Picture of Fireworks Controller
This instructable is on a 12 channel fireworks controller that I built during the summer. It was a lot of fun to build, and is a blast (pardon the pun) to operate! I couldn't find a good quality instructable on building a complete fireworks controller like this one, so I decided to write my own.

The information contained herein is for the sole purpose of information and education. Build this project AT YOUR OWN RISK. I have NO responsibility whatsoever for any injury, death, legal issues, encounters with law enforcement, or damage to property of anyone operating or involved with using this fireworks controller. In no event will the author be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from the use of, or in connection with the use of this firework ignition controller. Look up your local and state laws regarding pyrotechnics before starting this project and make your own smart decisions when it comes to using it.

Fireworks are dangerous, so watch what you are doing and don't do anything stupid with this. Be careful when handling explosives. Clear the area before launching the fireworks, check to make sure your battery is disconnected while wiring up the fireworks. Once again, build at your own risk.

Okay, now that that's over, on to the fun part!
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microman1716 years ago
Lots to read, so sorry if this has been said...

To figure out the fuse value the easy way, build a regular ignitor, and then put an ammeter (multimeter) in the circuit. Battery - - - (Meter) - - - Ignitor. Obviuosly you need to wire the return to negative, but the diagram shows to wire in series.

If the amps needed to make the nichrome (or steel wool) is say, 3 amps, you use a 3.5A fuse. Depends on what you can get.

I don't know why you would use a fuse here...? As long as your wiring and all parts are rated for higher amps (I reckon your wire is probably rated at about 10A).

Worst that can happen is you get a fire at the wool end... That's what you want anyway =)
Oh, and this is a great instructable!
systemf92 (author)  microman1713 years ago
Thank you!
That would be fine as long as you don't try to shoot more than one cue at a time or you would have to determine the maximum number of cues you want to fire at a time.

IMHO you are not talking massive circuitry here, and since the purpose is to blow things up, I wouldn't even worry about fusing it. The most that is going to happen is to inadvertently launch more cues than intended, which is just going to make it a better show anyway, so why bother. If there were an electronic timing circuit, then I could see doing that, or if there was an on-board battery charger that could overheat and short out, but besides that I wouldn't worry about it.
systemf92 (author)  microman1716 years ago
Okay, thank you, this is simpler than I had anticipated! As soon as I replace my broken multimeter I'll get to it. And, you're right. After building this I realized that there was no reason to have the fuse in the circuit considering it's only 12v and not too much power. Next time I won't complicate things. I had planned to just take it off of the parts list and instructions, but figured that that would confuse people when they saw it in the pictures.
cmazzei4 years ago
I work at Radio Shack I put together a parts list for everyone :-)
2300945 - 12v Sealed Lead Acid Battery
2750601 - Safety Toggle (we don't carry keylock switches)
2751533 - 3 Position Toggle Switch
2760079 - LED Mounting Hardware
2751547 - SPST Momentary Push-button Switches (We have a wide array. These were the most cost effective ones at my store.)
2740622 - Four Conductor Speaker Terminal
2701545 - Alligator Clips (Again, we carry many different packs and sizes)
6403058 - Battery Clips (Insulated Female Spade Connector)
2781221 - 22 Gauge Wire (Solid, Three spools: Red, Black, Green)
2700364 - Panel-Mount Fuse Holder (1 1/4" x 1/4")
2760022 - Green LED
2760041 - Red LED
2711115 - 470-Ohm Resistors
2711111 - 220-Ohm Resistors

*Note* We do not carry the exact same LEDs that systemf92 used. I spent some time doing the calculations. I used duncant20196's updated schematic and kept in mind systemf92's safety precaution with running the LEDs at a lower amperage. The 220-Ohm and 470-Ohm resistors would be paired up. Let me know what you think!!
What's the price? i want to do this project but i am on a pretty tight budget. i would also be willing to downsize on the number of channels.
I believe that list ran about $135. If I had planned ahead I would have ordered the stuff direct from East Asia for a third of the cost but I didn't stumble across this until a couple days ago. If you use FourSquare on your phone you can get 20% off of your purchase with your first check-in.
hhhdrb cmazzei3 years ago
wich ohm gets linked to led does it matter 470 0r 220
cmazzei hhhdrb3 years ago
I'm pretty sure it doesn't matter but I hooked the 470's to the LEDs. Resistors can be linked in series in any order. The total resistance of each series is just the sum of each resistor.
mmike1 cmazzei4 years ago
Hi I love Radio Shack but the employees at our local store are not nearly as technology inclined as you are. Could you transfer to the Katy, TX store plz.
cmazzei mmike14 years ago
Haha well tell them they better get on point...our headquarters are in Texas!
rankhornjp3 months ago
Great instructable! Im going to give this a shot.

Changes i would make are: 1)put the "test" lights where i could see them during hook up. It would prevent a lot of back and forth, and 2)put the key switch behind the toggle insted of in front of it (only key the "arm" circuit). That way you dont have to worry about someone switching it to arm while you are fixing a connection and setting something off.
Indyitguy4 months ago
If I want to use nichrome wire rated for 1.64ohms per foot what size resistor should I use?
Indyitguy4 months ago
If I have nichrome wire rated at 1.64ohms per foot what size resistor would I need?
Matt_Gambit4 months ago
I don't want to use those buttons to make it, what on-off toggle switches are an acceptable substitute as well as what would I need to do different to make it 10 firing switches? Thanks in advance
Dudley556 months ago

Thanks a Ton, I have been trying to make one (more like just designing) for quite a while now.

CCube551 year ago

how many watt do the resistors have to be?

So, I finally built my controller! It is a 20 channel version. I wired everything up correctly, but the leds don't light up at all. I tested the connections a little with a multimeter, and there is no current flowing in between the leds... What could I do?
Hello! Why is it that my leds glow very dimly with 2 or even 1 470k resistors? Please reply rapidly! Thank you!
r u using a 12v battery??
I'm setting mine up to use RJ45 connectors to Rail-8 units from Pyrosure. I'm using bi-colour LEDs. Can anyone tell me if this schematic will work?

It looks great, might have a go with that myself if you dont mind haha
mbragg11 year ago
Hi, I am using 30m of Speaker (13 strand) wire from the control board to the fireworks and when i ignite them the firework goes off but the Red LED only fades it doesnt go off, so can i use a bigger battery to push more power to fully burn the ignitor or will it blow all the LED's??? PLEAS HELP THANK YOU!
mbragg11 year ago
Hi, I am running 30m of speaker (13 strand) wire and when i ignite a firework it lights and gets fired but the LED stays on why is this? Could i use a bigger battery to push the power further down the wire or will this Blow the LED's?????? PLEASE HELP THANK YOU
Kitboga1 year ago
This will go great with my homemade fireworks. I've been learning how to make fireworks from this cool resource: How expensive do you think it is to gather all the parts I need ?
RJCo1 year ago
Hi, I'm building a 24 channel version with my son. You've probably solved the fuse issue by now seeing as this is a couple years old but here's my take.

Ohm's law (Voltage=Current x Resistance) dictates running 12V through your 940 Ohm resistors produces a current just shy 13 mA, enough to light your LED but not ignite the steel wool. (I read an FAA article somewhere that says the lowest amperage to ignite steel wool is 45 mA...). That's good for your test circuits and such, just what you want.

Running the same 12V through the circuit without a resistor (when you fire for example) puts extremely high current through it since the resistance is only that inherent in the wiring (which in theory is supposed to be next to nothing). This would explain blowing the fuses given your set up. Yes, in theory the circuit should break when the match ignites and the steel wool gets ignited dropping the current to zero for that channel, but IF for some reason it doesn't (who knows what? stranger things have happened...) the heat build up in the wiring could have some serious effects (i.e. blow up the battery potentially). Putting a 1.5 Ohm resistor (say between the fuse and key switch) would drop your current to 8A and allow you to use a 10A fuse and still produce enough current to ignite the steel wool.

If I've misstated something, someone please chime in and let me know.
roverman2 years ago
A great cable would be irrigation wire for sprinklers it has a ton of conductors
If you need a battery charger this one should work:
how do you charge the battery
adcurtin2 years ago
two things: I'd just use a 1k ohm resistor. Why waste time and money using 2 instead?

second, it is only 12v, but you are using a fair amount of current. an SLA battery can provide 10+ amps. Definitely worth having a fuse. I used some SLA batteries (a bit bigger than you use here) that were rated for 80ish amps output.
pyro_cat2 years ago
The test setting sends a low voltage current through the circuit to check continuity without supplying enough voltage to ignite the electric match.
Thanks sooo much im 13 years old and i manged to make this with ease thanks to you ill upload some photos of it later if I can.
Thanks again,
dema12co5 years ago
Just looked at this and thinking of making my own, I saw you used two 470 Ohm resistors on the LEDs though, the Lite-on spec pages call out 2.6V and 30mA max, which would be a 330 Ohm max resistor. Was your LED circuit setting off your charges or was this just a mistake in the calcs?
systemf92 (author)  dema12co5 years ago
Right, I decided to not run the LEDs at max output all of the time, so made the calculations based on them running at 20mA. Also, just to be safe and reduce the chance of there being enough power running through the ignitor. It was just a precautionary measure, and I do not know whether using 300 Ohm resistors would set off the charge or not.
Why did you decide to use two 470 Ohm resistors in series on each side and not just a single 940 Ohm resistor? (or one close by to that value)
say it if i'm wrong but if you flick the arm switch there goes a current through the igniter?
Does this current ignite it?
samirsky2 years ago
Will standard (Estes) model rocket igniters light the fireworks?
yaly4 years ago
In picture no.6 what is the thing from radio-shack on the top left? is it a pair of wire cutters?
Not sure... I got one in my soldering kit but have no idea what it is.
jtho3463 years ago
I just made this by following your instructable this afternoon and was so disappointed when I got done. I was tired and my neck hurt from looking down soldering, so when i found that it didn't work, i was sad. I was just about to go to bed and try again tomorrow when i realized that i didn't put any test leads in the speaker terminals... turns out it works! awesome instructable! Thanks so much!
Cool! You should enter the R/C Contest!
molyneaux4 years ago
can you send me a list of all the parts and where you get them
I bought all the parts I needed on ebay. I've got around $100 in leds, switches, battery holders, ribbon cable, and everything else. I also set mine up where the test feature will only use 3v. to check it and will use 12v. when it is going to activate the cues.
Try Radio Shack....... also is a good place to try but if you don't live in the United States idk where to send you
 How do you make the actual igniter? and how do you attach it to the electric igniter?
systemf92 (author)  ak47bobbarke5 years ago
Check out my other instructable designed to use with this one: Fireworks Igniter
Attach the controller to the igniters using two conductor speaker cable. This is described in step 5 of the above instructable, Using the igniters.
pittu systemf924 years ago
how much can you ignit in series in a single channel.
systemf92 (author)  pittu4 years ago
I wouldn't recommend series ignition hookups because of the nature of series circuits: The first ignitor that burns up will most likely be the only one that will light. As soon as it burns up, the circuit breaks and none of the other ignitors on the circuit will continue to heat up.
I posted previously that I was going to use RJ-45 cables, but after checking pricing I decided to go with a 100' 25 pair cable between the controller and the first box at the distant end. Then, on the box at the distant end I'm going to split out the cable, using wires 1 thru 20 as the hot leads and 21 through 25 will be used to provide the ground. Wires 1 and 21 would control cue 1, wires 2 and 21 would control cue 2, wires 3 and 21 would control cue3 and so on. On the controller you would have a rotary switch where you would set it to control which cues you wanted to activate. Position 1 would control cues 1 through 20, position 2 would control 21 through 40 and so on till you get to position 6 of the switch where if selected would feed to a second rotary switch that would control cues 101 through 200. You could gang a whole bank of rotary switches and add an unlimited number of cues that could be controlled. When I have it finished I will post an instructable on making it. Sounds confusing, but really it isn't.
Mr.KC4 years ago
I built a 15 channel controller last year based on this design. It worked beautifully! However, this year it's not working. The lights light up but when I press the button, nothing happens. There's enough juice in the battery because if I bypass the controller and connect the lead to the battery, it works. I looked and I can't seem to find any loose connections. Any help?
pdionne Mr.KC3 years ago
Have you changed the battery? Also, if you are going to test the battery with a voltmeter, make sure you either load it down with a resistor in series with the battery or leave the battery in circuit and test it with the load applied. Sometimes batteries will test fine without a load, but when you put it under load it fails because the charge is not good enough to maintain the voltage under load.
using a voltmeter can help you determine your problem. just start at the output and work backwards until you find where your losing the voltage.
Aron3133 years ago
WOW thats a nice board! Haha i use my cell phone to light fireworks! :D
pammi.roxz3 years ago
hey i wanna do this project...

what is the AIM of this project..?

and what is the USES from this...plz replay me as soon as possible..!

Damnn good project dear
Ebay5 years ago
Where can I get a case like yours?

docsmith Ebay3 years ago
Check out Harbor Freight item no. 35777. Low cost, I'm putting one together now, and it looks really promising.
Ebay Ebay5 years ago
Ok. Cool, Thanks
you could do what i did and use a Deal or No Deal case form a cheap game at Walmart
systemf92 (author)  Ebay5 years ago
I found mine at a resale shop, you might want to check around some places like that. Resale, goodwill, pawnshops, etc. I have heard that buying aluminum cases like these brand new is expensive. You might want to try looking for cases that are for specific products (i.e. because they seem to be cheaper than general purpose aluminum flight cases. Of course, you'll have to cut out whatever random molding it might have inside. Hope this helps, and best of luck to you on choosing a case!
does it matter what side the resistor is on the LED? also, i would have thought the resistor would go on the positive side if it did matter.
As a rule, I try to put all my resistors, diodes etc on the negative leg of components. It makes debugging a circuit so much easier.
systemf92 (author)  airsoftjunke5 years ago
no, it does not matter what side of the LED the resistor is on.
pastaking3 years ago
I. Want. One. Now.
dceljo3 years ago
oohhh i know tha they are 470 ohm resistors from the colors and you mustnt answer me.

good project and i made one like this, thanks
dceljo3 years ago
pls can you answer me what are the resistors are the resistors what you put in the 470ohm resistors because i dont know.

DjProToJeeX4 years ago
Ya so we were lighting off fireworks with this with our permit. An Apparently this is considered a bomb detonation device and requires i think he said class 3 pyro license or a class 2. Ya so regardless it was taken and we all got 2,000$ tickets and our names taken for homeland security. This will most likely be classified as a destructive device since it was hooked up at the time they were correct. So basically get your class 3 license to do it. now i have to go to court and use the instructables said it was ok to make defense and didnt say it was illegal to make. also this may vary state to state. or depending what country i live in WI, USA They also told me without a class 3 old dynamite plungers are illegal unless the mechanism is disabled.. ALL IN ALL NOT FUN AND WASNT WORTH IT. but i tell you the thing worked so nice it was amazing. i did my own adjustments and had it setup to light off even more so mine was a about 2x the size. looked like a giant sound board. oh ya we also have 200 acres and they came on our property and still took it.
I have a Type 54 ATF Display Fireworks Permit. We use electric firing systems routinely, including both wired and wireless units. I've never heard of a "class 3 pyro license". Is that a Wisconsin thing?

As with all pyro projects, you need to be aware of your state and local laws and regulations. You can hardly expect someone posting instructions on an internet list to research every law in every state, county and municipality in the world. Take some responsibility for your own actions!

BTW, this project is far cheaper to make than *anything* you can buy. That said, you could probably not use it for professional displays for the very simple reason that you would not be able to get insurance that would cover use of a home-made firing panel.
California has 3 classes of pyrotechnic/special effects license (movie business) along with several other specific classes. I wasn't aware of any other states having a similar classification system. California is generally considered the hardest place to get a license. What you need to do (aside from getting an attorney) is review you states laws. Usually what you built would be considered a firing system and what you where firing would be considered the destructive devise. The firing system itself should not be illegal. It could be used to simply orchestrate and beautiful choreography of led lights for a show. Again your firing box doesn't contain any explosives or flammable liquids excetra. It seems to me if you permitted to fire fireworks and had only the fireworks within the permit then there should be no problem with firing them electronically. The electronic ignition of pyro is far safer than using fire and fuse. Seems to me the cops were over zealous and they don't have a case provided you've given the correct information and you had a legal right to posses and fire the explosive devices in your possesion.
ingkiller3 years ago
what kind of fuse did you use?
Andrew1813 years ago
Instead of a battery would a transformer work?

Transformer Specs:
120V AC to 12V DC 200mA
hhhdrb3 years ago
is there a way i could add leds so i knew quick if the key was on and for test an armd if so how
hhhdrb hhhdrb3 years ago
i found out how to do ill post when i complete my project
hhhdrb3 years ago
What size push fuse would i need
Hawkeye90096 years ago
What about telephone cable? Could run a couple of telephone cables and have 12 channels. Or is that wire not strong enough? I'm only 18, not good with electricity yet.
systemf92 (author)  Hawkeye90096 years ago
hmm, standard telephone cable is 22 or 24 AWG I believe, you would have to see how much the wire's resistance would affect the amount of power that could get to the ignitor and light it. It would depend on how long the telephone cable is. 24AWG copper wire has 19.1 ft/ohm of resistance, so a 20ft length would give you a little over 1 ohm of resistance through the wire. Since I haven't calculated the amperage required to ignite a fuse, I couldn't tell you if this will work or not. Hopefully someone else will read this with greater electronics knowledge than mine and be able to better answer your question. I got the resistance of 24AWG wire from this website.
i was thinking cat 5 cabel need 2 sets for 12
No you would need 18 awg wire minimum 16 awg would be better.
systemf92 (author)  rocketman2216 years ago
okay, 18AWG is what I happened to use.
dcx094 years ago
I built a smaller version with only 2 channels, but I used a 18volt dewalt battery, and the socket from a broken drill, works like a charm.
I wish I could find a better ematch though.
Nichrome wire (26 or 28 awg) wrapped around the fuse will light it without needing matches. Just make about 5 turns around a small screwdriver and it will slip over the fuse.
I tried 34 AWG nichrome wire but I could not get a continuity reading. Steel wool worked great though!
Ole bally4 years ago
It's a cool project, but I'm not sure why you need all the gadgetry! If you can get 'igniter cord' and standard explosives fuse line, you can set the whole display up and using the different burn rate of the igniter cord and the fuse line, set the whole deal to go off with either an electronic detonator or a match! Takes some planning and forethought...and a healthy dose of safety consciousness!
ya i think for me that igniter cord idea seems to work out its what we always did and seems to be easier to ensure its controlled no hickups or loose ends just quadruple check the paths. . we used to also start it with a punk and have one end tied to the bottom and wait for it go at random. Really throws people off cause it could be 20 minutes or 60. :)
kef44444 years ago
i have the same workbench !
it is also from black&decker i can see their logo on yours!
Snappy834 years ago
Fantastic tutorial! thanks for making it :)
Rlangg4 years ago
After all of this planning, discussion, and tweeking, it (still) comes down to that little red match stick, doesn't it? I think this is an awesome project.
citadel4jc4 years ago
This would be great (possibly scaled down) for a model rocket launcher. Just be sure to follow all the NAR safety guidelines. Even if you made it with just the key switch and a single momentary switch in a smaller case. A separate key switch for each momentary switch might be ok, too. I know the launcher guidelines are specific, but I can't remember them off the top of my head. I think you might even be able to use a safety toggle for each momentary. Anyhow, I always thought the ones that come with the Estes kits were a little cheesy. I'll stop rambling now :)
Mikey85674 years ago
Instead of removing wood to thin it out to allow the LED holders to snap into place you can use a simple method of hot glue. Yes it sounds cheesy but really it's not, if you open a lot of stuff you find that manufactures use hot glue on a lot of stuff, this includes holding panel face components in (LED's, ect), they use it to hold small wires in place where a clamp or fastener can't be installed, providing support and clearance for displays, and many other things. By pushing the LED thru the front face of the panel and then applying hot glue to the back side your doing two things. #1 Holding the LED (and sockets) in place. #2 your providing strain relief on the small 22AWG wiring that is attached to the LED's. No hot glue isn't the answer for every thing and should not be used in some cases. But it has many uses and is a very cheap alt to a lot of support and fastening.
I agree with this :)
 I have a SPDT keyswitch, I think I could use that instead of a SPDT toggle and a SPST key.
systemf92 (author)  ossumguywill5 years ago
You will still have to have an off position, regardless of whether it is part of the keyswitch or independent. Don't just have an Arm and Test, you need a master switch too, or I assume you have one planned? Ideally one would use a three-way SPDT keyswitch, with a Test-Off-Arm wiring, but I couldn't find one at all that was a keyswitch. Let me know if you happen to find one.
 Yeah, that's what I have. The middle position is off, to the right is position 2 and the left is position 1.
Just get a 3 position switch and cut the terminal for the middle position. Thats all an on-off-on keyswitch it.
pdionne4 years ago
Why are you running individual pairs of wires, when you could have used a common ground and built the box to fire up to 31 shots? Seems like a waste to do it like you did. The design of the box is nice and efficient.
A common ground system would require blocking diodes on every cue else you risk setting off the entire system with the first shot.
You answered that RJ-45 cables could be used, but couldn't you use one pair as ground ans the other pairs as the fire wire? Also, are RJ-45 24ga wires heavy enough to carry the current to light the igniter? Another option could be using a multi-conductor shielded cable. They are expensive, but would be rugged enough to last a long time.

As far as using blocking diodes, not sure they would be necessary as long as the box was wired where the positive and negative wires run through the switch. In doing so, each pair would be isolated until the switch was pushed. Only time there would be an issue would be if there was a short in the insulation between the pairs, but as long as proper safety procedures were followed, and the connections to the controller where the last cables connected, no one would be in the vicinity of the mortars to be injured.
87bhoward4 years ago
Do you know what fuse to use yet?
gromanski4 years ago
When I designed one of these my first design was rejected "ILLEGAL" they said. To be safe the lines to the 'SQUIB' must be grounded, to prevent an EMF induced triggering to a detonator that was not intended to be fired. You need double pole switches with the line grounded when not being fired.
mwolverine84 years ago
Im making one of these too! I have a soldering gun and all the equipment. Mine is going to have a manual mode where i can ignite the fireworks by hand but also an automatic mode where i can program in the computer how i want my show to be! :D
If you do an automatic mode, be sure that you have a switch to arm the array... and that if that switch is reset, the signals stop so that you have an E-STOP switch in the event something goes wrong, or someone wanders into the show area.

Safety First!
systemf92 (author)  mwolverine84 years ago
Sounds great! Good luck on the build.
IcedZ4 years ago
Great instructable, but you definitely needed to be more clear on what the ignitors were. I wouldn't have known without the other commenter asking.
Hello there:

Nice looking board. I'm building a 48 Cue board as we speak. When your board is in test mode, what are you testing? Are you testing continuity? So if you unplug one of the wires from the top of the board that goes to one of your fireworks, the LED should go out indicating no continuity? I'm modeling my board after yours, thanks for your help.

systemf92 (author)  Music_Man6084 years ago
Hi Glenn,
Very very sorry for the late reply, I just haven't been on instructables in a while!
When the board is in test mode, continuity is being tested, correct. If one of the wires were to be unplugged, the test indicator light for that channel would go out, indicating no continuity. Let me know if you have any more questions.

cam0224084 years ago
Awesome guide man, I'm totally going to try this. Any idea if it would work with a regular DC power supply instead of a battery? (The kinda that you would plug into a wall socket)
systemf92 (author)  cam0224084 years ago
Seems to me like it would, just make sure your wiring is secure. Haven't tried it though, but experimentation is the way to go!
KaydenST4 years ago
What kind of resistor are you using? How many ohms. Or just give me the color code.
systemf92 (author)  KaydenST4 years ago
As described in "Step 1: Parts" of the instructable, forty-eight 470 ohm resistors are used in this project.
KaydenST4 years ago
What are the ignitors? Are they the ones you use in model rockets? And if they are, how would you attach it to the fuse?
systemf92 (author)  KaydenST4 years ago
The ignitors I use with my controller are home-made ones as described here:
The ones I explain how to make have two wires on them. Clip one alligator clip from the firing channel cable onto each wire on the ignitor. Described in Step 5 of the instructable I linked to in this comment.
Oh, and when I say fuse, I mean the wick on the firework that you light.
mwolverine84 years ago
what charger do you use to charge the battery? i need one
henryplumb4 years ago
How come when it is in test displaying green LED's for connected circuits it doesn't ignite the ignitor because it has power running through the igntior? Thanks.
systemf92 (author)  henryplumb4 years ago
In test mode, the power running through the ignitor is not enough to ignite it. It is dropped down with the resistors to just be enough to light up the LED. Once it switches over to the armed circuit, the full power of the 12v battery goes directly through the circuit and to the ignitor when the button is pressed.
Oh, I see! I am making my own one of these at home and plan on having DPST Switches so that I can have power and armed lights that run from a separate power supply so they down run down the ignition battery! :-) Thanks for replying.
systemf92 (author)  henryplumb4 years ago
Sounds like a good plan. No problem. I'd love to see pictures of it when you finish, send me a link!
Will do when I have finished, think I am going to mount it all kin one of those old cigar boxes! :-)
systemf92 (author)  henryplumb4 years ago
Awesome, sounds like a plan.
Do you think that it would be possible to use 1/4" audio jacks instead of the raw wire speaker connectors? Or maybe even RJ-45's to run multiple channels through 1 wire?
systemf92 (author)  mistercow.pnoy4 years ago
I believe both of these options would be feasible.
lynrock5 years ago
Is there a reason why a 1K ohm resistor for each LED would not work in place of the two 470 ohm resistors?  Also any reason why a120v ac to 12vdc power wall adapter would not work for this instead of a battery?
since when are people using fireworks inside?
I know this was seven months ago, but I just have to comment. Ever been to a concert with flashes of light, smoke, bangs? Those are indoor pyrotechnics, and I can tell you from experience, this board is FANTASTIC for them! Plus added benefit of board not getting wet if it rains. ;)

We still use the battery though. Much easier to move from indoor to outdoor sites and back if the system is totally portable. Ours, however, is modified so that the fireworks actually connect to the board on what we call a slat, a separate piece that attaches to the board by a 25ft 25pin db cable. The slat has all the speaker terminals.

Oh, and I should mention I'm a licensed fireworks supervisor (outdoor fireworks) and getting my pyrotechnician (indoor pyrotechnics) ticket this summer. :)
I actually have a 120v outlet on the outside of my house that would be perfect to plug into for this kind of project.
systemf92 (author)  justinRoss585 years ago
convenient! as duckythescientist mentioned, you might want to find out if a wall wart adapter would supply enough current to burn the igniters first.
There's such a thing as an outdoor outlet and they sell something called an extension cord at most home improvement stores and other big box stores. It saves the trouble of making sure your battery has a charge. As for fireworks inside, you'd need a special permit and a good reason.
1K would be fine. As for the wall wart, batteries can usually supply higher currents than wall adapters. This project needs to be able to supply large currents to the ignitors. If your adapter can supply the 2 or so amps that this needs, then you should be fine. Also, I'm worried about portability, but I'm going to be nicer about telling you that than some other people :)
macman8084 years ago
what exactly do the leds, do i thought red meant that chenal worked and green meant the button was pushed.
So I am obviously late to the party, but how many detonators could you fire at once from a 12 volt battery? It has already been said that you couldn't fire all at once.
what is the arm function for?????
When you switch to arm, you can set off fireworks.
rrrmanion4 years ago
using a motherboard connector would be good instead of lots of speaker cables, because it would mean you had one cable going to the launch site, then splitting into several separate cables, and a common negative can be used, so a 20 pin connector can branch out to have 19 ignition units. (or more if several are connected in parallel to fire simultaneously or with a delay if some form of timer is used.
i cant get the stdt switch from link
pryokid2174 years ago
When is your v2.0 coming out as i would like to make a reliable and safe controller??
G-force7774 years ago
what are the dimensions of the battery? also what is the purpose of the speaker terminals? and why are the fuses neccesary
Arduino Guy4 years ago
you can reuse the wire in the ignitor, just sand off the black stuff. and rewind on another match.
nl825 years ago
Is there a reason why a lead-acid battery is necessary? Or would a cheaper 12v battery such as the ones shown at this link do just fine? The voltage is the same, the amp-hours greater. Thanks.
PyromanX nl824 years ago
This battery is cheaper (as long as you ship it with something else to get free shipping) and is 5Ah. The batteries at your link have fewer Ah (they are measuring in mAh) and cost about as much.
WDMJin5 years ago
would I be able to use a power supply instead of a battery? Haven't taken electronics in a while but I have a power supply that can output 5v DC at 3amps or 1.5-15v DC at 1amp. does anyone know if this would work well enough to make it work? if not what could I modify to make it work?
jthomas3165 years ago
I would like to thank you for your work. I built a controller modeled after yours but I used Cat6 cable for the wiring. I made a 4 port 24 shot controller. It was awesome to see it in action. I used a couple of tweaks from reading the comments here and it really made for a fun project. On the cat5 I used two of the wires for ground and the other six for 6 push buttons. We were firing from 140 feet no problem. Thanks again!
PyromanX5 years ago
Ok, so I've thought some more on this, and I've got a few questions.

Can and should the battery be recharged, or will it drain so slowly as to be negledgible?

Can the battery stay inside the box while not in use, or is there a reason it must come out?

If it can stay inside, should it be hooked to a maintainer?

Or are the batts so cheap they should be replaced?

This battery would work as well (better, actually, 5 Ah as opposed to 3Ah) for half the cost, right?


This comment is a bit repetitive of one of my previous ones.
Also, I think I'll add connections at the top to test, arm, and neutral wires, so that it will be expandable. If I need more channels, I'll install them in another box and connect the three wires. Voila, more channels.
a16duvall5 years ago
Put a scrap piece of wood under your panel while you drill to avoid the splintering. Clamp it if you can or just make sure there is no gap between them and drill through both pieces. It'll make a big difference.
systemf92 (author)  a16duvall5 years ago
convenient! as duckythescientist mentioned, you might want to find out if a wall wart adapter would supply enough current to burn the igniters first.
systemf92 (author)  systemf925 years ago
umm, disregard the previous comment I guess? haha, I think instructables pooped this random comment of mine on yours, it's actually a reply to a different comment. Anyway: I hadn't thought of that before, I'll be sure to try it sometime. Thanks!
Jaxoat5 years ago
Another option would be to use 2 different Forstner bits. Forstner bits make really nice flat bottom holes. Drill from the front for the smaller "through" hole and then from the back with a larger. Secure your work and if possible, use a drill press to keep the 2nd bit from wandering.
systemf92 (author)  Jaxoat5 years ago
I will be sure to get ahold of some, next time I need to drill holes. Thanks! Wish I had a drill press, though... haha
T-Rave5 years ago
Any plans on making a demo video for this awesome device? Would love to see it in full action
systemf92 (author)  T-Rave5 years ago
As of right now, no. Sadly, I won't be doing fireworks for the Fourth this year :/ I will let you know if I do though.
This may seem like an odd comment, but I like your choice of case! I used a case exactly like the one you used-except it was silver-to build a prop bomb controller for a school stage production just a few months back. I built it as a simple one-channel controller that would set off some spot lights set behind stage, which would blink on and off rapidly (with the aid of a PICAXE and a couple relays...) to simulate an explosion. Sure was a fun project....I may just have to try out your instructable to give that case new life and a much more "meaningful" purpose. I'll be sure to report back if I try it out!
systemf92 (author)  MasterChief15175 years ago
Thanks! haha. That sounds like some nice props workmanship! I myself am involved in theatre, I do lights/sound and set design at my school, which is the reason I don't have time to update this instructable, or start on the next version of the fireworks controller haha. That project sounds like fun indeed. Sounds good, I'd appreciate that! Best of luck on the build.
PyromanX5 years ago
Something interesting, I put all the Jameco electronics in a cart with the minimum purchases with one small modification, that I used bipolar red/green LED's instead of seperate LEDS. The total is $53:79. The circuit would be easy to modify to accept bipolar LED's and it'd probably make a prettier board. I'd also rig up a light that turns on when I open the case.
systemf92 (author)  PyromanX5 years ago
Sounds like a plan! Bicolor LEDs will definitely be used in v2.0. I agree on making the board prettier.
camden s5 years ago
great idea i made a 6 chanel version my self lots off fun for my igniters i used nichrome wire so you can put it straigt on the the fuse.
systemf92 (author)  camden s5 years ago
Thanks! Nichrome works well I have heard, I don't have any though, but I'll have to try it sometime.
PyromanX5 years ago
I've been thinking and I've got a few Q's

1. Where can I find a battery charger for the battery? How much does one cost?

2. Why must the battery be removed as reccomended? Will it damage the battery somehow or is it just for safety concerns (If it's safety concerns, I believe that with the keyswitch, they'd be unnecessary, but if it's still concerning, I'd add a lit on/off pushbutton or toggle between the battery and all other components) ?

3. If the battery is able to stay in, how about an integrated port to plug the charger into?

4. Maverick, are you sure a 10A breaker would work? I like the idea of a breaker way better than a fuse, since it is reasonably inexpensive.

Also, here is a link to some cheap tri-color LED's. The caveat is that they do not come with data sheets, and so I'm not certain that they'd work. It's also worth noting that there's a $10 minimum order.

Sadly, I'll be out of town for the Fourth, so I guess I'll have to double up on New Years.
Great instructable, very cool, also can't wait for the ignitor instructable.
systemf92 (author)  technodude925 years ago
Thanks! Sorry I forgot to update the last step where it says coming soon... it's been up for a while now :/ Thanks for pointing it out though, so I changed it! Here is a link to it.
Maverick_TN5 years ago
I'm getting the materials together to build this, I'm thinking about a few changes though... Still cooking up a few ideas in my head, but the first one is circuit protection. I'm going to use this instead of a fuse. I like the idea that was mentioned before by someone about using a dual color led. But I'm thinking perhaps a tri-color led, and modifying it so that it's green, red, and blue. blue would be if the channel is open after firing, I'll post a update when i get more ideas and get to moving along with the project. Thanks for the wonderful idea.

Okay, this is a list of what I have in mind, and I know it makes this project a bit more complex, but it does address a few issues that have been mentioned in other comments plus a few changes/additions of my own.

Open circuit detection per channel with Tri-Color LED "Red", "Green" being used as previously defined, and "Blue" for open circuit.

Someone mentioned fusing each channel for protecting the led's and the push button switches from overload. I have a modified solution, use automotive relays per channel to handle the load with larger wire and use the push button as a trigger.

Push button circuit breaker instead of fuse. Keyed arm/test switch.

I'm thinking of options on moving the terminals away from the top of the console. I think they would get in the way if you had the lid on it and wanted to just prop it open.
Perhaps moving it inside the case with sticking a plug slightly recessed out of the edge of the case to piggyback a small project box with the terminals on it that can be plugged in and then removed and stored inside the case.

This way you can also isolate all of your terminals until the last minute when you are ready, just plug in all of them at once.

I'm using an alu case, so i'm going to ground the case and put a lug in it for an external ground. We setup every year at my cousin's house at this little table which is at the edge of a lot. I may just drive me in a ground rod there at one of the table legs and run a wire up from it.

Thinking about adding second keyed switch to ground the outgoing leads as an added safety.

Any comments or suggestions?
Mine blew up :( accidental short in wiring
systemf92 (author)  MACKattacksnipe6 years ago
sorry to hear that, thats a good reminder to make sure all possible short points are protected and inspected beforehand
cowen systemf925 years ago
This is a good example of why I fuse every channel. The fuse would go between the power and the button. This way pressing the button would blow a fuse if there were a short at the button, the speaker connectors, or down the wires. I have replaced so much wire and buttons in the past that I want to protect it all with that simple fuse device. The best place to fuse is before your button on every channel.
That stinks. Kinda ironic though.
Arirox5 years ago
wait so do we put the fuse in or not??
systemf92 (author)  Arirox5 years ago
No, bypass the fuse and fuse holder, they are not necessary.
cowen systemf925 years ago
Bypassing a fuse is really not a good idea. At the least put a 3 to 5 Amp fuse on the battery positive terminal. If you are like me you will want to put a fuse on every channel. 1 Amp should be sufficient. In the event you have a dead short on a channel then just that one fuse blows and the others are still viable for the show. If you have only the one fuse then you will have to locate the short fix it then replace the fuse. If you do not use a fuse then there is potential to short heat the wires to the point of burning up the ground and or the control and possibly bursting the battery. The fuse on each channel should be one to two size(s) higher then what it takes to "short" the ignition device to launch the firework. So if you blow the fuse at 1A then use a 2A and it holds either use that or make it a 3 or 4 Amp some devices will tell you the volt/amp required to burn the ignition device. if the device is a .5 I would just round up. .5 = 1 and 1.5 = 2 and so forth. You should test this to be sure the fuse size works with your project since there are to be varying size and type of ignitors being used. To do this connect your wire and the ignition device and start with the smallest fuse and launch until the fuse can hold the (short) ignition of the fire work. Then go one or two (next size up) for a small safety margin. Then main fuse should be no more then 10 Amp. Batteries do not harry a lot of amperage so you do no need a 30 or 80 amp you just want to protect the wires, switches, and the case from a potential fire if they heat up enough. Fuses are a good thing and any project should have at the least one when dealing with power. I have been tinkering with my truck adding lights, pumps, radios, and other sorts of things to it and from trial and error I now have a huge fuse block with every thing labeled and fuse. If a light goes out I look at the fuses and if they are fine I replace the bulb. It gets expensive to add fuses to this degree but I no long have to re wire the whole bundle of cables. In that Bundle I have 50 circuits now and I have only had 5 shorts that needed to be re ran. Past projects I melted down the entire bundle.
systemf92 (author)  cowen5 years ago
Cowen, this is the answer I have been looking for for a long time. Thank you. To everyone else who has asked about fuses in the past, please refer to the above. I figured, "well, it still works so why bother," but the safety issue still bothered me.
cowen systemf925 years ago
You are welcome. It is not the most scientific approach but with all the differing kinds of ignitors that could be used it really is hard to put a value on it. So protection would be a must working with fireworks and long remote lengths of wires. Mis-wires could blow a show (figuratively and literally). The best way as I mentioned was to start with a small fuse and experiment with your ignition devices until you do not blow a fuse. 1A is probably going to be your common value. A 3 or 5 A for Mains fusing in case you want to launch multiples that way the main power can handle the current draw. A ) standing for Amps You just do not really need much of a fuse for the ignotors. It would be a good thing to hear what others are using for an ignition device and what fuse worked for them to help others narrow down their builds.
So, we just put a wire to where the fuse would be but we dont put the fuse it then solder the wires to the battery to it then just clip it on/off the battery?
systemf92 (author)  Arirox5 years ago
mesmes5 years ago

You wrote once a firework is detonated, if the ignitor burned completely, the red light will turn off and you will know that that firework has already been used.

I make the circuit to one channel and it works properly. The think i want to know is that when you press the push button, the red light  will turn off only for the second that you press the button or it will stay off once it is already been used?
muadeeb mesmes5 years ago
The red light will go out when you push the button, and will remain out provided the ignitor completely burned.
ROCKETMAN5 years ago
I have only taken a casual look at your Instructable, so far it looks good. My question is could this be adapted to launch mulitple class "C" model rockets? For example at a club event or competion where mulitiple rockets would be preped in advance and then launched in sequance or in mass depending on the event.
systemf92 (author)  ROCKETMAN5 years ago
Great! Yes, I believe it would work, with minimal adaptation necessary, if any at all. The igniters I designed to work with my controller follow the same principle as model rocketry igniters, which I have worked with in the past. The only thing you need to do is test with a dry run (just the rocket igniter) and make sure that it does not ignite in test mode. If that happens, raise the resistance on the LEDs for the test circuit.
Thankyou. You project will be considered closely the next time I need to up grade launch control systems.
It would work fine for that
clzfishing5 years ago
How much did you pay for all of this ?
systemf92 (author)  clzfishing5 years ago
About $70 dollars, plus however much it costs you to find/obtain/buy an enclosure.
jonniesweb5 years ago
What kind of batteries did you use? Did you put them in parallel or series?
systemf92 (author)  jonniesweb5 years ago
As described in Step 1, a 12 volt Sealed Lead Acid rechargeable battery. There is only one battery, so parallel/series is irrelevant. Specifically, one of the following:
Thankz for the idea, MY dads birthday is the fourth of july so we always put up a show, i didnt have that high of a budget so i ended up making one of these controllers out of 21 light switches. it works great! thanks
systemf92 (author)  xmufinman13x5 years ago
You're very welcome! Awesome, sounds like fun. Glad I could help! Let me know if you have any questions. Send me a pic too, if you don't mind, I'd love to see what you came up with!
MOLE395 years ago
i was wondering ..Could I make a "All GO" switch so all of the ones conected go off at once? and if so how would i do it?
The thing that would make this difficult is the amount of current that would be required to fire all the electric matches together. If you only have a few circuits to fire, this may not be a problem, but you have to add the firing current of all the electric matches together which can add up to a significant amount. For example, ten circuits at up to two amps per circuit may require 20 amps or more to fire all at once. If the supply side of the circuit (including the battery, fuses, switches, wiring, etc.) is not capable of carrying the combined current of all the electric matches, some or all of them may fail to ignite producing a potentially dangerous situation.
you could mount a single-pole double throw switch next to each of the push button switches and connect the wire going to the push button to the middle pole and then connect the side toward the push button to the push button and then connect all the other sides together to another push button. this way the switch would toggle between single fire mode and group fire mode for each channel. That's really hard to understand from writing. did it make sense?
so what your saying is to put more switches next to the buttons that lead to another button like so?:
yes that looks right.
ok thank you
systemf92 (author)  MOLE395 years ago
you would connect more than one (however many you want to set off) positive lead to one side of the switch, and it would fire all of the ignitors connected.
but wouldent make them all go off again when i press another button that was originaly for only one firework because their connected together on another switch?
A.J.5 years ago
well, i think i have everything down... there is just one thing!
can i use these led lights instead of getting 2  of them for each switch?
systemf92 (author)  A.J.5 years ago
Sure thing! That would look really nice.
A.J. systemf925 years ago
also I was thinking about using cat5 networking ports and cat 5 cable to go to the launch system. I was wondering what you thought of that, and if it could carry the power like I am hoping... (i am making a 160 shot firing station and need to save on wire)

the reason i would use that is i will have my board with the speaker terminals out in the field and just all the electronics on the switch board. I will be using
20 switches with an 8 position switch to switch between 8 sets of 20 ... ques  I guess u would call them? anyway thanks for the quick reply

one more thing... (something i was thinking about) i thought it would be cool in future projects like this to wire the control panel high voltage (120v) and then use relays to change it to 12v for the field  module
Cat5 should be more than capable of handling the kind of power this project uses. You could get your controller box to be very space-efficient if you used RJ-45 jacks instead of spring terminals, and have 4 channels per connector. Run the Cat5 cables to breakout boxes with spring terminals or screw lugs and you're set.
ok, here is the picture... sorry for the double post
firework controller v9.2.bmp
systemf92 (author)  A.J.5 years ago
Using cat5 would sure be efficient when it comes to wiring. I can't tell you for sure about the power carrying capabilities of cat5 cable, but I can point you in the right direction, try this forum.

I would advise against using relays, but only because I have seen discussions about them in a pyrotechnic context, and it sounds like they run a risk of misfiring, due to the relays accidentally closing or connecting and causing a firework to launch without a signal to the field launching panel. Again, I haven't seen this happen firsthand, but I've heard about it.
SamK925955 years ago
 what is the "test"function for

To Test If All The Channles Are Working, Durr!
Arirox5 years ago
In The Next Tutorial, Or Model Of Your Controllor Add A Code With A Screen So U type The Number In, Turn Key And Flick Switch here is a number pad thingo
caspur5 years ago
This is awesome thanks for the tut.
systemf92 (author)  caspur5 years ago
You are very welcome! Let me know how it turns out if you build it!
Rob K6 years ago
Mine works but never had the chance. (build time 14+ hours over 2 days) I will put it up later as a sideshow. Its 12 channels crammed into a .50 cal ammo box. I got rained out. Rain started around 8:30 and stopped a little after 10:00. A little to late to setup, also I was having reliability issues from my ignitors.
systemf92 (author)  Rob K6 years ago
Aw, sorry to hear that you got rained out.... glad it works though, maybe for New Years! Can't wait to see the slideshow.
Rob K systemf925 years ago
My slide show is up. .50 CAL Ammo Box Firework Controller Build Wiring is basically the same. I changed a few parts from what you used. Tubular key lock and wire binding posts.
systemf92 (author)  Rob K5 years ago
Looks really great! I'm so excited you could build this and improve upon my controller. I also appreciate you crediting mine on your instructable!
febo93 Rob K5 years ago
                                                          hi everyone!!!
Credit for fireworks controller ....I have a few questions?)))))......
-how many amps the battery must be
-I have to give change if you put the resistor wire in excess of 20 m (example, 30 or 40m)...
I'm all done and only what I need to know whether change...
Everything is connected to 12V without the fuse but it would put the wires from 30 to 40m..
Now I have to give you change the resistors and voltage as the wires much longer if I should be and how much voltage resistors..
I am sorry to my poor English I hope you understand ..
 Hey man, about the fuses. Have you figured out what amp fuses to use?? That would really help to know man. 
My emails are: and Email me back. I would really appreciate it. Ive bought most of the parts i just need the fuses man.
Thank you
systemf92 (author)  ak47bobbarke5 years ago
Hey there, for now just bypass the fuseholder, don't worry about including a fuse at all, because it is not necessary for the operation of this controller.
farmboy325 years ago
I really like the way you made this controller, but I would like to extend it out to a 50 or 100 que panel. Can I put in a rotory dial so that I can use the same buttons over again so that the panel isn't so big. Any info you can give me would be great and I am not wiz in electronics.
systemf92 (author)  farmboy325 years ago
Thank you! You would be able to do that as far as I know! Something like this is what I'd like to include in the next version of my controller, but I am not going to have time start building or planning it yet. You might want to check with A.J. above, to see how he wired the 8 position switch to switch between the sets of 20. A rotary dial will probably be wired similarly.
Victor Lam5 years ago
can i use a motor cycle battery?
systemf92 (author)  Victor Lam5 years ago
As long as it is 12 volts and in good condition. probably a SLA battery, isn't it?
Arirox5 years ago
Hey Guys, I know heeps about electronis and all but idk what side plus and minus are on a led can you please tell me or dosent it matter? please reply
Generally, on LEDs with a rim around the bottom of the plastic part, the flat side is negative.
haha thortso thanks guys
longer side is positive
 Oh and my email is either or
Arirox5 years ago
So, we just put a wire to where the fuse would be but we dont put the fuse it then solder the wires to the battery to it then just clip it on/off the battery?
hi, problally dont remember me but i made some like this a couple of months ago and got the idea from here and now made an r/c one the works extreamlly well! ty for idea!
systemf92 (author)  Jason Bourne5 years ago
No, I remember you haha. Awesome! Glad I could be of assistance. Do you have any pics of it?
gizmohalo5 years ago
why are you hooking up the resistors to the negative side of the led light
systemf92 (author)  gizmohalo5 years ago
To tell you the truth, I don't know. Hey, it works, doesn't it? This was pretty much my first big electronic project, so I wasn't sure about all of the technicalities. Should they be on the positive side? If so please tell me, I'd like make sure I know for next time.

It doesn't make any difference which side you put the resistors

systemf92 (author)  steveastrouk5 years ago
flamesami5 years ago
how much did this firework controller cost you? I am thinking about making this, but I am very limited in price range (I'm a cheapskate). Thank you.
systemf92 (author)  flamesami5 years ago
Hi, the total cost for the controller was roughly $70 including the battery, not including the case, which I found for a very cheap price, and you can build the project in the enclosure of your choosing to save money.
would it be possible to add a led for when its "armed" ? 
systemf92 (author)  programedfiles5 years ago
Certainly, just add it in between the armed positive circuit and the negative return to the battery. Be sure to include the appropriate resistor in that circuit so as to not over-power the LED. Let me know if you would like me to make a schematic that includes this addition, if you do not understand.
this may seem like a silly question as i am new to the whole ignition box idea (im used to manually igniting)
but after you use the speaker wire for 1 ignition can you use it again for another? like is it re-use-able ? 
thanks in advance
systemf92 (author)  programedfiles5 years ago
Hi, don't worry, your question is a valid one. The speaker wire is reusable. It conducts the electricity in the circuit, but does not heat up or disintegrate like the steel wool does, because of its thickness. The only thing that needs to be replaced per ignition is the ignitor/e-match/steel wool that touches the firework's fuse.
You could remove R3 and R4 in the circuit and move the green LED and connect the cathodes together. That would save quite a bit of time and a little bit of money!
systemf92 (author)  duncant201966 years ago
you're completely right. I have no idea why I didn't do that. this is my first project after all, as you can tell I still have lots more to learn. Thank you for pointing that out!
hey ive been looking at this diagram and i cant figure out if the positive of the battery goes directly to the ignitor and the swicthes just controll the negative side
No problem!
Would it not be easier to use bicolor LED's aswell?
systemf92 (author)  CameronC6 years ago
the single color LEDs i used were $0.11 each, and similar bi-color red/green are $0.29, so its not that much more, plus it would look neater. Good idea, I'll use it on my next version.
This likely isn't going to save money, since you're probably gonna end up purchasing at least 100 resistors anyway. However, the image you've linked to is the equivalent circuit, in a simpler form, which could save a good chunk of time in assembly. Good catch.
edfel015 years ago
when i tested it all the lights light up what looks like randomly and every channel i test it on the green light but both of the lights on channel 4 always light...need help so close to finishing it...
A.J.5 years ago
so, would you use a 12v car/lawnmower battery for this?
braxtonb1105 years ago
what do you recommend for the fuze
systemf92 (author)  braxtonb1105 years ago
just bypass the fuse for now, it is not necessary.
would this fuse FUSE 32V SB 3AG 15A and this fuse holder work FUSEHOLDER,3AG from the Jameco web sight?
KDFAN5 years ago
Would it be possible to use a car battery instead of the type you suggest to lower the cost.
systemf92 (author)  KDFAN5 years ago
I'm not sure, I haven't tried it. I would think not since it is designed for starting power only, not continuous usage like a 12v marine battery, or a SLA rechargeable.
could i make this into a 6 channel by buying half of the stuff?
systemf92 (author)  joekickass3455 years ago
not necessarily half of everything, but just take a look at the schematic on step 7 and repeat the part in green as many times as you need. everything else you just will have to buy once.
braxtonb1105 years ago
24 gauge is really cheap is that usable for connecting to the fireworks
systemf92 (author)  braxtonb1105 years ago
I'd probably go with something at least larger than the gauge of the wires inside of the controller. probably at least 20.
batman965 years ago
soooooooooooooo cool!
systemf92 (author)  batman965 years ago
thank you, glad you enjoyed it. let me know if you have any q's
pontiacking5 years ago
Could you put the negative side of the red and green LED in the cinter and solder one set of resistors to both insted of one set to each LED
systemf92 (author)  pontiacking5 years ago
certainly, this will be part of the improvement of the next version of the controller.
Have you that of using D B pin connector's like for a PC and having slats for you're speaker terminals.
systemf92 (author)  pontiacking5 years ago
i'll also use this in the next version, i certainly find this much easier to set up then having individual wires. thanks.
farmboy325 years ago
I have never built anything like this before and I am going to try it, but is there an easier way to extend it out to control 75 fireworks with out firing them off at the same time.
systemf92 (author)  farmboy325 years ago
Certainly! Since the circuit is modular, all you'd have to do is repeat the portion of the circuit circled in green in the schematic on step 7 of the instructable. You can add as many channels as you like, assuming that you can find a panel configuration to safely fit individual launch buttons for each channel in.
tyler96135 years ago
Instead of using a million two conductor wires for each firework, couldn't you just run one wire out to the mortar rack to be used as the ground, or be connected to the black terminal (and split it to as many fireworks as you have when it gets to the rack)? You could save a ton of wire ! That way you could double your wire! Is this a good idea?? Will it work?
systemf92 (author)  tyler96135 years ago
yes, the ground is common across every channel, as you can see in the photos of the rear of the panel. in the future I will definitely use a system like this. when I built this one I hadn't really thought of configuring the connections that way, but I have learned tons throughout the process and by reading others' constructive comments like yours. thanks!
So, I've got a 6v 6.5 Amp/Hour blackout light battery. Will that work? Cuz I read the amp discussion above but this is half the voltage of the one you listed.
systemf92 (author)  misanthrope135 years ago
you would have to use two of these wired in series to work with my controller to create 12v as it is presently. you would have to make a few changes to get it to work with a 6v system.
Coodude265 years ago
Oh my gosh. ... This is so unbelievably similar to what I've been working on it's crazy. Speaker connectors, test Keep in mind, mine is about the size of a box of matches, but it has 2 channels and a recharge port for the battery. It's a little sloppy, but... My god. I just can't get over how similar they are. I might get a picture later.
pontiacking5 years ago
If I wonted more thin 12 channels how mane more can I ad
gary98675 years ago
How would you make this wireless? I was thinking of a wireless doorbell but am worried about interference.
yea, never use a door bell as a wireless trigger for any explosives, way to much interference, but you have a nice thought though, a wireless door bell would work on a great deal of projects.
systemf92 (author)  gary98675 years ago
Maybe someone has already clarified it in this posting, but no matter what size battery you use it will work, now I'm sure you want something with at least the recommended 3.2 amp rating, and nothing too big that would kill you, but as long as its 12 volts it will work, amperage is just the intensity over a period of time, but to the author, GREAT design, really nice work.
systemf92 (author)  alphamale9625 years ago
well put, thank you. I'm afraid my explanations on this weren't too clear.
I thank it is just right
macwhiz5 years ago
What do i use to open the DSN file?
systemf92 (author)  macwhiz5 years ago
as it mentions in the step, it was made in TinyCad, an open source schematic design program.
amazing idea, just a bit too pricey for the cheapest 13 year old ever. also, where could i buy a case without going to a flea market or something?
systemf92 (author)  lunchboxslayer275 years ago
this, and a simple search on google products can reveal a few options:

they seem to be pretty expensive new, all I saw were $100+, but they are much cheaper on ebay
macwhiz5 years ago
How much did it cost you to build?
systemf92 (author)  macwhiz5 years ago
around $70 dollars, assuming you can find a cheap used case
bowmaster6 years ago
No offense but this looks like something a terrorist would carry. Get a similar hard plastic case to carry bottle rockets (to protect the sticks) and a ski mask and you have a great terrorist costume for Halloween! Ridiculously awesome.
systemf92 (author)  bowmaster6 years ago
heh that would be a cool costume, but also the reason why i was weary of building on and shipping it to Chaset316 in the mail, there's no telling what the x-ray mail reviewers would think.
jrdur72776 years ago
well, i could build it, or pay you to build it (it looks like it would be a cool movie prop)
systemf92 (author)  jrdur72776 years ago
haha, let me know if you are interested in me building another one, I would be glad to.
systemf92 (author)  systemf926 years ago
Also, if you just want to use it as a prop, I could make it cheaper for you by not having all of the electronics in the back but leave it the same in front. The panel can be painted black or however you would like it to look.
Paint pictures of fireworks on it.
systemf92 (author)  bowmaster6 years ago
haha then it'd really look like a professional BOMB detonator that a secret agent would use, with some pretty fireworks on it
firehazrd6 years ago
This is an awesome 'ible. Good job, I'll have to revamp my launcher.
systemf92 (author)  firehazrd6 years ago
thanks, glad you like it!
mec_man6 years ago
would this be able to use a medium sized car battery? I will be running an hour long show with a 24 channel version of your design and need to fire up to 8 channels at a time.
systemf92 (author)  mec_man6 years ago
I couldn't tell you for sure that a car battery will work, but a deep cycle marine battery should, if you have access to one and need lots of power over a long period of time. I'm afraid this message might be too late, you probably did something for the 4th already. if so, how did it work out? If you haven't already done the show, you can read up here on the difference between the two:
Chaset3166 years ago
Today I ordered all of the parts I need and I have a case to put it in...i did 3 day air......would there be anyway i could ship the stuff to you and pay you and let you build it by 4th of july??? if ya then like how much and stuff
systemf92 (author)  Chaset3166 years ago
Unfortunately I would not have time to build an entire controller before the 4th, plus I'm weary of mailing the completed controller back, because fireworks aren't the only thing that could be detonated with it if you know what I mean. I'd love to help you, but I'm afraid it won't work out. I'd be glad to help you along if you build it yourself, though, let me know if you have any questions.
B_A_M systemf926 years ago
I'm rushing to build before the 4th too. I REALLY found this Instructable to be very helpful. My only problem is today's the 1st and I still don't have all the parts I need. It may be a late night...
systemf92 (author)  B_A_M6 years ago
best of luck to you, hope your parts come in! all night electronic projects are fun though, enjoy it.
B_A_M systemf926 years ago
Thanks, last night I figured out I don't have the right parts and it don't have a good enough drill. I have a 1/2" drill bit. but the bit can't fit in the drill... I went and got parts early this morning and looking forward to a night of soldering. I have to leave tomorrow and I have a meeting at 1:00 so I'll have a day EXACTLY to finish this. Fingers crossed. Thanks for your support... B_A_M
Any idea what the minimum necessary amperage for the battery is? For instance, would a 1.3A battery work?
systemf92 (author)  steventyler93056 years ago
not sure, by amperage, do you mean the Amp-Hour rating? If so, then 1.3AH will work fine, this number only refers to the amount of time that the battery can output a specific number of amperes. The lower the Amp Hour rating, the more often you might have to recharge it.

Here is a description from
The most common battery rating is the AMP-HOUR RATING. This is a unit of measurement for battery capacity, obtained by multiplying a current flow in amperes by the time in hours of discharge. (Example: A battery which delivers 5 amperes for 20 hours delivers 5 amperes times 20 hours, or 100 ampere-hours.)
Rob K6 years ago
I'm thinking of making one to fit inside a ammo box. Also how do you charge your battery?
systemf92 (author)  Rob K6 years ago
good question, actually i haven't had to charge my battery since I got it, but I do have a few extra 12v wall wart transformers that I keep for when I have to charge it. Battery chargers are sold, just search SLA 12v battery charger. As you can see, the ones they sell are basically wall wart transformers with alligator clips on the ends of the wires. This is what I am planning to do when I need to charge my battery, the board just doesn't use too much power so I haven't had to yet.
Rob K systemf926 years ago
Guess that explains the basic charging circuitry in my broken halogen flashlight. Wall wart plugged directly to the battery through a protection diode.
Chaset3166 years ago
did you figure out which fuse to use? and how hard is it to follow these instructions for the average teenager
systemf92 (author)  Chaset3166 years ago
hey, no i haven't yet. you don't need one in the circuit, so just dont even use a fuse. The positive wire from the battery will go straight to the keyswitch and not through a fuseholder. sorry for the confusion. Also, I am an average teenager haha, so you should be able to follow the instructions. If this will be your first time working with electronics, then it will be a little difficult, but hopefully the instructions will be clear enough for even first-timers. Just know that perfection is key with electronics, as any solder bridge or improperly connected wire could make the whole thing not work, so check your work more than twice before turning on for the first time! Let me know if you have any questions, I'll be glad to help you along. Go for it!
emaciver6 years ago
Can I use a 5amp battery...or do I have to use a 3.2amp battery?
systemf92 (author)  emaciver6 years ago
yeah, there's no problem with using a 5amp battery, in fact it will last longer!
Chaset3166 years ago
for the 12 wires should i use solid core or copper strand
systemf92 (author)  Chaset3166 years ago
I would go with stranded, since it will connect better to the speaker terminals and is more flexible, but either one will work in a jam
edfel016 years ago
Can u take a pic of the back when its all done bc i cant clearly understand how the battery hooks up how were u put the 2 conductor wire that leads to the ignition to? does both of the wires go in one terminal or one in a black terminal and one in a red terminal? Need answers ASAP!!!!! doin this for a projects thats do reeaallyy soon!!!! thx
systemf92 (author)  edfel016 years ago
For each channel, one long wire goes into the red, the other into a black. The negative side of the battery connects to the wing nut connecting all of the black speaker terminals together, and the positive side of the battery leads to a tab on the side of the fuseholder. The fuse is not necessary in this project so you can connect the positive battery lead directly to the keyswitch in the middle. What project are you doing this for? A school related one? If so, that's really neat.
crap i accendently clicked flag on ur comment hope that dosnt matter.... I'll take some pics of it i changed it from 12 channel to 8 channel so i could fit it in a certain container. This was a good first instructable.
systemf92 (author)  edfel016 years ago
Awesome, glad to see that you adapted the design to fit your needs, rather than just blindly follow the directions! can't wait to see...
kinda im doing this for 4-h its my first year doing electric so i thought i would try to start off good. It turned out really well i havnt tested it yet bc i didnt have time but i got 1st place on it. Thx for all the help
systemf92 (author)  edfel016 years ago
Oh neat, glad to have helped. Do you happen to have any pics of the controller? I'm curious to see how it turned out.
i just got done with mine and it looks rly good, but i fogot to make an instructable about it untill i got done so it's pretty much just gonning to be pictures. thanks for the inspiration!
systemf92 (author)  Jason Bourne6 years ago
Great, I'd love to see pictures! I'm glad to have inspired you, stay safe using it.
BOOJAN6 years ago
I must admit that you have really nice looking push button switch :D
systemf92 (author)  BOOJAN6 years ago
thank you,
they are from jameco electronics, I found out that they look better in real life than they do on the product page haha.
There are also several other stores that sell most of these parts for cheaper including All Electrinics ( and Mouser ( If you are lucky you can also find some of these parts on ebay in bulk for really cheap.
edfel016 years ago
oh and there was only one wire of the fuse that i can see does another one go on it? and is is suppose to be on the schematic?
systemf92 (author)  edfel016 years ago
The other wire from the fuse connects to a tab on its side and leads directly to the positive tab on the battery. The fuse ended up not being necessary and can be removed from the circuit. That is why it is not on the schematic, sorry for the confusion. Without the fuse, the positive wire from the battery would lead directly to the keyswitch.
edfel016 years ago
this is a great instructable it took some time to understand it, just because im new to this, but i loved it im going to try to build one and the only question is were do the long wires plug into? and what does the fuse do? +5
systemf92 (author)  edfel016 years ago
thank you and good luck building it! The long wires that go from the speaker terminals lead to ignitors that will ignite the fireworks. I will soon upload another instructable detailing the construction of the ignitors themselves and will let you know when I have it posted.
btw can i use a 9v instead of a 12v?
systemf92 (author)  Jason Bourne6 years ago
you would have to change the resistor values and depending on the battery it might not have enough amperage output to ignite the ignitor.
what about a 7.2volt?
systemf92 (author)  Jason Bourne6 years ago
that would probably be less likely to work, and any voltage change will affect the value of the resistors needed.
how about two 9 volts?
how about you reread the first two answers.
hemmikarl6 years ago
"turn toggle switch to test, make sure green lights are turned on for each channel that you have something connected to, if not check your connections and look for a short" If there is a short in the speaker wires the green light will still turn on, so it only tests that something is connected and if the battery works (at least like I see the schematic) otherwise it is a great project
systemf92 (author)  hemmikarl6 years ago
thank you, I'll change the wording in that sentence right now.
tudgeanator6 years ago
Looks awesome! But so confusing... It's not your instructable (which is very good and clear), its all those wires!
systemf92 (author)  tudgeanator6 years ago
thank you, yes it is pretty confusing at first but check out the schematic and you can work it out logically to better picture the circuit. let me know if you have any questions!
I get it now, and i am currently designing a firing box using ideas from this and others. It's gonna use 6 slats each with 20 cues for 120 cues total! Also each slat will only have 9 wires going from them to the main box (4 wires for row, 5 for column) saving on wire and money. Thanks very much.
i see u read popular science. i guse u were reading the one with the athlete om the front in that new suit
systemf92 (author)  Jason Bourne6 years ago
haha indeed i do, it's a cool magazine.
Padlock6 years ago
I made one of these a few years ago...
I used this and a couple of transistors coupled with high power relays to control it from a distance.
Padlock Padlock6 years ago
I used a high gauge (22-24) copper wire connected to some low gauge MAINS wire as an ignitor. About 20 amps from a car battery was enough to get the cable hot enough to light the fuse.
systemf92 (author)  Padlock6 years ago
very interesting! seems like a much simpler way of running wires to the fireworks if you only need two wires to control 10 outputs.
Very. I can control them from 100 yards away without spending atleast that much in cash for the cables. Also, I just use extension cords instead of speaker wire.
kiranshila6 years ago
I bet there is some way to do this with a PIC or Arduino. If someone made an instructable about that I would defiantly be grateful.
stunmi6 years ago
i think there should be a dead-man switch on the armed circuit so if something was to happen to the operator it would kill the board. the best way to do this would be to use a momentary toggle switch
Dr.Bill6 years ago
Hmmmm. This looks every bit as good as the ones they use out on Magic Island. We can watch the fireworks every Friday night. I knew the nephew of the guy that lit them off and got to see the control box. The only thing is they had a very expensive covered safety switch instead of the toggle you have. One for test and one for firing. I too have TinyCad and find it very useful but when I got mine it was still relatively new and tended to crash if I deleted too much. It don't do it anymore.
systemf92 (author)  Dr.Bill6 years ago
wow, that must be really cool to see so often. I rarely get to see pro fireworks displays, but enjoy them when I do. I'm sure they have stringent laws regarding safety for their big fireworks displays. I try to keep the main on/off switch key in my pocket at all times when the controller is out, I guess that works for safety!
...too bad you didn't have a drill press to do the drilling.....very nice though....
systemf92 (author)  explosivemaker6 years ago
yeah, it definitely would have helped make it quicker and more precise, but hey I manage to make do with what I have. Thank you.
....I don't have one (yet) did much better with hand tools than I would have done...thumbs up....
moorea76 years ago
You can get 2 position key switches that would enable you to have your test and arm controls in the same switch, it would also give you the ability to lock it into test mode!
systemf92 (author)  moorea76 years ago
Test and arm controls are already in the same switch, I don't understand. Are talking about On-Off-On 3 position keyswitches?
crapflinger6 years ago;jsessionid=ac112b1f1f4325aeae241937460e9936dc68c8d7b1d6.e3eTaxiNaN0Te3iQaNmRbhmNay1ynknvrkLOlQzNp65In0?sc=8&category=35&it=A&id=291

i've got plans to make a computer controlled contraption that uses the above relay board (actually posted an ible a year or so ago about it)...the advantage is that you can have all the firing "gear" (i.e. power and all the connections for the fireworks themselves) in once location....then run a 100' (or more) serial cable back to your firing station and use a laptop to fire...

you can either automate it (so that you can press go and drink a beer and watch) or make your own program (or use the one that you get from the kit maker) to do it manually...
also...i need to look it up...but someone here on ibles has posted info on using resistors as ignitors....passing 24v through the right sized resistor will cause it to ignite....they're ridiculously cheap and easy to wire up
systemf92 (author)  crapflinger6 years ago
yeah, I also saw that for the first time here on instructables after posting mine, I have to try this now...
systemf92 (author)  systemf926 years ago
and also, regarding those relay boards, those look good but are a little pricey. They would work nicely though. Let me know if you use one, I'd like to see how it turns out.
well...i bought a house this year so the gub'ment is giving me some money for stimulating the economy (neat!) so i plan on getting two of those kits and linking them (each has 8 relays so i'd be able to do 16 with it)...i plan on just making the controller setup modular(without the fireworks part)...that way i can use the controller any way i want once it's built.....probably going to use it as a computer controlled bar instead of a fireworks controller...but honestly...once the controller part is set up and's pretty much the same tell it to fire a relay and it sends whatever voltage you're pushing down the it should be able to turn on a pump, fire fireworks, turn on a dancing hula girl...etc...
found em this one talks about using 1/4 watt 10 ohm resistors as ignitors in a 24v system

i'm really interested in playing with the resistor ignitors...
Syko Pyro6 years ago
You might actully want to think about adding a diode either for each of the channels or right at the beginning of the circuit on the positive rail of the circuit closest to the battery. You could also do this on a PCB which would make things neater. If your not sure what a PCB is google it. (Printed Circuit Board)
Mikey D6 years ago
I built a model rocket launcher for the Cub Scouts (6 channel) using a similar method. Phone cable was plenty large enough to handle the amperage but I had to wire a 12 pole rotary switch into a parallel 6 pole config. I used a metal cashbox and drilled the top for all of the switches and led's. I am curious as to why you didn't just use a 1k ohm risistor instead of 2 470's in series. Great ible, very clear and good instructions. Mikey
Holden_vy_s6 years ago
Very nice work! Personally i would of used aluminium for the face plate to carry on the metallic theme from the case but thats just me.
systemf92 (author)  Holden_vy_s6 years ago
thanks! yes, aluminum would give it a nice touch. for this controller I used what I could easily get. I'll keep that in mind for version 2.0, maybe chemically etch the labels right onto the panel!
Hmmm... If you can access a laser engraver it would be really easy to label. Or if you have thin enough metal or strong enough laser it can make a quick job of cutting all holes. But I realize it is not practical for most people.
tobyfan576 years ago
Hey everyone. Having trouble finding a case like I was?

Well today (5/5) has a similar looking case for @15 bucks after shipping. This is a good deal if you can't get one at thrift store / garage sale because these retail around $100.
systemf92 (author)  tobyfan576 years ago
Awesome find! the next best thing to stumbling across one at a thrift store, not a bad price.
A thrift store would defiantly be cheaper, but I could not find such a case and it adds to the feel of the project.
bowmaster6 years ago
systemf92 (author)  bowmaster6 years ago
thanks, glad you like it!
How could you not?
pudi.dk6 years ago
Can aluminium sheet be used instead of plywood? Or is it too conducting
systemf92 (author)  pudi.dk6 years ago
Aluminum sheet could be used, assuming it is thick enough to not bend a lot when the pushbuttons are pressed. Also, you would have to be careful with the resistors since they aren't insulated and we count on them staying in the same position, so consider using heat shrink tubing or electrical tape to keep them insulated in case they were to touch the aluminum panel and create connections where we don't want them to be made.
this is a great idea. and i have a suggestion. Instead of running 12 separate pairs of wire from your controller to your display setup, use a printer cable or something similar. At the other end make a "break-out" box to split it back out to your individual fireworks. You can find some really long cables and you can plug one in to the next and as long as the cable resistance is low enough, your trigger should still work fine. peace,
systemf92 (author)  thatoneguydavid6 years ago
Excellent suggestion, I also realized that doing this would be much more practical after having to buy so much cable, 20ft x 12=240ft. This will definately be included in version 2.0 : )
Rob K6 years ago
I saw a nice version a wile a go that had a used 4017 counters and a 555 timers. A push button to select pad then push fire button to do a count down till it fires. A lot more complex then what you have here and you have one that is fairly simple and easy to follow.
systemf92 (author)  Rob K6 years ago
Ah, yes. I did see a few designs like that, however I don't have much experience using ICs and timers and such quite yet. I hope to soon learn how to incorporate these in my projects. Hey, simple is what I was going for, glad you thought so!
fwjs286 years ago
systemf92 (author)  fwjs286 years ago
sorry, I don't have one yet. Hopefully I'll be able to videotape it being used on July 4th!
sweetness...oh and 4.5/5 (no vid...)
tobyfan576 years ago
One more thing. In some place I see a fuse assembly in other I do not. Did you end up using if so what were specs?
systemf92 (author)  tobyfan576 years ago
I had planned to use a fuse in the project, and since having a fuse was discussed in the forum that I looked in for ideas, I bought a fuseholder and fuses to use. However, over at the forum they calculated that the fuse should be a 2.5 amp fuse. I trusted them and bought 2.5amp fuses, but when I tried using the whole controller for the first time the fuse blew immediately while pressing a fire button. Hmm, I thought, that's strange, and I knew that nothing was short circuited. I looked at a new 2.5amp fuse and saw that the tiny wire inside was even smaller in diameter than the steel wool used in my fuse. So long story short, the fuses I bought were way too low amperage and blew too easily, and I haven't gotten around to figuring out what amperage they should be to not blow under normal usage. For now, I just took them out of the schematic and parts list because it isn't necessary for the operation of the fireworks controller. It's nice to have if you can figure out what amperage is right, but not necessary.
I thought something like that may be the case. That clears it up. Maybe I will try to figure the amperage, if so I will be sure to put it in a comment so all can know.
systemf92 (author)  tobyfan576 years ago
awesome, that would be great. I assume it involves dividing 12v by the resistance of the ignitor & the wires leading to it from the board, but my multimeter is broken and I haven't gotten around to getting a new one or finding the resistance. If you happen to find out, that would be great, then I could make the parts list match all of the photos! If not that's cool too, I'll get around to it sooner or later.
Will try to investigate with my multimeter after I build.
tobyfan576 years ago
Awesome project. it is possible I missed it, but is there a schematic? Also I could not see in the pictures how you wired in the switches or LEDs. Thanks
systemf92 (author)  tobyfan576 years ago
Hey thanks, glad you liked it! im surprised you saw it already, it's not yet published or finished, I haven't uploaded the schematic and there's quite a few steps i have yet to write, a bunch between steps 8 and 9. I'll get it finished up soon I hope. Stay tuned, it'll get done soon. Just out of curiosity, how did you find the link? on my flickr page or on a forum or somewhere else?
It seemed like that may be the case. Strange that I found it. I simply goggled "build a fireworks controller:" and this was the first result. If you don't mind pm me when it is finished. One again nice Instructable.
systemf92 (author)  tobyfan576 years ago
Wow, that's surprising, google already has it indexed. oh well, that will be a good thing when it's finished. no prob, I'll be sure to let you know when it's done, and after that I'll be making another instructable that details making the igniters that I use with this controller. thanks again
Sounds awesome. Just out of curiosity basically what igniters do you use? I have a simple test system (only one channel, no frills) and I use nicrome (not sure on spelling) wire. Looking forward to seeing if you have a better way.
systemf92 (author)  tobyfan576 years ago
basically I use a match, with the head wrapped two or three times with thick (grade 3) steel wool and linked to two short lengths of wire on either side of the match. The wires are taped to the body of the match with electrical tape, and alligator clips from the controller go to each lead on the ignitor. When the button is pressed, current flows to the wire, then to the steel wool which heats up (it is against the match head) and ignites the match, which burns and lights the firework fuse. I decided not to use nichrome beacuse I have to order that online, and I could just pick up some steel wool for cheap at lowes or home depot. Nichrome is the standard for ignitors though, I assume it ignites more reliably, but I'm not sure.