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Sunburned face from sparks (REASON FOUND!? CHECK OUT 29th POST)

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Steve Conner

Thu Jan 11 2007, 12:57PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

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.

Thu Jan 11 2007, 02:01PM

Banned on April 7, 2007
Registered Member #277 Joined: Fri Mar 03 2006, 10:15AM
Location: Florida
Posts: 157

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

Avalanche

Thu Jan 11 2007, 02:42PM

Registered Member #103 Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845

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...?

Steve Conner

Thu Jan 11 2007, 03:06PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

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.

Dr. Slack

Thu Jan 11 2007, 03:17PM

Registered Member #72 Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659

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.

Sulaiman

Thu Jan 11 2007, 06:28PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

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.

Tesladownunder

Sat Jan 13 2007, 02:18AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

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

Peter

Sun Jan 14 2007, 12:21AM

Banned on April 7, 2007
Registered Member #277 Joined: Fri Mar 03 2006, 10:15AM
Location: Florida
Posts: 157

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

HV Enthusiast

Mon Jan 15 2007, 12:50PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

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 . . .

Thu Jan 18 2007, 04:19PM

Banned on April 7, 2007
Registered Member #277 Joined: Fri Mar 03 2006, 10:15AM
Location: Florida
Posts: 157

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".

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