E-cigarette Puff Counting via Airflow Temperature Sensing
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Solution Overview
Problem
Conventional methods for detecting the number of inhales in electronic cigarettes with small airflow, such as those using microphones, are inaccurate due to insufficient negative pressure detection.
Innovation Solution
An electronic cigarette design that incorporates a temperature sensing element within the airflow passage, where the temperature difference between inhaling and non-inhaling states is detected to determine the number of inhales, eliminating the need for negative pressure sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a microphone is used to detect negative pressure for inhale detection, then the method works for electronic cigarettes with large airflow, but detection accuracy deteriorates for electronic cigarettes with small airflow
Solution Approach 1:
The patent changes the detection parameter from negative pressure (microphone-based) to temperature difference (temperature sensor-based). This parameter change enables accurate detection in both large airflow and small airflow scenarios, as temperature difference remains detectable even when airflow volume is small, thereby improving adaptability while maintaining reliability
Solution Approach 2:
The patent replaces the acoustic detection mechanism (microphone detecting pressure waves) with a thermal detection mechanism (temperature sensor detecting temperature difference). This substitution allows the system to detect inhales through thermal field changes rather than mechanical pressure changes, making it effective for both large and small airflow conditions
2Measurement precision
If a microphone detects negative pressure to determine inhale count, then the detection method is simple in structure, but detection precision deteriorates when airflow amount is small
Solution Approach 1:
The patent changes the detection parameter from negative pressure to temperature difference. Temperature difference detection provides superior precision for small airflow amounts compared to pressure detection, while maintaining comparable system complexity since both approaches use single-sensor configurations
Solution Approach 2:
The patent transitions from pressure-based detection (one dimension of physical measurement) to temperature-based detection (another dimension). This dimensional change allows detection of thermal field variations caused by airflow, providing higher precision for small airflow volumes without significantly increasing device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly improves the accuracy of inhale detection by utilizing temperature changes, effectively addressing the limitations of existing methods.
Implementation Method 1
After the electronic cigarette is electrified, heat is generated within the cigarette body, and the heat heats air within the cigarette body. When the inhaling action is generated, outside air enters the air inlet passage from the air inlet and flows into the accommodating cavity, and the airflow flowing within the airflow passage is formed. The temperature sensing end of the temperature sensing element is used to detect a temperature of the airflow
Data Source
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AI summary
An electronic cigarette (100) includes a cigarette body (110), a temperature sensing element (120), and a circuit board (130), where the cigarette body (110) includes a cylinder (111), the cylinder (111) has an accommodating cavity (111a), the cigarette body (110) is further provided with an air inlet passage (111b), the air inlet passage (111b) has an air inlet (111c), and the air inlet passage (111b) is in communication with the accommodating cavity (111a) to form an airflow passage; the temperature sensing element (120) includes a temperature sensing end (121), and the temperature sensing end (121) is disposed within the airflow passage; the circuit board (130) is electrically connected to the temperature sensing element (120), and cigarette body (110) is electrically connected to the circuit board (130).