While in a holding pattern on flashlight builds, I finally got the motivation together to build out a concept. Actually there are a number of unrelated ideas and elements I wanted to visit and I was able to consolidate a number of them in a single, albeit goofy, conglomeration.
The ideas and elements to test and evaluate:
- half round acrylic bar for optic
- prototype "3 speed" buck converter for Makita Battery
- viability of an aluminum hardhat as the heat sink for headlamp
- adjacent mounting of linear array of LED's to minimize multi shadows
- integration of switch in Makita Dock
- FLIR evaluation of heat source and its spread in thin and remote sink surface
- FLIR evaluation of thermally isolated converter
More details, HERE.
Now in terms of conclusions, I knew the Makita battery and dock would be ungainly in both weight and exaggerated by its location on the hardhat. Beyond that though, the exercise was quite satisfactory and kind of exciting in terms of some ideas it presents.
I anticipate that there would be a good market and utility from LED based arrays mounted in hard hats and helmets used in industry as well as transportation. The aluminum is an obvious thermal solution but I would expect other solutions could be found with partial integration of either metal or thermally conductive plastics or laminates in a hat or helmet construction. The electronics and battery supply can either be on board or remote, depending on the application and needs.
Ultimately though, the key is in the beam and its distribution. On this note, the proverbial beam shot:
As it turns out, this prototype provided an almost ideal flood of good color rendering light which essentially covers the field of view to the hard hat wearer with little wasted light beyond the field of view. I think there is some real and exciting potential for us modders in using the simple half round acrylic rod stock for optics in head lamps as well as bike and other transportation type head lights. The acrylic is easy to work with and shape and then polish. You can even allow for focal adjustment of the bar in moving it into and away from the linear array of LED's. The Nichia 083's lend themselves well to such an optic because they have no raised dome and you can seat the optic down on top of them. The Osram Dragons without domes are also quite friendly to this. For LED's that do have domes, you may want to go with larger 1/2 round bar to capture and bend more of the light output.
My only regret in retrospect is not having done this "experiment" prior to building a LED cluster for my Vespa Scooter.