Well, I continue to learn something new almost every day. I would have it no other way
If you wish to keep a constant current and still observe impedance variations within the cell you could AC couple after the regulation into op amps. Then into your sound card. You could then listen to it or save the waveforms and look for some correlations. I'm going to look into this. Thanks for the info. Best regards, Arnold Beland ----- Original Message ----- From: Matthew McCann To: [email protected] Sent: Tuesday, November 23, 2004 11:41 AM Subject: CS>Is electrolysis noisy? Hello, Arnold, I replaced my current regulation circuit with a Thevenin element with the Thevenin resistance matching load resistance, with the idea of doing wheatstone bridge-type potentiometry later on. The rheostat proved so convenient to set the scale of the microammeter, I decided to stick with current limitation instead of current regulation. The latter may give more uniformity in particulate size, but who knows whether size uniformity is better or worse for product potency? Keeping the current low (<500 uA) keeps the size range low anyway. As you note, there is a trade-off. Current regulation makes a more uniform product. But current limitation makes transients measurable that may help elucidate processes occurring at the electrodes. I like the latter feature more because it is more of a research-grade circuit. There is a relatively new research method called Electrochemical Impedance Spectroscopy (abbreviated EIS, by coincidence) that is used to investigate electrolytic phenomena, especially corrosion phenomena, based on frequency response ranging from 1 millihertz to 100 kilohertz, which includes audible tones. Sophisticated analysis of the noise-laden current leads to equivalent RLC circuits that reveal quite a bit about what's happening at and near the electrodes. Ordinary people cannot afford the specialized apparatus used for Electrochemical Impedance Spectroscopy, but the human ear is a marvelous instrument and maybe could detect a lot. Noisy signals can contain a large amount of useful information - a good example is "star static," the nuisance RFI that became Radio Astronomy. Best regards, Matthew ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.289 / Virus Database: 265.4.1 - Release Date: 11/19/2004
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