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Recording the sound of electricity 1

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JFRiehle

Computer
Feb 4, 2013
3
Hi All,

I feel like a tourist in this forum as I am a sound engineer and sound effects recordist. A mechanical engineer friend of mine turned me onto these forums in hopes to help with a project. I am looking to record the sound of electrical arcing. I understand this is a somewhat silly pursuit as the source of the sound I would like to capture is dangerous and unpredictable. That said, I'm still looking. :) Any and all help would appreciated, even if its a finger pointing the in the right direction. (middle finger or otherwise) Thanks!

Best,
Jake
 
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There are a variety of somewhat safe and somewhat predictable arcs you might start with:
electric fence
arc welder
Jacobs ladder

If you have a foundry/smelter near by, arc furnaces are pretty exciting.

There are also lots of high voltage laboratories that test power system equipment. Most labs have an impulse generator that simulates lightning strikes. A few of the labs also do short circuit testing or arc flash testing. Where are you located?
 
Thanks so much for the reply!

I've recorded jacob's ladders and a few "small tesla coils". They sound good but a little more buzzy than what I'm looking for. I'm a total novice but I'd assume events like the one in the video link below are happenstance and or can't be replicated easily or safely enough to record?


That kind of sound would be amazing to capture.

I'm in California. I've seen some EAF videos on youtube as well, they look pretty intense. I'm sure arc flash testing is too. Have you been involved with any of this kind of stuff?
 
Maybe not as silly as you might think. Arc flash detection is an active area of research - established methods are optical (sense a bright light in the appropriate wavelengths) or to a lesser extent, electrical (measure the current waveform and pattern match it to arcing). Arc flash detection is important because the currents involved aren't necessarily up near the maximum that can be provided (at least not initially) so normal overcurrent detection can be a bit slow to react. And depending on where it is, an arc represents an enormous release of heat which can be very destructive, very rapidly. Fast, reliable arc detection is very important, and can be quite tricky.

So while I don't think acoustic detection is going to revolutionise arc fault detection (it would be too slow - by the time the pressure wave hits the sensor, the damage is done), creating arcs and recording them is not so unusual. As bacon4life suggests, high voltage test bays are the place to do it under controlled circumstances. Transformer manufacturers, power engineering companies and others often either have one or access to one.

Now replicating the fault in the video might be asking a bit much, but you'd only need to reduce either the duration or the voltage (and therefore arc length) by enough to get it within test bay limits.

You'll probably find test bays tend to limit their high power tests to well under a second (they typically have a charge-pulse system, rather than continuously feeding energy), so another avenue that just occurred to me is special effects studios? They'd be more interested in the visually/audibly impressive results and might have some methods that are more suitable.
 
another idea: try googling electric power companies for training films.... I know our local Pwr company comes to our dayton Hamvention most years and puts on arc demonstrations for safety; I bet there are safety training films out there with the site and sound you want....
 
Not sure if this is what your looking for, but take a 120 to 12 volt step down transformer and wire it in series with a stereo speaker (you may need a resistor between the the two). Speaker will churn out a distinct 60hz. (distinct from the 60hz buzz of a transformer.
 
Mbrooke said:
distinct from the 60hz buzz of a transformer
That would be because a transformer hums at double line frequency, or 120Hz on a 60Hz power system.
 
lol. Thanks @Stevenal, not exactly what I'm looking for entertaining nonetheless.

That said, thanks for all the suggestions! I'll try to explore some of these avenues but I think my biggest hurdle will be getting someone to allow me to come by and record this type of equipments/events. Who would the point person be @ a electrical company be to ask? Would universities with electrical engineering programs be a good place to start too?
 
I have some video clips of arc testing we performed on some LV switchgear. The sound of 80,000A on the loose is a bit muffled because we were in the control room behind armoured glass and blast doors, and the test cell was a good hundred yards away. The tests each lasted 300ms. I'll probably struggle to upload the clips because they are massive and my ADSL connection is s-l-o-w but I might be able to strip out the audio if I can persuade my video editing software to work on my Win 7 machine.

If it would be of interest I'll have a play later on and see what I can do.
 
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