The auto off circuitry itself is very consistant, however, there are other factors to include ion dispersion, crud on electrodes, even bubble buildup, container tracking , contaminants acting as cytalists to make ions into crystals of various sizes [which don't register as conductive] and so on. Any one of these can cause an early or late shutdown. Some elements can cause a feedback loop that leads to a mess that grows forever. Hydrogen bubble/silver growths on an electrode make it a semiconductor with a varying value. [the grey fuzzies] Hydrogen peroxide in the water makes silver flakes forever. and, of course, the circuits can't tell the difference between one source of conductivity and another.
The way to figure out 'when' to tell the gen to shut down is to run batches while monitering voltage drop until you get the results you like, then set the gen to shut down at that voltage as a reference with a comparator. If the circuitry is stable, that voltage will be stable. I use zener diodes for the reference voltage and a high impedence feedback circuit for monitering. I suppose that some people use resistors and depend on the input voltage to be stable. The voltage on the electrodes is relative to the constant current, electrode area, electrode spacing and assuming a uniform conductivity of the water. If all that is consistant, the resulting conductivity at shutdown is highly consistant as compared to the reading from any given single PWT. It does what it "sees", but vision 'can be' misleading and only what's between the electrodes can be seen. All the rest of it is attempts to design variables out of the water that are common to all water. Monitering with a voltmeter? Any 'odd' disturbance to the water will give you a spike or a drop lasting up to several minutes. Ramp up to the controlled current can vary by hours. There are ways to trick it into speed up mode. One way is to ionize water locally, then distribute it. [essentially 'seeding' a localized area] If you use an ohm meter on the electrodes with power off to get the water resistance, the meter itself acts like a generator, so when you switch leads, everything has to turn around and there is a delay. Ions move pretty slowly. If you leave the meter hooked up, you'll see the resistance slowly drop as you make more CS with the meter as the power source. It's probably better to calculate the resistance from current and voltage data with the generator turned on. Ode > >Also, I assume (unless you disabuse me) that most CS makers with automatic shutoffs (and I'm talking about Low Voltage DC setups with currents limited to about 1ma per square inch of electrode surface throughout this post...) monitor the effective resistance or conductance across the wet cell in order to determine when to shut the maker off. Whatever electronic method they use to determine this, they would have to shut down the process when the cell reaches a certain impedance. This would vary from maker to maker depending on the surface area of their electrodes and possibly some other factors. (Do they feel that the results with any particular CS maker is relatively consistent?) With this in mind, the last time I made CS I measured the "resistance" of the cell with my Voltmeter through the electrodes as they sat in the distilled water but with the power source disconnected. I also measured the resistance at the end of the process. It was interesting to note that at the! > end of the run I had quite a low resistance perhaps in the 20K ohm range (I don't have the data here) but with the polarity of the meter leads reversed I read a resistance approaching the Meg ohm range, I think it was .5M ohm. With clean electrodes at the start I *assume* that the resistance would be the same or nearly the same. Anyway, this would be easy to check. > >The point is, any crud or buildup on the electrodes is going to affect the process and perhaps affect the repeatability of results. And with different distilled waters there may be slightly different contaminants which would affect this. Perhaps regular intervals of cleaning would tidy up the test results. > >Incidently, does anyone have an ultrasonic cleaner? They could use one with a jar of clean distilled water to clean the electrodes between uses and even at intervals during CS making if they want to test the result of electrode crud on their process. Sorry, don't have one of those yet... > >Out of time... > >Dan > >_________________ >you wrote: > >Hi Dan, > >I do not want to be factious but if we hyphenate the word assume we have "ass-u-me." > >I cannot make those assumptions, and to establish it would require several weeks of work. >I do not have the time or inclination to do it, even though I have the equipment to do the testing. > > >There appears to be several variables that we are not aware of, in making this "simple" product. >Why is it that successive runs do not duplicate? This has plagued the making of EIS ever since >we started. > > >If someone wants to do the work, I will make a special test rate available for the project. >However the project must be defined and adhered to. > > >"Ole Bob" > > >I wrote: > >For current limited processes, wouldn't it be correct to assume that, taking the point where >current limit occurs as a reference point, the amount of silver generated up to the current >limit reference point in any case would be equal regardless of the water used? Also, for any >particular amount of time after the current limit reference point, the electrolysis would occur >at the same rate in all cases regardless of water used, and the total ppm increase per hour >would be the same? > > >(Assuming distilled water within a normal range of variation) > >Dan > > > > >-- >The silver-list is a moderated forum for discussion of colloidal silver. > >Instructions for unsubscribing may be found at: http://silverlist.org > >To post, address your message to: [email protected] > >Silver-list archive: http://escribe.com/health/thesilverlist/index.html > >List maintainer: Mike Devour <[email protected]> > >
