Fireworks Controller
Intro: 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.
DISCLAIMER:
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!
DISCLAIMER:
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!
STEP 1: Parts
Here is the parts list. I bought most of the electronics from Jameco , but also bought things from Parts Express , Radioshack, and Michaels.
From Jameco Electronics
1- 12v Sealed Lead Acid Battery
1- SPST (Off-On) Keylock switch
1- SPDT (3 position On-Off-On) Toggle switch
24- LED mounting hardware
12- SPST ( Off-(On) Momentary) Pushbutton switches
12 - Red LEDs
12- Green LEDs
48 - 470 ohm Resistors
12- Alligator clip pairs (24 total)
2- battery clips
1- 1/4" fuse (there is no specification on the fuse for right now, the original fuse value had not worked and I am currently figuring out what amperage fuse to use. Sorry for the inconvenience. You can still build the controller, since it still works without a fuse. Use a short piece of wire to bypass the fuseholder for now.)
From Parts Express
6- Four conductor speaker terminal
Check out this page for different types of terminals. This controller's circuit is expandable, so it can have as many channels as you want it to have, so be creative!
From Michaels or any craft store
One 12 x 12 piece of wood panel - must be 1/8" thick - available at Michaels, possibly at hardware stores
Other Parts
> A case to put it all in -I got mine at a thrift shop for $5.00. It was used as a carrying case for an old VHS video camera.
> 12 short wood screws (that fit inside speaker terminal mounting holes but can still reach the wood panel below them)
> Also, you will need wire for connecting the panel components. I used 22AWG solid wire, but any wire from about 22-18AWG should work fine.
> You will also need long speaker wire or any insulated 2 conductor wire. How much depends on how much you can afford or how far away you want to be from the fireworks. Both Lowes and Home Depot sell some cheap wire in bulk and in spools. Wherever you buy it, buy it in bulk to save money. We're not looking for audio quality here. I used 18 gauge lamp wire, which I bought in a bulk spool and cut into smaller lengths.
Not every one of these parts has to be used, feel free to experiment or use different switches, buttons, terminals, etc. Make yours unique to suit your needs, you don't have to build yours like mine, but you can.
STEP 2: Hardware Needed
Woodworking Tools
A drill press would help to cut the holes in the panel, but I don't have one of those and you can still cut the holes with a regular drill.
If you don't have the right size drill bit for all of the panel-mounted parts you can use a dremel to widen the holes like I did.
Electronics Tools
- Drill (hand or power)
- Ratchet brace (or a bigger drill). I have one of these, so I used it. You don't have to use this.
- Auger bits (spiral shaped large drill bits)
- Drill bits - check with the place you bought your components from for hole diameters and dimensions.
- Dremel or other rotary tool
- Dremel bits (sanding)
- A small saw (for cutting the plywood)
- C-clamps
- Screwdriver
- Pencil
- Ruler
A drill press would help to cut the holes in the panel, but I don't have one of those and you can still cut the holes with a regular drill.
If you don't have the right size drill bit for all of the panel-mounted parts you can use a dremel to widen the holes like I did.
Electronics Tools
- Soldering iron
- Rosin-core solder
- Electrical tape
- Needle nose pliers
- Wire cutters
- Scissors
- Helping hands (or buildyourown)
STEP 3: Designing a Template
I just sketched a template for the panel out on paper to start with. You can arrange things however you like on the board, depending on the size of the case you are putting everything in. I designed everything on a 8.5"x11" piece of paper and just centered it on the wood panel (12"x12") when it was time to start cutting.
Start with arranging the speaker terminals, which I put on top in two rows of three. They have an outside dimension of 2-3/4" x 15/16".
Next came the toggle switch, key switch, and fuse holder. I centered the toggle switch horizontally on the board right under the speaker terminals. The key switch is to the right of the toggle switch, and the fuse holder is to the right of the key switch.
Underneath these main switches are the pushbutton switches and LED status indicators.
The buttons I arranged in 4 columns of 3 buttons. Each button also has two LEDs; one on either side. I did not include the LEDs on the template, because I just eyeballed where to put them. You also might want to arrange them differently on yours, by putting the LED pairs under the switch or above them instead of on opposite sides.
Attached is a PDF template so you can print it out yourself. Print it and tape it over the panel you choose to use, and you can drill/saw through it to get everything properly lined up if you want to match my layout.
Start with arranging the speaker terminals, which I put on top in two rows of three. They have an outside dimension of 2-3/4" x 15/16".
Next came the toggle switch, key switch, and fuse holder. I centered the toggle switch horizontally on the board right under the speaker terminals. The key switch is to the right of the toggle switch, and the fuse holder is to the right of the key switch.
Underneath these main switches are the pushbutton switches and LED status indicators.
The buttons I arranged in 4 columns of 3 buttons. Each button also has two LEDs; one on either side. I did not include the LEDs on the template, because I just eyeballed where to put them. You also might want to arrange them differently on yours, by putting the LED pairs under the switch or above them instead of on opposite sides.
Attached is a PDF template so you can print it out yourself. Print it and tape it over the panel you choose to use, and you can drill/saw through it to get everything properly lined up if you want to match my layout.
STEP 4: Cut the Wood
Now that you have your template designed, its time to start cutting the wood. I started out cutting the key switch hole, since it was in the middle. I then moved on to the pushbutton switches, then the speaker terminals, and then the toggle switch and fuseholder holes. You can do it in whatever order you like.
One thing I do suggest is to cover the back with tape to prevent splintering of the wood since you are working with such thin material. I also drilled halfway through one side and then flipped it over to drill all the way through the other side to keep it from splintering even more.
After that you should drill the toggle switch and fuse holder holes (I didn't do this in order, don't know why not). I don't have the correct size drill bit, so I used the dremel to widen these holes to the correct size.
After you get those holes drilled, start cutting the slots for the speaker terminals. I used a drill to drill pilot holes at each end of the line, then a small saw to cut the wood in between them. The saw cut a wide enough line to slip the thin metal tabs of the speaker connectors through them. Use a dremel sanding bit to smooth out all the holes and cuts and get rid of rough edges and splinters.
After this you can test fit the components to make sure everything is lined up well and fits. Take everything back out when you are done, because there's more to do.
One thing I do suggest is to cover the back with tape to prevent splintering of the wood since you are working with such thin material. I also drilled halfway through one side and then flipped it over to drill all the way through the other side to keep it from splintering even more.
After that you should drill the toggle switch and fuse holder holes (I didn't do this in order, don't know why not). I don't have the correct size drill bit, so I used the dremel to widen these holes to the correct size.
After you get those holes drilled, start cutting the slots for the speaker terminals. I used a drill to drill pilot holes at each end of the line, then a small saw to cut the wood in between them. The saw cut a wide enough line to slip the thin metal tabs of the speaker connectors through them. Use a dremel sanding bit to smooth out all the holes and cuts and get rid of rough edges and splinters.
After this you can test fit the components to make sure everything is lined up well and fits. Take everything back out when you are done, because there's more to do.
STEP 5: Drill the LED Holes
Next we'll drill 48 holes for the LEDs. I did not use the template for them, I simply eyeballed their location. I used a 1/4" drill bit for them, and put them on either side of each pushbutton, slightly below center.
Arrange them however you want to on yours (below the buttons, above them, on one side of them, etc.)
After you have all the holes drilled, you'll have to sand down the backsides of them so that the back parts of the LED mounts can snap on to the front parts. The wood is too thick do do this without sanding it down. I used the barrel-shaped sanding bit for the dremel to do this, by pushing down on one side, rotating 180 degrees and doing it again (see pictures). If you can find a different way to mount the LEDs you might not have to do this.
Now that all the woodworking is done, we move on to mounting the panel's electronic components.
Arrange them however you want to on yours (below the buttons, above them, on one side of them, etc.)
After you have all the holes drilled, you'll have to sand down the backsides of them so that the back parts of the LED mounts can snap on to the front parts. The wood is too thick do do this without sanding it down. I used the barrel-shaped sanding bit for the dremel to do this, by pushing down on one side, rotating 180 degrees and doing it again (see pictures). If you can find a different way to mount the LEDs you might not have to do this.
Now that all the woodworking is done, we move on to mounting the panel's electronic components.
STEP 6: Mount the Components
Start out with the speaker terminals, since they are the biggest thing and they need to be screwed in.
Grab your 12 screws and your screwdriver, then place each speaker terminal block in each of the six slots on the top of the wood. If one or two don't quite fit through the slot, swap them out with another one. Some of the speaker terminal soldering tabs were more spread out than others on mine, and they all ended up fitting in one slot or another.
Screw in each speaker terminal with two screws, then use a dremel cutoff disk to grind down the part of the screw that sticks out on the other side so it won't cut through the wires that will be on the back.
After that, I installed the key switch, toggle switch, and fuse holder. All of these components had nuts on the back that would secure them through the mounting holes. Tighten them in with pliers or a wrench, but be careful not to splinter the wood; they don't have to be excessively tight, just tight enough to not spin when you turn the key or flip the switch, etc.
The pushbutton switches had tabs on the sides that put pressure on the sides of the hole and held them in. Reinforce them with hot glue on the back to better secure them and keep them from spinning in place.
Next, install the LEDs. Gather all the LED mounts and pair the tops with the bottoms. The tops are the ones with four tabs that come down, and the parts that go on the back of the panel are the plain rings of plastic.
To mount the LEDs:
1. Slide the top part of the mount over the top of the LED until it snaps into place with the four tabs past the bottom of the LED (not the leads, just the light)
2. Mount the LED on the board. Depending on the size of the hole it will snap through and stay there.
3. Flip the board over
4. Take the bottom part of the mount (the ring without tabs), and slide it over the LED leads and onto the top part of the LED mount. Due to the thickness of the wood, it won't completely snap onto the top part of the mount, so put a good dab of hot glue over the whole thing.
You also might want to label the back of the panel to help you remember what's what when you wire it.
Now that you have all the components mounted, we can continue on to the electrical wiring.
Grab your 12 screws and your screwdriver, then place each speaker terminal block in each of the six slots on the top of the wood. If one or two don't quite fit through the slot, swap them out with another one. Some of the speaker terminal soldering tabs were more spread out than others on mine, and they all ended up fitting in one slot or another.
Screw in each speaker terminal with two screws, then use a dremel cutoff disk to grind down the part of the screw that sticks out on the other side so it won't cut through the wires that will be on the back.
After that, I installed the key switch, toggle switch, and fuse holder. All of these components had nuts on the back that would secure them through the mounting holes. Tighten them in with pliers or a wrench, but be careful not to splinter the wood; they don't have to be excessively tight, just tight enough to not spin when you turn the key or flip the switch, etc.
The pushbutton switches had tabs on the sides that put pressure on the sides of the hole and held them in. Reinforce them with hot glue on the back to better secure them and keep them from spinning in place.
Next, install the LEDs. Gather all the LED mounts and pair the tops with the bottoms. The tops are the ones with four tabs that come down, and the parts that go on the back of the panel are the plain rings of plastic.
To mount the LEDs:
1. Slide the top part of the mount over the top of the LED until it snaps into place with the four tabs past the bottom of the LED (not the leads, just the light)
2. Mount the LED on the board. Depending on the size of the hole it will snap through and stay there.
3. Flip the board over
4. Take the bottom part of the mount (the ring without tabs), and slide it over the LED leads and onto the top part of the LED mount. Due to the thickness of the wood, it won't completely snap onto the top part of the mount, so put a good dab of hot glue over the whole thing.
You also might want to label the back of the panel to help you remember what's what when you wire it.
Now that you have all the components mounted, we can continue on to the electrical wiring.
STEP 7: Wiring the Components: Part 1
Connecting the components is probably the most daunting task of building this fireworks controller, but don't be afraid! Just follow step by step and watch what you are doing. Everything you have to do is covered here. Also, print out the schematic to double check your wiring after each step. It also helps to know how to solder. Search "how to solder" for more info.
I wired the push button switches to the speaker terminals first, running wire from one side of the pushbutton switches to each of the corresponding speaker terminal tabs. See the schematic for details.
After wiring these, I connected the fuseholder to the keyswitch and the keyswitch to the middle pole of the toggle swtich.
Next, connect all of the negative tabs of the speaker terminals (the pair in the middle) to each other and then together to a single wire leading to the quick connect tab that will later attach to the battery.
See the photos for more detail (they are in order). There is also the schematic file that made the image below. It was made in TinyCad.
I wired the push button switches to the speaker terminals first, running wire from one side of the pushbutton switches to each of the corresponding speaker terminal tabs. See the schematic for details.
After wiring these, I connected the fuseholder to the keyswitch and the keyswitch to the middle pole of the toggle swtich.
Next, connect all of the negative tabs of the speaker terminals (the pair in the middle) to each other and then together to a single wire leading to the quick connect tab that will later attach to the battery.
See the photos for more detail (they are in order). There is also the schematic file that made the image below. It was made in TinyCad.
STEP 8: Wiring the Components: Part 2
Before connecting the LEDs, we first have to solder together 24 pairs of the resistors. Remember that for resistors, direction doesn't matter. To make things easier, cut about half the length of of one side of each resistor before you solder them together so the whole assembly takes up less space.
Once all 24 pairs of resistors are soldered together, you can solder them in between the negative side of the LEDs (the shorter lead) and the side of the pushbutton switch attached to the speaker terminal for each channel. We'll be doing both the green and red LEDs in the same step, since they both connect to the same place.
To make things easier when soldering the resistors to the LEDs, where they connect to the pushbutton switch, you can solder the resistors for the red LED to the switch tab, and then solder the green LED resistors to the red LED resistor lead so they are not both attached directly to the small pushbutton switch tab. A diagram is included in the photos below to help clear this up since it is a bit confusing.
Once all 24 pairs of resistors are soldered together, you can solder them in between the negative side of the LEDs (the shorter lead) and the side of the pushbutton switch attached to the speaker terminal for each channel. We'll be doing both the green and red LEDs in the same step, since they both connect to the same place.
To make things easier when soldering the resistors to the LEDs, where they connect to the pushbutton switch, you can solder the resistors for the red LED to the switch tab, and then solder the green LED resistors to the red LED resistor lead so they are not both attached directly to the small pushbutton switch tab. A diagram is included in the photos below to help clear this up since it is a bit confusing.
STEP 9: Wiring the Components: Part 3 (Armed Circuit)
After you have the negative sides of both LEDs connected, we need to attach the positive side of the red LED to the armed circuit.
This will be achieved through the use of a short jumper connecting the currently unused tab on the pushbutton switch to the positive lead of the LED. The negative side of the LED is already connected to the speaker terminal via the resistors to the wire leading to the terminal blocks.
Cut 12 short lengths of wire, stripping each end about 1/4". Slide one end all of the way through the hole in the pushbutton switch tab, and lean the other against the positive lead of the red LED. Solder the jumper to the pusbutton switch tab and the positive lead of the LED, then snip off the extra wire on the LED side only. Leave the extra sticking out through the switch tab, since we will be connecting the main armed circuit to it. Do this for each of the 12 channels.
Now it's time to connect all of the individual channels to each other and to the armed circuit. Cut 8 more wire jumpers, once again stripping 1/4" off of each end. Use red wire if you want to keep things visually organized. The red jumpers will be connected between the extra wire on the black jumpers so that the left sides of the pushbutton switches are all connected to each other.
Connect all of the channels to each other in each column, then bridge each half of the columns together. The middle two will have a second jumper on the top channels (4 and 7) in each column that will run directly to the toggle switch. See the last picture below to clarify this.
Now the armed circuit is complete.
This will be achieved through the use of a short jumper connecting the currently unused tab on the pushbutton switch to the positive lead of the LED. The negative side of the LED is already connected to the speaker terminal via the resistors to the wire leading to the terminal blocks.
Cut 12 short lengths of wire, stripping each end about 1/4". Slide one end all of the way through the hole in the pushbutton switch tab, and lean the other against the positive lead of the red LED. Solder the jumper to the pusbutton switch tab and the positive lead of the LED, then snip off the extra wire on the LED side only. Leave the extra sticking out through the switch tab, since we will be connecting the main armed circuit to it. Do this for each of the 12 channels.
Now it's time to connect all of the individual channels to each other and to the armed circuit. Cut 8 more wire jumpers, once again stripping 1/4" off of each end. Use red wire if you want to keep things visually organized. The red jumpers will be connected between the extra wire on the black jumpers so that the left sides of the pushbutton switches are all connected to each other.
Connect all of the channels to each other in each column, then bridge each half of the columns together. The middle two will have a second jumper on the top channels (4 and 7) in each column that will run directly to the toggle switch. See the last picture below to clarify this.
Now the armed circuit is complete.
STEP 10: Wiring the Components: Part 3 (Test Circuit and Final Wiring)
Now we will wire the test circuit, which will be pretty straightforward.
Cut 8 short jumpers out of black hookup wire, stripping 1/4" off of each end, and solder them between the positive leads of the green LEDs in each column. Connect the first two columns together and the second two columns together using a longer jumper along the bottom of the columns. Then use jumpers to connect each half of the channels to the lower, unused tab on the toggle switch. This is the same arrangement as the armed circuit.
The last thing to wire is the positive connection to the battery. This will go directly from the fuseholder to a quick connect terminal and then to the battery, since everything past the fuseholder is already wired and ready to go.
Cut 8 short jumpers out of black hookup wire, stripping 1/4" off of each end, and solder them between the positive leads of the green LEDs in each column. Connect the first two columns together and the second two columns together using a longer jumper along the bottom of the columns. Then use jumpers to connect each half of the channels to the lower, unused tab on the toggle switch. This is the same arrangement as the armed circuit.
The last thing to wire is the positive connection to the battery. This will go directly from the fuseholder to a quick connect terminal and then to the battery, since everything past the fuseholder is already wired and ready to go.
STEP 11: Testing Your Wiring
After you have everything finished, connected, and soldered, it is a good idea to test each channel to make sure everything is wired right and there are no shorts.
Install a fuse in the fuseholder and attach the negative lead (that goes directly to the speaker terminals) to the negative connection on the battery and the positive lead (that goes to the fuseholder) to the positive connection on the battery.
To test my panel, I hooked up a short length of 2 conductor wire (2 ft or so) to the board, and on the other end just wrapped a strand of steel wool between the wires to use as a test. This way I could make sure the resistor values were correct for the LEDs (to not ignite the wire in test mode, but do so in armed mode) and that the steel wool burned up when the button was pressed.
Once you have verified that all LEDs operate properly and each channel successfully burns the steel wool in Armed mode only, disconnect the battery and flip the panel upside down. Cut off all excess LED lead sticking up past the solder connection on the jumpers and check to make sure there aren't any wires crossed that shouldn't be.
Find a good spot to place the board in the metal suitcase, or whatever you have decided to place the controller in, and make sure the battery is securely attached inside of the case.
The final step is to label it, and you're ready for some remote fireworks detonation action.
Install a fuse in the fuseholder and attach the negative lead (that goes directly to the speaker terminals) to the negative connection on the battery and the positive lead (that goes to the fuseholder) to the positive connection on the battery.
To test my panel, I hooked up a short length of 2 conductor wire (2 ft or so) to the board, and on the other end just wrapped a strand of steel wool between the wires to use as a test. This way I could make sure the resistor values were correct for the LEDs (to not ignite the wire in test mode, but do so in armed mode) and that the steel wool burned up when the button was pressed.
Once you have verified that all LEDs operate properly and each channel successfully burns the steel wool in Armed mode only, disconnect the battery and flip the panel upside down. Cut off all excess LED lead sticking up past the solder connection on the jumpers and check to make sure there aren't any wires crossed that shouldn't be.
Find a good spot to place the board in the metal suitcase, or whatever you have decided to place the controller in, and make sure the battery is securely attached inside of the case.
The final step is to label it, and you're ready for some remote fireworks detonation action.
STEP 12: Label the Front Panel
Labeling the front panel is important so that you don't accidentally arm the circuit instead of put it on test, etc.
I just used a Dymo embossing label maker, but you could also write it on the wood with a marker if you want to. I labeled each speaker terminal pair, each pushbutton switch, and the main switches (Toggle and keylock). See pictures below for layout.
I just used a Dymo embossing label maker, but you could also write it on the wood with a marker if you want to. I labeled each speaker terminal pair, each pushbutton switch, and the main switches (Toggle and keylock). See pictures below for layout.
STEP 13: Ignition Wires
Get the cheap 2-conductor wire, and cut it into 12 equal lengths depending on how far away you want to be from the fireworks. I cut mine at 20 feet each, but later realized that that is a little too short. The wires should be as long as you want them to be to feel safe about being at the controller and launching the fireworks from that distance.
Strip off about 1/2" on each end of the 12 wires, and solder the alligator clips on one end, or wrap the wire around the screw on the alligator clip. Make sure this connection is secure and wrap it in electrical tape. Polarity does not matter for the ignition wires, neither does the color of the alligator clip, it just has to complete the circuit with the ignitor.
Strip off about 1/2" on each end of the 12 wires, and solder the alligator clips on one end, or wrap the wire around the screw on the alligator clip. Make sure this connection is secure and wrap it in electrical tape. Polarity does not matter for the ignition wires, neither does the color of the alligator clip, it just has to complete the circuit with the ignitor.
STEP 14: Finished Board
To operate the board:
2- On the other side connect an igniter using the alligator clips, one on each wire.
- make sure battery is disconnected and all switches are on the off position
- connect all of the ignition wires, one per channel:
2- On the other side connect an igniter using the alligator clips, one on each wire.
- connect the battery
- insert key into the main on/off keyswitch and turn to on
- 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 make sure the ignitor is securely attached to the launch wires.
- clear the area around the fireworks and make sure you are at a safe distance from people, animals, cars, houses, trees, dry grass, etc. (the normal precautions)
- once all connected channels have green lights, flip the toggle switch to arm
- the red LEDs will turn on, and at this point pressing a pushbutton will supply full power to the ignitor, setting off the firework.
- 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.
- Turn the toggle switch to the off position
- Turn the keyswitch to the off position and remove the key (put it in your pocket)
- Disconnect the battery
- Unplug each of the long wires from each channel that lead to the fireworks
- Dispose of burned ignitors
STEP 15: Acknowledgements and Notes
You may notice that there is no specification on the fuse for right now, the original fuse value had not worked and I am currently figuring out what amperage fuse to use. Sorry for the inconvenience. You can still build the controller, since it still works without a fuse. Use a short piece of wire to bypass the fuseholder until we get the right fuse working.
Also, the construction of the actual igniters is covered in a separate instructable located here.
I would like to thank the following people for their answers, explanations, and contributions to this project:
Also, the construction of the actual igniters is covered in a separate instructable located here.
I would like to thank the following people for their answers, explanations, and contributions to this project:
- Jon Witucki for the inspiration to make this controller and info on speaker terminals
- everyone at electro tech online, especially eblc1388 for his schematics and electronics knowledge
- tobyfan57 for making me realize what wasn't clear on the instructable to start with and finding a few inconsistencies in the steps
- Also, thanks to TinyCad for keeping their program open source and easy to use so I could make my schematic
392 Comments
cmazzei 12 years ago
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!!
ebolson 7 years ago
Hey, do you mean that for each LED use one 220 and one 470 or are the 220-Ohm resistors used elsewhere? Also, where did you find duncant20196's schematic?
cmazzei 6 years ago
I looked back through and found duncant20196's comment:
"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!
http://www.duncan-tempelmeyer.net/wordpress/wp-content/uploads/2009/05/updated_instructable_led_resistor.jpg"
I think this was where I found the schematic but the content is no longer available. I searched Google cached pages as well as as the Internet Wayback Machine but still could not find it for you :-/
I'm pretty sure I used at least a 220-Ohm and 470-Ohm resistor for each LED. Beyond that, I cannot recall if there were additional 220-Ohm resistors used. I hope this is somewhat helpful.
airsoftdominator999 12 years ago
cmazzei 12 years ago
hhhdrb 12 years ago
cmazzei 12 years ago
mmike1 12 years ago
cmazzei 12 years ago
microman171 14 years ago
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 =)
microman171 14 years ago
systemf92 11 years ago
pdionne 11 years ago
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 14 years ago
diwanshuguleria 3 years ago
RJCo 10 years ago
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.
systemf92 3 years ago
arce6565 7 years ago
systemf92 3 years ago
Jason M.H 5 years ago
I know this post is over 9 years old now, but I just wanted to chime in and say that I've built mine for this year :)
I've touched up the wiring a bit with the resistors so that there is less of a chance of them bridging/shorting out when I put the board into the case. Unfortunately, I forgot to take pictures of that when it was done :(
I opted to go with Red LEDs for the "Test" with Green for "Armed". I don't know why, but I did.
I tested it with some ignitors that I purchased from Pyroboom, and it works great. I have 4 12v 7A batteries, so in case one dies, I can swap it out with another one and continue on with the show.
This year, a group of about 15 of us each dropped $200 (give/take) on fireworks, so we will have one hell of a show for the family.