Joule Thief

[Frederic2k1]

Where can I find latest schematic of circuit ?? 

[forest]

I have an idea. If somebody could propose/invent automatic switch which would ne be powered but when applied voltage above certain value it would switch two circuits then you could just use two identical large capacitors - one for power supply and one as output storage.When voltage on output cap will rise above certain level his cap should become power supply and the former - the output storage.
If you can do it indefinitely then it's OU

[Pirate88179]

forest:

I think The Daft Man and Lidmotor on Youtube have already done this.  I had been thinking about this too once I started using supercaps.  I don't know how to do it though.  Check their work on this and, if I am correct and they have done this, let me know how to do it.

Thanks,

Bill

[jeanna]

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How would you measure how measure farads stored in the capacitor though? 
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I agree and I think you stated this really well.

I think the time constant is maybe a great approach.
It may be possible to use a resistor in series with the caps to lengthen the time.

Others might have a good way to describe how to do this.
I am not very confident of how I should describe it myself, but when I was first learning about electronics, I made my teacher set up a rig for me to use a cap.
I filled the cap in a very short moment then hooked it up to the resistor-- led arrangement and counted the time.

So, because the time constant is a great way to calculate a cap, maybe that will tell which side is < and which is >.

jeanna

[jadaro2600]

I agree and I think you stated this really well.

I think the time constant is maybe a great approach.
It may be possible to use a resistor in series with the caps to lengthen the time.

Others might have a good way to describe how to do this.
I am not very confident of how I should describe it myself, but when I was first learning about electronics, I made my teacher set up a rig for me to use a cap.
I filled the cap in a very short moment then hooked it up to the resistor-- led arrangement and counted the time.

So, because the time constant is a great way to calculate a cap, maybe that will tell which side is < and which is >.

jeanna

Perhaps timing the supply side and then the charged side independently; by this I mean, having a separate testing circuit (this may require a 2~3V supply rather than the 1~2V we've been using?)... to determine how long it takes to discharge one which is fully charged, and one which has been charged via the fully charged.