Help With Making DIY Dive LIght

[Entacmaea]

Hey everyone- new here, but have been reading and reading and got inspired by a couple of the threads on making dive lights, and am going to give it a try.

I'd like to make a combined night dive light, and camera video/focus light. What I know and have built with before in aquarium lighting is cree 3 watt 20mm stars. Would those be applicable here? This is what I would like to do (I'll be making a custom aluminum enclosure for these), but I am totally open to suggestions. I am especially looking for knowledge on the battery angle, as I have no experience with that. This will likely be a canister type light- something I can mount to both my wrist and to my camera housing.


Three or possibly four 5-watt Cree 5-Watt XM-L stars Max 3000mA, about 5000K, ~2.9v forward voltage each. Not sure how many lumens this would be, but aiming for about 750-1,500 from low to high power. Along with those, I'd like to run three 3-watt RED XP-E led's, MAX 700mA ~2.4v forward voltage (these I'd like on a separate switch, for finding critters at night...) Probably looking at individual 12-degree narrow lenses.

Ideally the 5-watt Cree white LED's would be on a dimmer, or somehow control their brightness. I would do this on a potentiometer normally running AC power, but not sure what options there are with batteries, or if they are the same. I've seen some flashlight circuit board drivers like this one: 4-Mode 2500mA LED Driver Circuit Board for Flashlight (DC 5.0~8.4V) - Free Shipping - DealExtreme which might work for the 5-watt white crees.

If I were doing this with AC power it would be no problem, but with batteries- not sure what to do. What rechargeable batteries would you suggest, in what configuration?

I saw these http://www.all-battery.com/asizenimh...batteries.aspx Which are 1.2V and 2500mA, so does that mean I would need about 6 or 8 to run the 3-4 CREE's above, slightly under driving them?

I could probably put the 3 red LED's on another circuit, as I need to drive them at significantly lower amperage and want independent control of them- do I need a different battery whose output is 700mA? I think I might be missing some fundamental formula for calculating what I need

Help?

Thanks, Peter

 

[Kilili]

If you've not done so, you'll likely find more info on Candlepowerforums.

 

[3D diver]

Subscribed. Please post your progress.

I've been diving with stilldivin lately & he's got a DIY light that cranks out a lot of light. One thing he did was to seal the battery in the case & use a simple, removeable, PVC pipe fitting to cover the charging port.

View Profile: stilldivin - ScubaBoard - Scuba Diving Forum - Diving Social Network

 

[Entacmaea]

Yes, I tried posting on Candlepowerforums but no one is answering- so I'm hoping someone here who has specific DIY dive light experience can help. Thanks, Peter

 

[lucca brassi]

Three or possibly four 5-watt Cree 5-Watt XM-L stars Max 3000mA, about 5000K, ~2.9v forward voltage each. Not sure how many lumens this would be, but aiming for about 750-1,500 from low to high power. Along with those, I'd like to run three 3-watt RED XP-E led's, MAX 700mA ~2.4v forward voltage (these I'd like on a separate switch, for finding critters at night...) Probably looking at individual 12-degree narrow lenses.

12° angle is no way for video , you will have overburned dot on screen and other in the dark. For video is simplest way to put stars without any reflectors on milled aluminium rod and covered over with
plexiglass tube ( look on member Packhorse on CPF )

If I were doing this with AC power it would be no problem, but with batteries- not sure what to do. What rechargeable batteries would you suggest, in what configuration?

why AC???

I saw these http://www.all-battery.com/asizenimh...batteries.aspx Which are 1.2V and 2500mA, so does that mean I would need about 6 or 8 to run the 3-4 CREE's above, slightly under driving them?

You need CONSTANT CURRENT DRIVERr that might be BOOST ( which lift up voltage ) but need high current batteries , or BUCK which lower output voltage from input . If you made canister type light than pick up some high current bateries ( you have limited space ? )

I could probably put the 3 red LED's on another circuit, as I need to drive them at significantly lower amperage and want independent control of them- do I need a different battery whose output is 700mA? I think I might be missing some fundamental formula for calculating what I need

Help?

as you probably know red colour is very quickly absorbed in water ( so you need more lumens to compesate that ) , red is usable in brown muddy water and if you want on video higer CRI ( warmer colour tones )

 

[Entacmaea]

Hi Lucca- thanks for your help. Do you think that 30 or 40 degree lenses would be better? Seems I need to find a balance of penetration with even flood. I probably plan on doing less video than macro and stills, so I would probably say it will be used 75% focus light, 15% video light, and 10% night dive light (on camera or on wrist mount)

Do you have suggestions for a driver for, say 4 of the CREE's above at close to 3,000 mA, and one for 4 red LED's at 700mA? probably 3 steps is fine- high, med, low. I also came accross TaskLED: HBFlex Product Information which seems like it might work for the white CREE's, but it is unclear from the specs whether this driver has the stepped high/med/low function.

Batteries- is there a calculator out there for figuring out what batteries, voltage, etc. I would need for a given LED array? I plan on making two PVC tube canisters, each likely 1" diameter and 10-12" long, to mount to either side of my back plate for streamlined balance.

The link in your signature is really useful- I will have to pour through it!

I was basically going to use the red light to sneak up on critters at night- but you are right, I'll need more lumens when compared to white light. I've checked on the photography forum and the consensus is that strobes completely erase any red light when taking stills.

 

[lucca brassi]

Do you think that 30 or 40 degree lenses would be better? Seems I need to find a balance of penetration with even flood. I probably plan on doing less video than macro and stills, so I would probably say it will be used 75% focus light, 15% video light, and 10% night dive light (on camera or on wrist mount)

This is complicated question. For video you need ''even ''beam , for exploration you need penetration beam ..... you want all that in one lamp ! In that case you need is the best way variable focus.

In that case I would made lens with aspherics lens ( the simpliest way ) . For example focus length betwen led and lens is 18mm in spot position. If you close lens and led closer to 14mm you have fully flood and even beam without hotspot (perfect) . In that case you have to move or led with heatsink or lens itself . In front of lens you must have glass ( you must have airgap between lens and front glass or pojecting lens in water would not work right ) . With reflectors is a little more complicated because you need variable parabola , but that also exists .

How that work on praxis look on youtube , find some MBSUB X1-VB (i have it , but little upgraded ;-)

Do you have suggestions for a driver for, say 4 of the CREE's above at close to 3,000 mA, and one for 4 red LED's at 700mA? probably 3 steps is fine- high, med, low. I also came accross TaskLED: HBFlex Product Information which seems like it might work for the white CREE's, but it is unclear from the specs whether this driver has the stepped high/med/low function.

In that case you need separate driver one for crees and for reed leds . If you have led cluster then you will have only very wide beam or with suggestion DX cluster very hot spot with wide corona (but that is not usable for video )

Batteries- is there a calculator out there for figuring out what batteries, voltage, etc. I would need for a given LED array? I plan on making two PVC tube canisters, each likely 1" diameter and 10-12" long, to mount to either side of my back plate for streamlined balance.

Only calculator is how long dives you will make (time - h ) , how much current you will need (A =3000mA ) , gives you battery capacity in ( Ah ) .

Second is battery tension which is calculated how many leds you have in paralell , on each is drop 3,7V (3,7x3 =11,1V ) + some tension drop on driver ( low is better normal cca 2V , ) , so you get standard 13,2 V more or less )

so only problem is how many Ah you take + cca 25% for safety

 

[Entacmaea]

Thanks Lucca. I think it will be simpler for me to build a light with separate LED's for SPOT vs. FOOD, rather than have an adjustable beam. So, here is the outline for what I'd like to do:

2 XML 5w 3000mA (SPOT: narrow lenses for spotting)
4 XML 5w 3000mA (FLOOD: wide lenses or no lenses as you suggest for video/focus lighting)
4 XPE 3w 700mA RED led's (probably 30 degree lenses for mid-penetration)

Each of group above will be on its own toggle, for 3 switches total, so I can switch from spot, to focus, to red light, or burn spot/flood.

It looks like I would need 3 different circuit drivers, one for the spot XML's, one for the FLOOD, and one for the RED? It would be great if each could have 3 modes, low, medium, high that I could cycle through with each toggle. I saw some flashlight circuit boards, but I don't know how these should be configured. For instance, for the 2 XML spots, do I need a flashlight circuit board whose output current is close to 3,000mA and whose volts are more or less than the combined forward voltage of the led's they are driving? So, for these two SPOT XML led's, would this one work: 4-Mode 2500mA LED Driver Circuit Board for Flashlight (DC 5.0~8.4V) - Free Shipping - DealExtreme

I would also like to run these on 1 (or 2?) battery packs. Can you suggest how many batteries and of what type I would need? Looking for good burn time, and don't mind carrying a lot of batteries in a separate canister.

Thanks for your help!

Best, Peter

 

[bevansmw]

Thanks Lucca. I think it will be simpler for me to build a light with separate LED's for SPOT vs. FOOD, rather than have an adjustable beam. So, here is the outline for what I'd like to do:

2 XML 5w 3000mA (SPOT: narrow lenses for spotting)
4 XML 5w 3000mA (FLOOD: wide lenses or no lenses as you suggest for video/focus lighting)
4 XPE 3w 700mA RED led's (probably 30 degree lenses for mid-penetration)

Each of group above will be on its own toggle, for 3 switches total, so I can switch from spot, to focus, to red light, or burn spot/flood.

It looks like I would need 3 different circuit drivers, one for the spot XML's, one for the FLOOD, and one for the RED? It would be great if each could have 3 modes, low, medium, high that I could cycle through with each toggle. I saw some flashlight circuit boards, but I don't know how these should be configured. For instance, for the 2 XML spots, do I need a flashlight circuit board whose output current is close to 3,000mA and whose volts are more or less than the combined forward voltage of the led's they are driving? So, for these two SPOT XML led's, would this one work: 4-Mode 2500mA LED Driver Circuit Board for Flashlight (DC 5.0~8.4V) - Free Shipping - DealExtreme

I would also like to run these on 1 (or 2?) battery packs. Can you suggest how many batteries and of what type I would need? Looking for good burn time, and don't mind carrying a lot of batteries in a separate canister.

Thanks for your help!

Best, Peter

I think the 8x AMC 7135 drivers are probably the best cheap ones for driving the XML LEDs since they provide good efficiency, current regulation and accept input voltages in the range of 3V-6V or so which is close to the Vf of CREE LEDs. Input voltage needs to not be higher than 6V for them though, probably should actually be lower which isn't a problem if you're running them off Li-Ion cells in parallel (dangerous though) or Ni-MH in a configuration to get you to an ideal driving voltage.

The DX ones also don't often perform to the rated specifications and can end up providing less current to your LED than they're rated for.

Using multiple cells in a canister configuration in some sort of series/parallel configuration the safest way to go is with Ni-MH, charging the Li-Ion 18650s or whatever size used can be dangerous when they're in series/parallel configurations (like burning down your house dangerous). You can actually search candlepowerforums and see some of the damage done by exploding Li-ION cells (primarily in configurations where people have used multiple cells in some sort of series, parallel or series-parallel setup). That said I'm sure it can be done safely, I tend to just use single 18650 Li-ION lights that provide enough burn for a single dive and I can swap batteries during my surface interval. I have 4 of them modded, each for under $80 running a single XML U2 LED @ roughly 2.8A, one at 1.4A.

Also of note when considering your cells the closer you keep your battery pack voltage to the LED's Vf the more efficient your circuit will be. When you start using buck/boost drivers you're going to lose more efficiency (e.g. more power is lost in the driver as opposed to being used to produce light from the LED).

Other than the 7135 driver boards I'd look into drivers from taskled as they may actually be the best one to suit your needs but are more expensive. You could get by with multiple of the 7135 boards though and taskLED has some cool Hallsw boards that can help with your switch configuration that work great and are incredibly efficient.

Last here's a site with some ratings on driver boards available, you can search for some within your spec range and get some information on how well they perform as well as places to purchase them.

Aqualab: LED Driver List - LED Drivers and Regulator Boards (database driven)

 

[Guba]

This was my solution to the underwater video DIY light. It's a commercial 36 LED array that produces about 600 lumens at 5600 K. It's enclosed in a PVC three-in end cap with a 1/2 in acrylic faceplace routered to a top-hat shape. It seals with a quarter in. buna o-ring and three spring loaded latches. The light is re-wired so that a magnetic reed switch mounted inside the housing can turn the unit on and off (I mounted a magnet in a slide on the exterior of the unit. This light isn't adjustable for brightness, but it's very inexpensive...about $55 for the entire set-up. I plan to use two lights in tandem. It's not pretty or elegant, but it's simple and inexpensive! I know this unit lacks the sophistication and flexibility of the ones y'all are designing, but it suits my simple needs and it's within my skill set to build it. Let me know how your light turns out. I'd love to see i!