Brightest globe LEDs

[Souley]

Greetings!
I am an uber noob, embarking on what I thought was a simple lighting problem for an art installation piece I'm building - but I'm quickly overwhelmed and hoping someone here can help...
Let me describe what I think I need - and then I'll describe the piece and maybe between the two someone can point me in the right direction:

- Super bright LED; 700 lumen +
- single point source
- widest angle reflector possible (as close to a traditional incandescent globe)
- light weight
- Battery pack suggestions - also as light weight as possible
- Some sort of remote control switch


So OK - Imagine a light bulb - a traditional screw in incandescent light bulb that we all grew up with (before they got all swirly and screwy). Now think of it big - no, go bigger - nope - bigger than you - that's right - I'm trying to build a giant light bulb - 8' in diameter at it's widest - a 15' monstrosity! (Design: 8' weather balloon on 4'base on a platform) So if it's a light bulb of course I have to light it from the inside. So I'm trying to hang a lighting pack in the center of the balloon. So hopefully you see my dilemma. I need something light weight - but powerful. I need lots of light but from a single source b/c a ball of christmas lights is going to shed weird shadows. I can't use a flashlight b/c I want this to be lit as close to 360 as possible. I realize that I will have a shadow from the battery pack - but I think I can configure my set up that that shadow goes to the top of the structure and no one will really see it. Oh - and here's the icing: I'd like to either find a light+battery combo that will last thru a 5 day festival or jigger up a radio frequency switch so that I can turn the light off during the day to save battery. and finally - the cherry on top - at night it will cease to be a light bulb and we're going to let the balloon fly ~100' above this festival - so once again the pack has to be very light weight and the battery has to be able to operate in helium (so ZnAir is out). And thus my desire to have the brightest lights possible - I want this thing to be a second moon for the festival! I've seen LED globes for refridgerator lights -but I need the same thing - but jacked on steriods!
Please help!
Thanks

 

[Tekno_Cowboy]

It would take an awful lot of battery to put out those lumens for that long. With a single 18650, you might get an hour. Even assuming that you'd only be using the light for 6 hours a day, you're looking at at least 30 18650's. That would kill any lightweight you wanted.

What you could do is run a light gauge wire up whatever rope you're using to hold the balloon in place. If you use high voltage, low current up to the balloon, then use a driver to convert it to proper voltage/current for the LED, you should be fine.

A single MC-E at the bottom of the balloon with a delrin (or similar) diffuser would do the trick.

 

[RyanA]

What's your weight limit on this battery? I think you're going to need some serious energy density. You might want to look into lithium polymer batteries. They are typically used in RC flight so by necessity they pack a lot of energy density per pound. I think the mc-e with a diffuser is also a good recommendation. If you can, try to get it mounted on a pc-b that is wired in series, as efficiency should be a bit better with 12vf than 3a of current draw.
That's all I've got.

 

[Souley]

If my calculations are right - this size balloon should be able to lift upwards of 6.5Kg (after compensating for the weight of the balloon and cabling).
I have considered Lithium Polymer. Is that the same as rocking chair lithium batteries? Can you publically source them?

 

[Tekno_Cowboy]

6-8 of these should provide enough juice to power an MC-E in series at 700-800mA, if you have a large budget. The weight of the batteries would be slightly under 1Kg, according to the weight on the website, giving you plenty of extra to work with.

 

[smflorkey]

First, welcome to CPF. (and thanks for the interesting problem)

So OK - Imagine a light bulb - a traditional screw in incandescent light bulb ... 8' in diameter at it's widest - a 15' monstrosity! (Design: 8' weather balloon on 4'base on a platform) So if it's a light bulb of course I have to light it from the inside. So I'm trying to hang a lighting pack in the center of the balloon.

Or, since the base of a traditional screw-in bulb is opaque and you want your sculpture to float with the base down, why not put the power pack and light emitter in the base, shooting a tight beam up to a convex (light plastic) reflector near the top? That way your sculpture is nicely ballasted and 90% of the technical wizardry is outside the balloon which should stay pretty well sealed -- if you want to retain helium.

Oh - and here's the icing: I'd like to either find a light+battery combo that will last thru a 5 day festival or jigger up a radio frequency switch so that I can turn the light off during the day to save battery. and finally - the cherry on top - at night it will cease to be a light bulb and we're going to let the balloon fly ~100' above this festival...

Since you want to anchor it until time to release it would be no problem at all to have a connection to the power grid while it's tethered. When you break the tether to release it, an appropriate lithium power pack takes over for the dramatic flight. Now the battery just needs to be big enough for the desired flight time.

If my calculations are right - this size balloon should be able to lift upwards of 6.5Kg (after compensating for the weight of the balloon and cabling).

Sounds to me like you'll need to calculate the load vs. lift so you don't find your sculpture interfering with air traffic (the FAA would not be amused) and coming down in the next county. Test flights on a 100' rope may be in order. Remember to weigh the rope and compensate for it before your final, dramatic release.

It also sounds like a lot of fun. Take some pictures and let us know how it turns out! :thumbsup:

 

[bshanahan14rulz]

OP, I'll be honest, I'm only replying because I second the movement that you should post pics when you're done!

Will you be keeping the guts in the balloon and releasing it? if so, where is this festival, I am going to go catch -- er, watch it.

 

[Souley]

Hey all
Thanks for the responses!
Unfortunately we got the balloons last week - and the online company lied to me - not neoprene at all - standard latex. jerks.
so this changes the whole design problems - because I can't/won't hang anything from the center of these balloons. the material is just too thin... I don't trust it!
So I'm switching to a much simpler method of lighting up these bad boys:
flashlights!
oh i'm so glad i found CPFs!!
There are never ending suggestions on here - oh me oh my!

If you're interested - the festival is called Playa Del Feugo. it's the regional burn for the mid atlantic region. it's held very close to Cape Henlopen in Delaware. The art piece is called "A Wicked Bright Idea" (it will also sport devil horns )

 

[RyanA]

Hey all
Thanks for the responses!
Unfortunately we got the balloons last week - and the online company lied to me - not neoprene at all - standard latex. jerks.
so this changes the whole design problems - because I can't/won't hang anything from the center of these balloons. the material is just too thin... I don't trust it!
So I'm switching to a much simpler method of lighting up these bad boys:
flashlights!
oh i'm so glad i found CPFs!!
There are never ending suggestions on here - oh me oh my!

If you're interested - the festival is called Playa Del Feugo. it's the regional burn for the mid atlantic region. it's held very close to Cape Henlopen in Delaware. The art piece is called "A Wicked Bright Idea" (it will also sport devil horns )

Then you are in luck my friend...
http://www.candlepowerforums.com/vb/showthread.php?t=214515
What does the funding situation look like?:devil: