Just a buncha' balloons..

[BBadger]

Well, they're really not for that, and even that 30mA is often an abuse of them. Instead, I would connect the outputs to transistors and just switch those on or off depending on the input.

You can set up a circuit like this and handle the current regulation in the same step:

http://www.eleccircuit.com/constant-cur ... led-drive/

For 350mA, you'll need a 2-ohm resistor.

For transistors, use something like this.

I would also buy some diodes to drop the voltage for the LED colors that don't need as much voltage as the others.

[junglesmacks]

Well, they're really not for that, and even that 30mA is often an abuse of them. Instead, I would connect the outputs to transistors and just switch those on or off depending on the input.

You can set up a circuit like this and handle the current regulation in the same step:

http://www.eleccircuit.com/constant-cur ... led-drive/

For 350mA, you'll need a 2-ohm resistor.

For transistors, use something like this.

I would also buy some diodes to drop the voltage for the LED colors that don't need as much voltage as the others.

Hmm.. you're talking a lot of circuitry suspended in the air. It could work though I suppose. Build little PCBs for each balloon plugin..

Diodes to drop the voltage? As I typed out a "why?" to that, it made sense to me. Lower voltage means lower value resistor needing to be used means less power being burned off. Am I right?

..and yeah, I was already figuring in the different V+ requirements for the R vs the G and B.

[BBadger]

Hmm.. you're talking a lot of circuitry suspended in the air. It could work though I suppose. Build little PCBs for each balloon plugin..

Not that much. I'd just get a big perf-board and wire all the switching electronics at one place near the power source. Then send the wires out from there to the LEDs for the specific channels. No need to have it at the site of the LEDs themselves. Why distribute circuitry to the balloons where, if they break, it'll be a total pain in the ass to fix after you've weatherproofed them, and bundled them up. Keep all that shit centralized in a nice single package.

Diodes to drop the voltage? As I typed out a "why?" to that, it made sense to me. Lower voltage means lower value resistor needing to be used means less power being burned off. Am I right?

No, it's actually for what you said later, that it's because individual LEDs on that RGB star have different voltage drops. Red LEDs need 2.5-3V, greens and blues use 3.2-3.8V. You don't want to be over- or under-volting them (or at least over-volting). I put a fast 1V rectifier diode in line with the red LED to keep it 1V below what the others used. I still ended up burning out shit with too much voltage.

For what you said above, the resistor value is actually only a function of the transistor network. The two transistors form a feedback loop that regulates the current such that the voltage across the resistor is 0.7V. That 0.7V is magic because it's the tripping point for that left transistor. So a question might be: why even use the transistors at all? Well you want to control it right? We're using the transistors as a gate, but we also need to make sure that the current is regulated. The nice thing about that transistor circuit is that it will always regulate the current to that level, no matter what is above it in terms of voltages or whatnot. The transistor in series will actually eat voltage and heat up as necessary to maintain this condition.

Now that I think about it, maybe that two-transistor circuit is a bit overkill. You could just use a MOSFET as a simple switch instead (like this). I use the two-transistor circuit when I want an exact current rating or am doing analog dimming.

[BBadger]

One thing to remember about diodes: they don't save you power.

While diodes are not "ohmic" devices like resistors, Ohm's Law still applies to them. Diodes have a (relatively) fixed voltage drop. So if you look at Ohm's law, V = I x R, and fix V, then the resistance of a diode changes as a function of current.

What this means in terms of power is that diodes use power too, and that power usage is the same as any other electrical device: power = voltage x current.

So if you stick a rectifier in line with your LED to drop the voltage more, you're not saving any power. It might help the resistor not use so much power, but the diode picks up the slack. Use diodes to get your devices into voltage ranges that you need (like finding a more convenient resistor), but don't believe that they can or will save you power. There's are no exceptions to Ohm's Law.

[junglesmacks]

I think I love you.

[junglesmacks]

As I'm checking into the 3W RGB LEDs, I'm seeing a lot of mention regarding needing a separate heatsink for the module beyond the aluminum mounting plate that they come on. This would make it unfeasible to insert into the balloon for obvious reasons.

Has anyone worked with a 3W RGB LED before and know how hot they get? Would it pop a balloon?

I suppose also we could just not drive the LEDs at full brightness. 50% would be plenty bright I'm betting.

Found a 350mA LED driver chip: http://www.diodes.com/datasheets/ZXLD1350.pdf


EDIT: Found a schematic using these chips as a constant current driver. I feel like we could adapt this schematic to our own using the R, G and B output triggers of a WS2801 shift register IC. http://picprojects.org.uk/projects/hbld ... tic350.pdf

[illy dilly]

WOW

Sounds like you have all the lighting and power figured out, so I'll just let you run with it.
Let me know what you need me to work on.

[junglesmacks]

WOW

Sounds like you have all the lighting and power figured out, so I'll just let you run with it.
Let me know what you need me to work on.

Lol.. I'm getting there. What we're going to need is a good/CHEAP source for the balloons. A 6' balloon would be best since we could fill it up 80% of the way to 5' and have the extra thickness and strength. I've found a few websites but they're either really expensive or they don't have white. If you look hard enough, we should be able to find them for around $20 or less each. Find out what kind of necks they have so we can see how easy it will be to fit the LED module into it.

I'm going to go ahead and order some 3W fixtures from China just to play with. I can get them for like $20/10 with free shipping. If nothing else, I'll play with them for something else around the house.. you know me..

[FIGJAM]

What about dollar store beachballs?

[Ugly Dougly]

You'll poke your eye out, kid.

[junglesmacks]

What about dollar store beachballs?

Hmm.. that would work except that we need an opening large enough to stretch open to about the size of a silver dollar..

[FIGJAM]

Buy 1, then test cutting your 1 1/2" hole.

Those balls should be easy to create a patch for, and their a whole lot cheaper.

[junglesmacks]

Buy 1, then test cutting your 1 1/2" hole.

Those balls should be easy to create a patch for, and their a whole lot cheaper.

Hmmmmmm.....


So like.. cut open an access hole, put module inside.. but then.. how would you patch it? I could see using vinyl cement but the piece that you cut out is the same as the hole.. so what would patch it? Another ball cut up for vinyl material? I wonder how that would hold up to the forces of being blown up?

Also.. may be too heavy. One 5' balloon has about 5 lbs of lifting force. 12 balloons - 60 lbs. In that 60 lbs, we have to divide up the weight of the wires, led modules, paracord and balloons themselves.. plus have some decent lifting force to keep them upright in the winds..

[BBadger]

Can't you just connect the balloons to a valve and feed the light inside that way? Something like this:

http://www.bretkugelmass.com/uploads/6/ ... tation.pdf

Maybe use a metal pipe fitting and use that to wick away the heat.

[junglesmacks]

Can't you just connect the balloons to a valve and feed the light inside that way? Something like this:

http://www.bretkugelmass.com/uploads/6/ ... tation.pdf

Maybe use a metal pipe fitting and use that to wick away the heat.

Ooooooo.. Badg.. no.. you're on to something here. You could easily shine the light up into the balloon through an exterior valve like that and manage to keep the LED heat sink totally free air. Hmm. Need to give this one some thought. I think that may be a much better way..

[junglesmacks]

Thinking more about the idea above. I think this is the way. I checked around and sure enough, those LEDs do generate a good amount of heat and need to be free-air. They would definitely pop the balloon..

So, here's the design question. Below is a picture of the LED attached to an aluminum heat sink. You can see the solder pads for the wires, so I would solder them and then feed them back through the cutouts. I need so somehow attach this to a small tube the funnels the light upwards into the balloon, but also keeping the air sealed within the balloon.

Small piece of vinyl tubing epoxied around the LED only as to seal air and glue it to the heatsink?

[FIGJAM]

A short piece of fiber optic cable attachted to each led?

[junglesmacks]

A short piece of fiber optic cable attachted to each led?

The dome of the LED is about 5mm accross. It would take a cluster if fiberoptics which would be $$ and degrade the light I think.

[BBadger]

Yeah you could try a light pipe (i.e. a big fiber optic), though I don't know their losses.

Maybe something like this would work:

valve_diagram.png (18.79 KiB) Viewed 1425 times

[junglesmacks]

Yeah you could try a light pipe (i.e. a big fiber optic), though I don't know their losses.

Maybe something like this would work:

valve_diagram.png

A version of that is exactly what I've got in my head..

[BlackRockCityPimp]

Hydrogen filled ballons poked with long stick torches. Pick up moop afterwards. Not as moopy as a flaming piano trebuchet but it sure would look pretty and have more participation for more people. Consider HHO to get yer hydrogen via water using electrolysis. PM me if interested in HHO construction and deployment or just goto youtube and google.

[voiceinthedarkness]

I've been following this thread, as with many others, and this will be an amazing contribution. It may be somewhat presumptious for an outsider to weigh in, but may I offer some observations?
1. While I haven't been to the playa, I've spent some time in areas with harsh conditions. The rule of thumb is "KISS" - keep it simple, stupid. Anything that is challenging in your garage/shop will verge on very difficult once out in the desert.
2. It's been awhile since basic chemistry, but helium (I'm assuming helium is your choice?) is one of the smallest atoms in existence. It's small size is why even mylar balloons go limp. Trying to stuff electronics in a pressurized container, then sealing the helium-filled container, will be a logistical/maintenance nightmare.
3. It's been equally long since basic thermodynamics, but the temperature differential on playa borders on extreme, which, coupled with wind conditions, will likely cause the balloons (And the sealant used) to flex repeatedly, exacerbating the helium leakage.
4. The idea of a "light tube" with a T for re-inflating the balloons is outstanding, but somewhat challenging in a desert environment.

Would it be more effective to place your lift balloons in a separate net, secured to your cable, separate from your electronics containers? You could still use opaque white balloons filled with air to house your blinky lights, which gives generally similar artistic effects, while keeping your hoisting mechanism separate from the visuals. Re-filling hoist balloons would be simpler, and troubleshooting/repair of inop blinky lights could be as simple as remove/replace.

Just a thought, hope I'm not too far out of line.

[junglesmacks]

I've been following this thread, as with many others, and this will be an amazing contribution. It may be somewhat presumptious for an outsider to weigh in, but may I offer some observations?
1. While I haven't been to the playa, I've spent some time in areas with harsh conditions. The rule of thumb is "KISS" - keep it simple, stupid. Anything that is challenging in your garage/shop will verge on very difficult once out in the desert. Absolutely and I agree. I'm trying to keep this as basic as possible but still within the technical realms of what I artistically want to acheive, believe me.
2. It's been awhile since basic chemistry, but helium (I'm assuming helium is your choice?) is one of the smallest atoms in existence. It's small size is why even mylar balloons go limp. Trying to stuff electronics in a pressurized container, then sealing the helium-filled container, will be a logistical/maintenance nightmare. Yes and no. The electronics would be inserted prior to inflation, then the balloon filled, then cinched. Think about how you tie a balloon normally with pinching it off while you tie. Remember also that the necks of these balloons are large.. about 1/2" in diameter before you stretch them out. It really wouldn't be that bad, but it looks because of the heat issue that a better solution is to keep the LEDs on the outside of the balloons shining inwards.
3. It's been equally long since basic thermodynamics, but the temperature differential on playa borders on extreme, which, coupled with wind conditions, will likely cause the balloons (And the sealant used) to flex repeatedly, exacerbating the helium leakage. Extreme really is relative. For example, I live right now in Central Florida where the summer days are easily near 100 with 80% humidity. These types of balloons are built to withstand extreme winds and temps being as that they are heavy duty and made for more permanent installations and I've seen them myself get whipped to hell in the crazy summer thunderstorms here and also withstand the heat. Now, the cold nights to hot days could be another issue. I do hear what you are saying about flex and helium loss. We've found some coatings to increase the life of the balloons.. see the previous postings. Also, being as that they are HD outdoor balloons, the manufacturer is claiming a 5 day retention on the helium without any additives. We figure with the additives we could get 7.. hopefully! All we can do is try.
4. The idea of a "light tube" with a T for re-inflating the balloons is outstanding, but somewhat challenging in a desert environment. What isn't challenging in a desert environment? Really it's no biggie. It would involve simply filling the balloon and temporarily cinching it off while the tube/LED module was put into the neck and secured. How to secure it with that much pressure though could be challenging and something that would have to be tested here at home before being brought out there.

Would it be more effective to place your lift balloons in a separate net, secured to your cable, separate from your electronics containers? Not following this part? The LEDs need a couple of things to make them work right, and those small embedded eletronics need to be in the immediate vicinity on a small PCB: The WS2801 IC and 3 small switching transistors. This small circuit board would be about 1"x1" or so max.. You could still use opaque white balloons filled with air to house your blinky lights, which gives generally similar artistic effects, while keeping your hoisting mechanism separate from the visuals. Re-filling hoist balloons would be simpler, and troubleshooting/repair of inop blinky lights could be as simple as remove/replace.

Just a thought, hope I'm not too far out of line.

Hello! Thanks for weighing in! Contributions are very welcome. I've responded in red to the above quote..


Basically it all comes down to testing testing and more testing here at home to figure out what works and what doesn't..

[illy dilly]

Would it be more effective to place your lift balloons in a separate net, secured to your cable, separate from your electronics containers? Not following this part? The LEDs need a couple of things to make them work right, and those small embedded eletronics need to be in the immediate vicinity on a small PCB: The WS2801 IC and 3 small switching transistors. This small circuit board would be about 1"x1" or so max.. You could still use opaque white balloons filled with air to house your blinky lights, which gives generally similar artistic effects, while keeping your hoisting mechanism separate from the visuals. Re-filling hoist balloons would be simpler, and troubleshooting/repair of inop blinky lights could be as simple as remove/replace.

This actually isn't such a bad idea, something to keep in our back pocket, if we can't find large white-ish semi-translucent balloons. Most of the big ones I'm finding are opaque. I say that for now we stick with making our lighted balloons, the same as the lift balloons. But, if we have to, keep in mind using 3 or 4 really BIG "lift balloons", and like 10-15 smaller "light balloons". Though, I hear what your saying about the 1"x1" not necessarily fitting into a smaller balloon. We could always use condoms?
Might follow the fertility theme just a bit better, lol.

As for the expansion/contraction causing helium loss... I figure we're going to need to rent a big ass helium tank anyway, so we might have to refill once mid week?

[melodiousdirge]

This sounds like a very cool project.

Sorry if I missed it - but do you have a link to the balloon supplier? I'm thinking of a project myself that will require one or more heavy duty helium balloons. Thanks!

[Bob]

A few thoughts from skimming the thread --

It will "kite", even on a short line, so operate in a lateral space you can control. Things will break. Needs an operator, not a hippie. Respect BRC and its airport's airspace.

Talk to large kite people re: reels, line, forces, etc. Use your public library. The Usenet froup rec.kites used to be a good resource, mostly spam now, but you can still access an FAQ and archives here and there on the internets.

Make friends with marine suppliers in your area. Kevlar is lighter than steel. Careful with used equipment.

Re: hanging things inside, consider tethering via a "whipping" type of knot at the *tip* of the balloons, insert electronics attached to a length of monofilament, inflate and tie off at the top.

That raggy looking floating island thing (aka "Is Land") along the Esplanade in 2011 might be an object lesson in what to do, or not. Contact info for it and other balloon projects are here:
http://www.burningman.com/installations/11_art_honor.html

Wish this thread were in the Q&A topic area, might be more generally useful.

[AbundantChoice]

you can do some very, very cool things with balloons, LEDs, and little power winches:



Clearly something like this or this complicated would die a horrible death in the exposed playa, but consider potentially adding some sort of motion?

[inog]

I assume you are aware of the balloon LED's generally available. Just google LED Balloon Lights. These are made to be dropped inside a standard 12" - 16" balloon and then inflated.

You can bulk in 200 unit lots for about $0.60 each.

Best of luck!

[michazonders]

I am a professional balloon artist and experiment a lot with battery LED and how to rig them.
http://www.artistballoon.com and http://www.michazonders.com

just saw this!!! It is not real, but digital video...
http://creativity-online.com/work/asics-launch/26078
I specialize in putting LED inside smaller helium filled balloons.To not litter the environment I release the sculptures I make, but keep em connected to a fishing rod or something similar.
It is really beautiful. Getting it back in is just as much fun.

I also play around with Motion sensitive LED. By touch, they light up.

Also, I think I have many ideas on how to get wires through a balloon and then close the hole without it leaking air.
currently I am working on a project using giant banner balloons and get a LED hose through the balloons and make big sculptures out of them.
the dog in the following picture is made with these balloons.
https://picasaweb.google.com/lh/photo/d1pANnfW969R6mfoKs1xmtMTjNZETYmyPJy0liipFm0?feat=directlink
I succesfully drilled holes in the balloons, got the hose through, closed the gaps and filled it with air.

Let me read through the post so I can react on some posts.
which people are on board of this project?

[michazonders]

Also,

as living in europe, I have a close line to the manufacturer of the 6" heavy duty balloons...
in this 4 minute film you see some of my work on an indoor festival...
Are these the balloons you guys are all talking about ?
http://youtu.be/3eAF_tunEJc at 3m12s

cheers micha