Key Man wrote:Very impressive and nice work! You've got me thinking about doing something similar (albeit on a smaller scale) next year.
Thanks so much for the kind words! My feedback is that every single last little bit of blood sweat and tears you pour into your lighting project will be worth it once you get to the playa. Go big.. VERY Big. Take what you are dreaming now, and multiply it by 5 or 10 times. Do it! You have the time! The gratitude and amazement by fellow atendees will blow you away. I'm more than happy to help with any and all things LED/electronics that I can as are others on this board. Let's do it!
Key Man wrote:Just a couple of quick thoughts. The resistors are wasting a bit of power. Not sure what your running voltage is, but couldn't you wire it with LED's only, in series strings with the LED voltage drops equaling the source voltage? Might be simpler that way, too.
While the resistors are indeed wasting a little power, it's nominal and needed to keep from burning out the LEDs. Look at the beginning of my post where I explained the battery pack and subsequent source volatage that I'm using. Typically, you will find battery packs in the 3v or 6v or 9v range as this would be either 2 or 4 AA or a single 9v battery (1 AA battery = 1.5v). So my choices were pretty much limited to a source voltage of either 3v, 6v, 9v, 12v, 18v. Being as that I was going to do 5 x 15 rows of LEDs, for the ease of soldering the chains together I would do one resistor per chain of 5. Since green or blue LEDs need 3.2v per LED, this would mean that I needed 16v per chain to run them. So, 18v was the best option. Since I knew my source voltage and the forward voltage per LED, I could plug those into the wizard via the link that I posted to find the proper resistor value. Very easy. Keep in mind that while resistors do dissapate ("use") energy, they mainly just slow the flow. Kind of a technical discussion. Check out this link for a quick synapsis: http://www.candlepowerforums.com/vb/sho ... uot-energy
Now.. I'll tell you this much. I ran them at 15mA forward current initially with the 150 ohm resistor per string, and oh my god they were BLINDING when all put together. For individual LEDs on the playa, sure go with 15mA. But if you are making huge groups of them together you will be downright obnoxious if you don't town them down. I actually made little inline plug-ins using 300ohm / 1/2 watt resistors per channel to tone the whole thing down. So essentially, I actually was running a 450 ohm resistor per channel instead of a 150 ohm.. and I was so bright that people from over a mile away were seeking me out on bikes thinking that I was an art installation! This means that I was really only running those LEDs at around 5mA per LED!! Also.. I never changed batteries even ONCE.. and still have plenty of juice in them leftover after the burn.. and they are still so bright that I need the resistor packs. Seriously. Next time, I'm using a pair of 9v snap type batteries to save weight. I really didn't need to cart around 12 AAs with me all night.
Key Man wrote:Also, you might consider litz (fine fabric woven) wire for the interconnects. It will bend and flex over and over without breaking. It's a pain to solder (some kind of mini crimps might be easier and faster) but it would reduce your breakage issues and might make the costume more comfortable.
The weak point on this wasn't the LEDs twisted together, it was the summation of all the ground and positive wiring along the edges. In hindsight, I should have used say simple solid core 22AWG hookup wire just spiraled around it and soldered to it as a base. This is what would crack and break each night from flexing and bumping into stuff while partying. The twists on the LEDs held up fine.. it was just those long chains of ground with the pins bent over and soldered together. In TRUE hind sight, the base of becoming a weak point was using fabric squares with no rigidity to them as the basis for a panel of so many LEDs. You need something rigid, as not only do they flex but the LEDs bend over and you are always straightening them and stressing over it. Ideally, you need to solder them to a PCB. That is exactly what I am doing for next year. I'm talking now to PCB manufacturers and having custom PCBs made up that I can solder all of the LEDs and resistors to it. You could also just get basic breadboard/greenboard and solder jumpers and traces yourself.
Key Man wrote:But these are just ideas from afar, you know your project much better than I do. Congrats on conceiving and bringing it to life! Very nice, and wish I'd seen you on the playa.
Again.. you and everyone and the entire playa is so very welcome and I'm honored to have brought the gift of lighting to the playa. I'm pleading with the whole community on this one.. PLEASE BRING MORE LED LIGHT ART TO THE PLAYA!!
We need more! More!! LEDs along with fire and neon are truly what bring our night cityscape to life. EL wire is worthless and so expensive. You can't see the stuff farther than about 30 ft, and chemical glow products are HORRIBLE and make me want to gag. You can't see them and they are nothing but pure global MOOP. LEDs are cheap as anything.. easy to work with.. and you can make such incredible designs with them so well. Poke some through your backpack, jacket, skirt, hat.. whatever.. wire them.. attach a simple battery.. and voila! Instant, custom night art that you can see for miles. So awesome.
If you don't feel like dealing with resistors, you can even buy strings of lights or individual lights with resistors pre heat shrunk on already such as this: http://www.ebay.com/itm/B-50X-5mm-pre-w ... 5d3052fab3
All you would need is just a battery pack that matches.. you could even run these off a simple 9v snap battery. Get the harness from like here: http://www.allelectronics.com/make-a-st ... ers/1.html
It's soooooo simple.. it really is!HOW CAN I HELP YOU DO THIS?