[Home][2015 Index]
Do you have an image or video showing this? I don't think I have seen what you have talked about before. Here's example of spark discharges from my small coil forming streamers in parallel from what Jim mentioned. I don't see any of what you mentioned in photos from my other coils of various sizes. See: https://farm9.staticflickr.com/8376/8541493944_fe76f78891_b.jpg Guangyan On Tue, May 19, 2015 at 10:15 AM, Carl Noggle <cn8@xxxxxxx> wrote: > I have worked my whole life in high voltage and pulse power and made > several TCs. Therefore, I am highly qualified to dispense wisdom in such > matters as this. I've seen this phenomenon many times, with TCs and with > Marx generators. Beginning of wisdom ---> I have no idea. <--- end of > wisdom. The brightness of an arc is proportional to the current and to the > gas pressure, which are both pretty constant along an arc. I just looked > at a whole bunch of TC arcs that terminate in the air, and did not see any > of these bright sections. I think they only appear in arcs to ground or > some other low impedance point. The bright sections are usually more or > less in the middle of the arc channels. > > It might be enlightening to take a pix of this phenomenon with a plastic > diffraction grating. You could get an idea of the temperature of the > bright and dim regions from the relative brightness of different lines and > from the relative brightness of the lines vs the continuum. If you > photographed the arc in front of a black background such as flock paper, > maybe you would see dim discharges paralleling the dim section. > > Another interesting question is, why are the transitions between the dim > and bright channel sections so abrupt? That's weird. Could it be some > kind of glow-arc transition? There must be some real physics here. I > think this is something worth investigation by the TC community. Let the > experiments be made. > > ---Carl > > Reporter: "Mr. Roentgen, what did you think when you saw these mysterious > images?" > Roentgen: "I did not think, I investigated." > > > > > On 5/19/2015 5:14 AM, Jim Lux wrote: > >> On 5/19/15 3:09 AM, b alex pettit jr via Tesla wrote: >> >>> Hi All, >>> I have a low powered TC that can produce arcs in the 2" to 8" >>> range,secondary resonant freq 190 KHz. >>> On any power setting, if I use a conductive rod to attract arcs ( sparks >>> ) and space itto get individual, non branching arcs, there is surprisingly >>> a consistent, repetitive pattern of brighter and darker ( fatter and >>> thinner ) areas along its length.. Such as >>> -------=========----------===---------------------------------------- >>> Anyone have any ideas why this may be so ? I would have expected >>> consistency,but there are arc segments with a brightness maybe 5 times the >>> other portions. >>> What is the propagation velocity of an arc in air ? >>> This has been confirmed by others so it is not related to my 'visual >>> acuity'. >>> >>> >> What you see as a single spark is actually a lot of sparks following >> mostly the same paths. Not only is there a spark moving for each half >> cycle of the RF (way faster than you can see), but there's also multiple >> spark groups corresponding to the AC line voltage peaks. >> >> When the sparks happen to align (or not) changes the apparent brightness. >> >> If you see a picture of a TC operating in a small movement of air, >> sometimes you see the different sparks (for AC line voltage cycles) spread >> out in parallel. >> >> >> the other thing affecting apparent brightness is whether the spark is >> traveling exactly normal to the line of sight, or more aligned with it. >> This is really obvious when you are looking at a spark coming towards you: >> the spark segments that are exactly parallel to your line of sight look >> like really bright dots. Most people who have been in a "cage of death" >> faraday cage kind of situation have commented on this. I've tried to take >> a picture of it, but not been very successful: I think it's partly due to >> how the human visual system works in real time. >> >> _______________________________________________ >> Tesla mailing list >> Tesla@xxxxxxxxxx >> http://www.pupman.com/mailman/listinfo/tesla >> >> > _______________________________________________ > Tesla mailing list > Tesla@xxxxxxxxxx > http://www.pupman.com/mailman/listinfo/tesla > _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla