CS> From: Andy Gill Date: Mon, 11 Apr 2005 20:00:39 http://escribe.com/health/thesilverlist/m79505.html
> 1. IS 30-volts the optimum? With a conventional constant current generator, the maximum ionic concentration the cell can produce is determined by which electrode has the highest current density. This means anything that concentrates the current, such as sharp bends or the cut ends of the rods, will generally start producing silver hydroxide first. This limits the maximum concentration of silver ions you can achieve. At low current density, the limit is reached when silver ions start to plate out on the cathode. In either case, the cell voltage stops decreasing and reaches a plateau. This tells you all the ions liberated at the anode are combining to form silver hydroxide or plating out at the cathode, and no further increase in ion concentration is possible. You can improve things by bending the elecrode into a "U" shape, such as in the silverpuppy, or a "W" shape as some members use. Perhaps the ultimate in this direction is the minimum curvature stove spiral used in my Godzilla generator, which produces 21.5uS cs, or 21.5ppm ionic: http://escribe.com/health/thesilverlist/m62053.html Ivan Anderson beat this with a simple 9V generator to get 26uS. He noted the conductivity continued to rise after the current was stopped: http://escribe.com/health/thesilverlist/m14498.html However, Trem Williams SG7 generator easily surpasses this with 45uS, and in the never-ending ionic arms race, my double chamber cs generator is even higher (but I don't really know how much): http://escribe.com/health/thesilverlist/m78983.html Generally, the maximum desirable current density is stated as 1mA/sq.in. The silverpupply runs at 625uA/sq.in., and my generators tend to run below 100uA/sq.in. These numbers assume the current is uniform over the entire wetted area of the electrode, which is seldom true. The cell current is the current density times the wetted area. The voltage needed to pass this current is determined by Ohm's law: E = I * R The cell resistance is highest at the beginning of the brew, so the current source must be able to supply enough voltage to avoid saturation. For example, if the initial cell resistance is 30,000 ohms, and an operating current of 1 ma is desired, the voltage across the cell is: E = I * R = 1e-3 * 30000 = 30V If the current source cannot supply this voltage, it will saturate and only supply as much voltage as it can. This means you have to wait until the cell conductance increases enough to pull the current source out of saturation. The information above is for constant current generators, but the generator shown in your link is actually a constant voltage generator, similar to the original 3 nines described by Mark Metcalf. You can tell by the two batteries shown in the photo, and the miniature bulb used to limit the short-circuit current to 40mA. When a constant voltage is supplied to a cell, the current starts out quite low and increases exponentially. This means nothing seems to happen for a long time, then the current rises very quickly. You must be on your toes to turn the current off before the brew is ruined. Examples of the current vs time graphs for 18 and 27 volts are shown on my Shingles page (caution graphic photos) http://www.geocities.com/mrmonett/shingles/0shin.htm A 3 nines cs generator will normally produce 5 to 10uS cs, which is certainly usable, but not the best. However there are a number of flaws in the Gaia design which may limit the ion concentration even more. 1. The voltage is raised from 27 volts to 30 volts. This means the exponential rise happens faster, and you have to be quicker to stop the brew before it is ruined. 2. The electrodes are very short. If they are 12 ga, a pixel scaling measurement in Photoshop indicates the electrodes may be only 3 inches long. It appears that much of this is taken up in the terminal block and the air space to the surface of the water, so the wetted area is quite small. This increases the current density and the electrodes start forming silver hydroxide sooner, as in this photo: http://www.utopiasilver.com/images/gen3.jpg 3. The electrodes are very close together. A scaling measurement in Photoshop indicates they may only be 1/4 inch apart. This helps increase the initial current, which decreases the brew time. But it increases the apparent curvature of the electrodes, so the production of silver oxide starts sooner than normal. An example of the effect of close electrode spacing is shown in my proof of the insolubility of silver hydroxide, at http://escribe.com/health/thesilverlist/m79117.html and http://escribe.com/health/thesilverlist/m78851.html Due to the close electrode spacing, black silver oxide started forming almost as soon as current was applied. So the extremely close spacing of the Gaia will definitely reduce the maximum uS reading you can get. As far as the information on the rest of the page, most of it is pure technobabble and not worth comment. If you were to buy a generator, I'd go for the silverpuppy as a much better purchase. And if I had the money, I'd get a SG7 from Trem. Mike Monett -- The Silver List is a moderated forum for discussing Colloidal Silver. Instructions for unsubscribing are posted at: http://silverlist.org To post, address your message to: silver-list@eskimo.com Silver List archive: http://escribe.com/health/thesilverlist/index.html Address Off-Topic messages to: silver-off-topic-l...@eskimo.com OT Archive: http://escribe.com/health/silverofftopiclist/index.html List maintainer: Mike Devour <mdev...@eskimo.com>