Fan Motor Reset Current Reduction Circuit for Locked Rotor Protection
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Solution Overview
Problem
Conventional heat dissipation devices for CPUs face increased reset currents when the fan motor is locked, leading to increased waste heat generation and reduced device lifespan due to higher temperatures of the fan motor coils.
Innovation Solution
A heat dissipation device incorporating a reset current reduction circuit with a switch unit and digital/analog converter, which outputs a control signal to maintain a low rotation state reset current when the fan motor is locked, preventing excessive waste heat and protecting the device's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fan motor operates at high rotation rate to dissipate heat, then the heat dissipation capacity is improved, but the reset current increases leading to increased waste heat and reduced device lifespan
Solution Approach 1:
The control circuit detects the locked rotor condition in advance and preemptively limits the reset current before it can increase to harmful levels. By detecting the lock condition and responding immediately, the system prevents the problematic current surge that would otherwise occur during locked rotor operation, thereby protecting the device while maintaining heat dissipation functionality.
2Temperature
If the fan motor is locked at high rotation rate, then the heat dissipation capacity is maintained, but the waste heat generated by drive circuit increases
Solution Approach 1:
The invention converts the harmful effect of locked rotor operation into a beneficial protective mechanism. By detecting the lock condition and using it to trigger current limiting, the system transforms what would be a damaging scenario into an opportunity to protect the device. The locked rotor detection becomes a trigger for protective action, turning a potential failure mode into a safety feature.
3Temperature
If the fan motor operates at high rotation rate, then the cooling performance is improved, but the temperature of fan motor coils increases reducing device lifespan
Solution Approach 1:
The control circuit continuously monitors the operational state of the fan motor and uses this feedback to adjust the reset current in real-time. When the lock condition is detected through feedback from the motor's electrical characteristics, the system immediately responds by limiting the current, creating a closed-loop protective mechanism that maintains reliability while allowing high-speed operation under normal conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces waste heat generation and extends the life of the heat dissipation device by maintaining a low reset current when the fan motor is locked, thereby preventing temperature increases in the fan motor coils.
Implementation Method 1
the D/A converter 16 converts it from a digital voltage signal to an analog voltage signal
Implementation Method 2
a fan motor 12 performs the heat dissipation process for the CPU 18
Implementation Method 3
a heat dissipation device with low power consumption to dissipate heat
Data Source
AI summary
A heat dissipation device comprises a fan motor, a drive circuit, and a reset current reduction circuit. When the fan motor is locked, an input terminal of the reset current reduction circuit receives an alarm signal, and an output terminal thereof outputs a voltage signal, which is larger than a reference voltage generated as the fan motor is at a low rotation rate, so as to decrease a reset current of the fan motor.