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Igniting a Programmed Fireworks Display?
seg9585 asks: "I am interested in setting up a programmable fireworks display this New Years, and I was wondering if anyone from the Slashdot community had any advice as to how to set one up easily, inexpensively, and safely by someone with little experience with electronics/wiring. I do have a VEX controller which I can use for digital output, but I would rather not have to buy a ton of relays and create a spark by just shorting out the circuit. Is there a better way to do this?"
I'd suggest getting a professional to do it or having a professional teach and supervise you. Fireworks are essentially explosives so I'd be very cautious.
"When you sit with a nice girl for two hours, it seems like two minutes. When you sit on a hot stove for two minutes, it
I have a solution, but it involves midgets, whipped cream, and a tazer gun. Email me for info.
Have you considered using model rocket engine igniter? They're cheap, powered by electricity, and provide a decent flame.
Also, I am in no way liable for whatever you do here.
You could try using the igniters used in model rocketry instead of depending on a spark. They come cheap and are available at almost any hobby shop. They require only a low voltage current to ignite, if I remember correctly. Should be easy to burn a few to determine average timing delay, and then set up a timing script to control the display. Although I would definintely recommend going the professional route if you have any doubts at all of your competencies.
The rocketry community has had this under control for a long time. You can buy commercially made igniters for about $2 each that will fire nearly instantly with the application of a 12v power source. You can also buy (or make) low voltage igniters (called e-matches) for about the same price. In the US, you are required to have a Low Explosive User Permit(LEUP) to buy/store/transport e-matches but if you make them yourself and use them on your own property, then you only have to store them in a type-3 magazine (a good metal ammo box lined with 1/4 plywood counts as a type-3 magazine) In a pinch, you could use some 31 gauge nichrome wire that is connected to a 12v source but that will take 1 or 2 seconds to heat up.
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I had a friend who was a professional pyrotechnic for many years. On a job for a small new years eve festival something went wrong with the setup and he was killed. This was someone who had years of experience doing this, and was working with a group of other people who had been doing it for years. If you really don't know exactly what you are doing, the chance of you not only hurting/killing yourself, but others is there.
The sky above the port was the color of television, tuned to a dead channel...
There was a television special once - you know the kind, Discovery Channel or TLC or some such - on some fireworks experts. They were putting together a big display, something like the Washington, DC 4th of July fireworks, to be accompanied with some fancy-schmancy concert. After all the choreography business, and setting up the pyrotechnics, they wired it back to a control panel.
Now, this control panel wasn't actually your typical doohickey with buttons. It had a rows upon rows of exposed metal contacts (little stubs of wire sticking up vertically), and the guy in charge would activate them, one at a time, by touching them to a little hand-held device that I assume was wired up to the ignition current. I think he even had sheet music.
At first I wondered, "how disappointingly low-tech". But consider: you're dealing with pyrotechnics here. If it just takes a little current to ignite the high explosives, then you really don't want to hook everything up to an electrical circuit, microcontroller, electronics, any of that business. You keep the circuit open, until you're ready to close it. And if something goes terribly wrong, you really, really don't want anything to keep igniting rockets until you push a button to turn it off. You want to be able to just stop.
In summary, hands-free control is just not the way to go when dealing with pyrotechnics.
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Funny, I was going to post the same response to the thread about midgets, whipped cream, and a tazer gun.
My first attempt used a TINI controller board hooked up to relays hooked up to model rocket igniters. This worked well, but relays are expensive and don't scale well if you want to do this on the cheap.
My next attempt used a Freescale GP32 controller with MOSFETs. This worked very well, and is a more scalable solution. Again, I used model rocket igniters. If you look at my pictures, you can see how I made a nice set of firing racks, too, complete with power distribution scheme and chainable serial control. I wrote a program in Java to send control signals to the controllers to shoot the shells off in sequence.
After these attempts, I finally got sick of playing with the small stuff and got my explosives permit so I can play with 1.3g display fireworks. When you have your explosives permit, you're no longer limited to crappy model rocket igniters. You can buy professional quality e-matches that are meant for the task. They're a bit pricey, but they already are the right length of leads, and work GREAT. Also, the larger shells are MUCH easier to electrically fuse, since they use quick match instead of visco fuse. But, no vendor is going to sell you those nice e-matches without first seeing your LEUP. (Low Explosives User Permit.) That takes a bit of work to get, so I'll assume that's beyond your scope. Of course, there are also professional systems available for control, but they're pricey.
So, I'm going to take a guess that you don't have a LEUP and just want to hack something together to shoot off your 1.4g consumer fireworks. Here's what I've learned from my experience doing the same thing. It's not that tough to do, but don't underestimate the amount of wiring you have ahead of you if you intend on shooting off more than a few shells. With only a few weeks from new years, you'll probably get a more impressive display by buying several nice cakes. But, since that's not the slashdot way, here's how you can do what you want to do...
Please be safe about this! It's a ton of fun, but observe sensible safety precautions. I highly recommend taking a class on display fireworks to learn how to do all this right. Premier Pyro gives great classes on this every year, and you'll have tons of fun to boot. At the very least, give NFPA 11
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>set one up easily, inexpensively, and safely
Pick any two.
You might also want to be thinking about your last words for your friends to remember you by. Some of the more popular choices from previous Darwin Award winners are:
Have a friend shoot the video from a safe distance for your In Memoriam web page.
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