Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Sulaiman, Mon Jan 08 2007, 02:03PM

As far as I know, the shortest wavelength/maximum energy of spark induced X- or Gamma-rays
would be related to the maximum sparkover voltage.
So 1cm to 10cm implies to me well over 30 kV which is equivalent to soft/medium x-rays.
(same as but lower quantity of x-rays like those generated by crt/tv monitors)
I think Gamma rays are in the greater than 500kV range.
I hope this is not the cause of your 'sunburn' as it seems a generally hazardous quantity of x-rays are required for tanning.
A cheap complete GM detector could check for excessive X- or Gamma-rays.
(mine cost about GBP12 with p&p from ebay)

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Steve Conner, Mon Jan 08 2007, 03:30PM

I don't believe it either. I can't see how enough radiation could get through opaque plastic (it is opaque, right?) to give you a sun tan, unless it was the sort of radiation that would sooner give you cancer than tan you, and spark gaps don't generate that sort of radiation, unless the voltages and currents are high enough to generate thermonuclear fusion-like temperatures.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Marko, Mon Jan 08 2007, 06:07PM

I really wouldn't be that pessimistic with some sparks; if radiation was that powerful and penetrating we would all probably be dead due to radiation poisoning. O_O

X ray machines accelerate electrons in vacuum using high DC voltages and radiation results from their decelleration after hitting anode (Bremsstrahlung).

It seems that sparks, plasma in air need to get horrendously hot in order to produce that kind of radiation.

This hot:

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Kolas, Mon Jan 08 2007, 07:29PM

I'm not sure this applies.
When i was testing and using my carbon arc cutting torch, i frequently got "sun burn" through my clothes.

Of course the arc was many times hotter then the average spark gap, as the torch cut with a suspected 15kW of power. This arc was not sheilded by anything but my welding mask, and is suspected to be 15000 times brighter then the sun.

I found that leather did stop the burning and is a must to use the device.

Kolas

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Simon, Tue Jan 09 2007, 03:21AM

That's right. Thin clothing is necessarily a perfect barrier against strong UV. Sometimes here downunder you can get a tan through a light t-shirt.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Steve Conner, Tue Jan 09 2007, 09:42AM

Yes, high powered arcs like Kolas's cutting torch generate huge amounts of UV light. But, CM said that his spark gap was inside a solid plastic container. I assumed the plastic wasn't see-thru, and anyway, I was under the impression that even clear plastic stops the wavelengths of UV responsible for sunburn.

Also, there's a big difference between a continuous arc with 15kW of power, and a little spark gap charged by atmospheric electricity that fires a couple of times a second. A 15kW arc at arm's length will expose you to several times more radiation than the sun, sure enough. I imagine the heat from Kolas's arc would melt a plastic container in about 10 seconds.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Tue Jan 09 2007, 03:35PM

The spark gap housing is made of thick-wall PVC, so no UV is getting through for sure. After reading the above posts, I'm not sure what is causing the sunburn effect, all I know is that some days my face feels and looks sunburned after sitting infront of the spark gap all day long. Even to the extent that the right side of my face that is slightly more exposed to the spark gap area is more 'sunburned' than the left side. I measured it yesterday, the way my tiny 'lab' at the test site is set up, my face is about 12 inches from the PVC housing that encloses the spark gap. I prefer that the above posts are correct and that no appreciable amount of Xrays or Gamma are emmitted from the spark gap, as I understand those wavelengths are not very healthy. Besides the 'sunburn' thing, there is one other slightly curious thing that happens occassionally... and I hesitate to mention it at all since it might be just an optical illusion. As I work in my tiny lab, which is an RV (recreational vehicle) on a 300 acre tract of wide-open spaces land, I can see the acre of so of land below my antenna which is 3000 feet of wire in a pattern supporting 400 (+/-) of my patent pending HV collectors (patent filed in Feb 2006) supported in the air by four 130 ft towers. Sometimes, on days when there is mild cloud cover, I see in my peripherial vision, what appears to be a rapid flickering of a large area beneath the antenna grid. It is a very weak flickering, in fact, when I try to focus directly on it, I usually can't see it, but when I return to using peripherial vision, I can see it. I can't localize the flickering, and its not there all the time, in fact, it might be argued that its not there at all and that I need to get my eyes examined. Regardless if its real or not, it still interrupts my attention several times a week. If requested, I can post a pic of the spark gap and the test site. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Bjørn, Tue Jan 09 2007, 06:33PM

The peripherial vision can detect much faster changes in light so that is one possible solution to why you have trouble seeing it directly. It is also quite common to see flickering where there is none in certain conditions. I suggest trying a video camera to find out for sure.

When it comes to your face, have you done the obvious thing and measured the temperature inside your lab? It is not completely unknown for astronomers and other people that are focused on what they are doing to get hypothermia or heatstroke without noticing a thing.

Please post some pictures.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Dr. Slack, Wed Jan 10 2007, 08:10AM

Just curious CM, what sort of DC output power do you measure from your 1 acre of collector?

What HV input power do you expect from fine weather currents?

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Wed Jan 10 2007, 01:20PM

During the summer, it got a bit warm, but the last couple months its quite cool inside, I've been wearing a coat due to the coolness. As requested, attached is a picture of the spark gap (enclosed in the white PVC container) and my four 130 ft tall towers (FAA approved) that support my 400 (+/-) patent pending HV collectors, the red wire connected to the PVC container is the HV feed from the collectors. The white RV in the distance is my tiny 'lab'. The large air-space under the wires/collectors (collectors not visible in the small pics) is the area that occassionally looks like its flickering on darker/cloud covered days. Measuring the antenna output has been a bit difficult for me, I've destroyed one O-scope and fried several meters from not measuring properly, I do know from unpleasant experience that when I am tired or careless and get too close to the HV feed, it sparks to me, leaving a dark black spot on my finger and the smell of burnt skin... also gives me practice expanding my vocabulary of curse words. I'm not claiming this early version is ready to replace any power plants :) but it does demonstrate that small loads can be operated from 'ionic' collection even in zero wind condition (I have a weather station at the test site) also the triboelectric effect has a bit to add when wind is present. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Kolas, Wed Jan 10 2007, 02:39PM

Woah that's alot of metal in the air, do you have lightning arrestors on the HV feed running into your laboratory?

I foresee the possibility of those towers making an excellent target for lightning.

Which might result in unpleasant consequences.

Kolas

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Bjørn, Wed Jan 10 2007, 03:14PM

During the summer, it got a bit warm, but the last couple months its quite cool inside.

Since it is not the heat then consider irritation or allergic reaction. The static field may cause particles in the air to stick to your skin.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Wed Jan 10 2007, 03:42PM

You'd think so, but I've had various versions of my HV collectors up for approaching two years and no lightning trouble yet. No official lightning arrestors installed, but as soon as the collectors accumulate a few kV, the charge is transported by the wires and drained by jumping the spark gap. From what I understand, lightning occurs when opposite charges build up strong enough to initiate a lightning discharge. Maybe the reason there's been no lightning problem (that I know of) is because the collectors are constantly draining the nearby atmosphere of excess charge being transported by the wires down to the spark gap and HV/LV conversion circuit and finally to ground. However, when there is a thunder storm anywhere nearby (even over the horizon out of sight) the collectors and spark gap go ape-sh*t, big thick blue sparks, sizzling sounds, gets a bit hairy when the environment is that energetic, (1 inch blue sparks, about 1/16th inch thick) so most times I leave and go home when that happens. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Sulaiman, Wed Jan 10 2007, 10:18PM

On seeing the size of your collector array
I don't advise the direct resonant conversion for eht-to-lv conversion
(such as sparkgap to a Tesla Coil in reverse)
unless your authorities will allow the resultant rf transmissions.

Although the total power collection may be modest
(I've no idea, say 100W)
the conversion would be pulsed, e.g. One pulse of 10us per second
The power during that 10us would be equivalent to 100/10u = 10 Mega Watts
Radio pollution of 10 MW pulses don't usually get approval I'd guess.

Whatever conversion method you eventually use
the rf emissions of the collector array must be considered.
Probably implying that the capacitance of the collector array
cannot be used as part of a resonant circuit.
Also the use of a sparkgap on an aerial of this size would also be a massive transmitter.

Just a thought
To stay on topic - could also check for draughts of hot/cold humid/dry air?
Which may also carry allergens.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Steve Conner, Thu Jan 11 2007, 12:30AM

Good grief Sulaiman, you have a serious point. CM's array is bigger than anything most of us have used for real ham transmissions!

I've been thinking about this whole thing for ages, and just there I had a brainwave. Why not have the high voltage from the array drive an electrostatic motor, and make this drive a tiny DC generator? That sounds inefficient, but I bet it would end up more efficient than any static HV converter.

So, I googled a bit and found this

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Bjørn, Thu Jan 11 2007, 12:48AM

A very good point, electrostatic motors can be fairly efficient and with more than 10W power the generator can surely be made fairly efficient too.

Also consider a resonant piezoelectric crystal device. They can be efficient at transforming voltages.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Sulaiman, Thu Jan 11 2007, 01:23AM

Now that I've appreciated the scale...
I suppose there could be unexpcted emissions from the spargap stuture
and the first step I'd take is a sheet of grounded aluminium (foil?) between yourself and the sparkgap until you know/ as a test.
I guess even a large static electrostaic field may have effects.
I'd definately be 'scoping during the sparkgap discharges.

Reading up on how radio antennas are safety grounded is probably regulatory eventually
so may as well protect yourself now anyway.
Not my area but others may help (in a new thread)?

P.S. I have personally seen the after-effects of lightning and I wouldn't want that collector/sparkgap anywhere near myself!
I hope you are confident of the array's ability to supress a lightning strike!

P.P.S. For now I'd take a portable radio and listen on all available bands whilst sparkgap is operating - a sope with 6" wire aerial or loop will show primary resonant frequencies and of course a spectrum analyser would be best.
The rash could even be a capacitively coupled rf burn/irritation.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Tom540, Thu Jan 11 2007, 04:26AM

Hey why not replace that gap with a SISG? hehe

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Thu Jan 11 2007, 12:18PM

I've operated an electrostatic motor (Bill Beaty's motor design, Bill and I speak from time to time) on my antenna over a year ago, I have pictures somewhere of it spinning from my antenna, if you guys want, I can see if I can find the pictures and post here. It works, but unfortunately the torque of electrostatic motors in general seem to be very low. I've also cooresponded with the King of electrostatic motors Professor Oleg D. Jefimenko (mentioned in the article Steve goggled), Professor Jefimenko's attitude is not to bother with the electrostatic route as he and his students at West Virgina University spent years pursuing that avenue developing many different improvements to electrostatic motors, but none of them seem to produce sufficient torque, even when supplied with much energy, but they are fun to watch. To stay on topic, I am still mystified about the sunburn face, allergins could be involved I suppose because there is a good bit of stray 'static' running around the top of my desk, maybe it attracts grass into the RV on days that I leave the door open, I am allergic to grass, but I take allergy meds to counter its effects. On the other hand, it does not behave as a typical allergy reaction to grass, which usually involves my nose becoming congested, itchy eyes, etc. The only effect is that mainly the right side of my face... the side slightly more exposed to the spark gap, feels slightly burned and appears red. I would LOVE to hear more on how an SISG or resonant piezoelectric crystal device might be tested in my application! Please post here, or if too off topic, start a new thread, or contact me at **link**. Btw, my goal is to reach an efficiency level capable of driving a fuel cell round the clock, so far I can drive a fuel cell for short periods of time, with a bit more efficiency, it could be round the clock. Thanks. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Steve Conner, Thu Jan 11 2007, 12:57PM

According to this website Jefimenko has got 0.1 horsepower at over 50% efficiency from an electrostatic motor. I don't think any semiconductor circuit could beat one of Jefimenko's corona or electret motors coupled to a small generator (eg a precision motor from a tape deck, disk drive, pager, hard drive or whatever) at these high voltages and low currents. Even if it could be 100% efficient, it would be so expensive and complex that it would probably be more cost effective to double the size of the collector array and live with the 50-60% loss of the motor/generator approach.

So I expect the real problem is not that electrostatic motors suck, but that your array just doesn't produce very much power. Did you ever measure the power output? You could easily have done so, without using any kind of power electronics at all. A high voltage dummy load resistor, a couple of digital volt and milliamp meters, and some computer datalogging software, is all it would take. I spent several years testing solar panels and wind turbines with similar equipment. If you're trying to sell your device commercially, you will have to compete with these, because that's what people currently use to power things in off-grid locations.

To give you an idea, a 3ft x 2ft solar panel costs about $500, and delivers about 4-5 amps at 12V (~50W) in full midday sun. If you take into account weather, seasons, night time etc., then it delivers 5 watts average over the year. It will last for 10-25 years with no maintenance at all.

A wind turbine with a rotor about the size of an umbrella (0.7m diameter say) generates about 100 watts in a high wind, and costs again about $500. I don't have any figures on best-of-class power output and reliability, because the turbines I tested were experimental models that, to put it bluntly, sucked and fell apart.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Thu Jan 11 2007, 02:01PM

Haven't had good luck measuring the spark output, it happens so quickly my meters don't react fast enough. Also destoryed an Oscope trying too. I am sure someone with better skills could measure it. I had a tech guy come by in the early stages of my collector development and asked him to measure the output of the spark generated by 3 of my collectors suspended on a balloon. Using an Oscope, he 'guessed' it was 100 amps (+/-) for 2 nanno-seconds (+/-) during each spark, but... the more we talked, the less confident he and I were that his measurement was correct. I suspect I am losing massive amounts of efficiency in the HV/LV conversion, thus my continuing quest to find the most efficient means of HV/LV conversion. Already researched the electrostatic motor route, just didn't seem to be the answer, but I remain open minded. PV, solar panels are good, own some myself, but the investment must be repeated about every 20 (+/-) years as efficiency degrades with time. Also heard the rumor that it requires more energy to produce a PV solar panel than it will ever produce in its lifetime (?? rumor or fact??) Wind is good also (I've built many windmills, some with 16 foot long blades), but last time I checked, less than 5% of the USA has enough steady wind to make them economically feasible, they are very geographic dependent, plus being mechanical, there is considerable maintainance and replacement costs. Even with those shortcomings, I support both solar and wind technology advancements and ANY techonology that uses renewable environmental energy without producing pollution. The attraction (for me) to the HV collector approach is that the collectors harvest ions round the clock, night and day, good or bad weather, and is not geographically dependent. I've tested it in a number of different locations seperated by thousands of miles including the desert, 8000 ft mountaintop, and near sealevel. The power source (ions) are constantly being created, round the clock by nature, gamma rays striking our atmosphere, radioactive decay in our soil, lightning, etc. Just seemed to me that someone needed to investigate this approach, so I've been doing it for the last few years. Might lead to nothing commercially feasible, or might lead to a cost efficient means of producing Hydrogren round the clock from any location on the earth by suspending collectors in the air. Also, my collectors should work much much better on Mars, due to the extremely dense ionic conditions because of the almost non-existent magnetosphere (NASA data). Time will tell. Once my patent issues, I plan to mention this to NASA. Meanwhile, I continue looking for better means of converting HV sparks to LV and welcome comments from this well educated group of people here at 4hv.org. If nothing else, I might offer the technology to the suntanning bed industry :) :) :) CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Avalanche, Thu Jan 11 2007, 02:42PM

Don't know if I'm missing something here, but would it be possible to use the charging curve of a capacitor to 'step down' the voltage?

Because the array will have a relatively low output current but at many KV, connecting it to a capacitor will pull the voltage right down at first as the capacitor begins to charge, but then as the capacitor approaches full charge the voltage would rise higher and higher. The important thing would be to discharge the capacitor into a load before it gets anywhere near full charge, by use of a high voltage MOSFET or a cascode of MOSFETs that switch on when the voltage across the capacitor reaches, say 1 or 2 KV. The MOSFETs could then dump the contents of the high voltage capacitor into the primary of a ferrite transformer, to bring the voltage down even more, and maybe charge a final smoothing cap where you connect your low voltage load across.

Sure it would have it's losses, and the whole capacitor thing would be a very poor impedence match to the array, but it should work. I'm not sure how lossy it would be compared to other ideas...?

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Steve Conner, Thu Jan 11 2007, 03:06PM

When I said to measure the power output, I didn't say you should allow it to spark and try to measure the energy of the spark. (Though you could if you wanted, by letting it spark inside a vacuum flask and measuring the temperature rise of the air.)

What I meant was, that if the array can generate sparks, it must also generate a steady DC current. This current normally charges the capacitance of the array until the voltage is high enough for a spark.

So, instead of allowing it to spark, load it with a high value, HV resistor, and measure the voltage across it (using a meter with HV probe) and the current through it. Experiment with different values of resistors until you find the one that maximises delivered power (ie voltage * current). Also look to see if the resistor gets warm.

If you hired someone to make you a converter, they would ask you to do this characterisation anyway, or do it for you and charge you extra...

Avalanche: To extract maximum power from the thing you have to hold it at its "maximum power point", as found above, all the time. The maximum power point may change with weather conditions: characterizing this would be part of the converter development program too.

I see that Jefimenko got around one millionth of a horsepower from a 24ft antenna with a radioactive tip. So if you had 100 antennas each 10 times as tall, and your converter was twice as efficient as his, you might get something like two thousandths of a horsepower.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Dr. Slack, Thu Jan 11 2007, 03:17PM

A thought for an alternative conversion scheme. While the method is completely sound, with the theoretical efficiency being close to 100%, the implementation could be somewhat unweildy; though for somebody who has an array like that to recharge his mobile phone, who am I to guess what might be called unweildy?

The idea is to use the HV current source you have available to charge a series string of capacitors, perhaps up to 1000v each, so a string of at least 20 for an assumed input of 20kV, though the protocol I outline will need twice that, as the average voltage will be half through continual charge harvesting. This gives you multiple low-impedance sources of a reasonable voltage. Now you transfer energy from each one in turn to a 500v load, using a charging inductor and deQ diode to transfer the full charge losslessly. The trick is that the load must be floating, and must be able to float at least to your input voltage. The sort of image that's materialising in my mind is a large circle of capacitors and contacts, with a slowly rotating "flying" capacitor on a GRP arm contacting each in turn, then after a good break-before-make distance, contacting the fixed output load, through another inductor/diode change transfer. That gets you down to a sensible voltage of 250v or so from which you can run power electronics. A nicely balanced rotating arm need take little power, with the losses being air resistance (low if slow), bearings, brush friction (probably the largest contributor). The speed could be varied between strong and weak days, more frequent discharging is needed to limit the peak capacitor voltage when more sky current is available, so giving more or less constant efficiency. Any more tidy stationary contacting arrangement, pneumatically driven levers perhaps, would surely consume much more power.

Increasing the voltage per capacitor and reducing the number of stages might make this enormous air-spaced structure more practical.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Sulaiman, Thu Jan 11 2007, 06:28PM

A possible use for eht at low power may be water sterilisation (Oxfam, Water Aid etc.)
Since the optimum power will probably be
(1/2 x Peak Voltage) x (1/2 x Short-circuit current)
you may be able to directly strike and run a mercury vapour lamp
to produce sterilising uv rays for water purification?

IF your collectors are good then a modest height and area may be feasible for remote installations.

I guess installations that NEED FAA approval are less attractive.

The short answer to the possible cause of the 'sunburn' is
to build separate power and monitoring environments.
i.e. a production prototype convertor separate from your monitoring/experimenting room.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Tesladownunder, Sat Jan 13 2007, 02:18AM

Sunburn is sunburn. " after a full days work in a lab.." " which is an RV."

Peter

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Sun Jan 14 2007, 12:21AM

I think we've run the sunburn topic dry for now, it's not heat stroke, not excessive temperatures, (RV is equipped with air conditioner and heater to keep me comfy if I get too uncomfortable) not sun penetrating the very dark tinted small windows, and not really worth any more of our efforts trying to figure it out because it's only a minor curiousity, not that big of a deal. If my skin falls off in two years, we'll know it was some form of harzardous spark radiation afterall and I'll get written up as the newest freak in the New England Journal of Medicine, if not, who cares. Meanwhile, Bjorn: I tried a piezo electric buzzer, probabaly not exactly the device you intended, but it amazed me how well it recitified certain signals! Approaching the efficiency of the Schottckys I use. Quite interesting! You've inspired me to launch into a new google quest to learn more about Piezo device recitification. If you happen to have some links in your back pocket good for a crash course in Piezo rectifiction, please lemme know. Thanks. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
HV Enthusiast, Mon Jan 15 2007, 12:50PM

I once got facial sunburn from operating my dual Stereo Plasmasonic systems in a closed room for a corporate demo a few years ago. Of course, these were CW systems put out lots of UV light from the distributed "fuzzy" brushlike discharge, and I was in there for quite a few hours . . .

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Thu Jan 18 2007, 04:19PM

I know I said we've run this thread dry, but then I found the below. Looks like Bjorn gets the 4HV.org pat on the back for coming up with the most plauseable reason for my 'sunburned' face. Seems there is some basis for his static induced theory for why my face sometimes gets red when I am sitting infront of my spark gap, check it out:

"Over the last couple of decades there has been, at least in Europe, a great deal of concern voiced over the static electric field generated by monitors and television screens. It is this field that makes dust and other particles plate out on the screen, due to simple static attraction as well as polarization forces. If a person is sitting close to the screen, the field will be distorted and will converge toward the person's face, and the particles will then plate out on his or her nose, forehead, and cheeks. Studies have shown that any static field on a person's face will dramatically increase the plate-out rate of particles, and scientists have speculated that this may result in an increase in the occurrence of rashes and more-serious skin diseases such as eczema, given the presence of allergens or other unsavory substances in the air. " Bravo Bjorn! CM

In the below URL look under "Static Field Remover".

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Tesladownunder, Thu Jan 18 2007, 05:06PM


You seem very confident of your medical diagnosis with zero quoted evidence that electrostatic fields cause rashes. Sure there are 16 year old studies published in obscure publications (presumably not peer reviewed) that sitting in front of a VDU all day is not good for you. There is no proof that this is due to electrostatic fields however tempting the association may be to you. There are many possibiilities including people who don't sit in front of VDU's all day may actually be healthier. The diagnosis of eczema was not made by a dermatologist as far as I can determine and no placebo-controlled double blinded studies appear to be quoted.
Allergens in the air is not as far as I know, a recognised cause of eczema (unlike asthma and hay fever). Allergens on the skin need a portal of entry before through to the dermis before an allergic response can be mounted and even then you will get wheals rather than eczema.

If you sit in a car all day you need to consider UV exposure even though you may feel cool and glass blocks a good amount of UV. Sunburn is far less speculative that what you propose.

Peter

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Bored Chemist, Thu Jan 18 2007, 06:24PM

"Allergens in the air is not as far as I know, a recognised cause of eczema (unlike asthma and hay fever). Allergens on the skin need a portal of entry before through to the dermis before an allergic response can be mounted and even then you will get wheals rather than eczema"
I'm not a dermatologist, but I'm pretty sure that allergic dermatitis isa real phenomenon. Google certainly gives lots of hits for it.
Glass does a prett good job of blocking UV. Tinted glass does even bettter.
OTOH, unplasticised pvc has no chromophore that would absorb moderately long wave from a spark.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Thu Jan 18 2007, 06:52PM

Based on previous posts by what appear to be knowledgeable people here, the likelihood of Xrays/Gamma rays being produced by my spark gap in magnitudes great enough to radiate my face 'red' seems unlikely (or did I misunderstand those posts?). UV or sunlight getting into my RV is last on my list of suspects, the windows are tiny and all covered in very dark UV film, so dark that on some days I must turn on a light to work. The static induced 'rash' mentioned in the url is from a recognized authority in static Niels Jonassen, MS, DSc, Technical University of Denmark, where he has conducted classes on static electricity, ions, and indoor climate. He still runs his laboratory. Niels says "Studies have shown that any static field on a person's face will dramatically increase the plate-out rate of particles, and scientists have speculated that this may result in an increase in the occurrence of rashes...". True, it's not a diagnosis, but if we are to rule out spark emissions (?) and sunlight/UV (which I do), the static option seems the most likely candidate that's been mentioned so far. The publication you referenced also appears to support that static induced redness is not uncommon among people around static sources for extended periods of time complaining of "a glowing sensation, rather like sunburn" which is a great way to describe what I experience after sitting at my spark gap and static filled table top for hours. Thanks for the article. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
..., Thu Jan 18 2007, 11:10PM

Actually, how do you get to the site? There is a decent chance that you are getting sunburned on the drive to/from the site...

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Fri Jan 19 2007, 01:53AM

I drive my truck, tinted windows, no sunroof. If it were caused by sun/uv, I'd get sunburned whereever I drive my truck... not just when I drive to my test site. Also, I don't feel sunburned when I get to my test site, only after a long day sitting at my table (but not necessarily EVERY day). CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
ragnar, Fri Jan 19 2007, 07:53AM

Not that I have any idea on where your sunburn comes from... but if you're in the sun for a bit, the damage only appears (and feels tangible) several hours later.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Coronafix, Fri Jan 19 2007, 10:08AM

I think that CM has made it clear that he believes the source of his sunburn
comes from the spark gap on his desk. His face is more burned on one side (the spark gap side), it feels especially burnt after a long day in the lab, the RV is tinted, his truck is tinted. He feels he has ruled out all possibilities of other sources of his sunburn.
If his deductions are to be trusted (and why not since we have no other data), then it leaves only the spark gap as the source of the infliction.
We should then ask ourselves why?
CM, you said the spark gap is usually set between 1-10cm (10-100mm in my language), does the face burning feel any different when the gap is set at different distances?
By the way, I think that the electric field reaction is highly plausible.
A 100mm spark gap is quite a voltage, isn't the electric field associated with that also quite large?

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Fri Jan 19 2007, 05:41PM

I haven't paid close attention to the possible correlation between my occassional red face and the distance between the spark gap electrodes, but I'll start taking notice. The last week or so I've been setting the spark gap to very short distances so that the sparks jump around the clock... and coincidentially I haven't noticed any red face over the last few days. With the larger spark gap distances, there are times the V of the collectors isn't high enough to cause a spark to jump a large gap, so in order to keep a reliable (pulsed) charge going to the load, usually a bank of super caps, lately I've been using a narrow gap. The narrow gap increases the frequency of the spark jumping, at the expense of decreasing the V and current per spark. Overall tho, its starting to look like the narrow gap is best since it is easier on the buck converter (occassionally the 40 amp 1N1190AR diode in the buck converter will blow when using a large gap) and works round the clock when sometimes a larger gap won't, thus delivering a more reliable charging to the supercaps (me thinks). Testing continues everyday, in the pic, if you look hard you can see some of my highly skilled assistants near the base of one of the towers. (In fact, I could use some friendly advice from someone familar with HV highpass/low pass filters for my next test) I'm at **link** CM





mod edit: I guess you meant to add the picture?

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Tesladownunder, Sat Jan 20 2007, 04:23AM

I am talking about dust carried in the air (aero-allergens) of which typically house dust mite faeces and pollens are the main offenders in rhinitis for example but these are not as I am aware likely to be a cause of a red face. On the other hand Type 4 cell mediated immunity can be triggered by contact with allergens applied in liquid form such as allergy to topical cream preparations or with longer contact with solids such as with nickel allergy. We are not talking about that type but rather dust settling out of the air under the influence of electric fields.
The authority quoted may know his electric fields but I bet you none of his studies have made it into the dermatological journals.

I realise that glass blocks (short) UV well. I have done a lot of stuff with my TEA nitrogen lasers and 331 nm output. So here is some science.
Photo 1 Dual UV unit (which is switchable to either short or long wave UV).
Photo 2 Long wave UV (UVA) through tinted car window on to fluorescent marker covered paper. It passes without much attenuation. The tape casts a shadow to confirm the direction of the source.
Photo 3 Short wave UV (UVB) at 2500 angstroms is blocked but this is really short wavelength stuff.

Hence long UV wavelengths (UVA) may pass quite readily through a tinted window. These will still have energy enough to cause sunburn (and cancer) although not as readily as the short wave. Interestingly my UV coated glasses block both apparently completely.

Sunburn is sunburn and is a the most common cause of a red face. Second most common is jumping to conclusions without evidence.

Red faces aside, I envy your setup. I have had an interest in atmospheric electricity ever since waving the gate of a FET in the air and watching the drain source current change over 20 years ago.

Peter

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Sat Jan 20 2007, 06:36PM

TeslaDownunder:

Nice site that you have there. CM

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Sulaiman, Mon Jan 22 2007, 06:09PM

One day go to your field site, short across the sparkgap.
Put a current meter or resistor with voltmeter across it, across the sparkgap, remove the short.
Now you can spend your usual amount of time in your usual position - you could watch the current changing with time.
With no high voltage (since the resistor or ammeter 'shorts' the collector to earth) see if you still get a tan/rash.
Boring but objective.

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
Bored Chemist, Mon Jan 22 2007, 06:27PM

Or shield the gap (the easy way) or the windows (if you like that idea better) and see if the effect persists. Al foil is opaque to UV and Visible radiation. Lead foil (or shot in bags) will stop Xrays.
Or try sunscreen...
BTW, if you go out in the sun do you usually burn or tan?

Re: Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)
CM, Wed Jan 31 2007, 01:26AM

Each summer, I get a fairly dark tan from being outside in the hot Florida sun. But, I've also been lobsterized several times, mainly as a kid watersking all day without thought to how much time I'd been in the sun. I've experienced sunburn... this sensation is admittedly similar... but is even better described as a 'glowing sensation' as described by other people experiencing something similar in the Niels Jonassen article referencing static induced redness or rash. Who knows... could the sunlight or uv somehow be entering my RV in some unconventional way, in strong enough qty to burn one side of my face? Maybe... but not likely. If someone pressed me to make an educated guess... I'd have to say the static induced theory seems most likely. I have 400 collectors designed to collect and direct HV to a spark gap a few inches from my face. Probably not the best arrangement... but my RV is very small. CM