Fan Temperature Control Using Discrete Threshold Switching

The temperature control range is segmented into multiple discrete levels (first temperature level, second temperature level, third temperature level), with each level corresponding to a specific fan speed state (first speed, second speed, third speed). This segmentation approach simplifies the control system by replacing continuous PWM control with discrete threshold-based control, reducing device complexity while maintaining adequate control precision.

The patent replaces expensive single-chip computer-based PWM control with a simple circuit implementation using basic electronic components (comparators, resistors, capacitors, and transistors). This cheap circuit approach achieves sufficient fan speed control without the high cost and complexity of microcontroller-based solutions.

The system dynamically adjusts fan speed based on real-time temperature monitoring through three temperature detection circuits that continuously monitor temperature and switch between different fan speed states. This dynamic response ensures fans operate at appropriate speeds only when needed, improving energy conservation while maintaining simple operation through automatic temperature-based control.

The patent changes the control parameter from continuous voltage adjustment via thermistor to discrete temperature-threshold-based speed switching. By using voltage comparison circuits that trigger at specific temperature thresholds, the system achieves both operational simplicity and energy efficiency by eliminating unnecessary fan operation at low temperatures.

The patent merges multiple voltage comparison functions into a unified control circuit architecture where three temperature detection circuits share common components and control logic. The comparator circuits are integrated to simultaneously monitor multiple temperature thresholds and control fan speeds through a coordinated system, reducing overall circuit complexity compared to separate independent control circuits.

The control circuit is designed with universal components that serve multiple functions: the same comparator and transistor structures are used across all three temperature control levels, and the circuit can operate in multiple modes (single fan control, dual fan control) depending on temperature conditions. This multi-functionality reduces circuit complexity by avoiding redundant specialized components.

The patent replaces the mechanical/software-based single-chip computer PWM control system with an electronic analog circuit system using comparators and transistors. This substitution eliminates the need for programming and software-hardware coordination, achieving intelligent temperature-based fan control through pure electronic circuits that are simpler to manufacture and implement.

The control circuit is designed to automatically respond to temperature changes without requiring external control signals or software intervention. The temperature detection circuits continuously monitor temperature and automatically trigger appropriate fan speed changes through the comparator logic, achieving self-service intelligent control that eliminates complex implementation requirements.