Joule Thief

[Pirate88179]

Artic_Knight:

Thanks for the reply.  I like your analogy and, I believe I even understand.  One thing that is slightly different, which is what Dr. Stiffler was responding to, is that alone, the EB puts out 1.95 volts and now the supercap has close to 2.5 volts on it.  He says this can't happen.  Maybe the difference is that my meter in volt mode does not load the circuit.  We have read in the past that the EB can rise to the challenge when you place a load on it, to a point of course.  So if the EB sees the supercap as a load, which it is, maybe it is pulling more out of it than my no load meter will? (This is just a guess)

Yes, everything is hooked up correctly polarity wise.  There is a stern warning on the caps that if the polarity is not correct, it can explode with great force and cause damage or injury.  So, I was very careful in this.

Gadget is correct in that my meter can not handle the amp level and therefore the minus sign in that reading is probably just an anomaly that happened as I was about to fry the meter by reading it like that.

Thanks for your explanation and analogy.  These supercaps are really cool.

Bill

[altrez]

I have quoted a reply I received from Dr. Stiffler about my new supercap on Energetic Forum:


"Bill who told you that a SuperCap would continue to accept charge if the voltage across it remained the same?  Here are some basic facts that apply to all caps (SuperCaps included);  Q = CV C = Q/V V = Q/C  V is the voltage on the cap. C if the capacity in Farads and Q is the charge or Coulombs.  The energy in the cap can be found with a basic formula J = 1/2(CV^2) where J is Joules or WattSeconds. If you want WattHours then WHr = J/3600  So if yo have a cap of 650F @ 2.7V you get J=1/2(650*(2.7^2)) = 2.369E3 or 2,369 WattSeconds. Divide this by 3600 and 2369/3600= 6.581E-1 Watt Hours or 0.6581 = 658milliwatt hours.  Yes if you direct short this cap through the meter it should burn something up, but the fuse will not necessarily respond as the initial pulse is very short.  This is not much energy as the power is determined over time so you must use V*I*T.  The stored energy in a cap can also be found by W=CV^2/2 which I showed above.  Note that one Joule or WattSecond is only 2.78E-7 KwHr.  Hope this helps."[/]


He says that there is not much energy stored in my cap at all.  I don't know enough to argue with himbut look at what I was able to do with just two 10 farad caps and now I won't be able to do much with 650?  This makes no sense to me at all.  He is saying I will only have milliwatts for output and again, I find this very hard to believe.
As for the part about someone telling me the cap will continue to charge above my input voltage, well, I have seen that with my own eyes and so no one had to tell me anything.  1.95 vdc input from EB and now over 2.4 vdc on the supercap and climbing.  Something or someone is not correct here.

Bill

I am fairly sure the poster is right. However I am very weak in caps so I can not say for sure. I do know however that in my tests if you have a constant voltage the caps will only charge to that voltage. Your earth battery might have spikes that are pushing the cap to go higher.

-Altrez

[Pirate88179]

@Pirate88179
You don't need to worry about shock danger when working with low
voltages like 2 volts.  I doesn't matter how many amps you have.
You could stick your tongue across that super cap when it is fully charged
and you would just feel a tingle on your tongue.
Even 12 volts is safe to handle.  You can touch the 2 terminals of a 12 volt
battery with your fingers without feeling anything as long as your
fingers aren't wet.

As for keeping the voltage down to run a Fuji circuit I would recommend a voltage regulator circuit.
You need a 1.5 volt zener diode and a transistor to make one.
Lots of voltage regulator schematics on the internet.

Thank you.  Obviously I am out of my knowledge comfort zone here and I appreciate the input.  When the EB read 1.95 I was able to run the Fuji OK, no damage, but now nearing 2.5 volts, I think this is too high for it.  I will look up the circuit you mentioned.  Thanks.

Bil

[resonanceman]

@resonanceman

You are having some success with the joule thief self charger.
I have not been able to put it to work again.

Jesus

Jesus

Just  don't  give up .

Keep playing with it  .

It  worked  for me .....so there is something  there .

Have you  tried going back to the start ?
Building it   one piece at a time ....... and  checking   how it is  working  after  each piece


``````````````````````````````

My  charger actually lost  a little  voltage   today

I checked the  wires  and  found  a couple of mistakes . ......it is a wonder that it charged at all 
I  think I got  it fixed .........now I have to let it run for a while and find out if  it keeps charging  or  poops  out again


gary

[jeanna]

Bill,
I have been wondering about putting a diode into your EB collection system. The earth is not steady current. It is dynamic and filled with spikes and it goes more than alternating, it goes random and sideways. So, you have found a pair of spots that together give a kind of constant magnetic field/movement(?) I don't know the term, of course, but anyway, if you put a diode into the pos side you will create that as a more positive side.
If the diode doesn't work maybe you could use a bridge and really force all of it one way and into your cap.

Remember last week theNOP pointed out that in ac the cap will empty and fill when the direction changes.

So, my question is what is this big cap for if it will be too much for your fuji at 2.6 volts? I am surprised that this almost empty capacitor is too much?

Please explain, thanks,

jeanna