I created an LED plush toy in the form of a giant LED. The concept is that the blue light can be used to treat seasonal affective disorder during the winter months.
I really enjoyed working on this project but struggled to figure out how to get the right form for the top portion of the LED. After a trip to Canal Plastics, I decided to use an acrylic half sphere and a cylinder to create my form.
I ordered 5mm blue surface mount LEDs from superbrightleds.com so that I could mount them all to an acrylic circle and easily solder them. After laser cutting all the mounting holes, I mounted 10 of the LEDs. I soldered 100 Ohm resistors to each one and wired them up in parallel to a 3xAAA battery pack.
I then mounted the circle in the acrylic cylinder and tied a washer to the leads for strain relief.
I filled the cylinder and top of the sphere with plastic pellets and taped them together. I didn’t want to glue them in case I needed to get back in to fix the wires.
I then tried to cover the top with fiber fill and found it to be too lumpy when I covered it with white leggings.
I removed all the filling and tried quilting batting instead. The result was much more uniform! I sewed it up by hand and added some cotton legs which hide the battery pack and wires.