This is basically an addendum to my earlier i-cup project where I initially used a tri-coloured LED for a single ganzfeld eye mask.
I decided to use an LED pair inside a mask made from two individual plastic left and right cups respectively.
I made a power terminal for one of the mask LED’s from an old 9 volt battery which I took apart. This was bolted on to one of the blue screw on caps which are still interchangeable like previously.
The power supply is a simple games adapter running on the lowest 3 volt DC setting. However the actual voltage measured is a bit higher than this, namely about 4.8 volts.
The series voltage dropper resistor used with each LED is 1kΩ. Even so I still found the illumination a bit overpowering to say the least.
Beforehand I did increase the value of the series resistor when making the original i-cup. (See my Ganzfield project.) I also didn’t have a suitable pair of higher value resistors so I thought of using a diffusion method instead.
I found two identical semi-opaque shampoo bottle caps which roughly matched the internal diameter of the mask apertures themselves. I carefully cut these down to size and I sanded with a low-grade paper to scuff the internal surface in order to make the two covers more opaque due to the fine scratches.
I learnt this art from seeing the surfaces of scratched CD discs which often skipped.
When fitted, these diffusion covers help spread the light more evenly where I find the bluer light more appealing to the eyes during the quick transition between the range of colours.
For further experimentation I recommend using an FM radio tuned to static at a comfortable volume as it is an excellent source of background white noise.