PWM Fan Controller

Step 4 PWM Fan Controller - PWM Control Setup

The intent of this project is to keep the fan off when the drive is cool and since the drive spins down after about 5 minutes of inactivity the drive is allowed to naturally cool down. Also when the temperature is moderate the fan speed should be slow which will be as quiet as it can be. To come up with the temperature range of just running slow to running at full fan speed I used the data from the Google hard drive failure report.