umbilical diving light, help needed

[b-bassett]

hi all

first post here but have been looking through this site for a while and feel its about time to say hello and help....

im looking into building my own LED umbilical dive light with a nice tight beam for proper underwater penetration

i was going along the line of a maglight head with 4 Q5's similar to packhorse's rig, but i would very much like to be able to dim the light down for use on deco stops if needed/possible.

for batteries im leaning towards using an old kowalski 1250 speed (12v/3 Ah) mainly because i like the charging method and because i already have one.

i have access to lathes and mills so can machine most things, but its the electronics which are throwing me and any help would be greatly appreciated

thanks

jon

 

[Packhorse]

Just use the KD driver as I did. It had 3 power levels. Although that driver is best suited to 7-8 volt range especially with its low volt warning. I think you will need something with more capacity than 12volt 3 Ah.
I did a week of diving on the Mikhail Lermontov wreck last week with very poor viz (1-5 meters) and I found that I used the light on its medium setting most of the time. On deco it remained off.

 

[b-bassett]

thanks for the advice will look into the KD driver and a different power source.

would 14.4 v drill batteries do?

also how is the KD driver switched between power levels?

 

[Packhorse]

thanks for the advice will look into the KD driver and a different power source.

would 14.4 v drill batteries do?

also how is the KD driver switched between power levels?

As I said its best suited to the 7-8 volt range 14.4 volt falls some what out of that range. You could still use the battery but you will need a dirrent driver. Perhaps wire all LEDs in series.
Its switch by turning it off and on quickly.
Also those drill batteries are often limited in Ah. But if the LEDs are in series and you run them at 700ma then you may get 3 hours from a 2500maH pack.

 

[b-bassett]

ok thanks a lot for the help

batteries arn't set in stone yet, just trying to use what i had lying around and seamed easiest.

perhaps i would be better off just copying a working design

 

[b-bassett]

hi again

well iv spent the last few weeks working out what parts i needed and have orderd most parts

i have decided to go with 4 Q5's in 2p2s driven by a led dive light genie powerd from a 12V 7 Ah sla battery

now that the led's and aspheric lenses have arrived i have been trying to design a heatsink to hold both the led's as well as the aspherics in place.

i have come up with a solution which should also strengthen the sealing of the maglite aswell as the glass front. but have a few concern's as to wheather it will actually work and need some advice from the more experienced and wise minds out there.

this is what iv come up with

now for the concerns/ questions

1.
can i get enough room between led + aspheric for the corect focal legth? ( i belive packhorse used thes aspherics with 10-12 mm spacer tubes)

2.
will the lens retaining ring provide support for the glass and allow me to use a single 3mm peice, or will the large o-ring be compromised?

3.
have a drawn the aspherics the correct way up? as they as-symetrical i have no idea what side should face the light source


well thats all the problems i can think of for now any help would be greatly appreciated

thanx

jon

 

[b-bassett]

hmm pic was there befor i hit submit

well heres the link to it hope that works

http://www.photobox.co.uk/my/photo/full?photo_id=1587132119

 

[DM51]

There is something wrong with that link. Perhaps the image is no longer on the site.

 

[b-bassett]

hmm should be there i posted it there this afternoon

try again

 

[Icarus]

b-bassett,

what kind of aspheric lenses are you going to use? any link to where you got them?

still no picture(s)?

:thanks:

 

[b-bassett]

havent a clue whats going on with the pics, they show up to start with then get repalced with that image not avaliable one

aspherics are these ones

http://www.dealextreme.com/details.dx/sku.13903

does the photobox link work at all for the pic?

 

[Packhorse]

The fatter side of the aspherics points away from the LED

 

[b-bassett]

thanks packhorse

i thought they went that way round but wasnt totally sure

is the 10 mm focal length of the aspherics from the center of the lens to the emmitter ?

 

[Packhorse]

Its about 12.5mm from the bottom of the LED star (16mm Q5's from DX) to the bottom of the flange on the lens.

 

[b-bassett]

cheers, ill machine it to 13mm or so then give a bit of trial and error

 

[b-bassett]

anybody think the design will work?

was thinking of adding a thin rubber gasket between glass and alu heatsink to provide a little flex, and avoid the glass craking when compresed against the heatsink.

 

[Packhorse]

I think if the glass hit the heatsink it would indicate the O ring was not thick enough.

It should work but with my experience with the maglite it is not necessary.

Infact the stock mag lens is good to 40 meters! (but not 42 meters where it tends to go concave).
I have seen stepped lens designs but have not tried one.
My mag has been to 55 metes several times with nothing more than thicker O rings and a 3mm acrylic lens.

 

[b-bassett]

thanx, was hoping to use a stock 3 mm glass lens pressing against the heatsink to stop the glass craking under pressure.

might give it a go anyways without the electronics and see what happens

 

[b-bassett]

well the driver has how arrived + just needs to be solderd together so ill be able to test things out.

unfortunatly it will have to wait a few weeks as im going up kilimanjaro

at least ill have somthing to do when i get back

 

[girdles]

Hi Jon

How is the build going ?
Did you use the genie and is it any good ?
You will have to show me what its like and maybe give me a hand with the electronic side of building mine. I have 4 x Q5s on there way and may get a Genie if yours has done the trick.

Give me a call

Dean