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Capacitor Discharge Project Fireworks

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by hfireworks, Oct 18, 2006.

  1. hfireworks

    hfireworks New Member

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    I am looking for information to apply to my fireworks firing panel for commercial display fireworks.

    I am looking for a capacitor discharge to allow a 12 - 24volt DC system to output a capacitor charge of 250volts DC. I guess the closest i can come to is a stun gun or electronic flash, however I would like to stay in the 12v to 24 volt range with the 250-300 vdc output.

    Our electric ematch will fire on our standard panels 3-4 ematchs but public Fireworks Displays require as many as 20 ematchs to fire at once.

    These is a link to a capacitor discharge unit
    http://www.oda-ent.com/Blasting Box 2.html

    http://pyromate.com/capacative-discharge.htm

    The fireworks panel I am building now is a 24vdc unit, and I would like to adapt capacitor discharge to it as I build it.

    You can view the process at http://www.hancefireworks.com/864panel.html

    Anything would be of help here if there are diagrams of this or drawing to adapt this it would help.

    Thanks
     
  2. wakanga

    wakanga New Member

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    Anyone has ideas?

    guys anyone has ideas to his questions?...i also need a circuit same as his...12VDC or 24VDC supply will do...thanks...:)
     
  3. Sceadwian

    Sceadwian Banned

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    E-matches work on current not voltage. If you wire them in parallel you'll only need the same voltage required to light one of them. A PC power supply can supply 12 volts at 10 to 20 amps or more, more than enough to light as many e-matches as you can hook up to it.. Those capacitive discharge boosters are for series wireing them, which is only useful if you want to garuntee that none of them go off unless they're all hooked up in series. The same thing can be done with continuity testing of the leads before fireing.
     
  4. dave

    Dave New Member

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  5. wakanga

    wakanga New Member

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    thanks a lot sir for you inputs...i need a lot of amps because im using a nichrome wire (home made fuse 1amp to 5amps), im not using commercial e-matches..

    we do need capacitive discharge to fire them in series and we need more voltage because of the lenght of the cables from the controls (100 feet to 1000 feet)...we use 22gauge to 24gauge wires....

    can you suggest sir any circuit for this kind of application?
     
  6. Firnagzen

    Firnagzen New Member

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    How often do you need it to fire?

    I'm no expert on electronics, but I HAVE tinkered with various stuff before, and what immediately jumps to mind is a disposable camera. Y' see, those disposable cameras have flashes inside them, the circuit is one which steps up 1.5v to ~200v. You could use something like that, I guess. (Hey, it's cheap and easy!)

    Just an idea.
     
  7. wakanga

    wakanga New Member

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    just once per channel...so let's say i have ten channel...i have to build ten circuits of those if i don't want a waiting time tho charge it...or build just one wait for it to charge...i don't want the one that is from the flash of the camera...i've already stumbled upon...what i want to modify is this circuit...

    [​IMG]

    the only problem about this is it's input voltage of 9VDC...so if anyone would like to modify the circuit so i could input a 12VDC or 24VDC in it...thanks
     
  8. hfireworks

    hfireworks New Member

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    Thanks for the response to my post, I have developed a Capacitor Discharge system to increase the voltage output to my system. It is currently producing 200vdc for a 24vdc source with 9 capacitor banks to fire my 36 switchs. These capacitors put out and enormous burst of power to ingnite ematchs.

    I have tested 9 ematch in parrallel with 600' of 24 ga wire, I am developing this system to fire multiple slats of series ematch.

    You can check my links on the progress to my system
    Thanks
     
  9. Hero999

    Hero999 Banned

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    It's true that you need a high current rather than a high voltage but if you've got an enourmous length of wire then a high voltage is often required to achieve a high current. I would also add a diode in parallel with the capacitor to protect it from any reverse voltage generated by the cable inductance.
     
  10. hfireworks

    hfireworks New Member

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    I believe you would do just fine with 12volts on this 9volt system, they usually work fine.:)
     
  11. Sceadwian

    Sceadwian Banned

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    I'd say put a capacitor right at the source and charge it with a slow current and then use a trigger pulse to cause the capacitor to discharge through the e-match but that has some serious saftey issues as you're essentially creating voltage sources at the target that can't be locally controlled in case of a failure.
     
  12. hfireworks

    hfireworks New Member

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    That's a good Idea but if you have 864 cues to fire it could get a little expensive to build all your slats with Capacitors.

    Using higher voltage to carry low current will do the same thing with as little as 9 capacitors.
     
  13. Oznog

    Oznog Active Member

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    I'd think any attempt to put ematches in series would make them unreliable unless they're really consistently designed! Once one burns open, the circuit is broken and the rest get no current. If one is substantially faster than others the slow ones may fail to ignite. Homemade ematches are going to be less consistent and more likely to fail like this.

    There is also a capacity issue. A photoflash produces high currents, but only quite briefly unless the capacitance is quite large (several in parallel will increase the capacitance). A pulse of tens of amps or more lasting only milliseconds may still be unable to heat the matches to the required ignition temp.

    IMHO, it is also unsafe as well as unnecessary to use HV here. 250V is absurd. Ignition boards are often just an array of nails and a screwdriver with + voltage on it. Putting a photoflash cap there is just asking to get a major shock.

    If they are all in parallel then one opening up will not affect the others.
    A high series resistance from long, thin wire may necessitate a higher source voltage. 12V or 24V sounds plenty high though!

    If your interconnecting wire is too thin for the thick nichrome you have, it may fail to work because the current might heat the interconnect wire up to a burning point before the nichrome will heat up. In this case voltage and current is irrelevant- any current high enough to power the nichrome will damage the wire first and higher voltages will only damage the wire even faster.
     
  14. hfireworks

    hfireworks New Member

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    I would have to say that I don't agree with the fact that ematch should not be used in series. Most of the major firing system companies suggest that you use ematch in series, It becomes neccessary to run them in parallel when you need to use several slats to do fronts.

    High voltage with low amps is a common usage in the fireworks firing systems these days. I agree that photo flash units that produce 350vdc will work but not very good in this use, the charge time is too long and the voltage is too high considering most wires require 300v range. Not very practicle.

    If you take a better look at ematch, they a designed these days to not break the bridge wire as easily so using them in series is optimal, if you take a look at the demos on my web site you can see that in the 9 ematch at parallel video I fire the ematch several times to burn the bridge wire. Of course continuity testing becomes more difficult in series than parallel.

    http://www.hancefireworks.com/864panelpower

    I do not believe it is unsafe to use a 200vdc system with low amps, as long as the conductors are insulated and you handle them as you should, I believe it is more dangerous to handle a 6" 1.3g shell with an ematch attached than the firing system itself. Or even plugging in your hair dryer to an outlet. We are talking DC voltage not AC voltage anyways.

    NFPA guidlines require that while working with electronic firing systems the main cables to the field are to be disconnected and the power source be switched off by key until ready to test and fire.

    Just my thoughts:)
     
  15. hfireworks

    hfireworks New Member

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    In my test with capacitors it is not necessary to have a large high current to achieve our goal as long as you have the higher voltage to carry the current. normally you would want at least 75ma per ematch to achieve this but with Capacitors you can work with lower amps:)

    In my system I am using 600' 24ga wire with 9 ematch in parallel with only 150ma at 200vdc. Calculations say this is impossible and it would be without Capacitors.
     
  16. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    DC is generally considered the more dangerous!.
     
  17. hfireworks

    hfireworks New Member

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    We are also talking 150MA
     
  18. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    150 mega amps is a LOT of current! :D

    Be more careful with your capitals!.

    Regardless of the current, 150mA DC is more dangerous than 150mA AC.
     
  19. Hero999

    Hero999 Banned

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    Is it?

    The British safty standards state that DC voltages over 60V need to be insulated but AC voltages over 25AC need insulation.
     
  20. mybuickskill6979

    mybuickskill6979 New Member

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    this doesn't relate to the circuitry but just a comment. fire works rock. once i get a little more learned this would be an awesome thing to set up for the 4th of july. thats my favorite holiday :D
     
  21. wakanga

    wakanga New Member

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    based on electronics theory you are correct...but based on experiments and applications some theories dont' say so....

    on the series connections issue...in fireworks we would like to have as low wire resistance as possible because we are using an enormous/longer length of wires (say 600 to 1000feet) so putting those e-matches in parallel would just increase your resistance...and also our goal here is just to pop those e-matches with the most safety way as possible...whether we are talking on DC or AC voltages...if not handled the right way...it will cause injuries...besides we are (fireworks guys) using components based on our requirements...we don't use SPST switches that says 50V 12A and we will gonna put it on a system that uses 250V 50A...

    what we (fireworks guys) need is a system that could drive a small amount of current on a 22gauge to 24gauge wire with a length of 600' to 1000 feet (some uses 1 kilometer wires) on a 12VDC,24VDC or whatever VDC inputs they use, to pop as many ematches on a single channel/cue (simultaneous firing/pop)...that's what we really want to achieve...we don't want to use large wires because of the not so cheap prices of this wires...so our common goal here is how to achieve that kind of system using the less expensive way and safest way possible...

    right now (Fireworks DIY guys) already have designed Wireless Firing Systems,Computer Controlled Firing System and Music Sync Controlled Firing system using Less expensive components...

    and to add about home-made ematches...i've used 36gauge and 40 gauge nichrome bridged wire on may homemade matches and fire them in series using 24VDC input at a 50 feet length 22AWG wire...all of them fire without a hitch a on a almost zero instant pop once you switch the cue...my only problem is if i'm gonna use a wire of 100feet to 200feet in length i could not fire simultaneously but i could fire just one home made ematch using 24VDC (parallel or series)...so that explains why we do need more voltage to drive the current to pop those matches in batches....using 24VDC input...

    my two cents
     
    Last edited: Jan 28, 2007

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