sounds to me that the lower voltage is working because its more heating the nicrome (which is igniting the pyrogen) but the 12v because the ignitor (as it should) ignites faster, but your pyrogen is not sensitive enough to ignite.
when i 1st tried making ignitors i soon found lots of duds using bp ect but as soon as i tried Chlorate's, never have a dud since.
I'm sure coopperman can advise better as he is testing different pyrogens as we speak.
self dip Igniters
Started by
Guest_PyroPDC_*
, Aug 28 2009 12:01 AM
47 replies to this topic
#47
Arthur Brown
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Posted 16 May 2010 - 01:21 PM
Most of the composition problems are powder size problems. The dip needs to be like paint or double cream, and the solids must be fine enough to remain suspended.
http://www.movember.com/uk/home/
Keep mannequins and watermelons away from fireworks..they always get hurt..
Keep mannequins and watermelons away from fireworks..they always get hurt..
#48
BrightStar
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Posted 16 May 2010 - 03:01 PM
'leosedf', on 16 May 2010 - 10:30 AM, said:
The only problem i had is the voltage needed for these. My system is a 12V firing system and they keep misfiring. When i use smaller voltage like 1,5V - 6V they light up fine. Seems that the nichrome wire is pretty fine.
Firstly, igniters are current fired, not voltage. Typically they have a resistance of around 2 ohms. You will need to put about 0.5 to 1 amp through them to reliably fire. A fresh AA battery will do this just fine with typical 2m lead wires, though with a long cable run you'll need a higher voltage. As an equation:
Battery voltage / (match resistance + wire resistance + internal resistance of battery + resistance of switch) >= 1 amp
Standard #50 guage nichrome match heads need a Chlorate primer to fire - they won't ignite BP or Perc mixes directly. This primer needs to be coated with something less sensitive for safety and compatibility.
It is possible to 'overload' a standard match causing it to arc unreliably, but you'd have to supply around 100 amps for 10ms or so.
Edited by BrightStar, 16 May 2010 - 03:22 PM.
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