Temperature Controlled PC FAN

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This project is a temperature controller for a PC FAN. It regulates the speed of the FAN attached to it according to the measured temperature. Temperature is sensed using a simple NTC thermistor.

Description

In most PCs, the fan runs constantly, which may not be necessary. A simple circuit can regulate the fan speed according to temperature. This not only saves energy, but it also reduces fan noise. Only three components are needed to allow the fan speed to be controlled according to the actual temperature: one adjustable voltage regulator (LM317T) and two resistors that form a voltage divider. One of the resistors is an NTC thermistor (temperature-sensitive resistor), while the other is a normal resistor.

schematic

Components list

  • 1 x LM317T
  • 1 x 100K POTENTIOMETER 3296W 3296
  • 1 x 15K NTC
  • 1 x 100UF 16V Capacitor
  • 1 x TO-220 HEATSINK (OPTIONAL)
  • 2 x Latching Pin Headers 0.1″ Pitch 3 Way

This PCB has been designed so you can use a single resistor or a 100k potentiometer, i recommend using the 100k pot as this is far much easier to fine-tune this device for your needs.

Photos

SAMSUNG

SAMSUNG

SAMSUNG

SAMSUNG

SAMSUNG

SAMSUNG

PCB

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Dimitry

Can the transistor be replaced by a MOSFET instead to drive 12V 1A DC fan?

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