To start with, I should mention that I am relatively new to Arduino and have really only played with the basics. However, it occurred to me the other day while I was shopping for video lights for underwater applications that this might be something that - with a lot of effort and time - I might actually be able to build myself.
My project would involve developing a controller for a number of high power LEDs (white). From initial research, I understand that I will need to use transistors and an external power source for running the LEDs since the Arduino board cannot handle that much current.
I have not worked with high power LEDs and do no know anything about the implications of heat buildup that would be due to nesting them close together in the form of a lighting head.
All of this will need to be fitted into a housing capable of about 90 meters depth - here I may have an in a be able to get it machined at cost. The housing will need to have switches to control the LEDs (on/off, and it would be nice to have variable light output as well).
That much seems to be doable to me. I don't know much about batteries, however, and what would be available to run this setup. My constraints are mainly size - I don't want to try to put a lead-acid battery inside of an underwater housing. Smaller is better. Run-time at maximum power would be ideally 45 minutes or more and maximum light output would need to be somewhere around 3500lm or greater.
I guess I'm just looking for any input that you might have for me. I'm willing to spend some money on this project considering the alternative is buying video lighting systems which seem ridiculously expensive to me. (e.g. - this 4000lm video light for $1600: http://www.scuba.com/scuba-gear-56/026844/Light---Motion-Sola-4000-L.E.D.-Video-Dive-Light.html?gclid=CIz7-9mbqLMCFYN_QgodrToAPw )
Any suggestions of where to look to get started, or advice on whether or not this endeavor is even with worth my time would be very helpful.