I formed cone-shape screens, then punched in successive circles to form a concentric "ripple" pattern in the screen. This stops water from running off the cone-tip as a long stream (which would discharge the whole thing.) Also keeps the sharp cone tip hidden within the metal cleft: electrically shielded. DON'T let water run along the torus and drip from the bottom. Fig. 7 IMPROVED SCREEN FOR GIANT KELVIN DEVICE



High-velocity shower heads and cross-connecting conductors made from large-diameter pipes will complete the scene above: it's a "VandeGraaff Generator" version of Kelvin's Thunderstorm apparatus! NEWS: I suspended a bundt-pan by fishlines, then sprayed water through the center, so that the water did not touch the metal. I used a garden hose with a "water breaker" (a sort of shower head attachment.) I charged up the bundt pan with a 10KV power supply, and then measured the electric current between a collector pot and ground. It was 2.5 microamps! This doesn't sound like much, but it's at lease as much as some VandeGraaff generators can create.

I found that if I disconnected the power supply from the bundt pan, the current did not vanish. The charge on the bundt pan stayed the same as I watched for about 30sec. And this was in high humidity conditions! Fishing line makes a VERY GOOD insulator. The system kept working until I touched the bundt pan with my finger, then the electric current coming from the collector can fell to zero.

RUNNING A MOTOR



The above generators can be used to run a motor, if the motor is my Pop Bottle Electrostatic Motor at:

http://amasci.com/emotor/emotor.html

I find that these small Kelvin Waterdrop Generators are a little too feeble to keep the motor going continuously. Instead they make it slowly pulse. They build up a charge imbalance, then the motor starts turning and rotates a few times. This exhausts the charge imbalance, the motor stops, then it builds up again and repeats. This happens a couple of times per minute. A bigger waterdrop generator is needed if you want to run the bottle-motor continuously.

MULTIPLE DRIPPERS

I put multiple drippers on my waterdrop generator and this improved things considerably. The rainstorm should be like an actual rainstorm, not just a single stream. The best generator uses lots and lots of tiny drops falling in parallel, with the drops being created as fast as possible. If we use a cluster of dripper nozzles, the inner ones probably act as electrical shields for the outer ones. This is bad, since this will prevent the inner ones "seeing" the charged inducer cans, and they won't make any electrified water. Therefore a CIRCLE of nozzles is probably best. Or if you want to really get fancy, use a cluster of tiny squirt-holes, but run lots of thin wires across the "hole" of your metal donut, positioning the wires below the squirters, so they don't get hit by droplets. Then every single squirter sees the charged wires close below, yet its stream of opposite-charged droplets just passes through without touching anything. You've made a water-proton gun (or water electron gun, for the neg. side.)

I drilled a circle of eight tiny holes in a plastic bowl (using #64 drill bit), and this gave good results. A crude version of multiple-dripper: use a soup can, and punch a bunch of holes in the bottom by using a tiny nail. I've also seen a shower-head thing called a "water breaker" in the garden supply section of hardware stores. If a circle of tape was stuck to the center of one of these, it would plug up the middle holes and form a ring of about 100 tiny water jets.

SALT WATER? Heh, "Kelvin's Plastic-storm!"

The liquid has to be conductive. But will adding salt improve things? Will it stop working if we use distilled water, or "DI" deionized water? These questions are easily explored if we note that the water in the water-stream an in the hoses, is a resistor. How large can this resistor become before it screws up the generator's operation? First, use basic electronics concepts: see the generator as a voltage-source with a large impedance in series. If the electrical resistance of the water in the hose is much higher that this natural "series impedance," then the water acts insulating. If it's much lower, then the water acts conductive, and the generator will work.

Typical open-circuit voltage: roughly 10,000V, for a 1cm spark Typical short-circuit current: a fraction of a microampere. Let's guess 1/100, so 10 nA (nanoamps.) Zseries V/I = 10^4 / 10^8 = 10^12 OHMS HOLY CRIPES! A mega-megohm. TeraOhms. So it looks like distilled water will work. Deionized water will work. Probably alcohol, gasoline, most solvents will work. I wouldn't be surprised if even low-leakage HV transformer oil still works! It's hard to make extremely insulating liquids. The slightest contamination by ionized molecules will provide moveable charges during voltage-drops at HV. Solids make much better insulators, since any ions are immobile and locked into the solid's internal grid structure. With solids, all the leakage is through surface contamination.

Cross-check, actually how low is the current? Got a nano-amp meter? Well, the capacitance of the metal cans can be measured. Guess: 10pF? (Get a C meter and find the real value.) If the recharge is roughly linear, then we can use equation V/T = I/C. For a 3sec recharge to 10KV and 10pF can-capacitance, 10,000/3 = I / 10^-11, so current I = 0.33 microamps rather than my guess of 0.01 microamps. Maybe our giga-ohms are actually 33X smaller. Only 300 Gigohm rather than a TeraOhm. Still really, really insulating, at least in the usual sense.

So, to stop the Kelvin T-storm "Generator Effect," maybe we have to fill our tank and hoses with little plastic beads, polyethelene or teflon. And even then it still might start generating a voltage if the beads and hoses aren't kept really, really clean, and operated under low-humidity conditions. Heh, Science Fair trickery: try using a tank of tiny plastic beads, but beads which are all contaminated from handling: all of them with a molecule-thin layer of oily hygroscopic human-hand contamination. Will your Kelvin Plasticstorm Device still slowly charge up to 10KV? If not, use metal tubes rather than plastic, so the only "insulating fluid" is at the tips of the droppers where the bits of plastic (or oil droplets) are detaching.

SPEEDING UP THE RECHARGE

Whenever a spark discharges the generator, it also discharges the inducer rings. As a result, the generator takes quite a while to "ramp up" to full voltage again. This is exponential growth, and it's quite slow at first. There are several possible ways to solve this problem (I haven't tried them, you be first!) One solution is to insert very large resistors in series with the wires to the inducer rings (large = thousands of Megohms). Then always discharge only the collectors, not the inducers. The resistors will keep the inducers from instantly discharging. If the inducers remain charged, then the generator will quickly recharge with a fast linear voltage curve rather than a slow exponential curve. High-value resistors are expensive, so perhaps try making your own resistors. Use strips of paper with fine lines of india ink (india ink is conductive carbon.)

Another possibility: rather than using resistors, instead insert high voltage diodes. For example, use several 7,000-volt microwave oven diodes in series, available from Allied Electronics etc. Orient the polarity of diodes to allow the Inducers to charge but not to discharge. Diodes in one conductor should point upwards, and in the other conductor should point downwards. This way the collectors will charge up the inducer rings, but when you discharge the collectors, the diodes will turn off and become nonconductors. The excess charge on the inducer rings will remain high. Also, if you use diodes, the generator polarity would always be predictable, since the generator would not function if the polarity became reversed.

A third method: build a big generator, but don't connect the collectors to the inducers. Then build a second tiny water-drop generator, and use it to charge up the inducers of the big generator. Then always discharge only the collectors of the big generator, and leave the other metal parts alone.

If you want to use your generator to power a pop-bottle electrostatic motor, the above idea is the way to go. Build a separate generator to power the inducers of the larger generator, that way the motor cannot "short out" the inducer voltage and make everything stop.

Now that I'm thinking about it, here's another type of generator to build: a half-kelvin device with only two cans. How can it ever work? Simple: use the screen of an old TV set to charge the inducer! I bet that this would even work when the humidity is really high. A TV set normally cannot produce constant electrostatic energy output unless you keep turning it off and on. But it should be able to supply enough energy to power the inducer ring on half of a Kelvin's Thunderstorm device.

WEIRDNESS: antigravity?

If your generator really works well, you will see water droplets slow down and their paths curve upwards! No, this is not antigravity, this is just electrostatic repulsion. Alike charges repel.

WEIRDNESS: really really gigantic generators

In a private conversation someone told me that there were patents on a wind generator based upon the Kelvin Generator. Build two big parallel vertical metal screens the size of outdoor movie theater screens (or larger). The upwind screen has coarse mesh, the downwind screen has fine mesh to gather water droplets. Suspend them on insulators which are good for millions of volts. Charge the upwind screen with a power supply. Spray a fine mist of water into the screens upwind, and let the wind push the spray through the screens. The upwind screen will attract imbalanced charges into the sprayer tips, and the water droplets will have an imbalanced charge of opposite polarity. The wind takes the place of gravity in the classic Lord Kelvin device. Wind pushes charged water to the second, fine-mesh screen. Water droplets touch this screen and deliver their charge. The wind is slowed by repulsion of the water mist, the upwind screen uses no current, and the downwind screen puts out amperes at millions of volts of electrical potential (amps times megavolts equals megawatts). Simply step down the megavolts of DC, then convert it to AC. Ta-da, a wind generator with no moving parts! An artificial thunderstorm, harnessed as a commercial generator, powered by the wind.



DEBUGGING:

If your project will not work, it may be because the humidity is high and your device is having trouble "deciding" which side should be positive and which side negative. See my hints about humidity, found at http://amasci.com/emotor/statelec.html. With Kevin generators it takes voltage to make voltage. If your device starts totally at zero, it may take a minute or two to build up to maximum. Therefore give it a "goose" by holding an electrified object briefly near one of the cans while the water is running (for example: a balloon, a 2liter pop bottle, or some styrofoam, each rubbed on hair to electrify them.) This gives the generator a "kick start."

The two drippers must be neutral, so they need to be connected together electrically. To make certain they're neutral, connect a grounded wire to their water supply. These drippers should drip FAST. Many droplets per second. If your drippers are very slow, then your machine will charge up very slowly or not at all. To produce a fast drip rate, usually you need a tiny hole at the end of your water tubes. Plastic or glass pipettes are the usual way to accomplish this. Also, your machine will work better if you have many drippers.

If you really cannot get your generator to work, here's a way to "cheat." Put a piece of aluminum foil on a TV screen, connect this foil to one of the inducer cans on your generator, and then turn on the TV. This will make your generator run, at least temporarily. Don't let any water get near the TV set!!!

AVOID WOOD

Kelvin Generators usually can tolerate fairly high humidity. Watch out though. Materials with large internal surface area, such as wood, cloth, masonite, etc., usually absorb moisture from the air and become slightly conductive. Therefore, assume that these materials are the same as metal, and avoid using them as supports or framework when you build this device. Wood provides a leakage path and shorts out the high voltage. One experimenter even found that problems were caused by supporting their cans with insulating blocks glued to a wooden panel. The short lengths of plastic must not have been sufficiently insulating, and there must have been a leakage path across the plastic and through the wood. Switching to all-plastic supports solved their problem.

If acrylic sheets such as plexiglas(tm) or perspex(tm) are not available, large styrofoam blocks work well as supports. Avoid using solvent-based glues with styrofoam, it makes it dissolve. The plastic MUST BE CLEAN. Use new plastic if you can. If you wash the plastic, don't use much soap, since soap can form a conductive coating. Rinse it and scrub it with lots of clean water to remove all the soap. If you wash the plastic, then afterwards dry it thoroughly with an electric hair-dryer gun (but be careful, don't melt the plastic with too much heat!)

Nylon fishing line makes a good insulating support, especially during high humidity conditions. Long, very thin supports such as fishing line have small surfaces and therefore give less surface-current leakage than short, fat supports or flat panels. Don't use twine or string as supports, of course, since these materials become too conductive when the humidity is high.

If humidity is very high, even plastic can become slightly conductive. This can be temporarily fixed by using an electric hair-dryer gun to dry the plastic surfaces. Bathe the plastic in hot air for several minutes, taking care not to heat it so much that it softens! Try testing your generator again, and it may begin to work.

The water droplets must not touch the inducers. The droplets should pass through the inducers. The droplets should break free from the water while they are still inside the inducers. If continuous streams of water (not droplets) shoot out of the drippers, then move the drippers upwards to make certain that the droplets break away from the continuous streams while the droplets are inside the inducer cans.

The water droplets MUST touch the collectors. To start, simply let the collectors fill up with water. Once you have succeeded in getting sparks from your machine, then later you can try the trick with the cones of window screen (see far below.)

To detect the tiniest charge imbalance, build the RIDICOLOUSLY SENSITIVE CHARGE DETECTOR shown elsewhere on my web pages. (/emotor/chargdet.html) This device will detect a few hundred volts of electrostatic potential at a great distance from the cans. It is extremely sensitive. The tiniest sparks won't begin until the cans reach about 1,000v potential, yet the sensor responds to about ten times less. A sparking Kelvin generator can make the Charge Detector flash even if it is many feet away.

Don't neglect the balloon trick. If your device doesn't self-start, then momentarily hold a charged balloon near one of the cans while the water is running. (Verify that the balloon is really electrified, see if it raises your arm-hair when rubbed. Sometimes humidity is so high that the balloon will not aquire an imbalanced charge by rubbing on hair.)

A simple way to detect static charging: place a portable AM radio near the device, tune it to a blank station, then touch one of the cans with a finger. If your device is just barely working, there will be an imperceptible spark. But this will make a loud click on the radio! If you wear an AM Walkman headphone radio, it will extend your senses so that you can hear the electromagnetic pulses given off by the tiniest spark. Become a "Borg" from Star Trek, with the ability to hear electromagnetic impulses via a biointerface to electronic circuitry (Walkman headphones). :) Try spending the day wearing AM radio headphones tuned to an empty spot on the dial, and you will encounter all sorts of interesting electromagnetic "sounds" in the environment. You'll hear the "crack" noises of distant lightning even when the thunderstorms are too far away to hear the thunder. Electric fences in countryside farms make a periodic clicking. The overhead wires from electric city buses make all sorts of musical tones.

