Need a current regulator? (colloidal silver generator)

[Kephra]

I have made some custom made current regulator boards as shown below.
You would have to supply your own leads, no soldering required, and if you want, a box to mount it in.

The board has screw terminals for attaching battery and electrode leads
I have two current set points available, 8 or 14 ma.  I recommend the 14ma.

Can be powered by nine volt batteries.
Maximum input voltage is 36 volts, but works well with less.

It can make 250ml of 20ppm CS in under 6 minutes with only one 9 volt battery if  sodium hydroxide electrolyte is used!
It will not make colloidal gold, as colloidal gold requires a lot more current.

I am asking for a $30 donation to the forum for one of these to help defray the cost of running this forum.  It costs $600 a year just for the internet connection and an ip address.

PM me if you are interested, or use the DONATE button at the bottom of the page. (Be sure to note your shipping address and note your forum userid!)

I CAN ONLY SHIP TO US ADDRESSES!

[silverFalcon]

$30 donated. Thank you Kephra...

[Kephra]

No, thank you!.  I will send your regulator by first class mail within two days.

[Kephra]

Here's the result of a batch of CS I made to test the regulator I sent to silverFalcon.  I used:
250ml hot distillied water
6 drops 1M sodium hydroxide
0.5ml Cinnamon Extract
One nine volt battery for power
14 ma current
5.5 minutes

I adjusted the hydroxide so that the voltage at the electrodes was 7.5 volts

[silverFalcon]

Hi Kephra,
For 500ml would you double the ingredients? Do you mind posting a link how do you get 1M NaOH...

I encourage everyone to buy it to support the website (even though you already might have one regulator), as this is the best one out there...

[Kephra]

Hi Kephra,
For 500ml would you double the ingredients? Do you mind posting a link how do you get 1M NaOH...

I encourage everyone to buy it to support the website (even though you already have one), as this is the best one out there...

1M means 1 molar, and that means there is one molecular weight of a substance dissolved in 1 liter of water.

So, Sodium weighs 23, Oxygen weighs 16, and Hydrogen weighs 1.  That gives 40, so we need to dissolve 40 grams of sodium hydroxide in enough water to make 1 liter.

Actually, you probably want to make a much smaller batch, so 4 grams in 100ml makes 1M NaOH.

If you don't have a scale, you can approximate it by dissolve 1 level teaspoon in 3 ounces of water.  You then can calibrate it to your setup by voltage or current as I think I explained before.

If you want to double the batch size, you need to double the water, double the time, double the reducing agent, and hydroxide.

If you want to double the strength, you need to double the time and probably the reducing agent, but not the hydroxide. 


<a href="http://www.youtube.com/v/QpK1aurNR7M" target="_blank" class="new_win">http://www.youtube.com/v/QpK1aurNR7M</a>

[Serano]

Hi Kephra.

Question I hope you can answer.

I have ordered some 2N2222 transistor to make a power supply like the one above.  The emitter pin on my transistors is at at the top of the D when viewed from above like in your photo, however, when looking at the circuit diagram you posted, it looks like the transistors should be connected the other way around to that shown in the photo (assuming the emitter pin is at the top of the D on your transistors).  Am I missing something or doesn't it matter which way around the collector and emitter is connected.

Thanks.

P.S that video above always comes up as a "private", when I try to play it.

[Kephra]

Hi Kephra.

Question I hope you can answer.

I have ordered some 2N2222 transistor to make a power supply like the one above.  The emitter pin on my transistors is at at the top of the D when viewed from above like in your photo, however, when looking at the circuit diagram you posted, it looks like the transistors should be connected the other way around to that shown in the photo (assuming the emitter pin is at the top of the D on your transistors).  Am I missing something or doesn't it matter which way around the collector and emitter is connected.

Thanks.

P.S that video above always comes up as a "private", when I try to play it.

Oh, it absolutely matters.  It seems there is a difference depending on the manufacturer or the drawings.  When I got my last shipment of transistors, I looked up the pin-out on the web, and it said the emitter was at the top as you say.  I built two units, and neither of them worked!  I was perplexed, as I have used this circuit before.  So I looked up the data sheets from the manufacturer of the transistors I bought, and that showed the emitter at the bottom of the 'D'.  So,  the next units I built with the emitter in the correct position and they worked fine.  I don't know which way your transistors are pinned out, but I bet your drawing is wrong.  Viewed from the top (not the lead side) the emitter is on the bottom of my 2N2222s.

I will fix the video, but its a direct link and should work.

[Serano]

Ah thats interesting, I didn't get a data sheet with the transistors so not sure who made them (e-bay) so I looked it up on the internet and only found data showing them the opposite to the way you wired them.  I think i'll try it the same way as you initially, I have a pack of 10 so no problem if I blow 2, ha ha, I can blow up electrical stuff without any help from the manufacturers.

Thanks for the info.

[Stevie Mac]

Just received my current regulator in the mail! Thanks Kephra!

[Kephra]

Chalk one up for the USPS!  Enjoy!

[Treviso]

Is there noway you can ship out to the uk? itr would save me a whole heap of hassle!

[Serano]

hmmm, I've made the above circuit a couple of time now including the diode.  Both times the output has been measured and varied (I'm using a 100K and 1K ohm variable resistors) between 5 and 15 ma.  The first time I had the 100k pot set to 33K ohm and the second left at 50K ohm.  In both cases when left measuring (shorted on mA meter) the transistor in the top position gets very hot and eventually burns out usually taking out the fuse in my multimeter in the process.  I was wonder what the significance of the High resistance value was and weather the variable resistors are unreliable as I adjust them or as they warm up, I have no power dissipation figures for these.

[Kephra]

Serano,

How much voltage are you using, and which way are the transistors oriented? Like I showed, or like your picture?

At 36 volts input, and with the output shorted running 15ma, the upper transistor will be dissipating about .5 watts which is its limit without a heat sink.  Leaving a short across the output at that current and voltage would be pushing its limits.  In normal operation, the electrolytic cell resistance will be several hundred to several thousand ohms and most of the power will be dissipated in the cell.

Also, what kind of variable resistors are you using.  Ordinary carbon pot resistors like used for volume controls do not work well for dc applications.

[Kephra]

Oh, I missed one of your questions.  The high value resistor supplies drive current for the upper transistor.  The 2n2222s have a dc  current gain of about 100, so to get them to pass 10 ma, the drive current needs to be about 0.1ma.  The drive current is modulated by the lower transistor according to the voltage across the sense resistor.  It is not critical, and anything between 10k and 50k worked for me.

Edited to add:

Here is a link to the data sheet which shows the pinout: http://www.onsemi.com/pub/Collateral/P2N2222A-D.PDF