help me make a simple fireworks controller

[JBourne]

so this christmas we had got some fireworks and set the off with bbq lighters. it got me thinking why not ignite the fireworks electronically? so i found out there are this things called "electronic matches" and when electric current is applied to them they burn like a real match. you are supposed to tape the "e-matches" to the fuse of the fireworks and then you can set off them electrically.

so what i want to do for next year is to be able to flip a switch and each firework to go off one by one. i figure i will need between 2-7 second delay between each firework (so they dont just all go off at once). my problem is I dont know exaclty how to do this... the picture below is what i have drawn so far, the little blue dots are the electronic matches (to be taped to the fuses).

[Skimask]

Spend a lot of time on that did ya?

[JBourne]

hah, well i drew  that in photoshop just quickly as i could. i dont have any other program to draw circuits with. i think i will need some sort of programmable chip, but am hoping someone will tell me which one and how to hook it up.

[Skimask]

There's only tens of thousands of different ways to power this idea.
There's only hundreds of thousands of different microcontrollers, programmable chips, analog circuits, or otherwise, ways to drive multiple outputs.
There's only a million different ways to drive those outputs.
There's only one piece of required reading: http://www.catb.org/~esr/faqs/smart-questions.html

[JBourne]

i understand there are lots of ways to do it, but i am looking for the easy way (for someone to give it to me on a silver platter)

[Bored@Work]

for someone to give it to me on a silver platter

Sorry, we did run out of silver platters.

[Kevin.D]

Here try this .

[Skimask]

  Sa-WEET!
Where can I buy one of those?

[cwalex]

so this christmas we had got some fireworks and set the off with bbq lighters. it got me thinking why not ignite the fireworks electronically? so i found out there are this things called "electronic matches" and when electric current is applied to them they burn like a real match. you are supposed to tape the "e-matches" to the fuse of the fireworks and then you can set off them electrically.

so what i want to do for next year is to be able to flip a switch and each firework to go off one by one. i figure i will need between 2-7 second delay between each firework (so they dont just all go off at once). my problem is I dont know exaclty how to do this... the picture below is what i have drawn so far, the little blue dots are the electronic matches (to be taped to the fuses).

Probably the easiest way would be to use an arduino, some transistors and maybe some opto-isolators. If you have some programming experience you will find the arduino really easy to pick up.

You will need to know the voltage and current requirement of the e-matches. You will also need to learn how to use the arduino to read inputs and set outputs. There are really good starting from scratch tutorials for how to use arduino on youtube. Arduino is very affordable too.

I think you should VERY thoroughly test the thing before you trust it etc and even then probably don't trust it much. I would use a key switch or something on it so no one else can easily arm it.

http://arduino.cc/

[deth502]

where you at? here in the us you cant just go out and buy electric matches. they are regulated just as blasting caps are and classified as "explosives". you need many different licences and permits from the govt just to look at one.

that said, they are fairly easy to make, or you can use the igniters they use to set off model rockets. much more expensive (MUCH more) but easily and readily available. unless, of course, procuring electronic matches is not an issue where your at.

[fcb]

where you at? here in the us you cant just go out and buy electric matches. they are regulated just as blasting caps are and classified as "explosives". you need many different licences and permits from the govt just to look at one.

that said, they are fairly easy to make, or you can use the igniters they use to set off model rockets. much more expensive (MUCH more) but easily and readily available. unless, of course, procuring electronic matches is not an issue where your at.

Off-the-shelf here in Blighty...
http://www.pyrotubes.co.uk/ematchestalonignitors.htm
http://www.easypyro.com/e-match-2m

[AndersAnd]

i understand there are lots of ways to do it, but i am looking for the easy way (for someone to give it to me on a silver platter)

The easiest way is to just buy a readymade Wireless Firing System:

http://www.rfremotech.com/FiringSystems.html

Wireless Firing System
Wireless Radio
For Pyrotechnics, Fireworks Show

I have bought standard wireless transmitters and receivers from RFRemotech (E-MadeinCHN) before. They are cheap and quick at answering questions via MSN/Skype or email.

[Ton]

Next time you feel a good idea for some thing you would like to get on a silver platter tryout the beginners section, you might be lucky to learn some real electronic skills that way.

When you post in projects..... Then we(the users of the forum) expects you to come up with the idea, the major part of the content, including component choices. A good basic schematics or bloc diagram. Then based on this you will be offered good advice on YOUR design choices.

Half arsed sketches like this mostly provoke the worst side in most of us, and you get flack like the above.

So if you are serious and want to learn, I suggest you ask politely for help in the beginners section, but maybe spend a bit of time and define what it is you want, AND how you are going to learn this

Because when you want to learn  we want to help, but we don't provide free design services 

[zapta]

There's only tens of thousands of different ways to power this idea.
There's only hundreds of thousands of different microcontrollers, programmable chips, analog circuits, or otherwise, ways to drive multiple outputs.
There's only a million different ways to drive those outputs.

and there are 10 million different ways that something will go wrong with this idea.

[Skimask]

There's only tens of thousands of different ways to power this idea.
There's only hundreds of thousands of different microcontrollers, programmable chips, analog circuits, or otherwise, ways to drive multiple outputs.
There's only a million different ways to drive those outputs.

and there are 10 million different ways that something will go wrong with this idea.

10 million?
Is that all?
And here I thought it had the possibility of being dangerous or something...

[strangelovemd12]

For those playing the home game e-match=$0.02resistor+battery.

[Skimask]

Is there a Kickstarter campaign for the home version?

[Zero999]

i understand there are lots of ways to do it, but i am looking for the easy way (for someone to give it to me on a silver platter)

The easiest way is to just buy a readymade Wireless Firing System:

It's much safer too.

If you don't know anything about electronics, it's a bad idea to attempt to build something like this b4ecause if you get it wrong, it could set off the fireworks when you don't want it to.

[kolbep]

I am not a qualified EE, so I cannot provide an Iron Clad answer, so what lies below is merely to get you thinking. If you act on it, then it is all on you :

LM4017 Decade Counter (or 2 cascaded together)
Run them from a 555 counter.

Use a circuit similar to :
http://www.technologystudent.com/elec1/count1.htm
Just replace the LED's and Ballast Resistors with the Electronic Matches.

But first play a lot with the LED's (before replacing them).
You will need to make sure that the sequence starts at the right place, and that it does not provide an output pulse at the second the device is turned on, or you could have be a Premature Detonator    (Thanks Achmed).

Of course, you cannot use this type of device in any public place, or for profit,
and there is even a risk using this type of thing in your own back yard,
so if something blows up, or does damage, IT IS YOUR OWN FAULT/RESPONSIBILITY

P

[N2IXK]

I am involved in high power model rocketry, and have built quite a few launch controllers, pyrotechnic initiators, etc.

Obviously, safety is the overriding concern with electronics which control energetic materials of any type. The output circuits which feed the ignitors should have a dual interlock to prevent premature firing. A normally open circuit that prevents the application of power, and a normally closed circuit that shunts across the output until just before firing. Unless both circuits operate, the charges will not fire. You should always have at least one real mechanical pair of contacts to disconnect the power from your system, not simply rely on a MOSFET or other solid state device. A good heavy duty key-operated switch is an excellent idea. Such things are mandatory under rocketry safety codes, and may be for display pyrotechnics, as well.

True electric matches require an explosives license in the US. Model rocket igniters do not. Rocket igniters also require considerably more firing current, and are safer from unintended firing from stray currents, static discharge, etc. Quest sells an igniter called a Q2G2, which makes an excellent, non-regulated replacement for e-matches in most applications. Lower firing current than most other rocket igniters, but less sensitive than an e-match.

[Macbeth]

When I was a kid my physicist mate that we used to play DIY explosive with would use smashed open light bulbs as "fuses". He was richer than me, also they were not as good as hoped having only one element.

Me being more practical engineer that physicist realised using my mums wire wool pan scrubbers cost nothing and also would present many more burning elements than a broken light bulb. Once I perfected my soapy wire wool wrapping between some stiff electrical contacts, we never had a dud ever again, at least not electrically. Plenty of chemical duds though.

I stopped these fascinating experiments when I escaped death by the skin of my teeth, and a high pitched ringing in my ears that lasted two days and partial deafness for a whole week later. 

[alanb]

In my youth I made ignition devices by cutting a nick in the head of  ordinary matches with a scalpel blade and then putting a piece of fine fuse wire in the nick. Providing that the current was sufficient to melt the wire it always worked reliably.

[DakLak]

My employer makes a line of military/commercial robotic products one of which we call Thumper - it's a tossable (small) robot that can carry various options, one of which is a explosives delivery platform.

One version can drop a string of devices that are triggered sequentially, whilst another simply ignites a single payload.

We make our igniters as follows.

1. Using NICHROME wire - between 28 - 36 AWG (American Wire Gauge), 28 to 40 gauge, the smaller diameters obviously light faster than the thicker wire.

2. Locate/acquire a small drill bit 1-1.5MM size OR a small, unwound, paper clip;

3. Using the small drill bit (1-1.5MM), wind the nichrome wire around the bit with 'tails' about two inches at either end of the coil. Before sliding off the bit ensure that the coils are spaced apart. This can be done by winding a loose bit of nichrome wire between the coils to act as a spacer;

4. Place some form of tape (masking, etc) over the tails of the coil then carefully remove the coiled wire from the bit;

5. Using Lacquer Varnish/Dope, or Nail Polish, apply gently over the coils and allow to dry. This will secure the shape/spacing of the coils;

6. When the fixative has dried form coils in the ends of the wires to which you attach insulated cable. Since you can only spot weld Nichrome (we use Nichrome tape) the connection has to be by compression - holding the Nichrome and supply wires together. Twisting is effective also is small diameter tubing, squeezed tightly;

7. With care, remove the masking, or other tape, and slide Heatshrink over each joint and shrink. You could also add an additional, larger diameter, piece of Heatshrink over the two individual joints to secure them together;

8. Given the paranoia extant is the USA these days, when you buy the Nichrome say you are making a heater for your fish, or some other innocuous pursuit such as a Styrofoam cutter. Who knows what excuses the FBI needs to come visiting!

Suppliers include:
Jacobs On-Line < http://jacobs-online.biz/nichrome_wire.htm >

and

Pitsco < http://www.pitsco.com/Nichrome_Wire?SKU=53654& >

As for ignition, a simple sequential system might be best. One would be the 60 LED sequential driver circuit you can find by Googling (or PM me). You will also need a good, chunky battery to power your display. PLEASE include a MASTER SWITCH in the battery feed so you can be SAFE!

Our Thumper accessory is only a single use device, so we use four igniters and a Lithium Battery for our ignition source.

REMEMBER: A little experimentation on the Nichrome wire diameter and the number of turns in the coils will allow you to optimise the system for your application.