Klem
Enlightened
Here's a recent project you might be interested in.
With all the emphasis on LEDs lately I'm still a big fan of HID for throw, and as long as they are above 35W they get my vote over LED. I've been looking at the HID torches on Fleabay and wondering if they can be adapted for underwater use.
I went ahead and bought the lowest yield (24W) for the body only, as it was the cheapest of the range. I then bought a longer 65W ballast to swap out the 24W. The torch is this one (brand name removed);
Gives you an idea of the size. The reflector diameter is 58mm, so slightly larger than a Maglite. The all-aluminium body is 47mm and comes with two components; the ballast and the battery. The 65W ballast is this one and it has an integral igniter. There are three contacts on the base and you just solder leads onto the + and - for single mode, highest power;
There are a variety of ballast to choose from, including 24W, 50W,65W, 75W, 85W. The length of the ballasts extend as the wattage increases but the diameter is the same.
I discarded the battery as once the body had the larger ballast in it the battery extended out the back, plus it did not have the capacity I needed. Instead I machined a Delrin base with a cable gland. This was connected to an aluminium project box with a 3S5P battery of 18650's.
The waterproofing was fairly simple. Glued up the various joins and seals with metal epoxy and swapped out the lens for 5mm Perspex. Unlike a Maglite there's plenty of thread for a thicker lens.
Results;
As you can see I cut the cable off and have gone back to using a 75W vehicle HID with 100mm reflector. Don't get me wrong, it works - it is a narrow throw spot with a bit of wide spill but I was underwhelmed with what the narrow 58mm reflector could do with all that wattage. As far as a bomb-proof compact torch goes it fits the bill, and it is an easy mod, but I figure if you are going a high wattage HID then you squeeze as much light out of it as you can, and that means using the widest diameter reflector that the buoyancy generated by the void will let you. For me it is 100mm (I tried 150mm a while back and it was just too buoyant and bulky). My point being in my experience a 35W HID with a wider reflector beats a more powerful 65W with a narrower reflector hands down. The wider reflector collimates light more efficiently. In this case the 35W battery would last longer also, which is a bonus.
Also note the melted hot-spot in the centre of the Perspex lens where tip of the bulb was closest to the lens. You wouldn't want to turn it on above water without it being a glass lens.
The 65W 58mm HID is a bright robust throw light that fit neatly in a BC pocket, but for me a 75W 100mm HID is worth the extra bulk and build effort.
With all the emphasis on LEDs lately I'm still a big fan of HID for throw, and as long as they are above 35W they get my vote over LED. I've been looking at the HID torches on Fleabay and wondering if they can be adapted for underwater use.
I went ahead and bought the lowest yield (24W) for the body only, as it was the cheapest of the range. I then bought a longer 65W ballast to swap out the 24W. The torch is this one (brand name removed);
Gives you an idea of the size. The reflector diameter is 58mm, so slightly larger than a Maglite. The all-aluminium body is 47mm and comes with two components; the ballast and the battery. The 65W ballast is this one and it has an integral igniter. There are three contacts on the base and you just solder leads onto the + and - for single mode, highest power;
There are a variety of ballast to choose from, including 24W, 50W,65W, 75W, 85W. The length of the ballasts extend as the wattage increases but the diameter is the same.
I discarded the battery as once the body had the larger ballast in it the battery extended out the back, plus it did not have the capacity I needed. Instead I machined a Delrin base with a cable gland. This was connected to an aluminium project box with a 3S5P battery of 18650's.
The waterproofing was fairly simple. Glued up the various joins and seals with metal epoxy and swapped out the lens for 5mm Perspex. Unlike a Maglite there's plenty of thread for a thicker lens.
Results;
As you can see I cut the cable off and have gone back to using a 75W vehicle HID with 100mm reflector. Don't get me wrong, it works - it is a narrow throw spot with a bit of wide spill but I was underwhelmed with what the narrow 58mm reflector could do with all that wattage. As far as a bomb-proof compact torch goes it fits the bill, and it is an easy mod, but I figure if you are going a high wattage HID then you squeeze as much light out of it as you can, and that means using the widest diameter reflector that the buoyancy generated by the void will let you. For me it is 100mm (I tried 150mm a while back and it was just too buoyant and bulky). My point being in my experience a 35W HID with a wider reflector beats a more powerful 65W with a narrower reflector hands down. The wider reflector collimates light more efficiently. In this case the 35W battery would last longer also, which is a bonus.
Also note the melted hot-spot in the centre of the Perspex lens where tip of the bulb was closest to the lens. You wouldn't want to turn it on above water without it being a glass lens.
The 65W 58mm HID is a bright robust throw light that fit neatly in a BC pocket, but for me a 75W 100mm HID is worth the extra bulk and build effort.
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