Electronic Cigarette Buck-Boost Drive Circuit for Adjustable Voltage
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Solution Overview
Problem
Current drive circuits for electronic cigarettes either limit output voltage or power, failing to meet the requirements for high-power and adjustable voltage needed to enhance performance in terms of taste, smoke quantity, and operability.
Innovation Solution
A drive circuit comprising an MCU, buck-boost drive circuit, sampling circuits, and a boosting circuit, which includes half bridge drive circuits and MOS transistors, allows for adjustable output voltage and high power delivery by detecting input and output voltages and adjusting PWM duty cycle to boost or lower load voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the MCU directly controls the switching time of the MOS transistor, then the control is simple, but the output voltage is low and cannot be adjusted
Solution Approach 1:
The drive circuit is divided into multiple functional modules: MCU for control, buck-boost drive circuit for voltage conversion, sampling circuits for voltage detection, and boosting circuit for voltage enhancement. This segmentation allows each module to perform its specific function independently, achieving both simple control and adjustable output voltage.
Solution Approach 2:
The buck-boost drive circuit acts as an intermediary between the MCU and the power source, enabling voltage adjustment without complicating the MCU's control function. The sampling circuits serve as intermediaries to provide voltage feedback to the MCU, allowing indirect voltage control while maintaining simple direct control architecture.
2Adaptability or versatility
If the buck-boost IC is used to control the switching time of the MOS transistor, then the voltage regulation function can be realized, but the output power is relatively small
Solution Approach 1:
The patent combines the buck circuit and boost circuit into a single buck-boost drive circuit, merging two voltage conversion functions into one integrated system. This allows the circuit to achieve both voltage step-down and step-up operations, significantly expanding the output power capability while maintaining voltage regulation functionality.
Solution Approach 2:
The drive circuit uses a composite structure combining multiple types of transistors (first and second N-type MOS transistors) and multiple half-bridge circuits working together. This composite configuration enables the circuit to handle higher power levels while maintaining precise voltage control capabilities.
3Device complexity
If traditional low-power drive schemes are used, then the circuit is simple, but it cannot meet the requirements of high-power output for electronic cigarettes
Solution Approach 1:
The drive circuit dynamically switches between buck mode and boost mode based on the required output voltage and power levels. The MCU dynamically adjusts the switching duty cycle of the MOS transistors to optimize power delivery. This dynamic operation allows the circuit to adapt to different power requirements without requiring a completely different circuit design for each scenario.
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
The solution enables the drive circuit to output large driving power with adjustable voltage, improving the performance of electronic cigarettes by enhancing power conversion efficiency and minimizing losses.
Implementation Method 1
The first half bridge drive circuit is electrically connected to the second half bridge drive circuit through an inductor
Implementation Method 2
The first half bridge drive circuit comprises a first half bridge drive chip U13, a capacitor C14, a diode D9 and two first N-type MOS transistors U10, U12
Data Source
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AI summary
A drive circuit for electronic cigarettes includes an MCU, a buck-boost drive circuit and a power source. The buck-boost drive circuit is electrically connected to the MCU. The MCU and the buck-boost drive circuit are respectively electrically connected the power source. The buck-boost drive circuit comprises a first half bridge drive circuit and a second half bridge drive circuit respectively connected to the MCU. The first half bridge drive circuit is electrically connected to the second half bridge drive circuit through an inductor. One end of the first sampling circuit is electrically connected to an input terminal of the first half bridge drive circuit, through which the power source supplies power to the first half bridge drive circuit; the other end of the first sampling circuit is electrically connected to the MCU. One end of the second sampling circuit is electrically connected to an output terminal of the second half bridge drive circuit, and the other end of the second sampling circuit is electrically connected to the MCU. With the above solution, the output of the large driving power can be realized, the voltage of the drive circuit of the electronic cigarette can be adjusted, and the performance of the electronic cigarette can be improved.