Ultracaps tested for excess energy

[MileHigh]

Paul:

I looked at the ADC0809.  Is it set up to convert from 0 to 5 volts or did you change the Vref+ and possibly the Vref-?  For the sake of argument let's assume assume that the A/D converter sweeps from 0 to 5 volts.  5/256 = 19.5 millivolts per digital step.  In addition, the A/D error is +/- one least-significant bit.

The numbers above don't add up so did you change the A/D sweep range?

Here is my main point:  The accuracy of the A/D conversion depends on the programmable A/D sweep range and the fact that the built-in ADC error is +/- one least-significant bit.  Then this has to be related back to your very small delta-V which is typically 10 millivolts.

It is possible that your ability to measure a 10 milivolt change with the ADC0809 is +/-3% or +/-40%, it all depends on the ADC sweep range and the size of the delta-V you are trying to measure.  Can you clarify this issue?

Just the inherent inaccuracy in your ability to measure a 10 millivolt change in voltage ADC0809 can explain your fluctuations in capacitor value calculations.

What about your current source?  Are you using a bench power supply in current source mode and running that through a multimeter on current measurement?  What is your error margin here?

I am just trying to understand your measurement setup.

MileHigh

[Pirate88179]

Paul:

Just do you tests and ignore the peanut gallery.  If it is so, then we will know, if not, we will know that too.  I have faith in you.

As I have always said for the past year, these caps are different but, I kept getting comments on how much I don't know about caps, etc.  Well they are different and, I think you have seen that, at least as a possibility, as well.

I like interacting with folks that have open minds.  poynt was banned because he posted nothing but negative comments and also, many private pm's to Stefan from members here and abused his moderator privileges.

Carry on and we will see what is what.  If your tests should still indicate OU then, I am sure it can be evaluated by others and confirmed, or not.

Like I have said, these caps are "different", and we shall see.

Bill

[MileHigh]

Paul:

Using the example, the energy required to charge to capacitor to say 1V is 0.5 * 550F * 1V^2 = 275 joules. The energy gained is 0.5 * 5500F * 1V^2 = 2750 joules. Ten times the energy gain.

The above example is a hypothetical example and not from your data.

You are wrong here.  If the capacitance of the capacitor is dynamic and can somehow change with respect to time (to be determined what the speculated change mechanism is) then this will not be indicative of an increase in stored energy.

Yucca made the following statement wherein lies the answer:

Well I hope the apparent capacitance variances are indicative of excess charge and not just some peculiarity of the cap.

There is no mechanism in the experiment for there to be any excess charge.  You have complete control over the amount of charge stored in the capacitor with your timed current source.

If the capacitance of the setup is indeed dynamic with respect to time and increases, then this increasing capacitance will cause a decrease in the voltage across the capacitor.  Your example above is incorrect, the voltage will NOT remain at 1 volts if somehow the capacitance increases tenfold.  The voltage will simply decrease so that the amount of energy in the capacitor remains the same.  This test looks like a dead-end to me.

I will repeat my challenge to everyone again:  Try to suggest an alternative method for the apparent increase in measured capacitance in Paul's data.

MileHigh

[MileHigh]

Bill:

With respect, don't call me the "peanut gallery."  You seem to have a strong desire to stifle opinion, which is the antithesis of what this place is all about.  I am trying to HELP Paul understand what is going on and your comments are not appropriate.  This is not a Joule Thief thread and discussing the accuracy of his measurements is absolutely relevant to what is going on here.  Dismissing this as a "peanut gallery" comment is just another form of book burning.

There is nothing special about supercaps and Paul's testing can help confirm this.

MileHigh

[Pirate88179]

MH:

"There is nothing special about supercaps"  Again, this is quoted from your post.  You say it like it is law.  Talk about book burning.  This fellow Paul is trying to determine what is what and was big enough to say that he sees something unusual.  He does not have an agenda, and neither do I.  We just want to find out the truth but yet, you again post your posit as if it were proven, which it has not been.

Also, I did not refer to anyone in particular with my peanut gallery comment but, evidently you thought I meant you.  That is another one of your assumptions.

What I meant by that was....just let this guy do his work, which he is doing for free, on his own time, for his own reasons, and then we will see what he comes up with.  If the results do not match what you THINK you know about supercaps, then we can discuss other ways to verify or reverse his findings.  This is the way of science.

Gadget, and I have postulated that these caps are different, you say no.  Fine.  You still might be right.  We will see.  I have an open mind and I suggest you consider that option as well.  In other words, let the man do his tests and if you don't think he did them right, do your own and post your results.

Bill