brainfever Posted October 1, 2006 Share Posted October 1, 2006 Found another interesting page on this matter: http://www.aeroconsystems.com/tips/dahlqui...st_igniter1.htm This states that electrical igniters coated with a pyrogen like BP will fire reliably and without delay from about 7 Joules. Link to comment Share on other sites More sharing options...
Frozentech Posted December 12, 2006 Share Posted December 12, 2006 Just came across an interesting site, with some info on computer controlling an electrical firing system. I may have to make one of these ! http://www.instructables.com/id/ENLK3Q8ZD9ETVPK570/?ALLSTEPS Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 9, 2007 Share Posted December 9, 2007 I know this is a pretty old thread, but I have been having the same problem. I have about 50 feet of 18ga wire to a 6V Lantern battery. The igniter is just an ordinary home made E-match (32ga Ni-Chrome + Black powder/Nitrocellulose lacquer slurry.) Anyway, I brought this up because I have a question. Since I will obviously need a better power supply I was thinking, can I use some rechargeable NiMH battery packs like those used in RC cars and Airsoft guns? I was thinking of using two 10.8V batteries wired together so that I could eliminate the unwanted delay. Anybody know if this would work? Heres a link to the batteries I'm talking about : http://www.all-battery.com/index.asp?PageA...PROD&ProdID=482 Link to comment Share on other sites More sharing options...
WarezWally Posted December 9, 2007 Share Posted December 9, 2007 You will experience large losses with a lantern battery over 50ft, best battery to use is a 12v SLA. Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 9, 2007 Share Posted December 9, 2007 Well, I tested the 6V on a multimeter and it came 6.08V and then I tested it through the cables and it also came up 6.08V. Then I went outside with a 9.6V drill battery and it fired the e-match much quicker. I'm guessing this is a voltage issue, so if that means I can just hook a couple of the 10.8V batteries i linked earlier, that would be great. The reasons I'm looking at the NiMH batteries are because 1) There rechargeable so I don't need to go out and get a new battery every now and then. 2) They're pretty cheap to begin with. And 3) There nice and compact so I don't need to lug around a couple of 12V or 6V batteries. Link to comment Share on other sites More sharing options...
WarezWally Posted December 10, 2007 Share Posted December 10, 2007 Don't forget a charger, they may be expensive. Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 10, 2007 Share Posted December 10, 2007 Actually, I had some of these batteries a while back when I was into airsoft, and I had a couple but I would have never thought of using it for electronically firing things. Anyway, say I bought two of these, how would I go about wiring the two together? Positive 1 to positive 2, negative 1 to negative 2? Link to comment Share on other sites More sharing options...
WarezWally Posted December 10, 2007 Share Posted December 10, 2007 How do you want it? In series or parallel? I assume parallel as that will give you 10.8v @ 2.4Ah, so connect the positive wires to each other and the black wires to each other. Link to comment Share on other sites More sharing options...
TheSidewinder Posted December 10, 2007 Share Posted December 10, 2007 Just FYI.... Remember that voltage measurements (with no resistive load), are always going to read "normal" even over very long distances if you're using a simple voltmeter. You could probably have a mile long run of that wire and still read 6.08 volts. But put a load on it (like an ematch) and try to fire it from a mile away and it won't work. Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 10, 2007 Share Posted December 10, 2007 Yeah I was thinking about that sidewinder. It makes sense now. Thanks guys. And Wally, what would be the difference between series and parallel? Link to comment Share on other sites More sharing options...
ST1DinOH Posted December 18, 2007 Share Posted December 18, 2007 Yeah I was thinking about that sidewinder. It makes sense now. Thanks guys. And Wally, what would be the difference between series and parallel? lets say i have two 12 v 1.3 amp batteries i can either make a 24 volt 1.3 amp power source or 12 volt 2.6 amp power source. depending on your cable resistance, length, and e-match properties you need to play around with what works best for you. for my wired system i used a 24v1.3a and it popped my home made matches (picture framing wire and pyrodex/acetone dipped) from over 150 feet away. Link to comment Share on other sites More sharing options...
frogy Posted December 19, 2007 Share Posted December 19, 2007 My capacitor discharge system can "pop" a large loop of nichrome ematches even at a good 100 foot + distance... My cap banks only 300v... At the moment I'm working on a radio controlled capacitor system, but as of now I'm lacking the SCR to control firing... Link to comment Share on other sites More sharing options...
FrankRizzo Posted December 20, 2007 Share Posted December 20, 2007 BUT...your 250-300V capacitor needs a bit of charging time before it's useful for a second cue. The problem with using an SCR to fire this type of circuit is that you need to find one capable of handling the 10us pulse of 300V @ 100A without destroying it. Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 20, 2007 Share Posted December 20, 2007 lets say i have two 12 v 1.3 amp batteries i can either make a 24 volt 1.3 amp power source or 12 volt 2.6 amp power source. depending on your cable resistance, length, and e-match properties you need to play around with what works best for you. for my wired system i used a 24v1.3a and it popped my home made matches (picture framing wire and pyrodex/acetone dipped) from over 150 feet away. Ok, that makes perfect sense. Thanks for clearing that up. But say I wanted 24V 1.3amps, would I connect positive 1 to negative 2 and then positive 2 to negative 1? Link to comment Share on other sites More sharing options...
FrankRizzo Posted December 21, 2007 Share Posted December 21, 2007 No, that will form a short-circuit and destroy your wiring and possibly the batteries. You connect positive 1 to negative 2 (or positive 2 to negative 1..doesn't matter), then use the free terminals to power your circuit. This is called "wiring in series". Here's a photo I found on Pyrouniverse that should make everything clear: http://www.pyrouniverse.com/show/firingsystems/joepanelext/ExFire13.jpg Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 21, 2007 Share Posted December 21, 2007 Thanks FrankRizzo. That's helpful. As you can probably tell, my electronic skills are lacking quite a bit. Thanks again for everyones help. Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 28, 2007 Share Posted December 28, 2007 Alright, so I finally bought the batteries. I bought two of the ones linked earlier, and a universal smart charger. Now, the problem is they already have mini tamiya female connectors on them. Normally, this wouldn't be a problem if it was as simple as wiring the two batteries together, because the connectors could be cut, and the wires stripped. While I could do this, it would make it a nuisance to charge seeing as how they would need to be charged with say alligator clips. I'd have to make sure the two wires don't touch, other wise it would short circuit. So, my solution is: Leave the connectors on the batteries, but buy multiple connectors, and wire them together. This leads me to my question. How would I wire the connectors together? I don't know if it would be a matter of wiring them in series or parallel or just connecting them. I realize this may sound a bit foggy, so i drew it out: Edit : Sorry for the double post Link to comment Share on other sites More sharing options...
Miech Posted December 28, 2007 Share Posted December 28, 2007 I would suggest to put the batteries in serie. This will provide a twice as high voltage through your firing cable, and reduces the resistance of these cables, according to Ohm's law. Two fully charged 1200mAh batteries should be able to fire at least 150 times without being charged, when connected in serie. Link to comment Share on other sites More sharing options...
Gottagotomoz Posted December 28, 2007 Share Posted December 28, 2007 Ok, so now that the two connectors that connect the batteries are wired in series, how should these connectors be wired to the next connector. I edited the diagram above, does that look right? Thanks Edit: I think I screwed up all the connector ends. Don't think it makes a difference though. Anyway, all male should be female and all female should be male, on the above diagram. Link to comment Share on other sites More sharing options...
frogy Posted December 29, 2007 Share Posted December 29, 2007 BUT...your 250-300V capacitor needs a bit of charging time before it's useful for a second cue. The problem with using an SCR to fire this type of circuit is that you need to find one capable of handling the 10us pulse of 300V @ 100A without destroying it. I was planning on some IGBT's or SCR's for my CD ignition setup... What do you suggest from Mouser or Digikey parts wise? I've been looking at 350-1700v range (all the HV range they have of cut-tape/small tube, non-smd on DigiKey ) with 15-300A current ratings... I'm looking in the $5 range or less for one... Note that the 15-300A current rating isn't the pulse rating... The 2N6509 SCR is pretty nice...http://search.digikey.com/scripts/DkSearch...me=2N6509GOS-ND Only $1.73 for one at DigiKey, and it has a pulse rating of 300A x 6ms, which can handle over 400A with a smaller pulse duration... I'm imagining a pulse through a small amount of speaker wire should not be long... Speaker wire has pretty low resistance and inductance. Link to comment Share on other sites More sharing options...
Boomer Posted January 7, 2008 Share Posted January 7, 2008 Short note: What kills triacs/thyristors is not the current but the current rise speed, i.e. the whole crystal has no time to conduct and the small channel that forms melts and shorts. Look for something with units like .... A/µs. Even some 10000 Amp rated thyristors only survive 1000A/µs. These are mostly mains frequency devices (i.e. 8-10ms cycles). Link to comment Share on other sites More sharing options...
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