------- Forwarded Message Follows ------- Date: Wed, 25 Aug 1999 19:49:31 -0700 From: Victoria Welch <vi...@oz.net> Organization: Welch Research Laboratories Subject: Re: CS>Newbie tries new method - report. Goddess knows what I h
Hi Mike, Much appreciate your response! > Welcome aboard, Vikki! I haven't had a chance to make your > acquaintance before now. Pleased to meet you! > I have a long time hobbyist's interest in electronics myself, so I > really appreciate your experiments and tinkering. Hopefully they are helpful! Admittedly I am staggering around in the dark, but I feel like I am making some progress. > I think what you saw happening was the usual fluffy buildup > and dark roughened coating on the neg and pos electrodes, > respectively, being dislodged and falling off when the polarity > changed. I suspected it had to do with the polarity change, thanks for the confirmation. > I think Bob will encourage you to shorten the switching period to > only a minute or two, per his experiments. The faster rate doesn't > let much buildup occur before the states change so everything that's > being driven off the electrodes stays smaller and doesn't have much > chance to fall out of suspension. I was totally unsure where to go with this I can run it as low as 1ms (less starup and shutdown delays), I wasn't sure where I got the 20 minute value, but it did seem awfully long. I think the next batch is going to get the one minute treatment - I'll report on that, if not tonight then tomorrow for sure. > I have a question: Why are we even worried about H-bridges and > relays, anyway? Aren't the logic outputs on a STAMP microcontroller > or CMOS logic chip thoroughly capable of sourcing *and* sinking at > least a milliamp or two? Thank you for addressing this! I looked at this last night with those very thoughts in mind. On the Basic Stamp (Pic Processor) or most any (if not all) Pics (I usually use the 16F84 to prototype since it is flash ROM) can sink up to 25 ma per pin or source up to 20ma per pin . MORE than enough. The problem (such as I perceived it) was the 5 Volt +/-10% voltage. Now that you have mentioned it, I certainly can loose nothing by trying it :-). Once I can afford instrumentation I will have some idea what I am doing here. my current metrics are relative Tyndal effect and taste. I'm not sure just how ultimately meaningful either of those are :). > There's nothing that says you have to use 30 volts. Folks have used > everything from a few volts on up with success. The only difference is > how quickly the stuff gets made. This is something that had not been clear. I had *assumed* that the ~27V figure was given for some specific reason. I searched for a FAQ that might explain this, but no luck to date :-(. > Do you maybe have analog inputs for current monitoring and outputs > that also could be tricked to sink/source current if cross connected? > There's lots of possibilities there if so. There are tricks that can be used to do things like this, I am considering some of these thing, but trying to get something I can feel confident about before trying to improve things. The basic 27V, 2 gator clipleads and 2 pieces of silver wire (with either a resistor, LED or incandescent bulb for current limiting (or a carefully watched ammeter :-)) have worked far better than I would have expected, althought I still have no PPM values that I can relate my results to someone else with. Much to do and much to learn :-). > In the system I've been running lately, I limit the current to only > a couple of milliamps or so, to keep current density low enough to > keep the particle size down, per Trem Williams suggestions. Some one suggested that the 2.5 ma rate was good somewhere early on, so I have been sticking with that with an upper limit of 3ma. I think my next target current flow will go down to two (assuming I can still taste it or get a Tyndal effect that looks something like what I have been getting). > I use a simple current limiting resistor of a few kilohms in series > with my 30 volt supply. I'm not switching polarity at all, but that > would be the next step. This is on my mind as well, is there a real *point* to trying to improve on that. I always try to KISS and avoid creeping elegance :-). Being a tinkerer at heart makes life interesting sometimes :-). > So why not toss a couple of resistors in series with two logic pins > that, combined, limit the output current to a milliamp or two when > they're cross-connected through the cell? Then switch 'em every > minute and see what you get. As soon as I finish this missive :-)! > Try pulse modulating the two digital outputs with R/C networks on > them to get an adjustable voltage to control cell current. Might be a > problem with the switching transient, but, hey, who says you can't > program a delay to let the current drop to zero before powering up > the other side? Noted and filed :-). > Of course your analog outputs could do the same thing with a lower > parts count. > > Lots of possibilities, there! > > Of all the low voltage ideas discussed to date, I believe that Bob's > polarity switching combined with Trem's current limiting might make > a very consistent and easy to run low voltage design. It would take > longer to make CS, but would require a *lot* less monitoring. You > would have minimal or no buildup on the electrodes and could run > until you had as much silver in the water as you wanted to. You could > do time or conductivity based shut-off with your controller as well, > and perhaps even cell current integration for total silver content. > > Really deluxe stuff! It's the sort of stuff I'd like to see tried > next. Anybody's welcome to give it a shot. Let us all know what you > learn. I'm in a pretty good place and motivated to do this :-). Appreciate all the suggestions and guidance here, more than you know. Once I get the methodologies worked out (none to terribly difficult) I will need to be able to accurately measure what I am doing. > Be well, And you also! Again, thanks very much! Take care, Vikki. P.S. I almost sent this to the list before I noticed it came through email. If you wish to post this to the list, please feel free! -- Victoria Welch, WV9K, DoD#-13, Net/Sys/WebAdmin SeaStar.org, vikki.oz.net "Walking on water and developing software to specification are easy as long as both are frozen" - Edward V. Berard. Do not unto others, that which you would not have others do unto you. [Mike Devour, Citizen, Patriot, Libertarian] [mdev...@mail.id.net ] [Speaking only for myself... ] -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: silver-list-requ...@eskimo.com -or- silver-digest-requ...@eskimo.com with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: silver-list@eskimo.com List maintainer: Mike Devour <mdev...@id.net>
