Fan Control Circuit Speed Compensation for Voltage Drop

Solution Overview

Problem

Fan control circuits face challenges in maintaining heat dissipating efficiency due to decreased system power supply voltage, leading to reduced fan rotation speed and air flow, which affects heat dissipation efficiency.

Innovation Solution

A fan control circuit and method that includes a processing module, a driving module, and a speed compensation module, where the speed compensation module generates a speed-compensation parameter based on a variable input voltage and waveform, allowing the processing module to adjust the driving signal and maintain fan rotation speed, thereby stabilizing heat dissipation efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the system power supply voltage decreases, then the voltage for adjusting fan rotation speed decreases, but the fan rotation speed must be maintained to preserve heat dissipating efficiency

Engineering Contradiction:

Improveheat dissipating efficiencyVSAvoidvoltage for adjusting rotation speed

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent changes the parameter of control voltage by introducing a compensation voltage that counteracts the decrease in system power supply voltage. The compensation voltage is generated based on the detected voltage drop, and when added to the original control voltage, maintains the fan rotation speed despite the reduced system voltage, thus preserving heat dissipating efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the system continuously monitors the power supply voltage and adjusts the compensation voltage accordingly. When the system voltage decreases, the feedback loop detects this change and generates an appropriate compensation signal to maintain the fan's operating speed, ensuring stable heat dissipation performance

Inventive Principle:

Principle #23Feedback

2Productivity

If the fan rotation speed decreases due to reduced voltage, then the heat dissipating efficiency decreases, but increasing rotation speed requires additional energy compensation

Engineering Contradiction:

Improveheat dissipating efficiencyVSAvoidpower supply voltage

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The patent changes the parameter of control voltage by introducing a compensation voltage that counteracts the decrease in system power supply voltage. The compensation voltage is generated based on the detected voltage drop, and when added to the original control voltage, maintains the fan rotation speed despite the reduced system voltage, thus preserving heat dissipating efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary anti-action by proactively generating a compensation voltage that opposes the harmful effect of reduced system voltage. Before the fan speed can decrease, the compensation mechanism is activated to counterbalance the voltage drop, preventing the deterioration of heat dissipating efficiency

Inventive Principle:

Principle #9Preliminary anti-action

Data Source

PatentUS10161384B1Fan control circuit and fan control method

Publication Date: 2018.12.25 ANPEC ELECTRONICS CORPORATION

AI summary

A fan control circuit for controlling a fan includes a processing module, a driving module and a speed compensation module. The driving module is electrically connected to the processing module, and generates at least one driving signal to drive the fan. The speed compensation module is electrically connected to the processing module, and receives a first voltage. The first voltage is variable. The speed compensation module generates and transmits a speed-compensation parameter to the processing module according to the first voltage and a first waveform, and the processing module adjusts the driving signal according to the speed-compensation parameter.