E-Cigarette Chip Closed-Loop Voltage Control for Constant Heating Power
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Solution Overview
Problem
Existing electronic cigarettes face issues with unstable vapor production due to varying battery voltage and heating resistor resistance, leading to inconsistent output power, which existing solutions like PWM and full bridge buck-boost circuits fail to address effectively.
Innovation Solution
An electronic cigarette chip with automatic closed-loop control, featuring a built-in MCU module, full bridge buck-boost module, output voltage feedback circuit, and operational amplifying unit, which uses PID control and AD conversion to adjust output voltage precisely and maintain constant power by monitoring resistance changes in the heating element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If PWM is used to provide output voltage, then the circuit structure is simple, but it is impossible to provide required output voltage when battery voltage is lower than required output voltage
Solution Approach 1:
The patent employs a full bridge buck-boost circuit that can dynamically switch between buck mode and boost mode. When battery voltage is higher than required output voltage, it operates in buck mode; when battery voltage is lower, it operates in boost mode. This dynamic operation enables the circuit to provide a wide output voltage range while maintaining relatively simple structure.
2Adaptability or versatility
If full bridge buck-boost circuit is applied, then output voltage can be adjusted, but the circuit structure becomes complicated and size is too big for compact electronic cigarettes
Solution Approach 1:
The patent integrates the full bridge buck-boost circuit, control logic, and protection functions into a single chip. By merging multiple functions into one integrated circuit, the external component count is reduced and the overall device size is minimized while maintaining the ability to adjust output voltage.
Solution Approach 2:
The chip is designed with multi-functionality, serving as both the power management controller and the power conversion circuit. It can provide voltage regulation, current control, and protection functions simultaneously, eliminating the need for separate discrete circuits and reducing overall complexity.
3Adaptability or versatility
If full bridge buck-boost circuit is used, then voltage output is possible, but it lacks accurate output voltage control and stable output power control
Solution Approach 1:
The patent implements a closed-loop feedback control system with voltage detection circuit and current detection circuit. The voltage detection circuit monitors the output voltage and feeds back to the control unit, which adjusts the duty cycle to maintain stable output voltage. The current detection circuit monitors heating element current and enables constant power control by adjusting voltage based on resistance changes. This dual feedback mechanism ensures both voltage stability and power stability.
4Device complexity
If existing electronic cigarette chips with single switch transistor are used, then the circuit is simple, but they cannot achieve adjustable output voltage or constant power
Solution Approach 1:
The patent uses a full bridge configuration with four switch transistors instead of a single switch, enabling dynamic operation in both buck and boost modes. This dynamic capability allows the circuit to achieve adjustable output voltage and constant power control while maintaining relatively simple integrated circuit structure.
Solution Approach 2:
The chip incorporates built-in voltage detection and current detection circuits that provide real-time feedback to the control unit. This feedback enables the controller to adjust switching duty cycles dynamically, achieving both adjustable output voltage and constant power control functions that were not available in simpler single-switch designs.
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 solution provides stable and adjustable output voltage, ensuring consistent vapor production and reducing power consumption while offering protection against overvoltage, under-voltage, and temperature fluctuations, making it suitable for compact electronic cigarette designs.
Implementation Method 1
The operational amplifying unit module is configured to detect the resistance value of the heating element
Implementation Method 2
The full bridge buck-boost module comprises four N-channel MOS transistors and four PWM driving logic circuits
Implementation Method 3
heat and vaporize the electronic cigarette liquid by means of the vaporizer
Data Source
AI summary
The electronic cigarette chip with automatic closed-loop control for output voltage and a working method thereof are provided. The chip comprises a built-in MCU module, a full bridge buck-boost module, an output voltage feedback circuit module, an operational amplifying unit module, and a plurality of signal terminals. The signal terminal VOUT serves to provide output voltage to a heating element. The output voltage feedback circuit module serves to feed output voltage of the signal terminal VOUT back to the built-in MCU module. The operational amplifying unit module serves to detect a resistance value of the heating element and send it to the built-in MCU module. The built-in MCU module serves to perform operations based on setting signals of the external chip and feedback signals of the output voltage feedback circuit module, and automatically control the full bridge buck-boost module, to provide precisely adjustable output voltage by the signal terminal VOUT.