Fan System Circuit Module Soft-Start and Block Current Protection
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Solution Overview
Problem
Conventional fan systems experience voltage drops and noise issues due to high start currents when multiple fans are started simultaneously, and are prone to overheating and burnout from instantaneous full-speed operation and lock failures.
Innovation Solution
A fan system circuit module with a stable voltage input, an operation unit, and a drive chip that generates a soft-start signal to gradually increase fan speed and a block current signal to minimize start current and block current, preventing overheating and burnout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple fans are started simultaneously, then the fan system can provide immediate cooling capacity, but the power supply voltage will be pulled down causing other equipments to malfunction
Solution Approach 1:
The drive chip generates a soft-start signal that gradually increases the drive current from zero to the target value over a predetermined time period. This preliminary gradual activation prevents sudden voltage drops that would occur with simultaneous full-power startup of multiple fans, while still achieving the required cooling capacity.
2Speed
If fans are started with high start current, then the fans can overcome initial inertia and start rotating, but the voltage of the power supply will be pulled down
Solution Approach 1:
The drive chip dynamically adjusts the drive current during the startup phase, transitioning from a gradual increase phase to a full-speed operation phase. This dynamic control allows the fan to accelerate smoothly without causing excessive voltage drops, resolving the contradiction between needing high start current for rapid acceleration and maintaining power supply stability.
3Productivity
If fans operate at full speed immediately after start, then cooling efficiency is maximized, but the start rotational speed creates great noise
Solution Approach 1:
The fan operation is divided into two distinct periodic phases: a soft-start phase where the drive current gradually increases over a predetermined time period (producing lower noise), followed by a full-speed operation phase where the fan operates at maximum cooling efficiency. This periodic action sequence resolves the noise-efficiency contradiction.
4Productivity
If fans operate without block current protection, then the fan system can maintain continuous operation, but temperature will highly rise causing burnout of the fans
Solution Approach 1:
The drive chip continuously monitors the operational state of the fans and detects lock conditions. When a lock is detected, the drive chip generates a block current signal that stops the drive current output, preventing further temperature rise and potential burnout. This feedback mechanism ensures fan safety while allowing continuous operation under normal conditions.
Data Source
AI summary
A fan system circuit module including a stable voltage input terminal for receiving a stable voltage, an operation unit electrically connected to the stable voltage input terminal and a drive chip. The operation unit includes a first resistor, a second resistor, a first capacitor and a third resistor. After powered on at the stable voltage, the operation unit generates an operation signal for the drive chip to decrease drive current value of the fan. In case that a lock of the fan takes place, the drive chip can effectively decrease the block current. The circuit module has soft-start function and provides block current protection effect so as to avoid malfunctioning of the fan system due to too great start current of the fan and avoid burnout of the fan due to high rise of temperature.