i'm working on making a led cube lighting fixture similar to these two:
http://www.instructables.com/id/3D-LED-Cube/http://www.instructables.com/id/Led-Cube-8x8x8/and it's supposed to be in my living room and that poses a problem since not only that it has to look nice it must be practical provide enough lite and i figured that 512 leds should be enough, but then i thought a little about it and i and it hit me that it would only give me 1/8 of the light since every led lights up only for 1/8 of the time so i figured that i would have to have a mode in which all of the layers light up at the same time in order to give me the maximum amount of light.
that gave me a problem of current handling
so i figured i would use a similar setup to the one used in the 3d led cube instructable only i would use beefier pnp transistors to the ones used there (i will probably use bc327) so they can provide current to a whole column, i would use n-channel mosfets that would be controlled directly from the arduino to sink every layer.
i decided that i can't use the tlc5940 to sink current since it's limited to 130mA and that wouldn't be enough for 8 leds, and since these leds are paralleled i will control them with voltage and i added a voltage divider and three mje3055 transistors paralleled to handle the current and the power dissipation.
i attached what it my mind is the setup for a column, please tell me what you think about it, tell me if i need to add resistors anywhere especially around the mosfets and whether it's a good idea to control the leds with the voltage or maybe i'm just stupid and i can get leds that would light differently.
or maybe you have an entirely different idea of how i can achieve my goal, i would be glad to hear about it