Hardware PWM Fan Controller for CPU-Independent Thermal Regulation
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Solution Overview
Problem
PWM fan controllers require CPU processing resources, leading to instability when the CPU is busy or experiences deadlocks, as they share processing resources with other tasks and may not function effectively under high workload conditions.
Innovation Solution
A PWM fan controller design that includes a generator, multiplexer, sensor, and selector, allowing for the generation and selection of PWM signals based on temperature without occupying processing resources, using a configuration of JK flip-flops, AND gates, OR gates, and an analog-to-digital converter to regulate fan speed efficiently and stably.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PWM fan controller shares CPU processing resources through interrupts or polling, then the controller can read temperature and regulate fan speed, but the controller becomes unstable when CPU is busy or deadlocks occur
Solution Approach 1:
The patent extracts the temperature reading and PWM signal generation functions from the CPU and implements them in a dedicated hardware controller. The controller independently reads temperature from sensors and generates PWM signals without requiring CPU intervention, thereby eliminating CPU resource dependency and improving reliability under heavy CPU load.
Solution Approach 2:
The controller is designed to autonomously perform temperature monitoring and fan speed regulation without external CPU control. The hardware circuitry self-manages the entire control loop, including reading temperature sensors, comparing values against thresholds, and adjusting PWM duty cycles, making the system self-sufficient and immune to CPU busy states or deadlocks.
2Reliability
If PWM fan controller uses hardware circuitry independent of CPU, then the controller achieves stable operation without CPU resources, but the device complexity increases
Solution Approach 1:
The controller is segmented into distinct functional modules: temperature sensing circuitry, threshold comparison logic, and PWM signal generation circuitry. Each module performs a specific function with simple, well-defined circuitry. This modular segmentation allows the system to achieve reliable autonomous operation while keeping individual circuit components simple and manageable.
Data Source
AI summary
A pulse width modulation (PWM) fan controller includes a sensor, a generator, a selector, and a multiplexer. The sensor is configured for sensing a current temperature of an electronic device. The generator is configured for generating different PWM signals, each of which is suitable for regulating the rotational speed of a fan for dissipating heat for the electronic device of a corresponding temperature. The selector is configured for generating a selection control signal based upon the current temperature of the electronic device. The selection control signal is used for selecting a PWM signal corresponding to the current temperature of the electronic device from the PWM signals from the generator. The multiplexer is configured for performing the selection of the PWM signal.