Need help with current control with Colloidal Silver Generator

Hello

I’m new to electronics but have been learning allot, I have a arduino uno and would like to build a project, a Colloidal silver generator it’s basically a electrolysis process, I need to be able to change my voltage between 24vdc and 36vdc and have a constant current that I can set between 3ma and 25ma in 1ma incerments, does anybody know how I would go about this?

Thanks
Jeff

To change a voltage you can use a relay, or voltage regulator chip. Have a look at this doc: http://datasheet.octopart.com/LM7824CT-Fairchild-datasheet-492463.pdf Pictures 11 and 12 show how adjust output voltage. If you take, for example LM7824, with 24V as minimum, than you can get any value in between 24 and 36 simply applying 38 V (2 V for drop-off) or more at the input, than setting a transistors array (ULN2003 or ULN2803) with many R2 at the outputs( 7 or 8 ) different values. and switching them by arduino. You can get 256 voltages with 8 R2*. Measuring a current should also be easy, set a resistor in series with ground wire, and measure voltage by analog input (analogRead). For safety, put also resistor (20k) in series and zener 5.1V between input and ground to protect arduino . Tricky part would be to measure current in high side , than you need a dedicated chip: http://ruggedcircuits.com/html/circuit__4.html

LongDog: Hello

I'm new to electronics but have been learning allot, I have a arduino uno and would like to build a project, a Colloidal silver generator it's basically a electrolysis process, I need to be able to change my voltage between 24vdc and 36vdc and have a constant current that I can set between 3ma and 25ma in 1ma incerments, does anybody know how I would go about this?

Thanks Jeff

This sounds like a task for a power op-amp plus a DAC - the DAC controls a current source using the high-voltage opamp. The TI 3581J opamp seems up to the task at a very quick perusal, upto 30mA and +/- 70V and auto-shutdown. However the common-mode range is rather limited, you may need a +/-50V supply or similar - perhaps a +50V and -12V would be enough. There may be more modern devices, I found that one in a table in "The Art of Electronics".

Though a little more looking around suggests high power opamps are pretty rare these days and a discrete circuit might be required - perhaps using an adjustable voltage regulator in a clever way.

Thanks Magician & MarkT for all the help, I hope this isn't a dumb question but I see all these deferent electronic components like on ebay so many deferent types of current regulators is there on master book I could buy that has all the deferent components lister and how to use them like with a description on how thy work? problem no but thought it was worth asking, I got a radio shack lab and bought some books on amazon from make magazine & get an Arduino Uno but theres some much more out there and I don't know where to go from here about learning what I need to know to build this generator. any help would be much appreciated. Thanks

Free books: http://www.talkingelectronics.com/te_interactive_index.html and tutorials: http://www.electronics-tutorials.ws/index.html

Magician: Free books: http://www.talkingelectronics.com/te_interactive_index.html and tutorials: http://www.electronics-tutorials.ws/index.html

Thanks so much for these links, I know I will learn allot from them.

Thanks again. Jeff

Hi Jeff I have been studying Colloidal Silver for a couple of weeks now and could use help with code also. However, I have learned that the smaller the particle size the more effective the treatment. and also the larger the surface area of the 99.9999 silver the higher the current can be, or in other words the smaller the particle size with a given current. So with that I made my first batch in a mason jar of distilled water, with 2 10 gauge x 6" silver wires, and cheep voltage reg circuit from ebay. I set it to 3V @ 150 uA (150 micro amps, or 0.15 milli amps) to start with, after 12 hours it was up to close to 400 uA with a lot of particles you could see. Also would flip the polarity and give it a swirl every half to 2 or 3 hours. Although it was effective, I wanted the smallest particle size possible. So for the next batch I turned the V Reg. down as low as it would go to 1.2V @ 83 uA to start with. After 24 hours it was up to 260 uA. The larger particles were much reduced, much less cloudy too. Also the TDS meter read 006 on the first and 009 on the second batch, although I have read that the TDS meter is reading silver ions rather than silver particles.

So I am thinking I need from 0 to 3 volts at 1 to 500 uA. It would be really cool to have a display to read volts and micro amps, and also to flip the polarity every 30s. For those who did not know, nano sized colloidal silver will KILL ALL VIRUSES including Ebola. As if that weren't enough, it takes out bad bacteria, paracites fungus. Oh, and, it removes heavy metals like lead and mercury.

Thanks for any help, Mark

I've been working with colloidal silver generators also; here's a vid I just put on youtube. To see the sketch, click the link in the description... https://www.youtube.com/watch?v=SgoHzORenMw&index=1&list=UU0UOb5ofw6KMOfO4tVudgAg -Nick

I have been making colloidal silver with a system I designed with a Nano, I also made one for my wife based on the same design but this time used an UNO with a lcd shield. You can see some pictures in this post: My Generator in a Blender , btw that forum is the absolute best resource ever if you are researching Colloidal Silver, the guy that maintains it is a chemist and knows A LOT about it, there is a community of kitchen alchemists ( as they call themselves) that give advice to new comers.

Also check the Articles in the same forum. Its a gold mine.

hi

mfacen: Also check the Articles in the same forum. Its a gold mine.

Hello mfacen, I need your help. I saw your posts yesterday in another forum and fate came here by google and saw your posts here too. Im trying contacting you, I need your help.

This is the one I made for my wife:

Post of my setup in the CS forum here.

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In this image is still missing the labels and artwork.

Hi everybody :)

Mfacen, this is very interesting!

I have some idea for a similar project, and i found your beautyfull one. Sadly the link you provided gives me a 403 Forbiden error.

Is there more details about the project located somewhere ?

I was thinking in the line of a simple boost DC-DC converter to achieve the recomended 27V, controled by the mcu (pwm) and regulated by monitoring current at electrode (voltage through a resistor).

Electrode voltage could be monitored as well, but it isn't really needed as it can be calculated by the autoregulated pwm duty cycle. An empirical system that is :)

Add a way to set current limit (~1mA / square inch electrode?), and time limit (starting the count when current reach maximum), and it could be a very versatile coloidal silver generator.