Settling for Greatness

A Proof of Concept

There have been several more changes with our design since the last meeting. Due to the lack of fabrication tools, we decided it would be in our best interest to create the phone case system out of wood and attach it to a separate pre-molded phone case. As a result of this method, we have created a phone case system that can house and utilize the solar panels like planed, but is much larger than the design is supposed to be. As a result, this design has been deemed a "proof of concept" and will be used to demonstrate what the actual case would look like when it is compact. Other than the change in the purpose of the prototype, we have also made another electrical change to our system.

In the past, we switched from a three solar panel unit to a five solar panel unit, and then back again. This past week the entire system was wired up correctly and we ran a short field test with it and obtained some data. As it turns out there was a slight oversight in the electrical system in regard to our step-up that was included in our design. The step-up took the current that the solar panels were generating and created a higher voltage but by sacrificing current. This meant that with three solar panels we were achieving around 5.2V but only about .06A. As a result of this small problem, the step-up will be removed from the system and just replaced with a USB connection for the external battery. The system will also return to the previous 5 solar panel system, with the possibility of it going to 4 solar panels in case of a voltage that is too high. This should make the system create around 5.7V with 5 solar panels or 4.5V with 4 solar panels, with both systems making around .4A, resulting in around 2.28W of power for the 5 solar panels and 1.8W for the 4 solar panels. Overall the project hasn't gone quite as well as we hoped, but if we can create a working prototype, even if it is too large, we would be quite thrilled. That would mean that not only does our system work, but also that it can be improved and that our design works!