----- Original Message ----- From: Victoria Welch <[email protected]> To: <[email protected]> Sent: Thursday, 26 August 1999 16:19 Subject: CS>New experiment and observations...Comments solicited!
> Hi again all, > > I'm here to probably bore most of the list to death with this > technical crap :-). I'm interested. ;-) > I had thought about this and Mike (our illustrious list owner) provided > the final push to get me to try this. > > The BASIC Stamp (and Pics) are capable of sinking 25ma and sourcing > 20ma, which is more than enough current for CS. I was concerned that > this is at roughly 5 volts (+/- 10%). > > So I wired up a stamp, stuck a couple 2K2 resistors from the port pins > in series to the probes and cobbled up a short program to do the job. Why the resistors? > I started this at 2015 my time and it is now an hour later. The initial > current flow was 40 uA (micro amps or .040 ma). Now I have 48.8 uA. > All other conditions are as I have done in the past - same glass, DW, > probe spacing, etc. > > If this is going to work, it will take a LONG while, I think. > > Did a couple of things "just to see what would happen". attached the > probes directly to the port pins - no change in current flow > (expected). Immediately moved the jumpers back to the other side of the > resistors :-). Tried moving the probes closer together and at around > 1/8" (the wires are far from straight :) I got the current flow up to > 0.1 ma. Moved those back to the original 2.75" spacing. > > Not quite sure what to think. First thought is that a higher voltage > will get the job done a lot faster :-). Time is not quite of the > essense, but there comes a time that is too long. I'm trying to decide > whether to let this run overnight or not. May just let it run until I > go to bed. Anyones thoughts on this solicited. Yes, higher voltage will speed the process. Some comparisons: First the geometry of the generating container or cell; 1 cup (200mls, 7 - 8 oz) distilled water, with electrodes in the following arrangement, 2 x 2mm silver wire (14swg), wetted depth 45mm (1 3/4"), 45mm apart. I used a sterilite 1 cup, soft clear lidded plastic container with the electrodes pushed through the lid and parallel. The container dimensions are, 85mm (3 1/4") diameter by 65mm (2 1/2") deep. 9 volt ac wall adaptor (developing around 12 volts, output connected directly to electrodes) 10 ppm (as measured by Ion Selective Electrode) 3.0 hours 0.05 mA initial current .... 0.59 mA final current 15.5 volt constant. 10 ppm... 2:30 hours 0.06 mA initial current ... 0.72 mA final current 18 volt adaptor... 21.5 volt constant. 10 ppm ....2:20 hrs 0.09 mA initial current ... 1.2 mA final current 28 volts current limited 0.5 mA 10 ppm ... 2:20 hrs 0.09 mA initial current ... 0.49 mA final current 28 v initial voltage ... 11.25 v final voltage. All solutions stirred before measurements, about six times during run. Would be interesting to compare current densities of electrodes. A question: How would one go about turning off the power to the electrodes at a specific resistance as measured by voltage and current draw. Further, would it be possible to input starting resistance (calibrate as zero or some other nominal value) and then switch off at some other particular resistance. Anyone? Regards - Ivan > Thanks & take care, Vikki. -- 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: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] List maintainer: Mike Devour <[email protected]>
