14 cue system and capacitor?

[jukka]

Hello all electricians!

 

Im stuck on sucking my thump, again and would appreciate some hints.

 

I build this basic 14 cue system, soldered 75m of some (not labeled) ISP cable with 15 pairs on it.

the aluminium wires are really thin.

 

Now I have information on my eMatch seller that those matches need 0,4A to light up.

 

I would have new motorcycle battery, 12V.

 

But, heres the catch, the resistance is (both ways) 4+4=8 OHM @ temperature +3C

 

That would give me 8OHM / 0,4A = 20V.

 

So no change to light up these babys with 12V battery. And what happens to resistance when weather gets colder. Im a afraid then even the 24V battery wont be enough or at least Im not comfortable to build my mini show with these.

 

Im no electrician expert so only thing that comes to my mind is eather I switch to better cable (after looking my bank roll => I need to get alternative ideas ) or use capasitor.

What kind of capasitor? Where in my system I would need to add it? How long takes the reloding between fires? Or is capasitor totally wrong thing for my needs?

 

Lot of questions and I totally dont have the answers. Please, share the knowledge.

 

-Jukka-

[Updup]

Hello all electricians!

 

Well, I'm not really an expert.

 

But my advice to you, is you could make your own matches our of x-mas lights (see he thread in our member TUT's)

 

As far as using a cap on your device, seems plausible, and it would take no more than 2 seconds for a large cap to recharge, and no more than .1 for a little one. Have you looked in to using a transistor to increase your voltege?

 

Also, you are going to want to have a continuity test on your device, and it won't cost more than an LED, a 300-500 ohm resistor and a DPST switch.

[Arthur]

Check your Ohms Law

 

E = I R

 

So you have I and have R therefore E = I R = 0.4 x 8 = 3.2

So a 12v battery properly charged will allow enough current to flow.

 

Let's add a 2ohm realistic guess for the igniter

 

cable = 8ohms Igniter = 2 ohms total is 10 ohms

 

Volts is 12

E = I R therefore E / R = I 12/10 = 1.2 so the current through your circuit should be ample to make a reliable firing pulse

[jukka]

Thank You!

 

Damn, I have sweat for no reason. No need for anything else except to build that continuity test.

 

I modified that schematic diagram to include that continuity test switch, resistor and lamp.

Testing current is said to be 0,5MA, safety current 0,18A/5s. Can I use 0,1A for continuity test?

 

(Arthur, I hope I got this right now ) R = U / I so 12V / 0,1A = 1,2OHM.

 

For my my eMatch I planned to use for coating (just the tip of the eMatch, not whole chip) these:

 

(from passfire forum)

- First layer BP + NC (single based riffle powder dissolved in asetone)

- second layer, pyrogen (KNO3 60, S 10, Dark alu. 30) + NC

- third layer, protective layer, pure NC

 

Testing should start on next weekend. Any thoughts on coatings or schematic?

[Arthur]

That circuit and calculations need more work, at the moment they are rather more hazardous that you planned.

[Richtee]

Well, first off, I don't know what type cont lamp you plan on using, but a standard LED required only about 20mA to light. That's .02A. 12V/.02A= 600 ohms series resistance. 680 ohms is a standard value. No way would I want 100mA (.1A) flowing for testing. Especially since you are using home made igniters.

 

Second...your switch labeled "Fire" is actually- I ASSUME- the "armed" switch, and the 14 above are the fire switches. This is important in that you could not expect to close several "upper" switches and then hit the lower switch to fire, as the fire current in the parallel branches of the igniters would not be of a reliable value for ignition.

 

Given your wire (aluminum?? Soldered???) and length, I'd be tempted to use 2 bats in series (24V) and double the series resistor to 1.5 KOhms (1500 ohms) for cont test.

 

Aluminum wire? Really? You can't solder aluminum. Well, easily. You sure it's not tinned copper?

[jukka]

Well, first off, I don't know what type cont lamp you plan on using, but a standard LED required only about 20mA to light. That's .02A. 12V/.02A= 600 ohms series resistance. 680 ohms is a standard value. No way would I want 100mA (.1A) flowing for testing. Especially since you are using home made igniters.

 

Second...your switch labeled "Fire" is actually- I ASSUME- the "armed" switch, and the 14 above are the fire switches. This is important in that you could not expect to close several "upper" switches and then hit the lower switch to fire, as the fire current in the parallel branches of the igniters would not be of a reliable value for ignition.

 

Given your wire (aluminum?? Soldered???) and length, I'd be tempted to use 2 bats in series (24V) and double the series resistor to 1.5 KOhms (1500 ohms) for cont test.

 

Aluminum wire? Really? You can't solder aluminum. Well, easily. You sure it's not tinned copper?

 

Thanks for your inputs, I will drop the cont current for ematches just to be on the safe side.

 

Fire is push button for actual fire. Those 14 smaller switches are for one to choose what cue is going to fire, can be 1 to 14 with one fire button press.

 

For cable core, Ill need to re-check. Those are really thin ones, thinner than in normal cat6 cable and had 16 pairs, every pair twisted. No extra cover (some of those cables have kind of foil rapper all over them before the outer cover).

 

 

[Richtee]

 

Fire is push button for actual fire. Those 14 smaller switches are for one to choose what cue is going to fire, can be 1 to 14 with one fire button press.

Again...you cannot expect to fire multiple "ques" with this system. If you have more than one switch closed, your fire current will be divided among the connected igniters, making ignition at least unreliable, at most non-existent.

[Updup]

Have you thought about making this system wireless? It would be cheaper than buying the wires to run to your ematches. Unless you are planing on being a few feet away from your works.

[jukka]

Thats something I didn't think, of course the current will drop too much. So with this it will be one at the time. Thanks!

 

I have drooled on those wireless ones. I have looked up those Chinese cheap systems but, well thous are Chinese and what I heard, not that reliable.

Someone opens their car door and my finale shoots out, thats something I'm not looking for to see

If thats really something that non-electrician could build ( I still know how to solder) and U guys say that would be reliable, I really need to look deeper on this.

[Updup]

Thats something I didn't think, of course the current will drop too much. So with this it will be one at the time. Thanks!

 

I have drooled on those wireless ones. I have looked up those Chinese cheap systems but, well thous are Chinese and what I heard, not that reliable.

Someone opens their car door and my finale shoots out, thats something I'm not looking for to see

If thats really something that non-electrician could build ( I still know how to solder) and U guys say that would be reliable, I really need to look deeper on this.

 

Depends where your going to be shooting. Car fobs do work on the same frequency as this system does, I personally have tested 3 different car remotes around my system and it does nothing, not to say it never will, but car remotes have very little tramsmitting power compaired the the systems remote, meaning only if the car were within 100ft or so would there be any risk, and I don't think people will be parking cars that close to your fireworks.

 

http://www.goodluckbuy.com/rf-wireless-remote-control-radio-controller-switch-12.html

 

Thats the same one I got, they als have a 15 channel one if your set on 14 ces.

 

Next, I would get a nice project box to mount your stuff in. All electronics is cheap, and has good speaker terminals.

 

I can post shcematics if you want 'em.

[jukka]

Depends where your going to be shooting. Car fobs do work on the same frequency as this system does, I personally have tested 3 different car remotes around my system and it does nothing, not to say it never will, but car remotes have very little tramsmitting power compaired the the systems remote, meaning only if the car were within 100ft or so would there be any risk, and I don't think people will be parking cars that close to your fireworks.

 

http://www.goodluckb...-switch-12.html

 

Thats the same one I got, they als have a 15 channel one if your set on 14 ces.

 

Next, I would get a nice project box to mount your stuff in. All electronics is cheap, and has good speaker terminals.

 

I can post shcematics if you want 'em.

 

Well that was so tempting deal that I placed order already. Got also those terminals and boxes.

Also I purchased resistor, switch for cont test with led including power on led and switch.

So schema would be highly appreciated, would it be same as fredjr wrote fredjr 12cue remote control system ?

[Updup]

Well that was so tempting deal that I placed order already. Got also those terminals and boxes.

Also I purchased resistor, switch for cont test with led including power on led and switch.

So schema would be highly appreciated, would it be same as fredjr wrote fredjr 12cue remote control system ?

 

Yeah, same shcematics.

 

Did you get the right resistor? What kind of E-matchs are you using?

[Arthur]

If you take a look at Pyrouniverse.com I thing you will find their Firing Systems section very helpful, Lots of circuits to copy or borrow from.

 

I think I've just spotted the same supplier of bare e-matches, they are inert so can be posted, and come with instructions for the pyrogen -even a pyrogen kit (dry -needs acetone). From my experience with these you MUST mill the sensitive pyrogen components SEPARATELY till they freely pass 200mesh better they pass 300 or 400 mesh. This is critical. Once the sensitive pyrogen is in place almost anything sulphur free is good for the secondary pyrogen, then you dip he whole head in NC lacquer with nothing in, which keeps them dry and friction free. To make these you MUST work in tiny quantities and work very tidyly. 250milligrams of each pyrogen component when properly mixed will do over 100 ematches. As the left over bits are sensitive one must be very careful to dispose or destroy it carefully.

[jukka]

If you take a look at Pyrouniverse.com I thing you will find their Firing Systems section very helpful, Lots of circuits to copy or borrow from.

 

I think I've just spotted the same supplier of bare e-matches, they are inert so can be posted, and come with instructions for the pyrogen -even a pyrogen kit (dry -needs acetone). From my experience with these you MUST mill the sensitive pyrogen components SEPARATELY till they freely pass 200mesh better they pass 300 or 400 mesh. This is critical. Once the sensitive pyrogen is in place almost anything sulphur free is good for the secondary pyrogen, then you dip he whole head in NC lacquer with nothing in, which keeps them dry and friction free. To make these you MUST work in tiny quantities and work very tidyly. 250milligrams of each pyrogen component when properly mixed will do over 100 ematches. As the left over bits are sensitive one must be very careful to dispose or destroy it carefully.

 

I just finished some of those pages, very helpful.

 

That sensitive pyrogen calls for KClO3 and chinese needle. I don´t have those in my shop atm so I was hoping that dirty flash as pyrogen would work with BP and NC coating.

After reading your reply Im left with huge doubt that with these eMatches this would work.

Edited October 21, 2010 by jukka

[Arthur]

If you want these igniters to work you MUST get the sensitive pyrogen right. You need only a few microlitres of this but it must be right or they don't fire. Ask your supplier for the sensitive pyrogen kit 20g will do for a lifetime as you SHOULD use so little. Your small weighing skills will be taxed severely.

[Mumbles]

I've heard that the sensitive pyrogen ensures everything fires instantly. Using others can be made to work, but potentially at the cost of a delay in firing.

 

This is outside the realm of this thread, but I've always wondered about other chlorate or perchlorate mixes. There are several known with pretty low auto-ignition temperatures. Mixes with lactose come to mind. Heck, KNO3 and sugar may work.

[Arthur]

Lots of things are worth testing, BUT when the testig has been done for you with one mix that is safe enough and reliable enough then perhaps it's a good place to start, and for those with little experience, maybe the best mix to use.

K Chlorate 200mesh and Antimony tri sulphide 200 mesh say 250ng of each with 5 - 7% by weight NC powder mixed into acetone to a thick paint like thickness will make enough to dip dozens of igs for their first dip. If the powders are too coarse then reliability suffers.

[jukka]

I have had understanding that KClO3 should not be mixed with sulfur and this kind of mix would be also extremely shock sensitive.

Its not an problem to mix this kind of small amounts but self ignition worries me. Therefore I would not feel safe to build shells where eMatch with this pyrogen would be attached for storing.

 

Then again, it would not be first or definitely not last time when I would have understood something wrong.

Edited October 22, 2010 by jukka

[mike_au]

Chlorate and sulfur mixes are extremely sensitive but they won't go off without some sort of outside influence. By coating the sensitive pyrogen with a few coats of less sensitive composition you are creating a reasonable barrier. In order for the pyrogen to be exposed to impact or friction those outer layers would first need to be damaged, if that has happened your shell has obviously taken a hell of a beating and you aren't storing it properly.

 

Store your shells properly, and keep the matches shunted and you are reasonably OK.

 

If you are still worried, I've made ematches with just BP mill dust in NC laquer. They aren't instant but I never had a failure, so for most people they are probably fine.

[Mumbles]

Well, you mentioned your own problem and answer already. Don't store shells pre-e-matched. It's actually fairly unsafe, and I believe illegal commercially. Once you get in a groove, e-matching leaders goes pretty quick.

[Updup]

Here is my firing system, finished it last night.

 

I'm posting links because when I try and attach a file it is too small to see, and when I click the small image to enlarge, it zooms wayyyy to much.

 

Back of the front panel, notice I've solderd my commom (Ground) in, plus the resister for my LED

 

Finished close up of the front. (External battery, can run on 9v or 12v)

Finished picture with the remote

[skyfiller]

A capacitor close to the end of your run will store nearly the full battery voltage and will discharge rapidly on firing. However you will need a capacitor for every cue to make it worth your while, afterall the capacitor is a voltage source like a battery and will only charge to the max battery voltage. The only thing it helps with is the voltage drop of your wiring, so you have a little more voltage at the match.