megalomania
October 7th, 2002, 03:07 PM
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 23, 2001 12:37 PM
--------------------------------------------------------------------------------
i am going to be using an estes rocket ignitor to set off some AP crackers and i was wondering what is the best way to set off the rocket ignitors at the end of 20 feet of wire.
a) 1, 6 volt lantern battery
b) 1, 9 volt
c) 4, AA size batterys (lined up in a row)
thanks for all your help.
also, one more question, if i want to use thin copper wire as my ignition device would i need something like a car battery to make it hot enough to set off AP? this would also be at the end of a 20' piece of wire.
------------------
...Æ
Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 23, 2001 03:06 PM
--------------------------------------------------------------------------------
The lattern battery - highest current output and amps = heat.
It depends on how thick the copper wire is, stick it accross the battery teminals to find out if it will work. It will need to be quite fine for the few amps a lattern battery will put out.
To save lumping a car battery about, if you've got a cordless (whatever) the NiCd pack from that will work great, those batts put out some serious current!
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 23, 2001 05:17 PM
--------------------------------------------------------------------------------
so what you are saying current is the key? and also, i should use a lantern batterey. thanks for your help.
------------------
...Æ
Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 23, 2001 06:36 PM
--------------------------------------------------------------------------------
Yeah, voltage has no bearing heat.
100W at 1v (say flowing into a short circuit = no resistance{only that of the wire}) will produce a lot of heat
Whereas 100W at 100v will only produce a 100th of the heat for the same power (wattage) drawn.
That's why power lines are stepped up to several hundred thousand volts so that les power is lost through heating of the cables.
The lattern batty will give the most amps as the cells inside are physically bigger.
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 23, 2001 06:58 PM
--------------------------------------------------------------------------------
thanks man. lantern battery it is.
------------------
...Æ
[This message has been edited by CragHack (edited January 23, 2001).]
Jumala
Frequent Poster
Posts: 199
From: Germany
Registered: OCT 2000
posted January 23, 2001 09:09 PM
--------------------------------------------------------------------------------
Hello Anthony,
Your reply isn´t correct.
100W are 100W where it doesn´t matter wich voltage is used. At 1 V and 100W the current is 100A and at 100V and 100W the current is 1A.
When you put 100V at a resistor with only 1 Ohm you get 100A = 10000W.
1V at 1 Ohm gives you only 1W.
Power lines must transfer many Mega Watts of power. To get lower losses at a given resistance (the line) the current must be lower and to transfer the same amount of Watts the voltage must be higher (formula P=U x I or P=I²x R)
To get a reliable ignition you must have the most power at the ignitionpoint and not at the wire( like the power line). So the resistance of the igniter must be much higher than the wire-resistance
The best method is to use a resistor with a high resistance like 50-150 Ohm but for this you need a relative high voltage at lower current.
If you have only a 6V latern battery wich can deliver perhaps 10A you can calculate the optimal resistance with the formula R=U/I
6V/10A= 0,6 V/A = 0,6 Ohm. You see it is a small resistance and if you use a long and thin wire you will have undesired losses at the wire. To prevent this I suggest to use 3 6V batterys serial with a 1,8 Ohm resistor (available at electronic shops for max. 5 cents).
A piece of copper wire as igniter is bullshit. You would get the most power at the long wire and only a rest at the igniter.
It is pure luck when it works and certainly it is unsave.
Why don´t you all buy a resistor for 5 cents and simply test it. A resitor produces a nice flame, good for ignition.
The Real
Frequent Poster
Posts: 136
From: Columbus, OH
Registered: DEC 2000
posted January 24, 2001 08:14 AM
--------------------------------------------------------------------------------
No load is gonna pull 100A through a 1ohm resistor using a lantern battery, it also depends on what the power source is capable of.
But wattage is a little different, 2amps at 50v is 100watts, just as 1amp @ 100v is or 0.5A and 200v.
I do agree though, I can't see usinng copper wire as an igniter, less your pushing quite a few amps. I use 0.4mm-0.11mm nichrome wire. Just purchase light guage GHS Boomer Guitar strings, high "e" or "b", these are nichrome. Fine steel wool works as well, but not as well. Innoculating needles can be purchases made from platinum or nichrome as well, however the only source I know of is Fisher, which is typically expensive.
Anyways I've never paid more than $1.50 for a string and I get at least 20 igniters out of one string. A pyrotechnic coating is not necessary.
Also for a quick connect blasting circuit I use 1/4" head phone jacks. Female end on the device the male on the end of the leads, very often the male end is ok to use again. I've had them last for over 20shots (small things) and it's a fast safe connection. I use audio wire to run my main leads. But a word of advice, the small diameter the wire the more resistant and it's also proportional to length. I once ended up melting the insulatio off my wires from running 500ft of 18ga wire to a pretty heavy igniter, the power source was a running car. After the device failed to go off at connection I just hooked it up and let it set for about 10min. I ended up shooting the device with a .308 from 150yds from behind a tree to disable and/or detonate it.
Use heavier gauge automotive wire for best results. 22ga is pretty good.
Dracul
Frequent Poster
Posts: 73
From: Melbourne, Australia
Registered: SEP 2000
posted January 24, 2001 09:39 AM
--------------------------------------------------------------------------------
Go to the local place that develops camera films and ask for a used disposable camera with a flash. If you ask nicely you could get around 20. Charge the capacitor in it then connect the wires. If you want to use it on a regular basis then you can wire it up with switches in a plastic box that they sell at electronics stores. I've made one that has 8 350V-400V 100-200uF capacitors for long distance, its damn loud when you touch the wires without any resistance.
Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 24, 2001 07:12 PM
--------------------------------------------------------------------------------
I was working on a constant current supply, involving the fact that higher voltages will allow higher curents to flow at a set resistance would have confused things even more.
I personally use nichrome wire from a dead hair drier but a single strand of fine copper wire would work in a pinch.
Jumala
Frequent Poster
Posts: 199
From: Germany
Registered: OCT 2000
posted January 24, 2001 10:14 PM
--------------------------------------------------------------------------------
Yes, a electric foto flasher to charge a big capacitor is the best way.
For example you put 400V at a 40 Ohm nicrome wire or a carbon resitor you get a 4000W impulse.
This will vaporise the igniter.
Dracul
Frequent Poster
Posts: 73
From: Melbourne, Australia
Registered: SEP 2000
posted January 25, 2001 11:20 AM
--------------------------------------------------------------------------------
If you live in Australia you can go to Dick Smith's and the have these little tiny lights that are only 3mm across and are all wired up and have shrink wrap near the globe, the wires are about 15-20cm long. They are perfect for AP if you gently pop the globe with pliers but they are a little fragile so mix up some BP with a very small amount PVC glue and then add enough acetone to make it like paint. The PVC glue holds the BP together so it doesnt crumble, but if you add too much then they don't ignite.
I'm going to get a portable 12V strobe light from there too so that i can charge the capacitors faster with a lead acid battery. If I use the battery on a camera circuit it fries the transistor.
[This message has been edited by Dracul (edited January 25, 2001).]
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 25, 2001 11:13 PM
--------------------------------------------------------------------------------
if there is a subject that still baffles me it is electronics. now i know watts is the measurement for actual power, and Ohms is a measurement of resistance. but could someone define volts and current for me? thank you all for your help so far.
------------------
...Æ
ALENGOSVIG1
Moderator
Posts: 766
From: Vancouver, Canada
Registered: NOV 2000
posted January 26, 2001 12:07 AM
--------------------------------------------------------------------------------
Hmm, a good example is likle pressure in a pipe:.High voltage would be lots of pressure while low volatge would be small amount of pressure
------------------
Explosives Archive
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 26, 2001 12:20 PM
--------------------------------------------------------------------------------
and is the current how fast that pressure moves through the pipe?
------------------
...Æ
PYRO500
Moderator
Posts: 1466
From: somewhere in florida
Registered: SEP 2000
posted January 26, 2001 05:10 PM
--------------------------------------------------------------------------------
the current would be how big the pipe is around
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 26, 2001 06:34 PM
--------------------------------------------------------------------------------
wow, that really cleared things up for me man. thanks for the info.
------------------
...Æ
vehemt
Frequent Poster
Posts: 580
From: Canada
Registered: SEP 2000
posted January 26, 2001 10:01 PM
--------------------------------------------------------------------------------
Voltage = Pressure
Current = Volume
simply RED
Frequent Poster
Posts: 238
From: HELL
Registered: OCT 2000
posted January 29, 2001 05:08 PM
--------------------------------------------------------------------------------
I've made a lot of electrodetonators with Nichrom (Ni+Cr) wire. The explosives I've used were acetone peroxide, AP putty and HMTD, it works great! The wire was 1/12mm wide(like human hair). I've triggered the detonators with EBP-30N Alinco battery 7.2V 1 detonator from 100m with standard "sapper" wires. The detonators had standard form, made from thin alluminium.
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 29, 2001 10:07 PM
--------------------------------------------------------------------------------
well i am either going to use the NiCr wire, or a small capacitor with a polarity, and just hook that up the wrong way, which makes it pop. i am more than likely going to use the guitar string. i can get a box of the stuff for a buck (american) it will be cheaper and it is proven (by you guys) effective.
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 23, 2001 12:37 PM
--------------------------------------------------------------------------------
i am going to be using an estes rocket ignitor to set off some AP crackers and i was wondering what is the best way to set off the rocket ignitors at the end of 20 feet of wire.
a) 1, 6 volt lantern battery
b) 1, 9 volt
c) 4, AA size batterys (lined up in a row)
thanks for all your help.
also, one more question, if i want to use thin copper wire as my ignition device would i need something like a car battery to make it hot enough to set off AP? this would also be at the end of a 20' piece of wire.
------------------
...Æ
Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 23, 2001 03:06 PM
--------------------------------------------------------------------------------
The lattern battery - highest current output and amps = heat.
It depends on how thick the copper wire is, stick it accross the battery teminals to find out if it will work. It will need to be quite fine for the few amps a lattern battery will put out.
To save lumping a car battery about, if you've got a cordless (whatever) the NiCd pack from that will work great, those batts put out some serious current!
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 23, 2001 05:17 PM
--------------------------------------------------------------------------------
so what you are saying current is the key? and also, i should use a lantern batterey. thanks for your help.
------------------
...Æ
Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 23, 2001 06:36 PM
--------------------------------------------------------------------------------
Yeah, voltage has no bearing heat.
100W at 1v (say flowing into a short circuit = no resistance{only that of the wire}) will produce a lot of heat
Whereas 100W at 100v will only produce a 100th of the heat for the same power (wattage) drawn.
That's why power lines are stepped up to several hundred thousand volts so that les power is lost through heating of the cables.
The lattern batty will give the most amps as the cells inside are physically bigger.
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 23, 2001 06:58 PM
--------------------------------------------------------------------------------
thanks man. lantern battery it is.
------------------
...Æ
[This message has been edited by CragHack (edited January 23, 2001).]
Jumala
Frequent Poster
Posts: 199
From: Germany
Registered: OCT 2000
posted January 23, 2001 09:09 PM
--------------------------------------------------------------------------------
Hello Anthony,
Your reply isn´t correct.
100W are 100W where it doesn´t matter wich voltage is used. At 1 V and 100W the current is 100A and at 100V and 100W the current is 1A.
When you put 100V at a resistor with only 1 Ohm you get 100A = 10000W.
1V at 1 Ohm gives you only 1W.
Power lines must transfer many Mega Watts of power. To get lower losses at a given resistance (the line) the current must be lower and to transfer the same amount of Watts the voltage must be higher (formula P=U x I or P=I²x R)
To get a reliable ignition you must have the most power at the ignitionpoint and not at the wire( like the power line). So the resistance of the igniter must be much higher than the wire-resistance
The best method is to use a resistor with a high resistance like 50-150 Ohm but for this you need a relative high voltage at lower current.
If you have only a 6V latern battery wich can deliver perhaps 10A you can calculate the optimal resistance with the formula R=U/I
6V/10A= 0,6 V/A = 0,6 Ohm. You see it is a small resistance and if you use a long and thin wire you will have undesired losses at the wire. To prevent this I suggest to use 3 6V batterys serial with a 1,8 Ohm resistor (available at electronic shops for max. 5 cents).
A piece of copper wire as igniter is bullshit. You would get the most power at the long wire and only a rest at the igniter.
It is pure luck when it works and certainly it is unsave.
Why don´t you all buy a resistor for 5 cents and simply test it. A resitor produces a nice flame, good for ignition.
The Real
Frequent Poster
Posts: 136
From: Columbus, OH
Registered: DEC 2000
posted January 24, 2001 08:14 AM
--------------------------------------------------------------------------------
No load is gonna pull 100A through a 1ohm resistor using a lantern battery, it also depends on what the power source is capable of.
But wattage is a little different, 2amps at 50v is 100watts, just as 1amp @ 100v is or 0.5A and 200v.
I do agree though, I can't see usinng copper wire as an igniter, less your pushing quite a few amps. I use 0.4mm-0.11mm nichrome wire. Just purchase light guage GHS Boomer Guitar strings, high "e" or "b", these are nichrome. Fine steel wool works as well, but not as well. Innoculating needles can be purchases made from platinum or nichrome as well, however the only source I know of is Fisher, which is typically expensive.
Anyways I've never paid more than $1.50 for a string and I get at least 20 igniters out of one string. A pyrotechnic coating is not necessary.
Also for a quick connect blasting circuit I use 1/4" head phone jacks. Female end on the device the male on the end of the leads, very often the male end is ok to use again. I've had them last for over 20shots (small things) and it's a fast safe connection. I use audio wire to run my main leads. But a word of advice, the small diameter the wire the more resistant and it's also proportional to length. I once ended up melting the insulatio off my wires from running 500ft of 18ga wire to a pretty heavy igniter, the power source was a running car. After the device failed to go off at connection I just hooked it up and let it set for about 10min. I ended up shooting the device with a .308 from 150yds from behind a tree to disable and/or detonate it.
Use heavier gauge automotive wire for best results. 22ga is pretty good.
Dracul
Frequent Poster
Posts: 73
From: Melbourne, Australia
Registered: SEP 2000
posted January 24, 2001 09:39 AM
--------------------------------------------------------------------------------
Go to the local place that develops camera films and ask for a used disposable camera with a flash. If you ask nicely you could get around 20. Charge the capacitor in it then connect the wires. If you want to use it on a regular basis then you can wire it up with switches in a plastic box that they sell at electronics stores. I've made one that has 8 350V-400V 100-200uF capacitors for long distance, its damn loud when you touch the wires without any resistance.
Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 24, 2001 07:12 PM
--------------------------------------------------------------------------------
I was working on a constant current supply, involving the fact that higher voltages will allow higher curents to flow at a set resistance would have confused things even more.
I personally use nichrome wire from a dead hair drier but a single strand of fine copper wire would work in a pinch.
Jumala
Frequent Poster
Posts: 199
From: Germany
Registered: OCT 2000
posted January 24, 2001 10:14 PM
--------------------------------------------------------------------------------
Yes, a electric foto flasher to charge a big capacitor is the best way.
For example you put 400V at a 40 Ohm nicrome wire or a carbon resitor you get a 4000W impulse.
This will vaporise the igniter.
Dracul
Frequent Poster
Posts: 73
From: Melbourne, Australia
Registered: SEP 2000
posted January 25, 2001 11:20 AM
--------------------------------------------------------------------------------
If you live in Australia you can go to Dick Smith's and the have these little tiny lights that are only 3mm across and are all wired up and have shrink wrap near the globe, the wires are about 15-20cm long. They are perfect for AP if you gently pop the globe with pliers but they are a little fragile so mix up some BP with a very small amount PVC glue and then add enough acetone to make it like paint. The PVC glue holds the BP together so it doesnt crumble, but if you add too much then they don't ignite.
I'm going to get a portable 12V strobe light from there too so that i can charge the capacitors faster with a lead acid battery. If I use the battery on a camera circuit it fries the transistor.
[This message has been edited by Dracul (edited January 25, 2001).]
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 25, 2001 11:13 PM
--------------------------------------------------------------------------------
if there is a subject that still baffles me it is electronics. now i know watts is the measurement for actual power, and Ohms is a measurement of resistance. but could someone define volts and current for me? thank you all for your help so far.
------------------
...Æ
ALENGOSVIG1
Moderator
Posts: 766
From: Vancouver, Canada
Registered: NOV 2000
posted January 26, 2001 12:07 AM
--------------------------------------------------------------------------------
Hmm, a good example is likle pressure in a pipe:.High voltage would be lots of pressure while low volatge would be small amount of pressure
------------------
Explosives Archive
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 26, 2001 12:20 PM
--------------------------------------------------------------------------------
and is the current how fast that pressure moves through the pipe?
------------------
...Æ
PYRO500
Moderator
Posts: 1466
From: somewhere in florida
Registered: SEP 2000
posted January 26, 2001 05:10 PM
--------------------------------------------------------------------------------
the current would be how big the pipe is around
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 26, 2001 06:34 PM
--------------------------------------------------------------------------------
wow, that really cleared things up for me man. thanks for the info.
------------------
...Æ
vehemt
Frequent Poster
Posts: 580
From: Canada
Registered: SEP 2000
posted January 26, 2001 10:01 PM
--------------------------------------------------------------------------------
Voltage = Pressure
Current = Volume
simply RED
Frequent Poster
Posts: 238
From: HELL
Registered: OCT 2000
posted January 29, 2001 05:08 PM
--------------------------------------------------------------------------------
I've made a lot of electrodetonators with Nichrom (Ni+Cr) wire. The explosives I've used were acetone peroxide, AP putty and HMTD, it works great! The wire was 1/12mm wide(like human hair). I've triggered the detonators with EBP-30N Alinco battery 7.2V 1 detonator from 100m with standard "sapper" wires. The detonators had standard form, made from thin alluminium.
CragHack
Frequent Poster
Posts: 606
From:
Registered: DEC 2000
posted January 29, 2001 10:07 PM
--------------------------------------------------------------------------------
well i am either going to use the NiCr wire, or a small capacitor with a polarity, and just hook that up the wrong way, which makes it pop. i am more than likely going to use the guitar string. i can get a box of the stuff for a buck (american) it will be cheaper and it is proven (by you guys) effective.