A few of my friends had a blind gift exchange for the holidays, with a $20 limit. I waited until pretty much the last minute to come up with my gift, so Amazon was pretty much out of the question. I was racking my brain what I could get my friend, so I went to Marshalls to try and find something. Eventually I came across a couple of Growlers for sale. Now my friend works at a brewery, so just getting him a growler would be pretty silly. But seeing the growler reminded me of a project he had asked me about a couple of yeas ago. He wanted to know if he could make growler lamps to put around the brewery. We talked about a couple different ways to accomplish it, but we never did anything with the idea. So when I saw the growler, I decided to buy one and make him a Growler lamp.
Now just making a simple lamp would be easy enough - wire up some LEDs and resistors and attach them to a battery. The metal on the lid could easily be drilled for a switch, and that would be the end of it. But what I really wanted to do was make the whole project wireless! I grabbed a set of wireless charging modules and tested them with my LEDs, and they worked like a charm!
I was a little worried that this project wasn't going to come together for a couple of reasons. First the charging coil was much larger than the mouth of the growler, so I had to bend the coil. The coil is pretty tightly packed and glued together for structural integrity - the shape and the windings of the coil are vital for operation. Once I got the coil (just barely) through the hole, I used a couple of rods to try to flatten out the coil. Despite my manhandling the coil, it still worked! Once I got it in the bottle it was sliding around quite a bit, so I had to fix some foam tape to it and carefully use the rods to position it right in the middle. Several attempts and a roll of foam tape later, i finally got the coil where I needed it.
For a base, I repurposed some prototype Motor Wheels. The rubber wheel acted as a nice place for the bottle to grip onto as well as gave me clearance for the coil. The holes in the wheel plates made it easy to get the wire from the coil to the underside.I added some large bumpers on the bottom for traction and to give me some clearance for the wire to the power supply - I used an old 5v wall wart I had hanging around. Admittedly the base isn't too pretty, but it works.
Now the question is, how long would it take this wireless charging module to charge a 12v lipo, so I can make a charging base for our hexapods!