I think fritz15 is right. The 683lm/W is for 555nm light, and this is practically irrelevant for us because our LEDs are “white”. The luminous efficacy depends on the spectrum, so that efficiency column in the wikipedia article is misleading because it compares every luminous efficacy to that of 555nm light, which hardly relevant.
The 260-300 lm/W value for LEDs is the theoretical maximum given the typical LED spectrum (blue peak and a yellowish peak) and it represents 100% conversion of input power to photons.
This is the reference wikipedia quotes for the 260-300lm/W number and it explains with a bit more context:
They have made white LEDs close to the theoretical efficiency, but only with very small outputs. I can see why you might be a bit skeptical that it would produce very little heat (proportionally), but it looks like it is the case.
Edit: here is another reference from that wikipedia page: [1309.7039] Maximum Spectral Luminous Efficacy of White Light
They calculate the maximum efficacy of truncated black body spectra; they only consider the part of the spectrum that is within the visible wavelength range. They get numbers around 250-350lm/W. A truncated black body spectrum is approximately what a white LED spectrum looks like; light is only produced in the visible range.
Allright guys, i’m done wrestling with the pixels…
Must say i ran into the limits of what i work with quite often, and still i had many many options, but i think it ain’t half bad like this:
The shelf for the LED sits in the middle of the fins.
Simple lines, not only because it’s very difficult (for me) to do otherwise, but also with the production costs in mind.
And i like simple lines too.
The anti rolling blocks are now milled into the head, which is easier to do properly.
This is with a 100mm deep reflector.
I hope you like it, although i only have this simple view of it, i have no 3D model.
Nice pics Jerommel, I like the one on the right the most. Albeit you put a lot of effort in it I have to confess I like Fritz 15 light more. But as you say, yours will be easier to manufacture, less milling.