Capacitor Discharge Project Fireworks

[hfireworks]

You hit the nail right on the head, If there is a need, you need to find it.

This is not really an electrical issue as much as it is a fireworks issue.

 

[mybuickskill6979]

so an e match is a unit that "catches fire" from the heat of the wire? and with too long a wire or too little Wattage or a lack of either amperage OR voltage the whole wire will not heat? basically do to the wires own resistance? dude you really peeked my interest with this here!

 

[mybuickskill6979]

i was looking at your site and saw the this is America, it kicks box. lol i like the last line. not for weak people!!

 

[wakanga]

@ hfireworks,
just explain the points that they needed to know so that they could think of a design that could also help us overcome our problem =)

@ mybuickskill,

you've got it right sir...an e-match has tip covered with black powder with some binders to stick to the wire...and inside that black powder is a think wire use for heating/igniting it known as nichrome wire...

our only problem...that's why we are continue researching and asking is because of resistance due to that long wires/cables...and yes it is because or due to the wires/cables own resistance...i hope i've clear things up.....

so if anyone thus know or do know some ideas that might help us to overcome this please do throw your genius ideas here...so both you and us could benefit from it....good day guys...=)

 

[Nigel Goodwin]

Is it?

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

The peak to peak voltage of the AC is about the same as the DC, that's why.

But an AC shock spasms your muscles and throws you clear (you might break your neck as you fall though), a DC shock freezes your muscles stopping you letting go!.

 

[mybuickskill6979]

what about a transformer type deal. i just learned or read about inductance, like a step up tranformer to get some more amperage(i think i got that right) but instead of say 110 turns(main) to say 500(secondary) causes its step up go 200 main to 1,000 secondary. to a BIG cap?

im no where near a genius and if i confused something i'm sorry!! =)

 

[Nigel Goodwin]

With a transformer (and assuming an AC supply) you can increase the voltage at the cost of decreasing the current, or increase the current at the cost of decreasing the voltage.

 

[wakanga]

we are using DC voltages only...so AC voltages is out of the question....do anyone has a bright idea on how to overcome this wire resistance in terms of lenght?

 

[Nigel Goodwin]

Either use more batteries in series, or an inverter to change the DC to AC, as in the simple capacitor discharge design. To make it charge faster, you simply need a MUCH more powerful inverter!.

 

[wakanga]

we are only restricted to DC voltages...i'm already using two car batteries connected in series giving me 24 a VDC input..and adding more batteries is not the most practical way in doing it...that's why the title of this thread is capacitive discharge because we need a circuit that does this and charge at no waiting time...24 VDC to 110VDC output...

 

[Nigel Goodwin]

Like I said above, you need an inverter to convert the DC to AC, a transformer to up the voltage, then a rectifier to convert back to high voltage DC to charge the capacitor. You need to build a powerful enough inverter to charge the capacitor quickly.

 

[wakanga]

ok thanks nigel for your ideas...one more thing i want to ask...i've noticed that your into microcontrollers....could i ask you what chips do i need to communicate with RS232 (Serial Port) that could decode SMTPE codes and make those signals as a cue/channel to communicate with our firing system? i could expound my explaination if you need so...thanks a lot...=)

 

[Nigel Goodwin]

I would imagine any PIC would be able to do it?.

 

[wakanga]

actually it already does exist...kindly check this system...https://www.fireone.com from there i think you could already get some ideas...waiting for your kind response...thanks =)

 

[hfireworks]

I am trying to build a power supply to power my 864 cue firing system to allow me to fire multiple front locations.

To do this I needed a higher voltage sytem to carry the low amps current through the 1000' of 22ga wire to ingnite several ematch in parellel.

Ematch require 75ma to ingite, but using a high voltage low current (150ma) system you can do this with several ematch in parallel and an even greater amount in series. As seen on my web site.
http://www.hancefireworks.com/864panelpower

Ematch is constructed of a bridge wire or nichrome wire that heats up to ingnite the pyrogen head (match head) usually without breaking the bridge wire until explosion of the shell, Allowing for several milliseconds to ignite more in parallel or series.

This picture is a power supply I have built that will do this, it is a step up converter that converts 24vdc to 200vdc at 150ma, voltage can be dialed in using the 10k pot from 0-210vdc. Each capacitor will fire banks 1-9 on the firing switch's for a 0 wait time for the capacitors to charge.



If you are interested in fireworks electronics you can go to
**broken link removed**

Pyrouniverse is a great forum for all fireworks topics.

This is the 864 system I am building.

 

[hfireworks]

I would imagine any PIC would be able to do it?.

Nigel:
I have been browsing your web site and I am interested in your work.

I am seeing others using mididecoders to build firing systems such as this board. It is a 128 midi board which will connect to a computer to allow for computer controlled fire.

This is not my area but it seems to be a way of communicating with a relay based slat system.



This would make a great 128 cue firing system.

 

[Nigel Goodwin]

Midi is just a form of serial interface, specifically designed for use with musical keyboards - although much other midi equipment has since appeared. The chip that has 'Midi-decoder' stuck on the top is probably a PIC, or other micro-controller. Because it was designed with music in mind, it specifies an opto-coupled input, in order to prevent earth loops and hum.

I can see it would apply well to your application, because it already does much of what you want - allowing you to have just a couple of wires from your firing position, and individual control over many channels.

 

[hfireworks]

Midi is just a form of serial interface, specifically designed for use with musical keyboards - although much other midi equipment has since appeared. The chip that has 'Midi-decoder' stuck on the top is probably a PIC, or other micro-controller. Because it was designed with music in mind, it specifies an opto-coupled input, in order to prevent earth loops and hum.

I can see it would apply well to your application, because it already does much of what you want - allowing you to have just a couple of wires from your firing position, and individual control over many channels.

Any thought as to expanding this, 128 seems to be the largest boards I have seen available.

Or any other suggestions as to using micro-controllers to do computer firing?

 

[Nigel Goodwin]

Any thought as to expanding this, 128 seems to be the largest boards I have seen available.

128 may well be the largest number Midi is designed for?. But as you're not planning using it to play music (presumably?) you could extend the format easily enough.

Or any other suggestions as to using micro-controllers to do computer firing?

Essentially PIC's output logic levels, either HIGH or LOW (0V or 5V), you would need to connect those to some kind of firing circuit.

 

[hfireworks]

I understand the consepts of the midi control, although my experience is amature to electronics I have some good experience and capablities as a hobbiest.

What ways are available to expand these boards or will new boards have to be designed and built? Or can one board be built to controll several of these 128 boards?

I would like to build a system that is computer controlled but with a larger number of cues than 128. I beleive I could build one with this board and low voltage relays.

Computer software is available for fireworks systems such as
http://www.showsim.com/showsim/home.aspx
although this is a scripting software it still needs a way to shoot the fireworks from the computer or be downloaded to the firing system.
others are available also.