Electrolysis Power Source

[JPG]

Faster is not the objective, JPG. This is a lab project for me not just a way to get rust off the tools. For a few dollars more than I have spent on wasking soda I could go buy new tin snips.

BTW, you are the one who first indicated a curiosity about the current and voltage. I just happened to be the one with an ammeter and a brew going.

The jabber is done!

I did not mean to demean the 'jabber'. Poor choice of words. Yes I am interested in the 'lab' project results.

I do not think my experience is as good as it could be! Perhaps I also am expecting too much too soon! It does get it done however!

If the battery charger is unfiltered, the voltage readings(dc) can be misleading. What does not show up is the ripple content. It can be measured(coursely) by taking an ac voltage measurement using a coupling capacitor. A scope would really tell the tale(I do not have one).

The reason for my 'interest' is that I have come to the conclusion that the area of the electrodes(and their condition) along with the applied voltage are what determines the current. If that be so, the voltage essentially determines the current density(amps/area) and therefore the rate of 'conversion'.

I agree that the smell good washing soda(with additives) may not be as effective as plain washing soda. Then again as I said, it doesn't really matter what has made the water conductive. Various other 'stuff' supposedly works also(baking soda, lye, salt(NaCl),'sea water', they just vary in their effectiveness and relative 'safety'.

[mikelst]

You could also in theory just measure the ac voltage on the dc lines by setting your meter to ac. Then if you want peak voltage multiply the ac voltage by 1.41 to give you the peak to peak voltage for the ac.
eg 120vac measured on a voltmeter = 120 *1.41=169.2 volts peak to peak.
That's right folks your 120vac in the house is the RMS reading. The peak to peak is about 170 volts.
(RMS stands for Root Mean Square)
This gives you the ac voltage riding on the dc so....
you have to divide the ac voltage by 2 as only half of the voltage adds to the dc, the other half subtracts.
so assuming a ripple voltage of 5 volts (RMS) ac on a 12volt dc line would give you a 7 volt peak to peak signal on the 12 volts meaning a peak voltage of about 15.5 volts but also reducing the DC component to 8.5 volts for an equal time.

This means that in this application where you are using only the dc component to move the electrons as the ground is always ground. The ac component cancels itself out.

OK sorry fo going into lecture mode:o

[reible]

Hi,

So who has a scope we can hook up to look and see what a battery charger output looks like... to be more accurate what "one" charger looks like.

I guess my idea is that there is "ripple" but have no idea what it will look like. Does it ever go negative or is it all above some level. If I had to guess I would say the ripple is all centered at say 12 volts with the "noise" with say a peak of 14 volts and a low point of 10 volts. I'd also say it is not a sine wave....

I do have a scope but it was one I built many years ago and has been stored in the garage for years... so if it still works it may not work very well. No time base so it would be raw and unmeasured....

I also have pocket Fluke scope but I have a feeling the battery is long gone on that and since I don't do much of this any more it would be unlikely I'd be willing to buy a new battery just to do this test.

So there must be someone with access to a scope who is interested in seeing what is happening.

Ed

[reible]

Here is an interesting story about something that happened during a electrolysis session:
http://www.globalsoftware-inc.com/coole ... emoval.htm

Look for the title "Funny but potentially dangerous story "



Ed

[JPG]

Hi,

So who has a scope we can hook up to look and see what a battery charger output looks like... to be more accurate what "one" charger looks like.

I guess my idea is that there is "ripple" but have no idea what it will look like. Does it ever go negative or is it all above some level. If I had to guess I would say the ripple is all centered at say 12 volts with the "noise" with say a peak of 14 volts and a low point of 10 volts. I'd also say it is not a sine wave....

I do have a scope but it was one I built many years ago and has been stored in the garage for years... so if it still works it may not work very well. No time base so it would be raw and unmeasured....

I also have pocket Fluke scope but I have a feeling the battery is long gone on that and since I don't do much of this any more it would be unlikely I'd be willing to buy a new battery just to do this test.

So there must be someone with access to a scope who is interested in seeing what is happening.

Ed

Unfiltered dc looks like the positive portion of a sine wave repeated twice rather than a positive half cycle followed by a negative half cycle. Thus it is 100% ripple.

Filtered dc has a fixed dc component with a positive ripple that resembles the part of the sinewave that exceeds the dc component. This usually takes the shape of the positive going sinewave, but resembles a discharging capacitor when the voltage passes its peak value.

For that reason the 'manipulation' of values measured by factors of .707 or 1.414 will probably lead to incorrect conclusions. Add to that the fact that d'arsonval type meters are average responding(.636) peak values and when having an 'ac' scale, are calibrated assuming the waveform and say .707 when they actually are responding to .636.

Ripple does not fit the waveform assumption. Digital meters are dependent upon the individual design and not so predictable.

Also merely setting a meter to ac scale does not always cause it to ignore the dc component present in a 'rippley' voltage. If you get a smaller reading when you couple the meter through a capacitor(of sufficient capacitance) then the meter is also responding to the dc portion of the voltage.

Lecture(2) end.

[reible]

Hi,

Since I have never opened my battery charger this might not be the case but are we talking a center tap transformer and 2 back to back diodes and a filter capacitor across the output? Full wave bridge? More filtering like perhaps a choke?

From JPG's description the wave form has a |\|\|\|\| look to it?

Maybe I should pull the cover off mine and have a look inside...

Ed

[mikelst]

This is a page that shows a 'pretty standard' full wave bridge rectifier and its resultant wave forms.

http://www.electronics-tutorials.ws/diode/diode_6.html

As a side note I have frequently seen a 60hz sign wave ripple on a dc level but...
This is usually a noise issue caused by florescent lighting, noisy transformers, or unshielded transmission lines in the area. and it is a much lower signal than the above 'for example' 5 volts.

[JPG]

The resultant output waveform for the full wave centertapped transformer with a filter capacitor would be the same as that illustrated for the full wave bridge with a filter capacitor.

Excellent post!

A typical low budget battery charger has a transformer with a center tapped secondary and two diodes as illustrated in the previous post.

Since its purpose is to charge a lead acid storage battery, there is no need for a filter capacitor. The battery itself acts similarly and actual charging takes place only when the instantaneous output voltage exceeds the battery terminal voltage. Thus the 'ripple' looks like a flat line with 'bumps' on it that are shaped like the tops of the sine wave. The space between the bumps is flat.

When said charger has a charge rate power switch, the switch is switching between primary winding taps. This causes the output voltage to change.

There are more 'exotic'(smart)(start current) chargers out there, but most are as described.

[mickyd]

.........
I agree that the smell good washing soda(with additives) may not be as effective as plain washing soda. Then again as I said, it doesn't really matter what has made the water conductive. Various other 'stuff' supposedly works also(baking soda, lye, salt(NaCl),'sea water', they just vary in their effectiveness and relative 'safety'.

JPG's just giving examples. Some of the other 'stuff' makes a good electrolyte but can also trash the base metal (i.e. salt / acidic based solutions) so stick with washing soda / baking soda.

[JPG]

JPG's just giving examples. Some of the other 'stuff' makes a good electrolyte but can also trash the base metal (i.e. salt / acidic based solutions) so stick with washing soda / baking soda.

Who ya gonna clean up after when I am dead and gone?????:D

Good point made there!:)