Automatic Temperature Based Fan Control (for Media Cabinets)

Capacitor 100 µF

Arduino Yun

DC motor (generic)

DHT11 Temperature & Humidity Sensor (4 pins)

Soldering iron (generic)

Teensy 3.1

Resistor 4.75k ohm

<h3 >Introduction</h3><div class="se-component se-video-container __se__float-none" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 56.25%; padding-bottom: 56.25%; margin: 0px;"><iframe frameborder="0" allowfullscreen="" src="https://www.youtube.com/embed/zq1ni1V_5Iw" data-proportion="true" data-percentage="100%,56.25%" data-size="100%,56.25%" data-align="none" style="width: 100%; height: 100%;" data-index="0" data-file-size="0" data-origin="100%,56.25%"></iframe></figure></div><p >I have a small cabinet in which I keep my video gaming consoles, as well as a Mac Mini. It tends to get quite hot. I needed to install a fan in it, but since the cabinet is located in my bedroom I needed the fan to be very quiet most of the time. I decided to have it controlled via a temperature sensor so the fan really only spins up if the cabinet goes above 80F.  </p><h3 >What we did </h3><p >I used a USB-powered Thermaltake Mobile II fan which has a potentiometer control. I removed the potentiometer and used the Arduino to emulate it.</p><p >Using an Arduino PWM pin to send variable voltage to the analog fan, this created a whining sound as the Arduino rapidly switches voltage on and off.  I built a simple low pass filter to act as DAC and the whining was resolved.  </p><p >I used a DH11 sensor which was a part of an OSEPP MHUM-01 board.  It took a bit to figure out the pin out of the MHUM-01, but once that part started working as well, the project was basically done.</p><p >Some shrink wrap packaging later and I was ready to frag (or be fragged).</p>

Automatic Temperature Based Fan Control (for Media Cabinets)

Media cabinets often get very hot. This project combines a temperature sensor with a fan to cool them down.