Project help needed ..very very simple for the lot of you probably.

[fotoobscura]

Hi.

I am building a large nighttime art project on the waterfront where I live in Burlington, VT.  It requires very, very bright led's encapsulated inside waterproofed plastic bubbles.  The distance from the viewer to the bubbles will be at the very most 300m but perhaps more.  The brighter the better.  I am wondering what sort of circuit I will have to build for this.  The bubbles will have to be fabricated beforehand and as such the battery + led will have to remain on for some weeks. 

I am under the impression that blue led's are either a) nonexistent or b) hard to find.  I am looking to use blue led's preferably because I am under the impression that blue is the most sensitive color to the eye and as such will travel further and design this piece of art better.  I prefer not to use red but white led's (lightbulbs?) are fine if blue or violet are nonexistent or too expensive, etc.

I know my soldering and can build very, very basic circuits but cannot read schematics too well.  I can learn, of course.  My initial thought was to basically solder a battery to an LED but i'm sure thats just way too easy for it to work  

Thanks for all advice, tips, etc.

View attachment 37038

 

[EdwardM]

Hi fotoobscura,

interesting handle and even more so project.

If I can throw my $0.02's worth in, my first thoughts are that a series of 4/5 LED's+resistor+battery could be put in per bubble and could have a lifetime of several weeks, but I think that at the ranges involved, the LED's will do little more that mark their own positions and not provide any sensible amount of illumination for the artwork.  An alternative but more expensive solution would be to have a battery + inverter + small fluorescent light per bubble.  The light output from fluorescents being much greater, could be greater still with a reflector 'behind' the fluor., Iguess this could be arranged because line of bubbles is effectively fixed and a small weight fixed underneath each would provide a 'down' direction.  Is the budget huge enough for me to come over? any good hotels?

Seriously, an interesting project and I wish you well with it!

Ed

Forgot to mention: If you go for fluorescents, the bubbles can of course be colored blue 

 

[Alun]

Hi.

I am building a large nighttime art project on the waterfront where I live in Burlington, VT.  It requires very, very bright led's encapsulated inside waterproofed plastic bubbles.  The distance from the viewer to the bubbles will be at the very most 300m but perhaps more.  The brighter the better.  I am wondering what sort of circuit I will have to build for this.  The bubbles will have to be fabricated beforehand and as such the battery + led will have to remain on for some weeks. 

I agree with EdwardM, the LEDs will only acts as indicators and won't be bright enough to illuminate the artwork.

I am under the impression that blue led's are either a) nonexistent or b) hard to find.

They were 10 years ago but they're quite common now and while they still are more expensive than the other colours they're not too expensive.

I am looking to use blue led's preferably because I am under the impression that blue is the most sensitive color to the eye and as such will travel further and design this piece of art better.

No the human eye is the least sensitive to blue, the peak sensitivity is somewhere in the green/yellow band of the spectrum. Having said that blue LEDs are often bright but you can buy much brighter green and yellow LEDs..

I prefer not to use red but white led's (lightbulbs?) are fine if blue or violet are nonexistent or too expensive, etc.

Red LEDs have the highes output but yellow appears brighter as the eye is more sensitive to yellow than red. White is availible and violet exists as well but it's dim as the human eye isn't very sensitive to violet as well as the LEDs not being very bright..

I know my soldering and can build very, very basic circuits but cannot read schematics too well.  I can learn, of course.  My initial thought was to basically solder a battery to an LED but i'm sure thats just way too easy for it to work  

Thanks for all advice, tips, etc.

The normal circuit is just a resistor in series with the LED but you can buy switching regulator chips that are far more efficient.

As per Ed's suggestion of using a small flouresent tube, I don't know, I have a feeling that tubes this small aren't as efficient as LEDs but I could be wrong.

 

[EdwardM]

Hi again fotoobscura

having thought a bit longer about it, this may seem a bit obscure, but I'd  be tempted to look at this from the other direction and that's to work out the light level needed at the artwork to illuminate it as required taking into account any sky illumination, street lights and building lights - this also depends on the reflectivity of the artwork itself.  If you can get to a figure for illumination/contrast required then you should be able to work backwards over distance x and work out the distributed source illumination which will finally give you a light density requirement and thus the type of lighting available to satisfy it.

As I said, a bit obscure

Best of Luck

Ed

 

[fotoobscura]

Thank all of you VERY much!

So fluorescent sounds the right way to go!

Perhaps white fluorescent bulbs with a regulator and a battery on a tiny board?  I'd like to either use white or blue...Price is not a concern, but time is..sort of (entire project which contains much more than the electronic part) needs to be done by August at the latest.

What sort of bulbs am I looking at for brightness?  This circuit will need to fit into a 45mm plastic "ball" and will be permanently sealed after it is turned on.  The distance is what i'm concerned about.  I can do tests with various voltages and bulbs..

If its of any design significance I will have several *thousand* of these strung together (unknown so far the distance between each) so perhaps others that mentioned the led's wouldn't be bright would be actually bright enough as result of the sheer amount of led's in the water.

Thanks again ...the response in 8 hours was amazing!

Alex

 

[fotoobscura]

P.S. to ED:

You have some great points.  All lights that are on will be turned off on the path by the city and will remain off all night.  There will be a faint amber flow from the rear of the viewing area but for the most part it will be dark.  Of course providing there is a full moon which in case will cause a big, big problem   So i'll be checking the phase of the moon in a few minutes for that date

Alex

 

[Alun]

How big do you want these plastic bubbles to be?

I assume thes bubbles will be imersed in water possibly floating - is this correct?

If these lights will be floating in the water theb you'll need something (like rope) to stop them floating away. You could power them of a car battery or the mains if a power point is availaible and then use the cables as ropes to stop the lights from floating away.

One idea would be to build an inverter to power the flouresent tubes which will be powered from standard balasts.

It all depends on what you want to do.

ps.
Flouresent lamps always work off high voltages the mimimum starting voltage is about 100V and this could be a safety hazard especially around water. If you run it off the mains or even an inverter (depending on the output power and frequency) you'll need to us a safety device called an RCD that will shut off the power if an earth leakage occurs.

 

[audioguru2]

Hi Obscure,
You won't be able to fit a car battery into a golf ball. Besides, if you do, it would sink. :

Seriously, you are talking about power from nuclear batteries that you need to steal from a roving spacecraft or UFO.
You must be tethering the bubbles, so send land power down the tether cable.

I doubt that you'll find a flourescent bulb small enough to fit into a golf ball. Go to www.lumileds.com and look at their Luxion extremely bright multiple LEDs. Also notice how much power they consume. ;D

 

[Alun]

Hi Obscure,
You won't be able to fit a car battery into a golf ball. Besides, if you do, it would sink. :

I wasn't talking about having the car battery in the bubble ;D, I meant  to put the battery on the bank and have a cable going out to the lights.

Seriously, you are talking about power from nuclear batteries that you need to steal from a roving spacecraft or UFO.
You must be tethering the bubbles, so send land power down the tether cable.

Or you could be smart and use the radation from a radioactive isotope to excite a phospor and give a very bright light. ;D

I doubt that you'll find a flourescent bulb small enough to fit into a golf ball. Go to www.lumileds.com and look at their Luxion extremely bright multiple LEDs. Also notice how much power they consume. ;D

Golf ball?
You think too small, I was thinking foot ball sized. ;D

 

[fotoobscura]

I'm sorry what I thought about fluorescents were that they would be fluorescent "type" bulbs but small like regular lamps..perhaps they don't exist? 

They need to fit in a small ball that is 45mm in diameter.  I was thinking, perhaps naively, that I could fit a bright light and a battery inside such a small enclosure.  Is this perhaps inaccurate?

I am not wholly comfortable with my electrical skills to float (accurate, by the way) these balls through a constant source of electricity from one shore to another.  I suppose it would save me a whole lot of individual batteries but I was envisioning a battery, resister, bulb/led/of some sort in each ball and then separated by a thin filament wire x distance.

Something like that, i'm still solidifying the idea.  Primarily based on what you folks say

If I haven't already mentioned i'm talking about several thousand lights that *must* bob in and out of the water.



Thanks!

 

[audioguru2]

I'm sorry what I thought about fluorescents were that they would be fluorescent "type" bulbs but small like regular lamps..perhaps they don't exist?

I have never heard of a small flourescent bulb.View attachment 37040

 

[EdwardM]

Stand-up all those who've never heard of small fluorescent bulbs, shame on you  ;D

Imagine a regular bulb, about 3 ft long, now scale it down to about 4 inches, these are sold as backlights, interior illumination for cars and as part of some flashlights and for other purposes.

Ed

 

[audioguru2]

Hi Ed,
I've seen 4 inch flourescent tubes on night-lights and 3-way flashlight toys  at the dollar store.
Their small amount of light output illuminates things only a little when up-close. they are more than twice too long to fit in a 44mm golf ball. ;D

 

[Alun]

fotoobscura,
How are you going to stop the lights floating away?

Just use an external power source as I said before, the cable could be used to secure the lights in the position you require , if flouresent tubes are too big then use one of those LEDs audioguru suggested. I think this is the only way you'll be able to achieve anything near what you want.

 

[EdwardM]

Hi All,

hate to labour the point but I will  ;D

http://www.titoma.com.tw/energy_saving_light_bulbs.shtml , one example of many, the link describes a small 12v fl bulb, whilst I doubt that it would fit within the size/power/illumination constraints, I'm not sure that the other possibilities will either, roll out the flood lights.

Btw, I can remember being hyper impressed some years ago when I first came across fl light as car interior illumination, knocked everything else into a cocked hat.  8)

Ed

 

[Alun]

How many of these do you need,the minimum order is 1000 pcs. I suppose you could always buy a load use what you need, then flog the rest on ebay, you might even make a small profit. ;D

 

[EdwardM]

Hi Alun,

guesstimating the distances involved from fotoobscura's original post, I'd think the min order qty wouldn't be a problem.

ebay sounds good afterwards  ;D

Ed

 

[audioguru2]

I've never seen those tiny fl bulbs that have an inverter inside. Look at their high cost.
I figure that a few thousand would draw about a thousand amps. :

 

[EdwardM]

Hi fotoobscura

there have been a lot of interesting suggestions arising out of your post, as a finalish one can I suggest that you try to get your local university EE department interested, because of the range of research/disciplines involved I'd have thought they'd jump at the chance, even though I recognise that time is fairly short.  Another possibility is to invite an electronics/similar company to participate - lots of praise and honour for them.

Best of Luck

Ed

Audioguru, agree high cost but no soldering/electronics, just fit/forget, current consumption will be high - there are always trade-offs involved  :'(

Ed