration method comprises the steps that S1, an electronic cigarette is powered on, the electronic cigarette detects an external pin signal or internal configuration, and if the electronic cigarette chip detects that the external pin signal input or the internal configuration does not have a trigger air pressure threshold value, the electronic cigarette enters a calibration mode; s2, natural air pressure P0 is applied to the electronic cigarette, and the electronic cigarette detects a capacitor charging and discharging count value M0 of the microphone under the natural air pressure; s3, then applying a target triggering air pressure P1 to the electronic cigarette, and detecting a capacitor charging and discharging count value M1 of the microphone under the triggering air pressure by the electronic cigarette; and S4, calculating a trigger threshold value of the electronic cigarette, writing the trigger threshold value into internal configuration, and exiting the calibration mode. The method has the advantages that the internal capacitance detection value is obtained according to the natural air pressure and the external triggering air pressure condition, then the threshold setting value is reversely deduced through the internal capacitance detection value, the repeated iteration process is reduced, the setting threshold is obtained at a time through the algorithm, and the calibration accuracy and the calibration efficiency are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic cigarettes, and in particular to a sensitivity self-calibration method for an electronic cigarette chip. Background Art

[0002] The electronic cigarette is mainly composed of smoke oil, atomization device, capacitive microphone, controller, constant current source and power supply. The electronic cigarette microphone includes a capacitor composed of a metal pole piece and a diaphragm. The microphone mainly completes the smoking action detection function. When the user has a suction action, the diaphragm inside the microphone is deformed. At this time, the controller detects the capacitance change. When the capacitance change reaches the set threshold value, the control IC outputs a smoking signal, so that the heating wire of the electronic cigarette is heated to produce smoke; when the user has no suction action, the diaphragm inside the microphone will hardly be deformed. At this time, the capacitance value of the microphone will not change. Accordingly, the control IC will not send a smoking signal, so that the electronic cigarette does not work.

[0003] The sensitivity of the electronic cigarette microphone depends on the manufacturing process of the microphone and the process of the microphone chip. The different tightness of the microphone capacitor film due to the processing technology will lead to different capacitance of different microphones, and the capacitance value will fluctuate to a certain extent due to mechanical vibration. The tolerance of the microphone structure causes the different distances between the diaphragm and the metal base of the microphone, as well as the different areas of the diaphragm and the metal base, resulting in different capacitance of different microphones. The process deviation of the microphone chip leads to different charging and discharging currents; different charging and discharging control thresholds lead to different charging and discharging count values ​​of the capacitance detection circuit.

[0004] As customers' requirements for microphone sensitivity continue to increase, the range of negative pressure values ​​triggered by microphones has a tendency to gradually narrow. For example, the original requirement was -200Pa±50Pa (-150Pa~-250Pa), and the subsequent requirement will be -175Pa±25Pa (-150Pa~-200Pa), or even smaller. At present, it is generally not easy to achieve a concentrated range for the sensitivity index of microphones. The sensitivity index of microphones is normally distributed within a range.

[0005] After a batch of microphones are produced, they need to be screened and classified into different sensitivity ranges. They are then shipped to different customers according to their sensitivity requirements. This can cause trouble for microphone manufacturers, because they cannot predict the number of microphones in each batch that fall into different sensitivity ranges, making it impossible to accurately formulate production plans. Microphones in some sensitivity ranges may not be sold for a long time due to a small number of selected customers, resulting in excessively high backlog costs.

[0006] Patent application CN117918576A discloses a self-calibration method for the sensitivity of an electronic cigarette chip. It is necessary to provide the trigger threshold intermediate value -200Pa required by the customer. At this time, the microphone detects the -200Pa air pressure and generates a detection value. This detection value is compared with the default threshold (1 / 16 of the power-on reference value). If the detection value is less than the reference value - the reference value * 1 / 16, it will trigger smoking. If the detection value triggers smoking, the threshold is lowered, and the step of lowering the threshold is 1 / 256. It is continuously lowered until smoking is not triggered, and the last threshold value is recorded; if the detection value caused by the -200Pa air pressure is greater than the reference value - the reference value * 1 / 16, the threshold is not triggered. At this time, the threshold is increased, and the step is 1 / 256. It is continuously increased until smoking is triggered, and the last threshold value is recorded; when no calibration value is found between 1 / 256 and 1 / 16, it indicates that the microphone is abnormal and the calibration is terminated. This abnormality standard is not easy to determine. When adjusting down to 1 / 128 or 1 / 64, an abnormality may occur; when adjusting up to 3 / 64, an abnormality may occur. It needs to be judged based on the process and failure of the microphone. It cannot be uniformly judged that an abnormality occurs only when 1 / 256 or 1 / 16 cannot be adjusted successfully. The above method has many calibration steps and takes a long time to calibrate, resulting in high calibration costs. The calibration process is complicated, with many steps, long time, low efficiency and high cost.

[0007] Patent application CN117122105A discloses a self-calibration method for the sensitivity of an electronic cigarette chip. This method requires distinguishing different smoking intensity levels (gears), and each level may require a calibration test; it is necessary to test the discharge pressure thresholds of different gears; a relatively complex algorithm is required to calculate the adjustable range of each gear, and then select a reasonable gear; if unsuccessful, it is necessary to traverse the calibration code value; the calibration process of the above method is complex, has many steps, takes a long time, is inefficient, and has high cost. Summary of the invention

[0008] In order to solve the problems existing in the above-mentioned background technology, a calibration algorithm is added inside the microphone to automatically generate the smoking trigger threshold of the microphone according to the external standard trigger air pressure, so that the trigger threshold value of the microphone just matches the standard trigger air pressure, so that each microphone can smoke stably under the standard air pressure.

[0009] A method for self-calibrating the sensitivity of an electronic cigarette chip comprises the following steps:

[0010] Step S1: the electronic cigarette is powered on, and the electronic cigarette chip detects the external pin signal or internal configuration within a preset time after power-on. If the electronic cigarette chip detects that the external pin signal input or the internal configuration does not have a trigger pressure threshold value, the electronic cigarette enters the calibration mode;

[0011] Step S2: Apply the natural air pressure P0 to the electronic cigarette, and the electronic cigarette detects the capacitance charge and discharge count value M0 of the microphone under the natural air pressure;

[0012] Step S3: Then apply the target trigger air pressure P1 to the electronic cigarette, and the electronic cigarette detects the capacitance charge and discharge count value M1 of the microphone under the trigger air pressure;

[0013] Step S4: Calculate the trigger threshold value of the electronic cigarette according to the detected capacitance charge and discharge count value M0 under the natural air pressure and the capacitance charge and discharge count value M1 of the microphone under the trigger air pressure, write it into the internal configuration, and exit the calibration mode.

[0014] Preferably, in step S2, the steps for the electronic cigarette to detect the capacitance charge and discharge count value of the microphone under the natural air pressure are as follows. Within the time T0, ensure that the microphone is in an environment with a natural atmospheric pressure of P0. Let the capacitance value of the microphone be C0. The controller controls the constant current source to charge and discharge the microphone capacitance with a current of i0. When the voltage value of the microphone is charged to the preset value Vh, it discharges. When the voltage value of the microphone discharges to Vl, it starts to charge. In this way, a triangular wave is formed. Within the time ΔT, record the charge and discharge times as M0.

[0015] Preferably, the steps for the electronic cigarette to detect the capacitance charge and discharge count value of the microphone under the trigger air pressure are as follows. Within the time T1, ensure that the microphone is in an environment with a trigger air pressure of P1. Let the capacitance value of the microphone be C1. The controller controls the constant current source to charge and discharge the microphone capacitance with a current of i0. When the voltage value of the microphone is charged to the preset value Vh, it discharges. When the voltage value of the microphone discharges to Vl, it starts to charge. In this way, a triangular wave is formed. Within the time ΔT, record the charge and discharge times as M1.

[0016] Preferably, the trigger threshold value Th = (M0 - M1) / M0.

[0017] Preferably, in step S5, after calibration, apply the trigger air pressure P1' to the electronic cigarette. Let the capacitance value of the microphone become C1'. Within the time ΔT of the microphone, the charge and discharge times of the voltage value of the microphone from V1 to Vh become M1'. When Δm = M0 - M1' >= M0 * Th, it is determined that the smoking action is effective; when Δm = M0 - M1' < M0 * Th, it is determined that the smoking action is invalid.

[0018] Advantages of the present invention: By obtaining the internal capacitance detection value according to the natural air pressure and the external trigger air pressure conditions, and then inversely deducing the threshold setting value through the internal capacitance detection value, the process of repeated iteration is reduced. The setting threshold is obtained once through the algorithm, greatly improving the calibration accuracy and calibration efficiency. Description of the Drawings

[0019] Figure 1 It is the working principle diagram of the microphone of the electronic cigarette in the prior art;

[0020] Figure 2 It is the circuit structure diagram of the e-cigarette microphone head;

[0021] Figure 3 It is the flow chart of the sensitivity self-calibration method of the present invention;

[0022] Figure 4 It is the structure block diagram of the sensitivity calibration device. Specific embodiments

[0023] As Figure 1 shown, the microphone head mainly completes the function of detecting the smoking action. Its principle is the capacitive film principle. Usually when not smoking, the capacitive film and the substrate are parallel. Assume the distance between the capacitive film and the substrate is L0 and the capacitance value is C0; during the smoking process, due to the negative pressure generated by smoking, the capacitive film deforms, resulting in a reduction in the distance between the capacitive film and the substrate and an increase in the capacitance value. Assume the distance between the capacitive film and the substrate becomes L1 and the capacitance value becomes C1 at this time.

[0024] If the smoking force is large enough to cause Δc=(C1 - C0)≧Th (Th is the preset smoking threshold value), then a smoking action is generated; if Δc=(C1 - C0)<Th, then no smoking action is generated.

[0025] At present, the value of Th in the scheme is generally a preset value, preset to 1 / 32 of C0 or 1 / 16 of c0; at this time, a problem will occur. Due to various differences such as the dimensional tolerance of the capacitive film, the difference in the tightness of processing, the difference in the charging and discharging current size of the control chip, the generation and judgment difference of the charging and discharging threshold of the control chip, and the clock difference of the control chip, each microphone head C0 is different. For the same smoking negative pressure, Δc is also different. As a result, for each batch of microphone heads produced, although the preset smoking threshold is set to be the same, the actual negative pressure value that triggers smoking is different. This negative pressure value that triggers smoking may be distributed in the range of -50pa to -400pa, or even a larger range. The negative pressure value of smoking represents the sensitivity of the microphone head, which is a very important indicator, and customers' requirements for this indicator are getting higher and higher. At present, for capacitive microphones, the negative pressure value index is generally ±50pa of the trigger intermediate value; for silicon microphones, the negative pressure value consistency index is generally ±20pa of the trigger intermediate value.

[0026] In order to ensure that each microphone head can meet the sensitivity index required by customers after production, it is necessary to calibrate the sensitivity of the microphone head. The calibration method should avoid complex processing procedures and also achieve as high a calibration efficiency and as high an accuracy as possible; the e-cigarette system block diagram is as Figure 2 shown.

[0027] An e-cigarette chip sensitivity self-calibration method, characterized by comprising the following steps:

[0028] Step S1: The electronic cigarette is powered on, and the electronic cigarette chip detects the external pin signal or internal configuration within the preset time after power-on. If the electronic cigarette chip detects that the external pin signal input or the trigger pressure threshold value does not exist in the internal configuration, the electronic cigarette enters the calibration mode; after the electronic cigarette is powered on, it enters the calibration mode according to the external pin input signal of the controller or the internal configuration. The external control signal can be provided through an input control pin, and this control pin can be reused with the output pin. That is, within a preset time after power-on, the output pin is configured as an input state. At this time, if the output pin is given a high level externally, the chip enters the calibration state. In the T0 time period before entering the calibration state, natural air pressure is provided externally, and when T0 ends, standard trigger air pressure is provided externally. When the signal becomes a low level, it means that the capacitor charge and discharge count values ​​M0 and M1 have been obtained, the trigger air pressure can be stopped, and the threshold value can be calculated. Or if there is no trigger pressure threshold value in the internal configuration, the calibration mode is automatically entered; if there is a trigger pressure threshold value in the internal configuration, the normal working mode is entered. In the internal configuration mode, the natural air pressure is provided externally during the T0 time; the standard trigger air pressure is provided during the T0 to T1 time period; after the T1 time period ends, the threshold value is calculated.

[0029] Step S2: applying natural air pressure P0 to the electronic cigarette for a duration of T0, and the electronic cigarette detects the charge and discharge count value M0 of the microphone capacitance under natural air pressure; the specific steps are as follows: within T0, ensure that the microphone is in an environment with a natural atmospheric pressure of P0, set the microphone capacitance value to C0, and control the constant current source to charge and discharge the microphone capacitance with a current of i0, discharge when the microphone voltage value is charged to a preset value Vh, and start charging when the microphone voltage value is discharged to Vl, and repeat this process to form a triangular wave, and record the number of charge and discharge times as M0 within ΔT time.

[0030] Step S3: Then, the target trigger pressure P1 is applied to the electronic cigarette for a duration of T1, and the electronic cigarette detects the capacitor charge and discharge count value M1 of the microphone under the trigger pressure; the specific steps are as follows: within the T1 time, ensure that the microphone is in an environment with a trigger pressure of P1, set the microphone capacitance value to C1, and control the constant current source to charge and discharge the microphone capacitance with a current of i0, discharge when the microphone voltage value is charged to a preset value Vh, and start charging when the microphone voltage value is discharged to Vl, and so on to form a triangular wave, and within the ΔT time, record the number of charge and discharge times as M1;

[0031] Step S4: Calculate the trigger threshold of the electronic cigarette according to the detected capacitance charge and discharge count value M0 under natural air pressure and the capacitance charge and discharge count value M1 of the microphone under trigger air pressure. The trigger threshold Th = (M0-M1) / M0. The trigger threshold Th will be written into the internal configuration and exit the calibration mode.

[0032] Step S5: After calibration is completed, the e-cigarette enters the normal working mode. Th is used as the threshold for determining whether a smoking trigger occurs. Apply a trigger air pressure P1' to the e-cigarette. Assume that the microphone capacitance value becomes C1'. Within the time T0 of the microphone, the number of charge and discharge times of the microphone voltage value from V1 to Vh becomes M1'. When Δm = M0 - M1' >= M0 * Th, it is determined that the smoking action is effective; when Δm = M0 - M1' < M0 * Th, it is determined that the smoking action is ineffective.

[0033] Therefore, Th is a calibrated value. In the same environment, M1 and M1' are very close. The possible differences are calculation errors, slight fluctuations in voltage and current, and minor vibrations of the capacitor film. These errors are all controllable.

[0034] In this way, the trigger air pressure value of each microphone in each batch is very close to the standard trigger air pressure. If the customer requires a sensitivity range of -180pa ± 50pa, we will calibrate according to the standard trigger air pressure of -180pa. Then, it is certain that within the air pressure range of -180pa ± 50pa, the smoking action can be triggered. Because our trigger threshold is the standard air pressure of -180pa, considering some environmental fluctuations and anomalies, ± 50pa can fully cover these fluctuations. Generally speaking, if we calibrate according to our calibration scheme, calibrate according to -180pa, the final sensitivity range can be controlled within the range of -180pa ± 30pa (capacitive microphone), or even smaller; the silicon microphone can be controlled within -180pa ± 20pa, or even smaller.

[0035] This self-calibration method has a simple process flow. The core part only requires 3 steps, namely Step S2: Detect the charge and discharge test M0 value of the microphone under natural air pressure; Step S3: Conduct the charge and discharge test M1 value of the microphone under the standard trigger air pressure for smoking; Step Four: Just perform a simple calculation based on M0 and M1. Only a stable standard trigger air pressure needs to be provided externally, without repeatedly providing various different air pressure values and without iteration. The entire calibration system is simple; the calibration efficiency is high. The 3 steps require a short time and do not require repeated iteration, and the calibration value can be obtained at one time; the calibration accuracy is high. The accuracy of the threshold can be accurate to 1 / 1024 of the reference capacitance value, or even higher.

[0036] In order to provide natural air pressure and standard trigger air pressure during the calibration of the e-cigarette, a special calibration device is designed, and its structural functional block diagram is as Figure 4 , The special calibration device consists of a box shell, a power supply, a control module, a precise air pressure sensor, an air pump, an electronic valve, an induction sensor (or a weighing sensor), control signal lines, etc.; the precise air pressure sensor and the induction sensor input the collected signals to the control module, and the control module can control the air pump, the electric control valve, and the control signal lines to work;

[0037] The control module determines whether it is in pin control mode or time control mode according to the configuration of the microphone being tested.

[0038] If it is the pin control mode, when the induction sensor of the dedicated calibration equipment detects that the tested microphone is placed at the specified position of the test equipment, the control signal line provides a high level to the control pin, and the control power supplies power to the microphone. At this time, the precise air pressure control module cooperates with the vacuum pump and the electronic valve to provide natural air pressure or 1 standard atmospheric pressure in the box. The control module counts to T0. At this time, the internal circuit of the microphone has obtained the M0 value. The control module controls the precise air pressure module to generate a standard trigger threshold and waits for t1 time. The internal circuit of the microphone obtains the M1 value and pulls the control signal out low. At this time, the internal threshold value calculation and EFUSE burning begin. After waiting for t2 time, the calibration ends.

[0039] If it is time control mode, when the tested microphone is detected to be placed at the specified position of the test equipment, the control power is turned on, and the precision air pressure control module provides natural air pressure or 1 standard atmospheric pressure, and the timing reaches time T0. At this time, the internal circuit of the microphone has obtained the M0 value, and the control module controls the precision air pressure module to generate a standard trigger threshold, and waits for T1 time. The internal circuit of the microphone obtains the M1 value. After waiting for T2 time, the internal threshold calculation is completed and burned to EFUSE, and the calibration is completed.

[0040] The difference between the time control mode and the pin control mode is that in the time control mode, the length of the t1 time is determined when the microphone is designed. This time takes into account some margin to ensure that there is enough time to generate the M0 and M1 values ​​internally. The second stage of the control method of the calibration equipment can only be slightly longer than the t1 time; while in the pin control mode, the end time of the standard trigger air pressure can be adjusted according to the actual measurement situation. This time can be shorter than the preset time to improve the calibration efficiency.

[0041] In order to improve calibration efficiency and reduce calibration costs, the test equipment can be equipped with an automatic sample delivery machine and an automatic pin identification module. These two parts are not related to the content of our application and protection and will not be introduced in detail.

Claims

1. A method for self-calibration of sensitivity of an electronic cigarette chip, characterized in that: It includes the following steps: Step S1: Power on the e-cigarette. The e-cigarette chip detects external pin signals or internal configurations within a preset time after power-on. If the e-cigarette chip detects an external pin signal input or there is no trigger air pressure threshold value in the internal configuration, the e-cigarette enters the calibration mode; Step S2: Apply the natural air pressure P0 to the e-cigarette, and the e-cigarette detects the capacitance charge and discharge count value M0 of the microphone under the natural air pressure; Step S3: Then apply the target trigger air pressure P1 to the e-cigarette, and the e-cigarette detects the capacitance charge and discharge count value M1 of the microphone under the trigger air pressure; Step S4: Calculate the trigger threshold value of the e-cigarette according to the detected capacitance charge and discharge count value M0 under the natural air pressure and the capacitance charge and discharge count value M1 of the microphone under the trigger air pressure, and write it into the internal configuration, then exit the calibration mode.

2. The electronic cigarette chip sensitivity self-calibration method according to claim 1, characterized in that: In step S2, the steps for the e-cigarette to detect the capacitance charge and discharge count value of the microphone under the natural air pressure are as follows. Within the time T0, ensure that the microphone is in an environment with a natural atmospheric pressure of P0. Let the capacitance value of the microphone be C0. The controller controls the constant current source to charge and discharge the microphone capacitance with a current of i0. When the voltage value of the microphone is charged to the preset value Vh, it discharges. When the voltage value of the microphone discharges to Vl, it starts to charge. In this way, a triangular wave is formed. Within the time ΔT, record the charge and discharge times as M0.

3. The electronic cigarette chip sensitivity self-calibration method according to claim 2, characterized in that: In step S3, the steps for the e-cigarette to detect the capacitance charge and discharge count value of the microphone under the trigger air pressure are as follows. Within the time T1, ensure that the microphone is in an environment with a trigger air pressure of P1. Let the capacitance value of the microphone be C1. The controller controls the constant current source to charge and discharge the microphone capacitance with a current of i0. When the voltage value of the microphone is charged to the preset value Vh, it discharges. When the voltage value of the microphone discharges to Vl, it starts to charge. In this way, a triangular wave is formed. Within the time ΔT, record the charge and discharge times as M1.

4. The electronic cigarette chip sensitivity self-calibration method according to claim 3, characterized in that: The trigger threshold value Th = (M0 - M1) / M0.

5. The electronic cigarette chip sensitivity self-calibration method according to claim 4, characterized in that: Step S5, after calibration is completed, apply the trigger air pressure P1' to the e-cigarette. Suppose the capacitance value of the microphone becomes C1'. Within the time ΔT of the microphone, the charge and discharge times of the voltage value of the microphone from V1 to Vh become M1'. When Δm = M0 - M1' >= M0 * Th, it is judged that the smoking action is effective; when Δm = M0 - M1' < M0 * Th, it is judged that the smoking action is ineffective.

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