philba
Registered
Cool project. I've got lots of questions about it though. My background - I've got a lot of experience designing and building all sorts of electronic systems including LED drivers and such. I know this is a bit late but hopefully some of you are still reading.
- heat production/management is a big issue for high power LEDs. In an enclosed space this could be an issue. Certainly an aluminum housing would help a lot though it's all about the thermal efficiency of the "heat sink". In a PVC housing, I wonder what the heat production limits would be. PVC has really crappy thermal efficiency so there is clearly some limit on how much power you can produce but PVC is very compelling from a cost perspective.
- Color temperature. What is the best temperature? I see 5700K bandied about . Since ambient red disappears at interesting depths, wouldn't one want something a lot lower to correct for lack of ambient red? At least for photography. Well, closer photography - 5-10' or so? I definitely need to learn more about this.
- I have to admit some trepidation about using LiPo/LiIon batteries. Many of the available products on the market don't use rechargables. In particular, a leak would probably cause a serious rapid discharge with overheating, possible a fire and maybe even an explosion. Also, electrolysis of salt water produces chlorine gas though there might not be enough to be harmful. To be clear, I have no idea what happens with a salt water short circuit of a LiPo but they do misbehave badly with a metal short (videos are easy to find of this). They are tempting due to capacity and performance. And I am personally biased against solutions that use disposable batteries though this might be a good case for that - alkalines just get hot when shorted since their internal resistance is higher than LiPos.
- However, rechargeables might have a big advantage in that you could build the charging circuit into the housing and then use a wireless/contactless charging method. Not having to ever open the housing is an intriguing idea. Of course the idea of recharging at sea is kind of ludicrous.
- Dual use lights - explore vs photography. If these can be produced fairly cheaply, why not just make different ones rather than complicating the design for dual purpose? I belong to the KISS school of design.
