Originally Posted by jpack

Hello,

In February, 2008, I decided to build a helmet for my sister but had difficulty finding 1072 nm LEDs so I used 940 nm LEDs instead. She used this helmet from April through September of 2008.

In May I found a source for 1070 nm LEDs and was told that the primary wave length shifted to about 1072 nm after it was turned on and heated up to 30-35 degrees celsius. I purchased 50 of these LEDs and built a revised helmet that my sister has been using for nearly 7 months. There are two primary problems with this LED. It is very expensive and sells for about $400 each from Marubeni. I was able to get some knocked off the price but I'm not sure of the present supply and price. The other problem is the heat the LED puts out. It is technically 60 diodes put together in a single package and it dissipates a lot of heat. When I powered up the first test of a single LED I only had power to it for 3 seconds and it got so hot I couldn't touch it.

My major design goals were: 1. Control the heat 2. Protect the expensive LEDs and most importantly 3. Make sure I produced a helmet that was absolutely safe for my sister's daily use.

I think I accomplished these goals and the helmet has been working well since Early October. I have several improvements in mind for the next helmet which will hopefully be completed within the next 3-4 months.

I would consider building another helmet for someone under the right circumstances and would be willing to talk to you about it. If you are interested please post a follow up to this message.


jpack