Advice needed on HID/LED setup

Hello,

I've built a 10AH cannister light with a 35w halogen lighthead. I bought the parts at various places, I didn't really make anything myself. I'm very happy with the result, but I owned a 25W HID light once (till it broke ) and so I'd like to make a 35W HID light from an automotive kit.

All the ballasts/ lamps I've seen are the same shape (rectangle) and since I have a MR16 lighthead I'm thinking about making a remote ballast setup with just the ignitor in the head. The inside of my lighthead precisely fits an MR16 bulb + the holder. Is it possible to put an HID bulb in there? I can't find any info on the dimensions of the ignitor and the bulb. Also, what reflector would you use and where can I find them? I want a nice tight beam.

Any other useful info?

Greatly appreciate your input,

Naick

Re: Advice/help needed on HID setup

Yes, 35W MR16 HID bulbs are available, however the only two types I'm familiar with are 12degree and 24degree beam spread...The globes do not come separate to the reflector as MR16 is one glued package. 12 degrees is not very useful if you want a tight beam for a primary torch.
http://www.hidtechnologies.com.au/35W.php

The price is also way more expensive for a MR16 bulb than an automotive bulb, but, you do get an inbuilt MR16 reflector with the globe, in a neat package. With an automotive bulb you need to source a reflector and then waterproof it, but with that effort comes a potentially tighter beam of a better quality.

Yes, you can put the igniter in a wand handle but the wand handle must be at least ID 40mm+ to allow the dimensions of the rectangular igniters that come with the 'slimline' ballasts (ballasts that have a separate igniter and ballast). Typically they are H 25mm, W 30mm, L 50mm. Failing that you can buy an integrated ballast/igniter and put it all in your canister. As long as there are no issues with the high voltage (23K V) over the distance of cable between your canister and globe then you are laughing.

My first 35W HID build...5AH Li-ion battery in an Otterbox9000 rated to 100ft depth. PVC piping and a pond housing for the MR16 globe. Still works, but lies in the 'Torch Museum' at the back of my shed.



Or, for something more solid...



35W Ballasts put out a fair bit of heat and enclosing the ballast in your canister contains that heat. It will work, but the excess heat is not healthy for your batteries.




You could look at waterproofing the ballast and mounting it outside the canister. In fact, do away with the canister and cable altogether. 3-cell 10AH battery's are in these for 2hrs+ glow time.





Now for the real advice...As you can see I've built a few 35W dive torches in my time, and they have evolved down the page to what I use as my primary night torch today. All are 35W HIDs, but I would never consider using a 35W MR16 HID again...The last photo sums up why. What you are planning to put in your torch is on the right, compared to what is possible on the left. The difference comes from a wider reflector (100mm as opposed to 50mm) a tighter beam (collimated as opposed to 12 degree), and from a larger automotive bulb. It comes from the torch on the left, which is also more compact than the original canister design and with twice the battery capacity.

Also consider...anything with a wider spread than the spotlight on the left can be reproduced in LED. And LED can match anything less than 35W HID.

Food for thought.

Re: Advice/help needed on HID setup

There is another big difference automotive bulbs are almost all AC (35W and over W) lower are DC.

But general :if you want to use powerful HID you need big reflector.

Re: Advice/help needed on HID setup

Hmm thanks a lot Klem and Luca. Not really what I wanted to hear but

I guess I'll stick to my halogen for now.
A powerful LED sounds good too. I've been reading a lot on here, but I don't really know which way to go with LED. Also, its pretty complicated and I don't have any access to a lathe to make a heatsink etc.

But what would you recommend on LED. I'd like something close to 21W HID. It should have a nice spot and some spill arround it. I've seen some setups with 4 LED's and some with a single LED like the SST50 and SST90. What's the main difference

Re: Advice/help needed on HID setup

I agree with Lucca that you need a decent size reflector to do a HID justice. But you can go too big and run into problems.

In using HID for diving you need to consider the greater the diameter of reflector, the more volumetric weight you have to offset to keep the torch negatively buoyant.

Take these two examples below. The HID on the left has a 100mm diameter reflector. The HID on the right is 150mm (a 6" Hella car spotlight). The reflector volume more than doubles. I have to add lead weight (internally) to offset the buoyancy in both torches, but moreso in the 150mm. Not only that, the centre of gravity needs to be close to the reflector so you can put the torch down underwater and it doesn't immediately tilt to point at the surface.



Along with that is the size/bulk of the reflector so there is a point when it gets too big, heavy (out of water) and clumsy to go diving.

Here's a 55W HID 150mm concept torch on the right. I ended up tying a 3lb lead weight to it just to get it to sink.




My opinion of the perfect compromise between light and volume is a 100mm diameter...and that is what I dive with now.

Would be great if you could source a solid lens/reflector similar to an LED TIR, only bigger... 100mm diameter. A solid cone of glass with a test-tube space for the globe that would solve the volume issues, and also resist water pressure.

I'll let the other guys comment on LED recommendations.

Re: Advice/help needed on HID setup

Interesting Klem that with big HID. What you have inside peli on display -voltage ?

I try to made for long ago 35W HID or more with car bulb D1R Osram in test tube stayle ( less buoyant ) but I despair at D1R socket -ignitior.

but some have success like http://personal.inet.fi/yritys/innov...ideo_light.htm (library)

Then I try with to big housing actually two which stays in closet but it could be usefull for old video -big cameras (looks like H video enclosures). These days are cameras so small with HDTV...

But as I say once problem is with bulb manufacturers ...

@Naick

I made some old scubapro halogen light to HID with brightstarr kit. All details you can see at my signiture at '' RESURRECTION SCUBAPRO-SCUBALUX 350HP'' and then simply ask if something is not clear. For balast and bulbs look under sticky library - special cylindrical shaped balasts

also I recomended modification some old halogen lamp.

Lucca,
Yes, it's a Lithium battery 'fuel' gauge. It clips into a JST socket and automatically detects the cell-number of your torch. It then constantly cycles through the cells giving individual voltages, then an overall voltage.
http://www.dealextreme.com/details.dx/sku.10787
Works underwater fine through the transparent walls of the Otterbox. Plus the LED display is active, so it's good for night dives (no separate light needed to view it).

I also carry one in my battery box. Quick voltage checks, plus the individual cell info tells you if the pack is unbalanced and by how much.



JST sockets are on all my Li-ion packs for balance charging so the sockets and wiring are already there. Torch power comes from the Deans plug via the PCB so the JST socket lies idle during the dive...may as well use it for something.

I've got three of these things and have checked them all against a voltmeter... they are accurate.

I can't sing their praises enough for the couple of dollars it costs. And when you compare it against what's on offer at Batteryspace for twice as much you have to shake your head.
http://www.batteryspace.com/fuelgaugeforpcbof111vli-ionbatterypack1.aspx

I've also seen this recently, which might be useful for some, especially as it signals with noise, for those without a window in their torches..
http://www.dealextreme.com/details.dx/sku.35609


If you look inside the lid of the torch you can also see what I am talking about with the need to add weight to make it negatively buoyant. I use lead bullets and glue them in with a hot glue gun (I tried lead shot before but a pack split open and the inside was covered in tiny marbles). As you know, If I can use spare space inside then it requires less weight than affixing it outside, plus it displaces more volume of potentially humid air that's prone to condensing when the thing heats up.

Total weight of this 35W HID including 10Ah battery is 1.75kg, and it displaces 1.45kg's of water, so 300gms underwater....It's all relative I guess. I have smaller lighter torches but this is the main 'Punisher'. The 150mm concept torch weighed about 3kgs, so no wonder manufacturers use 'test tube' housings for the big reflectors.

Still...a solid cone of glass would work.

Nice!
My friends with RC models uses here a lot parts from Hobbyking , special this V,A,Wh analyser because you can instantly chech how much power you still have in tank
(they also have all gadgets -that DE have )

http://www.hobbycity.com/hobbyking/...ct_Name=Turnigy_Watt_Meter_and_power_Analyzer

Ah yes, all good. I also had a look at the HID site link in your earlier post... Way more serious than my backyard 'production', and with prices to match!

The availability of test tubes on their site for HID globes is an interesting one, and as long as you can waterproof the test tube to the reflector base then there's a lot of volume that no longer needs to be offset for buoyancy.