Joule Thief

[nievesoliveras]

The incomplete information of the aweet vta is here:
http://jnaudin.free.fr/html/vta.htm

Maybe somebody has the missing vta3.zip.

Jesus

[Pirate88179]

@ All:

For a long time, everyone wanted me to do longevity experiments and tests on my JT circuits.  Well, my 82 year old mother's JT night light is still going strong on a "dead" AA battery now for 40 days burning about 10 hours per day.  (Night actually)

It uses the ferrite bead 1" OD X 2" long, 2N3904 transistor, 1K resistor, and a super bright 10mm white led.  I should have measured the volts in the dead battery before I started but I did not.  It came from my dead AA bag that has all of the batteries my electronic devices say are dead.  So, just guessing, probably about 1.1 volts or so.

So, 400 hours and counting. (or thereabouts)

Bill

[freepow]

Hello  BILL, from freepow,  About your 400 hour plus night light, How many turns on your ferrite    bead, also what is the current draw ?
Is the LED fairly bright ?
                                   

[mrbr00k5]

Hi everyone, I mostly hang out in the crystal cell thread, but I had a question about the joule thief. Based on the considerable amount of variations and experiments that have been done, in this thread alone. Could someone please post a schematic, of what they consider, the best joule thief is so far. Which one is the longest lasting, and most efficient? I hope this request doesn't sound lazy, but surely you can understand that a 1000 page topic is a little intimidating! I've built the battery switching joule thief charger that Lidmotor and Kubikop showed on youtube, which is really cool, but I know I'm way behind in joule thief design. I started tinkering with joule thieves about a year ago, and then got involved in researching crystal cells, so I missed a lot of progress I'm sure. So what's the most long-lasting, amperage squeezing, design you guys have come up with!?

[jeanna]

Hi Mrbro0k5.

I think the reason those 1000+ pages are so interesting is that there were many of us sharing many different design ideas with each other and inspiring each other as we did.
So, there is no substitute for reading it all.

I would say that the first 105 pages are essential.

To make it easier I will say a little about my angle of experiment...

My designs have all been to use the jtc as a pulse generator.
I do not use the C-E of the transistor to make the light unless I am dealing with very low voltage or amperage.
Instead, I use the toroid which is pulsing a magnetic field, because it is part of the jtc, to wind a secondary. It is from this secondary that I produce whatever it is that I produce.

If you want to see my experiments, you might read the thread I started called "AC from joule thief".
I was confused about "my" circuit in the beginning but I was clear about the question I was trying to answer and the direction I was heading.

I will let any others who want to say what they want about their own circuit experiments.

Have fun. This is a really great circuit.

jeanna