What is colloidal silver? It’s made up of silver particles suspended in water. You can search the internet and read, on one side, people who claim its a miracle cure all and on the other end, that its a scam.

It’s up to you to decide if colloidal silver has any benefit, but as an engineer, developing a simple colloidal silver generator seemed like a small and interesting enough project. You could find devices that claimed to generate colloidal silver, but i was unable to find anyone sharing a schematic design. After more searching i was able to extract some key parameters that others were using for these designs.

1.  A voltage needs to be applied across 2 silver rods, suspended in distilled water. Voltages others were using ranged from 18 to 32 volts.
2. Use silver rods of a very high purity. I’ve seen people use rods made from canadian silver coins that are 99.99% pure silver.
3. Limit the current to about 2 mA
4. Reverse the voltage on the rods every once in a while to avoid having a large amount of build up on the rods.

And that’s it. The following design implements these parameters.

The key component is the LTC6995 which generates the timing for the reversing of the polarity. The relays allow the polarity to flip. D1 is a current limiting diode, fixed at 2mA. You may have to update some resistor values to change the rate at which the polarity is switched.

You can do a test simple test for silver concentration using a Total Dissolved Solids (TDS) meter. Seems like most websites recommend a concentration of 15 -20 pmm.  This prototype does not automatically shut off the voltage. You need to monitor it until it reached the desired concentration.

Here are pictures of the original breadboard, which does not look pretty. Then of the pcb that was fabricated.

So, does it work? Feel free to test the design and let me know.