Pyrotechnics controller - What it is, what it looks like, what it does, and how to build one.

A pyrotechnics controller is a device that is used to set off pyrotechnics effects.

It can be as simple as a little plastic box with a button, a battery and a safety gadget, but usually it is a bit more advanced than that;

Because most pyrotechnics effects are explosives, it is important that the controller is 102 % safe. Especially for some of the heavier effects, you wouldn't want one of them going off in your hands.

What does one of those controllers look like?

I have built mine myself, so it looks a lot like a desktop computer case, with lots of buttons and LEDs on it. They can (as mentioned) look from very very simple, to highly advanced DMX- like controllers (The kind that is used in theatres to control lighting). For very advanced firework displays (think Disney World, Newyear's eve and everything else that's large and nifty), the controller looks like a computer (usually a souped up laptop), because, eh, well... That's exactly what it is.

What do they do?

Pyrotechnic controllers come in three flavours:

Powercabled

This is the cheapest and easiest way - two cables are needed to set off the prop. The least complicated way is to have a button that connects the prop (like a body squib or something) to a battery. The disadvantage is that if you have a 100 props that are 50 feet away, you need 100*2*50 = 10,000 feet of cables. Takes ages to put out, ages to clean up, and chances of someone tripping over one of your cables grows very big.

If you build some IC's into your controller, you still need two cables to set off your prop, but you can do it in a bit of a smarter way:
- Two cables set off two different props
- Three cables set off three different props
- Four cables set off six different props
- Five cables set off ten different props
- etc.

This, however, makes the cabling on the other end (i.e where the props are) rather complicated. Complicated = dangerous. Dangerous = bad. (If there are two or more ways to do something, and one of those ways can result in a catastrophe, then someone will do it)

Controllercabled

This is the DMX approach. If you have all your props on stage, you only need to run two cables to the stage: One for power, and one for control. The signals you give on the controller are sent to a box on stage that sends electricity through the wires that you want electricity sent through. Works great, but is rather expensive.

Radio controlled

RC is fun, but in these times where everyone and their dog have mobile phones, it can be hell to work with. Mind you, a cell phone setting of a pyrotechnics prop is extremely rare. However, when I'm handling a fire cannon that is able to launch a 20 foot flame ball, I really wouldn't like to have that odd chance against me. As such, I personally prefer using powercabled system. The only time where RC is really handy seems to be when using body squibs.

How to build one

Most people with the vaguest idea about electonics (not even electronics, to be fair.. Just some logic and some soldering paste) would be able to build one without this recipy.. But hey :)

This will be a powercabled controller.

       _
9V    | |--A-+--+--+--+--+
battery |    O  |  |  |  |
      |_|----+--|+-|+-|+-|+
                || || || || 
                |B |B |B |B
                || || || ||
                TT TT TT TT

A: key circuit breaker. This is your safety device - when you are rigging the pyro, you really want to turn off your device and have your key in your pocket.
O: This is a small LED that lights when your key is in the "on" position. If the light is on, you don't want anybody near the props
B: Button. When the key is on, and the button is pressed, power goes through the cables, and your prop goes off.
TT: I use quick release speaker terminals here. You know, the kind where you press a button, you slip in your cable, and let go of your button, securing the cable in its socket. You can, of course, use basically any way to connect the controller to the props, but this system is reasonably secure, and reusable.

Well.. That was simple, wasn't it? You can, of course, add as many terminals as you want to.


Back to the node on pyrotechnics
Please read the disclaimer. Also, make sure you have read the Pyrotechnics safety tips. SAFETY FIRST