/diy/ - Do It Yourself

>>1218683
>LEDs are cheap.
Not these ones, $8 each for some Cree super-flux LEDs with 90° viewing angle at 3000mcd gives approximately 5.5 lumens of radiant flux. At 69c/$ they're the best white LED my local store sells, assuming my approximation about the 50% brightness point being the firm boundary of a cone is good enough. The shop is a little behind the times because they're not selling any raw COBs, but at least that made it easy enough to document every LED they sell on a spreadsheet to sort statistics by.

I'm sure I could get better performance from a Chinese COB bought online, but I set myself a goal to make this from locally sourced parts, for whatever reason. My rule isn't actually discretes only, but locals only, though they pretty much are the same thing.

The Cree datasheets don't list a temperature coefficient, so I'll have to assume based on their chemistry(?). I'll also have to do a voltage regulation analysis of my power bank at different levels of charge and different drains, which should be fun.

Or is pic related better? Both NZD, by the way.