Designing the portable phone charger involved two parts: the circuit board and the box.
1. The Board
The circuit design was fairly straightforward. The main parts included:
Once I soldered on all the resistors and capacitors, I tested the board by connecting my phone charger to the USB port and plugging in my iPhone. Nothing blew up—and it started charging!
2. The Box
Using SketchUp, I designed a box to hold the circuit board. I made the walls 1/8” thick, and I made it slightly bigger than the circuit to make sure it would fit. I included two holes: one for the mini-USB and one for the USB. After creating the appropriate files, I had the box 3-D printed.
The result simply didn’t work. When you tried to plug in a phone charging cable, it couldn’t reach the circuit board because I’d made the box too big. Each time you wanted to see if the device was done charging, you needed to physically open the box and check. And the circuit rattled around in the box. Not really what I wanted for a low-profile, portable phone charger.
I decided to make a list of requirements that would enable me to make better choices about the design. The box needed to allow the user to:
I was proud of how the device came out, and that it was something that I would actually use. Check out the next post for some pictures of the finished device!