Aerosol Inhaler Bridge Circuit for Precise Heater Temperature Sensing
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Solution Overview
Problem
Existing aerosol inhalers face challenges in accurately detecting the temperature of the heating element within the appropriate temperature range, which is crucial for efficient aerosol generation and user safety.
Innovation Solution
The aerosol inhaler incorporates a power supply unit with a specific circuit configuration, including a microcontroller unit (MCU), sensors, and an operational amplifier, which allows for precise temperature detection of the heating element by utilizing a differential input signal from a bridge circuit, ensuring accurate temperature control within a detectable range of -10°C to 300°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple resistance measurement circuit is used, then the device complexity is reduced, but the temperature detection accuracy deteriorates
Solution Approach 1:
The patent introduces a bridge circuit as an intermediary measurement system between the heating element and the microcontroller. This bridge circuit converts the resistance change of the heating element into a voltage signal that can be accurately measured, thereby improving temperature detection accuracy without requiring direct complex measurement of resistance at the microcontroller level.
Solution Approach 2:
The patent replaces direct electrical resistance measurement with a voltage-based measurement system using the bridge circuit. This substitution allows the microcontroller to measure voltage differences rather than directly measuring resistance, simplifying the overall measurement architecture while improving accuracy through differential measurement capabilities.
2Measurement precision
If a bridge circuit with operational amplifier is used, then the temperature detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The bridge circuit configuration serves multiple functions: it acts as a temperature sensing mechanism, a signal conditioning stage, and a differential measurement system all in one structure. The operational amplifier simultaneously performs signal amplification and differential voltage measurement, reducing the need for separate components and thereby limiting the increase in overall device complexity.
Solution Approach 2:
The patent combines the bridge circuit, operational amplifier, and temperature detection functionality into an integrated measurement system. By merging these components into a unified circuit architecture, the patent achieves high temperature detection accuracy while minimizing the increase in device complexity that would result from using separate independent components for each function.
3Ease of operation
If the resistance value of the heating element is measured directly, then the measurement process is simplified, but the detection accuracy in appropriate temperature range deteriorates
Solution Approach 1:
The bridge circuit serves as an intermediary measurement system that converts the resistance change of the heating element into a measurable voltage difference. This intermediary approach maintains ease of operation by providing a straightforward voltage measurement process while significantly improving detection accuracy within the appropriate temperature range through differential measurement.
Solution Approach 2:
The patent changes the measurement parameter from direct resistance measurement to voltage difference measurement. By measuring voltage differences across the bridge circuit instead of directly measuring resistance, the system achieves higher detection accuracy in the appropriate temperature range while maintaining operational simplicity through standard voltage measurement techniques.
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 configuration enables high-accuracy temperature detection and control of the heating element, ensuring efficient aerosol generation and maintaining safety within the specified temperature range, thereby improving the performance and reliability of the aerosol inhaler.
Implementation Method 1
an output signal of the operational amplifier is input to the analog-to-digital converter... the non-inverting input terminal of the operational amplifier is connected to a first series circuit of the first element and the heating element... the inverting input terminal of the operational amplifier is connected to a second series circuit of a second element and a third element
Implementation Method 2
a heating element... capable of vaporizing the liquid... an electric current flows through the heating element from a power supply unit
Data Source
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AI summary
An aerosol inhaler includes: a first branch circuit including a load, a first resistor, and a first node; a second branch circuit including a second resistor, a third resistor, and a second node; an operational amplifier of which a non-inverting input terminal is connected to one of the first node and the second node, and of which an inverting input terminal is connected to the other of the first node and the second node; and a control device having an upper limit temperature and a lower limit temperature. A differential input of the operational amplifier is larger than potential of a negative power supply terminal of the operational amplifier or a minimum value acquirable by the operational amplifier in a first temperature range, and is equal to the potential of the negative power supply terminal of the operational amplifier or the minimum value in a second temperature range.