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  1. #31
    Join Date
    19th January 2009
    Location
    Coopersburg, PA
    Posts
    82
    Ok guys, these showed up today...

    Click image for larger version. 

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    It will be a little while before I can fully test them but I had to quick fire off a couple to see how they compare. The quick take away is, these things are a lot faster than the eBay ones, both in ignition and burn time. Here's a capture using the same 5 ohm resistor setup that I've been using. I trimmed the 1m Firewires to the same 30cm lead length of the other ones to keep things on equal footing.

    Click image for larger version. 

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    For the first one, the element conducted current for 1.62ms before fusing open. The second one (trace above) conducted for 1.57ms, so in general the element is lasting about 1/10 the time of the eBay initiators. You'll also notice that right after the element opens up, the plasma current starts to ramp up right away, only lasts a little over 2ms, and ends rather abruptly. This also coincides with what I observed. The Firewires have a loud quick pop, almost like a small firecracker going off whereas the eBay initiators have a small pop and then burn for about a second.

    Randy


  2. #32
    Join Date
    10th July 2007
    Location
    Melbourne, Australia
    Posts
    1,468
    I have significant experience doing both of those things for industrial, mil and aerospace applications.
    I figured you had some high-end applications if you were concerned about inductance in this application Must have worked on some nice projects along the way.

    It will be a little while before I can fully test them but I had to quick fire off a couple to see how they compare. The quick take away is, these things are a lot faster than the eBay ones, both in ignition and burn time. Here's a capture using the same 5 ohm resistor setup that I've been using.
    Great demonstration of the variability of things that are sometimes considered equal. Nice experiment and demonstration Randy.

    TRA 13430, Level 3

    "Everybody's simulation model is guilty until proven innocent" (Thomas H. Lawrence 1994)

  3. #33
    Join Date
    19th January 2009
    Location
    Coopersburg, PA
    Posts
    82
    I fired off a couple of the Firewire initiators this morning at about 0C and the results looked almost identical to the waveform I posted above (post #31). The only difference is the element lasted for about 1.7ms to 1.8ms vs. the 1.5ms to 1.6ms I got at room temperature. The length and amplitude of the plasma current were basically the same.

    I'm not going to waste any more of the Firewires to testing since they obviously fire off much more quickly than the eBay ones. The bottom line is that 1A seems to be plenty of current to fire off either type of initiator.

    Randy

  4. #34
    Join Date
    21st May 2014
    Location
    Gardendale, AL
    Posts
    1,879
    Do you ever spend time testing the all fire voltage? I'm still new to understanding how to measure voltage vs amperage when it comes to achieving continuity tests vs firing the igniter.
    NAR #99604 L2
    L1 - 08/15/15 - Estes Partizon - Aerotech H128W - Birmingham, AL
    L2 - 02/04/17 - MadCow 4" PAC-3 - Aerotech J350W - Talladega, AL
    L3 - TBD

  5. #35
    Join Date
    10th July 2007
    Location
    Melbourne, Australia
    Posts
    1,468
    I am planning on taking some to work (maybe tomorrow) and putting an ESD gun onto them, just to see how sensitive they are to electrostatic discharge. I really don't have a feel for how robust they are in that realm at all. Could be interesting.
    TRA 13430, Level 3

    "Everybody's simulation model is guilty until proven innocent" (Thomas H. Lawrence 1994)

  6. #36
    Join Date
    18th January 2009
    Location
    Austria
    Posts
    794
    Quote Originally Posted by OverTheTop View Post
    I really don't have a feel for how robust they are in that realm at all. Could be interesting.
    For comparison, here are the official specs that igniters need to comply with in Germany. The document is auto-translated, but reasonably accurate for electrical purposes. Type A is sensitive (typically used for fireworks, not allowed for blasting anymore), type U is insensitive (allowed for most blasting applications) and type HU is very insensitive (required for blasting under hazardous circumstances, like in tunnel construction or near to electrified railways).

    If you test them, please consider testing them both "wire-to-wire" and "wire-to-head". I suspect the igniter is much more sensitive in the latter scenario, at least when tested in the human body model, because of the comparably low resistance of the bridge wire.

    Reinhard

  7. #37
    Join Date
    10th July 2007
    Location
    Melbourne, Australia
    Posts
    1,468
    Thanks for the info.

    If you test them, please consider testing them both "wire-to-wire" and "wire-to-head". I suspect the igniter is much more sensitive in the latter scenario, at least when tested in the human body model, because of the comparably low resistance of the bridge wire.
    Great idea. I won't be able to test them till I get back from a European vacation, so looking like sometime in June now. I don't think they would allow me to take an ESD gun on holdiay tour

    TRA 13430, Level 3

    "Everybody's simulation model is guilty until proven innocent" (Thomas H. Lawrence 1994)

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