6 replies to this topic

[ChrisD82]

Been looking at some of the blue led lighting options out there for night fluo diving and in the end just finding it way too expensive what it is so looking at the DIY options. I use those inexpensive $30 ebay 2000lm dive lights from China (not really 2000lm but bright enough) for my regular dives and has over 25 dives so far without flooding so far.

 

I'm now looking at trying the more powerful 8000lm rated ones like the Skyray the under $80

http://www.ebay.com....=item487c88a305

 

How hard would it be to open one of these type of lights to desolder and replace the LED's with the equivalent royal blue 450nm LED's?

Not sure if this would be the right one but something similar:

http://www.ebay.com....=item1c373d9ad7

 

From that point I think its only a matter of ordering blue excitation filter to replace the front glass on the torch or to stack on top depending on thickness. I've seen them for around $20-30.

 

That would end up being under $140 for a 5x Royal Blue LED light. - I'm planing to build 2-3 of these for photo/video rig.

 

All the other components like yellow barrier filters for mask & camera are affordable so definately buy ready made options.

 

Thoughts?

 

 

[LarsB]

Hi ChrisD82,

first of all, there are no blue equivalents for the white Cree XM-L type of LEDs.

Replacing them with other LEDs may exceed the LED's and/or the torch's specs, which may cause damage to either, or both.

You may not even notice at first, it can be that the LEDs will simpy age much faster than normal and lose brightness rather quickly.

Moreover in many torches access to the LEDs can be difficult (e.g. the torch may be glued shut and/or require special tools to open) and the LEDs may be soldered in place through flow-soldering, which may be difficult to unsolder and even more difficult to resolder, because this is difficult to do at home and because you may not be able to get the parts out of the torch, or there may be others components soldered on such as SMD electronic components which might get damaged in the process.

Finally, replacing the front glass with a dichroic excitation filter is a very bad idea, because the filter's glass substrate is thin and brittle. It is certain to break at a certain depth and to flood your torch, probably ruining it, or at least the batteries and/or the electronics inside.

Often there is no space inside the torch for an additional filter, and having the original front glass coated by the manufacturer is expensive and tricky, some glasses have a protective coating which makes coating them with the filter impossible. And last but not least you have to know exactly which type of filter to apply/order.

Some torches are indeed easier to modify than others, the difficulty is finding them (without spending a fortune).

[bvanant]

I think the simplest approach is to use the dichroic filter glued onto the front glass using UV cure adhesive but you still need to get the blue lights into the torch. Not simple at all as Lars points out. There are up conversion phosphors but they are expensive. There are a bunch of blue LED torches on ebay, waterproofing them might be an option.

BVA

[LarsB]

I think the simplest approach is to use the dichroic filter glued onto the front glass using UV cure adhesive but you still need to get the blue lights into the torch. Not simple at all as Lars points out. There are up conversion phosphors but they are expensive. There are a bunch of blue LED torches on ebay, waterproofing them might be an option.

BVA

 

If the glue is applied only to the rim of the dichroic filter and the front glass, the air pocket caught between filter and front glass will inevitably cause the dichroic filter to shatter under water pressure.

If OTOH the glue is applied to the entire surface of both the dichroic filter and the front glass, the glue may not be fully transparent, e.g. might contain small air bubbles, or might dampen the light output (even without air bubbles), which is not very desirable either.

 

What you can do for example however is to use some piece made of rubber to hold the filter and attach it to the torch, e.g. a rubber collar used in plumbing to connect tubes of different diameters, something like that.

Or make your own mount, e.g. of rubber or plastic.

The idea is that the water should be able to flow relatively freely, in order to avoid captured air bubbles and in order to make cleaning easy after a dive, while at the same time providing some protection to the filter.

The water flow may also be important for cooling.

 

When replacing white LEDs with blue LEDs, check out the specs whether there are compatible types.

Some Cree LEDs for instance have both white and blue variants, such as the XR-E and the XT-E, for example.

Check out http://www.cree.com/.../Products/XLamp

You'll always want "Royal Blue".

Edited by LarsB, 05 May 2015 - 09:27 AM.

[okuma]

"Some times you can't get there from here!'

[ChrisD82]

I was playing with my cheaper T6 that looks like this link: http://www.ebay.com....=item27fc186a9e

 

On these style torches the outer glass is held against the O-ring and head via a threaded cap. Its easily removable giving your access to the reflector area and to place a dichloric filter inside provided you get one 2mm or so smaller then the outer glass.

 

In terms of trying to get to the LED I found it almost impossible to take apart the head enough to gain access. For that one I can't pull apart without destroying the head but if I could recycle that waterproof metal body and install a new bulb module/driver unit could be an option.

 

I did find some unused 15+ year old Ikelite Super 8 and 2x Ikelite RDC dive lights in the garage from when I first started diving. I ordered a 10w royal blue 455nm module/driver set I'm going to try and fit into one those housings. The 26650 batteries fit easily where the D size usually go so can fit 4 of them inside easily.  On these ones the acrylic front glass is permanently glued so have to work everything in from the inside. Looks like will need to drill and dremel to open up the area where the incandescent bulb used to be and do some extra wiring but probably an easier project then the one I though about earlier. Im still working about how to cool the LED module though so went with the smaller 10w (There's 1-100w royal blue models available). The most expensive bit would be the larger dichloric filter to be attached from the outside once done.

 

Royal Blue 10w module + driver link: http://www.ebay.com....=item5b1182e637

[LarsB]

I was playing with my cheaper T6 that looks like this link: http://www.ebay.com....=item27fc186a9e

 

On these style torches the outer glass is held against the O-ring and head via a threaded cap. Its easily removable giving your access to the reflector area and to place a dichloric filter inside provided you get one 2mm or so smaller then the outer glass.

 

In terms of trying to get to the LED I found it almost impossible to take apart the head enough to gain access. For that one I can't pull apart without destroying the head but if I could recycle that waterproof metal body and install a new bulb module/driver unit could be an option.

 

I once had a similar torch (see e.g. http://www.diveright...ght-p-3380.html).

The LED was mounted on a unit that had holes to put the tips of some pliers in to unscrew it.

However, the thread was a left-hand thread instead of the usual right-hand thread!

You had to turn it as if you were TIGHTENING a normal thread in order to actually LOOSEN it.

Edited by LarsB, 28 May 2015 - 01:41 AM.