by klattimer, published
An Equilateral triangular PCB supporting 10 Common Cathode RGB 5mm LED's.
Used to build 3D light shapes from equilateral triangles. e.g. icosahedron
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Both sides of the board and the silk screen are included in the file.
Prints can be done for photo exposure or toner transfer (make sure you mirror correctly for the 2 sides).
Lining up for toner transfer can be difficult, I suggest pre-shrinking the boards by ironing before applying the transfer and cutting the toner transfers to an identical size as the board. I printed 15 of these this way and cut the boards individually from a large sheet.
If you're making a lot of them (as they do interlock) it's a good idea to print every third as a mirror image, this way you'll be able to hook up more of them to each other.
You'll need to feed them about 200mA per channel, that's 600mA for full brightness - I drive 15 boards using a BD242C power transistor for each channel - each board has 3x22R power resistor for setting the current, adjust the power resistor value for the voltage, in my case operating at 5V, 22R is ideal.
WARNING DO NOT USE DISSIMILAR LEDs, USE IDENTICAL LEDs DUE TO CURRENT VARIATIONS AND USING ONE RESISTOR FOR 10 LEDs.