Fan Detection Circuit for Automatic Single- and Dual-Rotor Identification
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Solution Overview
Problem
Existing electronic devices struggle with precise control of fans due to the baseboard management controller (BMC) being unable to actively determine the type of newly connected fans, necessitating manual configuration, which affects heat dissipation efficiency.
Innovation Solution
A fan detection system and method that includes a fan unit, a fan connector unit, a sampling unit, and a control chip, where the fan connector unit sends a detection signal to the sampling unit, which processes it to generate a second detection signal within a preset range, allowing the control chip to automatically determine the presence, type, and potentially fault status of the fan unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual configuration of fan type is required in the electronic device system, then the baseboard management controller can control the fan, but it cannot actively learn the type of the newly connected fan, which deteriorates the precision of fan control
Solution Approach 1:
The fan unit automatically performs self-identification by outputting different voltage levels (12V for single-rotor, 5V for dual-rotor) based on its type, enabling the BMC to autonomously detect and identify the fan type without manual configuration, thereby achieving self-service in fan type recognition
Solution Approach 2:
The patent utilizes voltage parameter changes as a distinguishing feature between fan types. Single-rotor fans output 12V while dual-rotor fans output 5V on the presence detection pin. The BMC detects these voltage parameters to automatically identify fan types, transforming a manual configuration task into an automatic parameter-based identification process
2Adaptability or versatility
If the detection signal voltage is not limited, then the full range of detection signals can be received, but the control chip may be damaged by excessive voltage
Solution Approach 1:
The sampling unit acts as an intermediary between the fan unit and the BMC. It includes a voltage divider circuit that attenuates the fan's output voltage (12V or 5V) to a safe level for the BMC, and a level shifting circuit that converts the voltage to a standardized logic level. This intermediary structure protects the control chip while maintaining adaptability to different fan types
Solution Approach 2:
The sampling unit performs beforehand cushioning by pre-processing the detection signal from the fan unit. The voltage divider and level shifting circuits are designed in advance to limit and condition the voltage signal before it reaches the BMC, preventing potential damage and ensuring the signal is within safe operating parameters for the control chip
Data Source
AI summary
A fan detection system including a fan unit, a fan connector unit, a sampling unit and a control chip, the fan unit being connected in series between the fan connector unit and the control chip, the fan connector unit being configured to send a first detection signal to the sampling unit based on a connection of the connected fan unit, the sampling unit being configured to sample the first detection signal to obtain a second detection signal, a voltage of the second detection signal being in a preset range, the control chip being configured to receive the second detection signal and determine a presence state and type of the fan unit based on the voltage of the second detection signal, the fan unit type including a single-rotor type and a dual-rotor type, and the first detection signal having a corresponding relationship with the fan unit type.