233 replies to this topic

[pyrotrev]

This is a difficult one. Unless you're firing a ground maroon - more or less guarantees an open circuit there's quite a good chance that what's left of the igniter will have some residual resistance, either through it's remains or fused metallic/ionic residue from the pyro. The circuit may measure several hundred ohms, but with the typical detector circuits used this will still measure as a "made" circuit, others may go short. The best way (though doesn't help with shorts) is a circuit which detects less than 50 ohms.
BTW, 50mA test current would be considered a tad high, the igniter specs I've seen say a max of 10mA test current to ensure non-ignition. I would guess from your description of the igniters that they're Chinese, possibly from Cosmos, though that's not certain.

[paul]

Sorry to butt in guys!

I have a question: Do you think This circuit
will do any good charging two flash caps (each 360V) in series?! The output is 800V max and the AC is easily converted to DV to charge the caps. Power is 2W max.

That thing costs 2euro so, do you think it will be as easy as that? I use a camera flash unit for 2 years now but wanna try different circuits...

[BrightStar]

I have a question: Do you think This circuit
will do any good charging two flash caps (each 360V) in series?!

Interesting one... The potential problems are that the CCFL inverters operate at vey high frequency - several hundred kHz, so you'll loose quite a bit of power in the rectifier diodes. You'll have to use balancing resistors to even out the voltages in the series caps - another source of loss. The inverter will be optimsed for constant voltage, not the constant current that's best for cap. charging.

It might work, but with a long charge time. Very dangerous though - a few tens of joules stored energy at 800v could kill you. Just how long is your firing wire to need this???

[Andrew]

The biggest problem you have is that the device is designed to strike and run a tube. This module will not be able to supply much current all. It would take ages to rectify and store enough energy to blow a que, in the region of several to tens of minutes. It's not really suitable and would not last very long, unless you found a way to prevent it running at full power (making the charge time even longer).

[pyrotrev]

As Brightstar pointed out, do you really need 700 volts+??? Using normal cabling (13/0.2 twin or 7/0.2 coax) you can fire stuff at 500m with 48V. The rectification/smoothing problems are all easy to solve with he right components, it might be worth looking for a lower voltage inverter - I can remember seeing some 50...70V types advertised.

[paul]

Thanks for all the really helpful input guys! It is not a matter of what is really the limit (I know that 800V is way too much and that these voltages are not use in industries...)

I just wanted to know IF this circuit would do any good in charging caps. And you guys pointed out that this won´t work very well, which I am very thankful for!
I will try what is possible and what is not.

Again, thanks!

[Wyvern]

i have been looking into electronic ignition for my mortars and i think i have come up with a nice design which doesnt require any sort of e-match.

with my experience with high voltage im thinking of placing 2 thin nails which penetrate the lift bag from the bottom of the mortar which links to a 9v-3000v dc-dc setp up which is attached to the base of the mortar it is operated by a 9v battery and a switch inside a hand piece. Basicly when you flick te swithch 9v goes through the long wire to the mortar gets setpped up to 3000v and arcs across the nails and igniting the lift charge.

let me know what you think

[karlfoxman]

I can imagine a few dangers, one is a spark when lowering the shell. Sparks from metal. And secondly you run the risk of damaging the shell or causing a hole in the shell case. I think its dangerous.

[leosedf]

Not to mention the cost when you have 500 mortars...

[delta]

hey guys...hows the project of brightstar?....i'm so envy with one of the equipments here when i watch their show...when i look what system they are using...it is FIREONE...they have to controllers one is for wired and the other is wireless...i gotta say it is awesome!!....they just push the fire button and the rest is on the firing module...sync with music...i would like to ask is this achievable by an ordinary enthusiast like us??can we do this...or are we just stuck on our good o'l push all you want firing system?? guys give me a head up please...thanks...

[hoarp001]

I made a high voltage spark generator for one of my large combustion spudguns. It works in a very similar way to a stungun. It steps 9v up to 100,000 and will arc about 1inch. This is a painful and uncomfortable spark, but no where near fatal. It merely gives you a dead leg/chest etc etc for about 5 mins. I have already thought about using this to ignite lift charges and in my trials, it did not work. The spark just is not hot enough to ignite granulated BP.

BigClive has a circuit diagram for a stun gun on his site (www.bigclive.com) If you transform this schematic into a PCB layout (using pcb wizard or similar) you could then print the artwork out onto acetate, post it to me and I can make a proper PCB for you. (or you could do your own with the peel and press stuff and a jar of ferric chloride) Afew years ago there were problems with building these. The main components, the pulse transformer (a blue block in the photos on bigclive.com) were not available for sale over here. Now, however maplin sell them. Search for pulse transformer on maplin.co.uk

This means you could easily build your own HVSG (high voltage spark generator, as we call it in the spudgun world). This would probably ignite a fine powder, especialy if it atomized and airbourne, but not granuels....

You could use a neon transformer though. If you find an old retro shop being gutted, look for the neon transformer which produces thousands of volts and a dangerous current. These things can kill you so be careful.

Let me know if i can help...

[Wyvern]

You could use a neon transformer though. If you find an old retro shop being gutted, look for the neon transformer which produces thousands of volts and a dangerous current. These things can kill you so be careful.

Let me know if i can help...

Yeah i have a few Neon transformers kicking about from various tesla coil and jacobs ladder projects, i have tried the spark my step up makes and it does seem to ignite granulated bp as it is a hot plasma arc rather than just a spark, the only thing i need to sort out now is what im going to use as the media which ill arc over, as Karlfoxman says there is a slight possibility of sparking when i lower the shell.

[hoarp001]

hmm, yeah i think high voltages like that would travel over aluminium, or you couuld use brass or copper which are not so prone to sparking...

[Wyvern]

yeah, ill try some brass tacks, might be just what im looking for

[delta]

hey guys...hows the project of brightstar?....i'm so envy with one of the equipments here when i watch their show...when i look what system they are using...it is FIREONE...they have to controllers one is for wired and the other is wireless...i gotta say it is awesome!!....they just push the fire button and the rest is on the firing module...sync with music...i would like to ask is this achievable by an ordinary enthusiast like us??can we do this...or are we just stuck on our good o'l push all you want firing system?? guys give me a head up please...thanks...

anyone has a answer for this?