After searching ibles, I realised that all the firework detonators were big. After googling "pocket sized fireworks detonator" there was nothing in the internet that could be called "pocket sized), so, I decided to make my own. All the parts from this project were salvaged from old appliances and the 9v battery used for the casing was free, becouse it was dead. This detonator doesn't have a internal power supply, so you have to connect a 9v battery outside to it and carry them together. Anyway, it is also a good thing, becouse when it dies all you have to do is use another, no need to unscrewing or screwing anything and you use other power supplyes that have a 9v battery plug. However, If you make one you can buy a gate remote 12v battery, which is very small and could easyly fit inside.
For this projec you will need:
An old 9v battery,
A new 9v battery,
Two pushbuttons (mine from an old DVD player),
A 3mm red LED (mine from an old kids toy),
A 270 ohm resistor (mine from the same place as the LED),
A key switch (with the key, of course), (mine from an old telephone),
A speaker plug (it's origin it's pretty self- explanatory),
Wire (from somewere),
Hot glue gun,
Hot glue sticks,
Paint (mine is yellow, and looks great),
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Step 1: Battery Massacre
The first step is to gut the battery. Try not to destroy it and not to bend the outside more than is needed.
First, using the screwdriver bend the metal in the battery's end in order to remove it's bottom, and, of course, remove the bottom.
Then, push the battery terminals inside and the whole battery's guts should come out. If needed use something to push them.
Now you should have 3 things:
The battery's bottom,
The battery's case,
And the battery's terminal and inner batteries.
Now cut the terminal and dispose the small batteries and the bottom environmentaly safe way.
To open the case use the screwdriver to unfold the battery case's joint and open it.
Step 2: Electronics
For the electronics just follow the schematic.
Remember one thing when you reuse the battery terminal, it's polarities reverse, so you will have to solder the negativ (-) wire to the positive (+) terminal of the battery and vice-versa.
Step 3: Drilling
Now you have to drill the battery case. Choose the layout you prefer and drill it. Don't forget to drill slightly bigger holes to the pushbuttons.
Step 4: Mounting
Now mount the key switch and finish the soldering job by soldering it and hot glue the pushbuttons, LED, battery terminal and so in place and insulate exposed wires and LED leads. You don't have worry if there are exposed wires touching the battery case becouse it doesn't conduc electricity, however, insulate them anyway.
At last, with everything in place, close the case. Idiscovered that the case's joint was bent, so I had to hot glue it in place, so make sure you don't close yours. Now, with the case closed just hot glue the battery terminal in place and the speaker terminal too.
Step 5: Optional, Painting
After building it, I realised that it wasn't visually appealing, so I gave it a quick yellow paintjob and wrote the functions in it.
Step 6: End and Use
Now you have a pocket sized fireworks detonator / model rocket laucher.
How to use:
1- you plug your appliance to the detonator using the speaker plug,
2- you plug the 9v battery using the 9v battery clip,
3- insert and rotate the key to ON position,
4- now the ARMED light will light up, meaning that you can now detonate/ launch whatever you have plugged into the detonator
5- press both pushbuttons (whether at the same time whether sequencially) and it will detonate / lauch it!
6- undo al the previous steps.
OPTIONAL- repeat the process.