LED CONVERSION FOR UK SL6
I had been wanting to convert my UK SL6 to an LED version for a while. Since UK had not come out with one, I found some DIY threads on a couple of forums. They are provided at the end.
The LED module is a “drop in replacement module” which means that it is a complete module including the 3W LED, DC to DC converter (voltage regulator), and reflector. I used the Cree 3W 6090. Source information is provided at the end.
As shown in the pictures below it comes with the LED electronic module, a reflector and a spring. The left picture shows the module from the front and the right picture shows it from the back. In each picture I have a complete module beside a module with the parts separated. The advantage of the LED module being threaded into the reflector allows you adjust the height a bit. In addition, if you have access to a machine shop you could actually make your own reflectors.
The LED module performs extremely well in my opinion. Both my wife and I use UK SL6s with a “Goodman Handle” extension from http://whatworks.ca/. We therefore use them as small canister lights and use them constantly on every dive in Ontario and we have used them for night dives in Cozumel.
The fact that we both use them and only mine has been converted to the LED module has created a great opportunity to compare the LED version with the Xenon bulb version. The LED version is much brighter and the light is very white compared to the yellow Xenon. The centre beam is also larger. I get twice the battery life using the LED version, about eight 40 minute dives with the LED and four 40 minutes dive with the Xenon bulb. We use 5500 mAHr C batteries.
Here are some comparison pictures.
SL6 LED by itself:
SL6 Xenon by itself:
SL6 LED on left and SL6 Xenon on right.
SL6 LED on left and SL4 Xenon on right. SL4 batteries may not be fully charged.
Fitting Modules into a SL4 or SL6 head.
It would be too easy if you could actually just drop them in, but you can’t as the reflector is much smaller. My solution was the following:
1. Hacksaw off the large flange section of a UK SL4 or SL6 bulb. Using a burnt out bulb would make sense. On my third time doing this procedure, I left about a 1 mm ledge instead of cuttng just at the base of the sloping edge. This created a slightly smaller hole. I then used a dremel and sandpaper to enlarge the hole until it would just fit over the LED insert module. A round file would suffice as well.
Here are some pictures of the pieces after the cut:
2. If you are as lucky as I was, the large flange from the SL6 reflector should just slide over the reflector from the LED module as shown:
3. Screw in the LED module to its reflector to ensure it is the same total height as the original SL6 bulb.
4. Attach a wire between the reflector and the bottom contact as shown below. It is very difficult to soldier to aluminium so I simply press fit the wire between the SL6 reflector flange and the LED reflector. I actually filed a slight groove in the SL6 reflector flange to provide some allowance for the wire but only enough so that it would still actually squeeze the wire when slide together. I soldiered the other end to the bottom of the LED module.
5. Fasten the SL6 reflector into place. Ensure that both reflectors are flush. I did this by simply resting them face down. I used plumbers glue ( shown below) since soldier is so difficult.
6. Note that the polarity of the LED module is backwards compared to a Xenon light!!!! You must reverse the direction of all batteries.
Current / Power measurements.
As part of a comparison between the 3W Cree and the Q5 Cree I took some current measurements to help charaterise their performance. They are summarized below.
|
# batteries |
Voltage |
Model Name |
Model # |
Current |
Watts |
|
4 |
5 |
3W Cree |
6090 |
1.2A |
6W |
|
Cree Q5 |
11621 |
1A |
5W |
||
|
6 |
7.5 |
3W Cree |
6090 |
0.9A |
6.75W |
|
Cree Q5 |
11621 |
0.75A |
5.6W |
Acquiring Drop In LED modules.
The three recommended types consist of:
3W Cree (6090), Cree Q5 (11621) and the Cree R2 (11836). I purchased three of the first, one of the second and one of the third. The cost was $8 USD for the 6090, $9 for the 11621 and $13 USD for the 11836. Please note that the Cree R2 (11836) was not very bright and I would not recommend it.
I am currently experimenting with the Cree Q5. The tests so far would show that it performs quite well. The centre spot seems about the same as the 3W Cree if not slightly brighter and larger, but the spill area is not quite as bright. This would agree with the slightly lower power useage of the Q5. It also seems that the centre area may be slightly more white. After we do some underwater tests, I will update this comparison.
Websites:
They are available for free shipping from http://www.dealextreme.com
3W Cree 6090: http://www.dealextreme.com/details.dx/sku.6090
Cree R2 (11836): http://www.dealextreme.com/details.dx/sku.12501
Cree Q5 (11621): http://www.dealextreme.com/details.dx/sku.11621
DIY threads on Dive Forums I used to gather information about these LED modules
southwestmafia.com: http://www.southwestmafia.com/forumswm/showthread.php?t=4997
cavediver.net: http://www.cavediver.net/forum/showthread.php?t=6451
ScubaBoard.com:
http://www.scubaboard.com/forums/lights/241849-uk-sl6-sl4-led-comparison.html