If you are interested in building this project yourself, be sure to download the project files using the 'Project Download' link below. Also, I have put together an accompanying video which goes through the build as well. There also may be a ‘Makerspace’ in your area that could help you with the build if you are not familiar with producing etched circuit boards at home, soldering, etc…
Project Download Page:
The first order of business is to take a look at the ‘Parts List’ excel spreadsheet in the project download. Once you have acquired all the required components it is time to get started on the build.
Step 1: Etching the Circuit Boards
To produce circuit boards at home I use the toner transfer method. In the past I have used a Glossy Photo paper, however I have found simple ( and cheap ) Magazine Paper is the most effective medium for transferring the toner to the copper clad board. I have a fairly old Samsung ML-1740 laser printer that I use which works well enough. When feeding the Magazine Paper into the printer it is much easier if you place it on top of a standard sheet of plain printer paper.
Prepare the circuit boards by cutting them to size, cleaning with a scotchbrite pad, and then with Acetone. Be sure to wear some type of rubber gloves, as the oils from your fingers will most likely ruin the transfer. When the boards are prepared, cut the printed circuits to size, place over the copper board and tape. I have found, at least with my laminator, that at least on the first two passes the paper can move ( possibly not the case with a more expensive laminator ). I have one of those cheap $19 purple cow laminators from Costco, which works fine, but I have to run the boards through 7-10 times to get a good transfer. Place the boards into water ( or run under the faucet ) in order to remove the Magazine Paper. I have found that it is extremely easy to remove the paper, and the traces turn out perfect almost every time.
With the toner transferred to the boards, prepare a small sponge that you will use with a small amount of Ferric Chloride to etch the boards ( if you use something else by all means go for it ). You can attain the needed chemicals from your local RadioShack. I like to work over a disposable Rubbermaid container, and be sure to wear rubber gloves. Saturate a small sponge with a small amount of Ferric Chloride. Gently rub the sponge back and forth over the board, and within about 5 minutes the board should be etched. Rinse the finished boards off with water, and then clean the remaining toner off with Acetone.
You can now optionally add the silkscreen layer to the boards if you like. You would simply print out a mirror image from the eagle file ( or use the pdf which is already mirrored ). You transfer the toner to the fiberglass and remove the Magazine Paper under water.
Step 2: Drill & Populate the Boards With the Components
Photos definitely do this step more justice than words, but basically solder all the components on the boards that you just made. If you take a look at the video I have a frame by frame section of the board being populated with the components.
Step 3: Test the Electronics
You will also make two more cables from 2 conductor telephone cable ( or speaker wire ). One of the cables is used for the electrodes, and the other for the connection between the interface board and the laser module. Do not solder the alligator clips onto the electrode wires at this time, but you can strip the ends down such that you can test the voltage with a multimeter when you turn the device on ( same goes for the laser +/- cable ).
Using a PICKit2 ( or 3 ) and the 1×6 PICKIT header on the Controller you can now program the PIC12F510 using the ‘SilverMAX.hex’ file found in the ‘Software’ directory of the download for the project.
To test the generator at this stage you will want to use the 12VDC wall wart and plug it in. Mess with the switches a bit to ensure that all the indicator lights are working as expected. Then you can proceed to test the variable speed fan control, by switching the Magnetic Stirrer Enable switch on, the Run / Standby switch on, and the Power switch on. You can then adjust the Magnetic Stirrer’s speed knob watching for a change in speed of the fan. Next you will want to test the output leads for the Laser – you should see a +5V there with a multimeter. You can now proceed to test the electrode output – you should see +12V or -12V. Every minute or so you should also hear a clicking sound from the relay on board, and should also notice the polarity of the electrode leads switching automatically.
Step 4: The Magnetic Stirrer
Test the hold of the magnets on the stir bar, by placing the stir bar in your flask and holding it over the magnets. Ensure that the bar locks in the center of the flask and spins appropriately when you turn the fan by hand.
Place the magnets on the fan, ensure the orientation is correct, and then prepare the 5 minute epoxy according to the directions on the package. Glue the magnets down to the moving part of the fan ( they should stick to the magnet in the fan, and be on the outer edge ). As the epoxy sets up move the magnets in a bit closer to the center without having them touch ( can be a bit tricky ).
Once the epoxy has set, I attached a screen of sorts to the back of the fan in order to protect the electronics / cables. I used a cut piece of scotchbrite pad and zip ties for this – the scotchbrite came in a 12×12 sheet and was porous enough for air to flow through it.
Step 5: Preparing the Enclosure
Once the fan mounting holes are drilled, prepare the mounting posts. I used 8-32 x 1″ machine screws with 2 washers and 1 nut as a spacer between the enclosure and the fan body to provide enough clearance for the magnets.
Using the ‘silver_generator_v1_interface_template.pdf’ print out the template for the interface board’s mounting holes. Tape the template to the face of the enclosure and drill accordingly. I find using a center punch to mark the holes first is extremely helpful at drilling these holes accurately.
Locate two holes in the back of the enclosure, one for the electrode cable and one for the panel mount DC jack. Locate another hole on the right side of the enclosure for the laser light cable. Drill these holes out.
With the interface holes drilled, fit the two 10k panel mount potentiometers and lock in place with their locking nuts. Carefully place the interface board in the enclosure, and line up the switches and leds with the drilled out holes. Push into place and lock down the interface board using the panel mount switch nuts.
It’s now time to put the fan back into the enclosure on the mounting posts and then lock it into place using 4 additional nuts. It is a bit tight space wise, but I was able to get it done with a little effort.
Next you will want to place the controller board on the Fan’s screen, and then mount the DC jack to the case via the hole that was drilled out for it. Also, run the electrode cable through the hole in the back of the enclosure, and the laser cable through the hole that you drilled in the side of the enclosure.
You can close the enclosure for now.
Step 6: Additional Preparations
You will need to take the #7 rubber stopper for the Flask, and drill two holes, about 3/4″ apart, that will fit the two 14 gauge 99.99% pure silver wires snugly. The wires I used were 5″, however I would recommend using 6″ wires with the 500ml flask. Push the two silver wires carefully into the stopper, ensuring that they are parallel to each other.
Step 7: Testing the Colloidal Silver Generator
At this point you are ready to test things out. I would recommend looking at the ‘Instructions.doc’ file in the ‘Documents’ folder of the project download file on the projects page.
Some simple tests to start, would be to ensure that the magnetic stirrer is working as expected – turn the power on, run / standby to on, stirrer enable to on, and then adjust the speed with the left adjustment knob. You should also try the laser on / off switch ensuring that the laser is working as expected. I would recommend at this point letting the generator run for 5 hours with the right knob set at the middle position. You should purchase a TDS meter to determine the ppm of silver produced after that time period – my first prototype device produced 15ppm of colloidal silver in 5hrs.
Step 8: The Laser Mount
Step 9: Final Thoughts