Thanks for the replies Guy, Jon & Windy. I'll be interested in your findings Guy.
I think Jon is probably correct in that the small size of the light is the most relevant factor in the heat dissipation.
Nevertheless it would be interesting to know if the "safe" time that the light can be kept on is increased for the 4th and 5th levels, for example.
Hi easilyled,
Was going to grab my IR thermometer but can't see it (too many boxes of things out right now).
I did a quick comparison and it does definitely seem to me that the copper transfers the heat further down the body of the light with the part towards the tail feeling warmer, faster on the copper than with the titanium version, which does make sense.
In terms of performance impact, having tested a fair number of experimental copper PCBs, drop-ins, etc..
the difference in performance is often visible the longer a light is kept on, because as heat builds up, there's no where else for it to go and performance starts to drop.
Often times I found little difference (but some) during the first 10 sec... (in other tests) and as time went beyond the 30sec mark, the diff became far more apparent and easily measurable over the course of 60-120 sec.
Size is a key limiting factor as Jon mentioned though, but as a guess, I'd say there should be "some" performance advantage in mode 4 (lower temp at the LED means more power is converted to light OR less power is used to deliver the same amount of light) less advantage at lower levels where heat is a less of an issue, and at mode 5, some slight advantage as the battery becomes drained and output drops. When the battery is fully charged, at mode 5, the heat build up is (most likely) going to be way faster than the possible dissipation with either Cu/Ti until I can further improve the thermal link from the LED to the body (which I have worked on, made some proto's but for now are proving to be very expensive to make in small sizes.
eg. the cost of making a 3mm ~ 4mm thick pure copper MPCB with some "special" design innovations (beyond just direct thermal bonding) was almost as expensive as making the entire HF-R head.
Fortunately, there is STILL room for further optimization (which could improve peak output by ~20%)
Tgwnn
