To the right is the schematic used to construct the LED nerd glasses (see the results here). The rectangular square piece in the middle of the LEDs represents the PCB. The middle acts as a neutral, and the sides each provide 3 volts when connected.
The 3 volt coin cell battery (Energizer 2032) that I used should really have a 33 Ohm resistor connected (see LEDcalc.com to easily calculate this) before going into each 3 volt bus. I’ve neglected this in my design, so the LEDs will be overpowered and will most likely burn out prematurely. Also an actual switch and battery holder would be a nice touch. As it stands now, the neutral is held onto the battery with electrical tape and the positive or signal wires are tapped onto positive by hand.
The circuit itself is very simple, but when working with LEDs, one must remember to connect them in the correct direction. Where the metal piece inside points toward is the positive lead which is also generally longer. The milled PCB has three distinct layers, two positive and one at zero volts DC. These pieces of copper are separated by layers that I milled into it with my CNC router. The wires as well as the LEDs were soldered to their respective strips of copper through holes that I cut in the back.
You could make these glasses with wires, of course, but since I had access to PCBs I decided to try this instead. I had actually considered using infrared LEDs for the glasses instead of visible lights, but I haven’t done it yet.
If invisible LEDs could be hidden effectively enough and were bright enough, it could possibly create a virtual disguise for someone since infrared lights are generally seen by cameras, but not human eyes. If you were very paranoid about people tracking you, this might be one method of keeping your identity “off the grid.” On the other hand, if Big Brother were watching you and knew you liked to walk around with an IR light attached to your head all the time, this would make things much easier. Also, some cameras may have a filter for this, so not being a security expert, I have no idea if this would work.
Be sure to check out the the post where I give details about machining the PCB and attaching everything together. If you missed it, be sure to check out the first post in this series with the results and video!