Hi all.
Just wanted to get some feedback on the type of electrical firing systems you use, cable type, voltage, capacitor or battery etc.
I am sorting out one of my own, I was going to purchase a 100m roll of 240v rated figure eight wire, but I thought, well if I'm going to make a small blasting box from a camera, the capacitor is probably more than 240v, and I wasnt sure if that would work so well on 240v wire, so I didnt buy it. Thats if I get the camera blasting box going, this Fuji camera I got is not so easy to take apart, I got a shock from the damn capacitor. :o

But then again, I might just use the afore mentioned cable and use a battery, I havent had anything to do with electronics for a while but I understand resistance, voltage, current etc.
Could I connect a few 9v batteries in a series to work it up to about 24v? I remeber something like that, but with two 12v batteries, when I was working with the pyro company last year. I'll still keep working on the capacitor discharge type (from the camera) but I want a reliable one up and running soon, for use on ANFO, and to try something other than fuse. Any advice would be very greatly appreciated, I have searched and got some info as well.

Edit: I just damaged the PCB from the camera, the capacitor is still intact, so is there any reason why I cant design a basic system where the capacitor is charged by a battery, then when the battery has been isolated from the circuit, another switch could be used to discharge the capacitor? I have a feeling a transformer is needed to charge the capacitor though.....forgive me for not remebering things, as I said, I havent been into electronics for a while.

green beret-

The rating on that "figure eight wire"? is for continuous duty. Is this the typical 2 conductor 18 gauge stranded conductor wire used for lamps and small appliances? We call it "zip wire" here (USA). If so, the insulating jacket is good for considerably higher voltages and the conductor is capable of much higher currents for the short pulse applications of a capacitor discharge system. If you've got 18 gauge wire and a 12V gel cell, you don't really need a capacitor discharge system unless you're contemplating shooting a number of charges with the igniters in series or over a hellaciously long run of wire.

I use several commercial firing systems, and nearly always use purpose made 22 gauge solid 2 conductor shooting wire with a 600 V rated jacket. For most of my uses, 24 V is sufficient. I have a capacitor discharge blasting box that will shoot 200 commercial e-matches in series in a run of up to 1000' of the 22 gauge solid for mine fronts & such.

Here's where I get most of my equipment:
Pyromate firing systems (http://www.pyromate.com/)
Seminole wire & cable blasting products (http://www.seminolewire.com/new_page_1.htm)

If you're going to design a capacitor discharge system, you're going to need to learn basic electronics first. If you're going to use ANY electrical firing system you should learn the basics of power handling, and how it applies to the job at hand. Are you at least familiar with Ohm's law? And have you searched the forum? There are at least two threads on fiing systems I've seen here.

I am going to stick with the 12v system, I have done some searching, and couldn't find out anything much about the difference between lead acid and gel cells- apart from the weight difference, would a 12v lead acid work as well as a gel cell for this application? I can obtain a maintenence free lead acid battery for a low price, otherwise I would have to special order the gel cell as the local places I have been to said they dont stock them usually. For 12v anyway.
Thanks.

Gell cells are lead acid with a gelled electrolyte, they are just more spill proof, no maintenance batteries. You can use any battery that will provide the voltage and current you need, of course. Only you know how much weight you're willing to carry-
Are you familiar with Ohm's law?

i use a 12v gel cell about 100mm cube. i also use a 100m reel of bellwire. i don't bother with all this fancy switch shit. i just have a very sensitive ignitor. 0.08mm nichrome, 4mm long bridge, initiating dextrinated 30/70 charcoal/KClO3. i basically short out the battery by connecting the 100m of wire to the ignitor then the wire to the battery. as there is such high circuit resistance it does the battery no harm. the sensitive ignitor still gets enough power to work though :)

Thanks guys, I appreciate your help. Yes bert I am farmiliar with Ohm's Law. I'll try and get some very thin nichrome wire, like what you have kingspaz, beats using expensive rocket igniters.
Cheers.

Its a little late now but Holiday lights are a great source for E-ignitors, they can work withas low as 1.5v although I wouldn't rely on that, but 6v is plenty for these little guys. At $3-4(usd) per string of 100 its a fair deal, when you consider the amount of patients it would take to make 100 nichrome ignitors.

The easiest ignitors I have ever dipped were conductive bridgewire ignitors. The bridgewire was lampblack wetted with NC laquer, the cables were CAT5 pairs stripped on one end (about 1cm) and bent as to be parrallel with around a 2-4mm gap the length of the stirpped section. The stripped ends are then dipped into the NC/C goo and left to dry. You can cover the conductive layer with whatever pyrogen you want, these ignitors do however require 12V at a decent current to ignite. These were used in place of easier bulb fillament ignitors in this case as they had to fit in relatively small rocket nozzles.

Blackhawk: I've been known to get analog type crap totally backwards, but it seems to me you could make your ignitors more sensitive by using a shorter bridge. At least if I am correct to understand that the carbon/NC compound is the actual bridgewire. What I'm thinking is, your stuff probably has high resistance, so a short bridge would allow more current and heat faster at lower V. A wide and long bridge would have the same resistance as a short and narrow one, but that means the heat would be spread through a larger volume. Or something. Anyway, I have a feeling I might soon dream of testing a 1x1mm carbon/NC bridge.

Blackhawk, what kind of lampblack did you use? I tried something with ground charcoal a week ago, and learned only after wasting a decent amount of my smokeless that the carbon itself was not conductive :mad: It seems the wood was not fully converted and there must still have been enough organic crap in it to stop it working.
Actually, my recent RPG project became an ignitor project of late, and I have yet to find a system that works. It may be my electrical setup, which consists of a switch and 9.6v model car battery I ahd sitting around. It actually reads 10.6v, but probably can't supply much current.
I was going to try a photo flash unit; I had a really shitty digital camera sitting around, but the flash unit was connected to the main board by eight leads and I wasn't going to fuck with that.
Instead what I did was, I took out the flash tube and soldered leads in its place, and also replaced the photodiode that's supposed to turn the flash off when there's enough light with another few leads I may later turn into a 'safe' switch. If it worked, I would've been able to take crappy pictures of stuff from too far away to see, just as it blows up :) It even has a 30s auto timer.
What went wrong was, my soldering iron had a short cord, and I only had under table outlets, and nothing to hold the workpeice in but my hands, as well as the iron and the pliers with which I was gripping the part I wanted to extract. The end result was all eight leads from the flash unit tore off the main board. Assuming the "1" markings by two of the pads denoted lead 1, the leads should all be in the right place, but I'm afraid I must have cooked the main board with all that soldering :(
Also, the flash tube was involved with three leads: one at each end, across which there was a small voltage (I think there's actually a filament), and one wire simple taped to the back of the tube. Does anyone have any idea which of these would actually have the hv output across them?
Aside from that, I tried steel wool, and it itself ignites, but without near enough heat to set anything off. Half the problem is I have #0000 steel wool, which is way the hell too fine, but even when I use multiple strands of this (hell, varying thicknesses of steel 'yarn'), whenever I coated them with any kind of laquer or match head/laquer, it didn't do anything. It even still had continuity, but it didn't do anything.
About the only positive thing I learned is that #0000 steel wool burns on its own if you stretch it out. Aside from being cool, this is an easy source of some form of iron oxide, possibly suitable for thermits. Still, I'm not going near that until after the ignitors and recoilless projects are done.
I guess I'll just have to find some christmas lights.

I had that idea as well, couldn't you just burn Fe instead of putting it through elctrosys or other methods which take a while?
I don't know what you would get out of burning Fe exactly, but surely its a type of iron oxide?

It forms small balls of slag which travel up the fibers as they burn, and some fibers simply have a small incandescent region that moves along them. After the first burn, there is usualy some uncombusted steel. After the second, it's very difficult to get any to burn. All products are gray.