Electrical Firing System

pyrotechnist,

Think of it this way...
In your house you have light switches, the light switches are connected to a circuit breaker. If everything is of then there is no light, if you turn the light switch on there is still no light as the cicuit breaker is off.
Now, if you turn the circuit breaker on, there is no light but if you then turn the light switch on then the light will come on.

Simple idea for a 20 cue firing pannel, get 1 key switch, 20 push button switches, 20 speaker connectors (type that you push and it opens so you can insert a wire then realease and it holds onto the wire), and a power source.. battery and a long lenght of 12 pair cable (24 wires inside) and 2 box's.
Mount the key switch and all the push button switches on one box and mount all the speaker connectors on the other box.
From the (-) side of the battery, connect 1 wire, the same wire connect to every black connector on the back of the speaker connectors.
Now connect every wire (1 wire) to each of the red sides on the speaker connectors and the opposite end of each of the wires onto one side of each of the push button switches. (not the wires used to the (-) side of the battery and you will also have 3 spair)
When this is done, connect a wire from the (+) side of the battery to one side of the key switch, connect another wire from the other side of the key switch to every push button switch.
Now when you turn the key switch, it allows power to one side of the push buttons but not up to the speaker connectors, if you push any of the buttons now it will allow the power to travel to the speaker connector and fire the attached device(s).

This is very a basic system. you can add in bits to do continuity tests and little LED's so you can see which buttons are active etc.

Mark

Edited by The_Djinn, 15 July 2004 - 08:07 AM.

Hmm nice thanks. How come some firing systems have channels and cues on the same control box?

How do you say which slave box you want to go to on the system you need a button for that or rotary switch? Thanks.

DJinn could you pleas drwa a diagram of what you are talking about i can understand it better ? Thanks agian.

Edited by pyrotechnist, 15 July 2004 - 07:00 AM.

I knew you were going to ask about different channels but I thought I would keep it simple.

To add another channel, make a second box identicle to the one with the speaker connectors on it.
Buy a rotary switch (for this example a 2 position switch) and mount this on the main control box.
Cut the wire that is connected to the (-) side of the battery and connect from the (-) on the battery to the common connector on the rotary switch. Now connect the other side of the wire you cut (side that connects to the black connectors on the speaker connectors) to position (A) on the rotary switch. Take the spair wire that was not used in the first post and connect it to the position (B) on the rotary switch and the opposite side to the black connectors on the second box you just made.
Now you have to link each of the connectors on the red speaker mounts on box (A) to each of the red speaker connectors on box (B).

The principle is that if the rotary switch is in position (A) and you push any of the buttons you will fire devices on box (A) and if the rotary switch is in position (B) you will fire devices on box (B) - you now have a 2 channel system capable of firing 20 cues per channel giving you a total of 40 cues on 2 channels.

using a 12 pair cable (24 wires) and a 4 way rotary switch you can create a 4 channel system capable of handling 80 cues.

Read what I have said caerfully and draw it out as I have explained it... it is very simple.

Mark

Edited by The_Djinn, 15 July 2004 - 08:05 AM.

Ok thanks I will try lol .

This is a firing panel that myself and two friends made.
It runs on 12v.
Has safety key and arm light.
Has green LED's that draw the current and light when the circuit is good.
When fired the LED's go out to let you know the circuit is clear.

Ive tested it with both homemade and Estee e-matches and it works well here's a piccy.

hope this link works

That looks very professional! Job well done.

Second that. Well made tools inspire confidence.

One point lots of pro firing systems fire a pulse of about 100+ volts from a capacitor ( charged from a battery by a small oscilator) this allows several igniters to series fire from one circuit and allows the use of smaller/longer wires to the devices. There are crimps like scotchlocs for joining wires also RS do some hand squeezable reusable connectors. ( 178-6676 is the reusable spring connector. 239-3988 is a suitable crimp ( one time only needs pliers! ) )

Edited by Arthur Brown, 26 July 2004 - 06:56 PM.

Capacitive discharge isn't really that practical, there are other ways of going about it... it's also worth remembering that igniters are current devices not voltage ones, so unless you are after massive cable runs on thin wire, I'd recommend 24v.

Don't use Cat5 cable unless you get "patch lead" style stranded conductor, single conductor/core cable is mean for installation not for regular movement.

Yanhua

This is the one point that sold me on Fireone equipment. No multi core cables, just plain simple lamp cord / speaker cable to the addresable firing modules.
If I had a system that used multi core cable I would want to cary a complete set of spair cables with just in case of a break.

But I agree, the panel chemicalwazi has made is very neet and professional looking. Shows someone who takes pride in what they do.

Mark

Hi thanku i have been away for a bit doing 3ds modeling on fireworks lol. Thanku chemicalwazi for that awsome firing panle you havem ade the pictures. Also for the rest of you to thanku thanku thanku .

I want to make a really simple electrical firing system to set off single devices. I have 50 metres of insulated copper wire and a load of nichrome wire. As well as a load of various switches. I am planning to make simple e-matches with the nichrome by bridging a gap in the copper wire and covering it in something like dark flash or meal paste. What I need to know is what kind of battery I will need i.e. voltage and ampage needed. Also will I need a capacitor to send a sudden strong electrical charge down the wire? Sorry if I am sounding stupid but I know nothing about electronics.

Sorry if a similar topic is not already on the forum.

Do a search on the forum, I basically spell out a design for a firing system on here. It starts as a 12 cue system if I recall but I go on to explain in a fair bit of detail how simple it is to icrease this. You can quite easily tailor my posted layout to suit your needs.
As for the niachrome wire e-match.. depending on the gauge niachrome you have will depend on the battery requiered.. Motorcycle battery can do the job.

A proper pyrotechnic igniter is made to NOT fire at 20mA and certainly fire at 500mA. It is also lightly primed and then covered in lacquer to prevent chemical incompatibilities.
The 20mA not fire part of the spec is to enable the completed firing circuit to be carefully checked for continuity. A typical igniter has a resistance of 1.4 - 1.6 ohms and will fire at 500mA so a PP3 / PP9 / 12v lead acid alarm battery will work fine. Why not BUY igniters and a PP3 based firing system, Its likely to be more reliable.
Also Nichrome is too hard to solder well and having a batch of dodgy igniters is very scary you end up walking back to a lit device to see why it didnt do as expected - VERY dangerous.

I seems like since we don't remark people are going back to old habbits. PLEASE SEARCH BEFORE OPENING NEW THREADS!!!!!!!!!!!

Electrical firing systems have been discussed in a different thread and any new posts on the subject should be done under that thread.

BigG,
Where can I find Electrical firing systems issue in this forum.
Thank you