Stepless Fan Speed Control Using MCU and Variable Input
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Solution Overview
Problem
Existing fans cannot freely adjust air speed, limiting user experience and operational performance.
Innovation Solution
A stepless regulation fan system that includes a fan main body with motors and fan blades, and a control circuit board with an MCU, a stepless regulation element (such as a potentiometer or rotary encoder switch), and a driving circuit. The stepless regulation element allows for continuous adjustment of air speed, and the MCU adjusts the power output to the motors based on user input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional button-based speed adjustment is used, then the fan structure is simple, but the air speed cannot be freely adjusted
Solution Approach 1:
The patent implements dynamic speed adjustment by replacing fixed button-based speed levels with a potentiometer that allows continuous variable adjustment. The potentiometer's wiper moves along the resistive element to provide a continuously variable resistance signal, enabling the motor speed to be dynamically adjusted across a continuous range rather than discrete levels.
Solution Approach 2:
The patent changes the control parameter from discrete button inputs to continuous potentiometer resistance values. The MCU reads the varying resistance value from the potentiometer and converts it to corresponding PWM duty cycles, allowing the motor speed parameter to be adjusted continuously based on the physical position of the potentiometer wiper.
2Ease of operation
If three fixed speed levels are provided, then the control circuit is simple, but the user experience is limited
Solution Approach 1:
The patent replaces the mechanical button-based discrete selection system with an electronic potentiometer-based continuous adjustment system. The potentiometer provides a mechanical rotation interface that translates rotational position into continuous electrical resistance values, which are then processed by the MCU to control motor speed smoothly.
Solution Approach 2:
The patent introduces the potentiometer as an intermediary device between the user's manual adjustment and the motor control system. The potentiometer converts mechanical rotation into electrical resistance variations, serving as a mediator that enables continuous control signals to be generated from simple rotational input.
3Adaptability or versatility
If stepless regulation element is added, then the air speed can be continuously adjusted, but the device complexity increases
Solution Approach 1:
The patent makes the control circuit board universal by integrating multiple functions into existing components. The potentiometer serves both as the speed adjustment interface and as a signal source for the MCU. The existing MCU and PWM generation circuitry are utilized to process the potentiometer signal and control the motor, avoiding the need for dedicated separate control circuits.
Solution Approach 2:
The patent merges the speed adjustment functionality with the existing control circuit board by integrating the potentiometer into the same PCB. The potentiometer's output is directly connected to the MCU's analog input pin, combining the user interface and control processing functions into a single integrated control unit rather than separate modules.
Data Source
AI summary
A stepless regulation fan includes a fan main body and a control circuit board. The fan main body is equipped with first motors and fan blades connected to the first motors. The control circuit board includes an MCU, a stepless regulation element and a first driving circuit. The stepless regulation element and the first driving circuit are electrically connected to the MCU. The stepless regulation element is used for user operation, and the first driving circuit is electrically connected to the first motors. When the stepless regulation element is operated, a stepless regulation signal within a preset regulation range is fed back to the MCU. Based on the stepless regulation signal, the MCU outputs a rotating speed control signal corresponding to the stepless regulation signal to the first driving circuit. The first driving circuit adjusts driving power output to the first motors based on the rotating speed control signal.