Matt photo


Temperature Controlled Backpack Cooling System

by Matt Fisher

Published on September 28, 2015

It's been a long, hot, and exhausting day at school and now you've got the long bike ride home to deal with.  You're tired, hungry, and sweaty.  The sun is beating down you relentlessly from above.  What is there to do?  Well, you could always have your temperature controlled backpack cooling system kick in and cool you down for the long bike ride home.  

Duration: 1 hour

Credits: UNCG School of Education - SELF Design Studio Paige Sorendo - SOE student Sarah Prescott - SELF Studio Manager

How To Make It


Setting the Temperature The first thing is to set the threshold to respond to the desired temperature. We used a number bit to set the threshold to 75. We referred to this video: order to understand the threshold bit.  We paused the video, created our circuit, and only later found out that a temperature-based item was then used as an example!

The initial circuit was set up as power-->slide dimmer-->number-->threshold-->LED.  We realized quickly that the slide dimmer did not work in the same way as the regular dimmer, and so switched it out.  Thus:


We used this to test the on and off threshold of the LED.  We used the number to set the number 75.


Detecting the temperature Then we replaced the dimmer with the temperature bit and used our own hot air or fans to light up an LED (to make sure the circuit was working). If the number displayed a temperature over 75, the LED lit up. If the number bit displayed a temperature under 75, the LED turned off. Once we had confirmed the premise worked....


Hook up the fans ...we replaced the LED with the fans!  


Mounting By now, time was growing short, so we mounted the circuit to a couple of mounting boards and tied these to the straps of the backpack. Future iterations might include sewing for stability, or placing the fans on both sides of the backpack!

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