Joule Thief

[WilbyInebriated]

hey bill, how about a 'drinking bird' that makes the battery connect? that way you are staying away from something that uses more of your battery, ie: the 555, etc.

[Koen1]

That is a direction i like !

Things to think about , First the cap charge time , someone told me they change depending on the overall charge percentage , if that is true then we can take advantage of it , lets say it charges faster the first 10% , then you get a one rated at 1000v the 10% faster means 100v after that it still charges then but slower.

Yeah, ok, but I think the point I was trying to make is not clear. I'm sorry, can't really pinpoint where that point is, but I do feel some friction
in thinking about this... I shall try to indicate the point roughly, by the following. If it is not clear, then I apologise in advance.

Thing is, I hear a lot of talk about volts, as if the volts are the charge. They are not. The charge is in the form of electrons which each carry the actual charges.
The number of electrons therefore must effectively be the amount of charge. The number of electrons is indicated by the number of Coulombs, where 1 Coulomb
is one mole of electrons. For more charge to be stored on a capacitor, more Coulombs should be stored in it.
The amount of Coulombs that can be stored is indicated by the Farad count, 1F = 1C / 1V. So for the maximum actual charge to be stored, a high F cap
would seem to be needed. A low Farad high Voltage capacitor stores less charge per volt, even if the volts are high. A 1F 100V cap should store 100 times
less charge per volt than a 100F one.
Now high Volts can of course be used to induce charge movement in a medium, if there are already charges available, and this explains (partly)
why AC can light the gas filled lamps Tesla used for example. So for use in lighting the high voltage AC is of course usefull.
But if we want actual current ouput, then it seems to me that we want to store actual charge, not just have high tension and little actual charge.
Or do you feel I am mistaken in that? If so, please indicate where I'm off?
Then, on a side point, there is the matter of capacitor leakage. Lower Farad caps generally have a significantly higher energy leakage than
high Farad ones, due to the quality of their dielectrics. So it would seem that, in order to minimise capacitor losses, a higher F cap is
better than a lower F cap. Again, if you feel I am off, please say so.

Oh, perhaps it helps if I mention that, obviously, the actual voltage on a cap is directly related to the amount of coulombs stored in it,
so it still comes down to the amount of charge. The more charges accumulate, the higher the voltage of those charges on the cap.
So in the end, it is still primarily the coulombs ond only secondly the volts that the capacitor handles.
Hmm... I am afraid I can't really put it much more clearly than that, and that I may still not have made clear what the point is...
I suppose it is something along the lines of "Which is more important for our actual energy output, is it high volts, or is it
the amount of charge?" and in that respect, is it indeed high volts with hardly any charge that we want to store in caps,
or is it rather low to medium volts at a significant charge that we want to store?

I am not entirely sure why people keep bringing up the parallel pickups or parallel wires low F caps...
Sure, they can be charged and discharged faster, and at that high voltage at low charge is easy to handle with low F caps,
and sure, you can discharge them in parallel and get the combined charges out, resulting in more amps.
But would it not be equally easy to wind the pickups with much less turns so they put out high charge at lower voltage,
then connect them in parallel and via diodes to a single high F low V cap?
Energywise it shouldn't make much difference, and the high F cap may even prove to be more efficient in use due
to its lower leakage...

... I suppose it dpends on what you want to do with the output.
If you want high voltage output for some reason (?) and you want fast charging and discharging, then low F high V caps would
be best. If you want charge rather than voltage, and you want energy instead of speedy switching, then high F caps would
seem to be better.

And again, please do point out any problems you see in this, and other replies are also welcome of course.

Kind regards,
Koen

[WilbyInebriated]

"i would just like to know what an electron is" 

[electricme]

@Koen,
I agree with you entirely, got no beefs at all, I see you have also poped in to your post a mini post from MK1. MK1 did this in reply to my suggestion.

As we all know the forum is made up of several people having a joint aim to develop the JT, but there are different ends to the outcome.
My main aim id to try and get grunt so I can make muscle to drive a motor, others want to squeese as much out of a AA battery as it is physically and electrically possible, and I take my hat off to them, what they have achieved so far is enormous.

The only way to get grunt/muscle is to have a heavy current draw from a battery capable of doing it, the NiCad can deliver this for me.
So I have drawn up the circuit here to give all an idea of what and how I want to do it.
This is not a be all and end all circuit, but I will also change it in a few days so capacitors and MOSFETS can be used, well its 11PM an I gotta have a sleep or I go troppo lol.

@bill,
I also looking forward to having a go with your scope he he, thanks for the plug about scope skool.

@Jeanna thanks also for all the good tips you sent so I can post bits of quotes, TA.


jim
 

[WilbyInebriated]

i'm still trying to figure out if koen is suggesting the electron is a discrete particle...