Susceptor Heating Control Using Resonant Frequency Feedback
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Solution Overview
Problem
Existing aerosol-generating devices face challenges in achieving high energy efficiency and consistent temperature control during inductive heating, leading to potential burning of the aerosol-generating material and a suboptimal user experience.
Innovation Solution
A method for controlling the heating of a susceptor in an aerosol-generating device that transitions between using a determined parameter of an oscillating circuit and measured internal temperature to estimate temperature, with a predefined heating profile, ensuring accurate temperature control during dynamic and stable phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the heating power of the susceptor is increased to improve aerosol generation performance, then the aerosol output is improved, but the risk of overheating and thermal damage increases
Solution Approach 1:
The patent implements a feedback control mechanism where a temperature sensor continuously monitors the susceptor temperature and feeds this information back to the control circuit. The control circuit adjusts the heating power based on the detected temperature, reducing power when temperature exceeds a threshold and increasing power when temperature is below the threshold, thereby maintaining optimal operating conditions while preventing overheating
Solution Approach 2:
The patent employs dynamic adjustment of heating parameters by varying the duty cycle of the switching element based on temperature feedback. The control circuit dynamically modifies the heating power delivery to the susceptor in real-time, transitioning between different power levels according to thermal conditions, which allows optimal aerosol generation while preventing thermal damage
2Reliability
If temperature sensing is added to control heating, then overheating is prevented, but device complexity increases
Solution Approach 1:
The patent combines the temperature sensing function and heating control function into a single integrated control circuit. The control circuit includes both the temperature sensor and the switching element in one unit, allowing it to perform both monitoring and power regulation functions without requiring separate independent control systems, thereby minimizing the increase in device complexity
Solution Approach 2:
The control circuit is designed as a multi-functional unit that simultaneously performs temperature monitoring, temperature evaluation, and heating power regulation. This universal control element handles multiple tasks (sensing, processing, and actuation) that could otherwise require separate dedicated components, reducing overall system complexity while maintaining reliable overheating prevention
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 method provides improved energy efficiency and a consistent, high-quality vaping experience by accurately controlling the heating process, preventing material burning and enhancing user satisfaction.
Implementation Method 1
a heating element arranged to move relative to the capsule and heat the capsule material to a temperature sufficient to vaporise the liquid or melt the solid material
Implementation Method 2
a temperature sensor arranged to detect a temperature of the susceptor
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A method for controlling the heating of a susceptor (7) of an aerosol-generating device (1) is described. The susceptor (7) is inductively heated by an oscillating circuit driven by an inverter. The method comprises a pre-heating phase of the aerosol-generating device (1) and a subsequent heating phase of the aerosol-generating device (1). A step of estimating or determining a temperature of the aerosol-generating device (1) is performed during the pre-heating and heating phases. At the start of the pre-heating phase, the estimation or determination of the temperature is based on a determined resonant frequency of the oscillating circuit (6) or a determined indicative electrical value of the oscillating circuit, e.g., a capacitor voltage. The determination or estimation of the temperature is transitioned to being based on a measured internal temperature of the aerosol-generating device (1).