Joule Thief 101

[Pirate88179]

Great job Bill.
It is good to see some one that knows what a JT was designed to do.


Brad

Thanks Brad.  I really do appreciate that.

Bill

[MileHigh]

Brad:

Already done that.

Are you trying to suggest that you have done an analysis of how a Joule Thief works at extra low voltage when the normal switching cycle breaks down?

If yes, where is it?

MileHigh

[Magluvin]

Magluvin:

We will take a reality check on this one.  You will not find a single statement by me saying that I am against improving the efficiency of a Joule Thief.  So why are you agreeing with him?  Of course between the lines in Smoky1's statement is that "Smoky1 is attempting to bring increased efficiency to the Joule Thief by preaching that "resonance" will make a Joule Thief more efficient so if you challenge Smoky1 then you are 'against such attempts to improve efficiency.'"  But Smoky1 has only talk to offer that you have seen many times before so why would you agree with him before he has shown any evidence that his pitch is real?

Don't do the "degrading insults" play.  If you read me carefully I never take a first step in that direction, never.  Tinman and I are "fighting" over how a Joule Thief works.  If he says something nasty I might respond, but I am never the initial aggressor.  If his behaviour shows some attributes that are not conducive to an orderly understanding of how a circuit works and he is all over the map and it gets frustrating, I will call him out.  Your own record on "degrading insults" is one of the worst on this forum and I assume that you have thought long and hard about that as well as thinking about the whole raison d'être for this forum which had you doing some soul searching about how much time to invest in "the search."  I commend you for that.  Your one-time tag-team "partner in crime" is getting serious push-back on EF for his horrible behaviour and people are openly expressing how unacceptable it is.  I only wish other people on this forum challenged you and your tag-team partner when it was absolutely horrible around here.  It's the one time that the people on EF have outshone the people on OU and demonstrated some backbone and character.  Again, don't put the "degrading insults" label on me because it is not true.  It's just another cynical card to play.

The gist of it is this:  People have to get past the back-slapping and mutual stroking when discussing simple circuits in fake imaginary terms that actually don't make sense in real life.  That's is what was happening about the Joule Thief.  I made my case and got push-back, and then I pushed-back.  There is nothing wrong with that.

So you got a nearly 1 MHz sine wave on your scope display.  What next?  That's the hard part and I wish you luck.  What you want and need to do is figure it out just like I annotated your scope shot for the regular Joule Thief.  You have to do that to see where it is going to lead you.  Will it be a dead end or "improved efficiency through resonance?"

MileHigh

Well lets just see what happens. If Smoky for what ever reasons doesnt want to fully demonstrate a device then it is what it is. If he is willing to spend some time here and help out toward a more efficient goal, then im fine with doing what he suggests. Its a JT. Not much to do but tinker some mod ideas. So on that end, lets not beat the horse before race.

If you want to argue with Brad about what a JT is, then thats what is going to happen.  I dont care if what I end up with is even remotely close to being a JT, as long as I can possibly get some 'better' performance. If I happen to end up with a circuit that runs best at 3v, then I suppose its not under the jt rules any longer. Or in the end, this can be called a modified jt, as long as it can run an led with a AA as low as .3v at very low amperage.   Like scooping ice cream with a spoon in the bowl. Using an ice cream scoop, which is simply a modified spoon, will get the ice cream out much easier.


What next?  I think I just put some thoughts on that in my last post. Also, I have reached the goal that Smoky asked me to get to. Soo, lets calm down and see what happens next.

Mags

[MileHigh]

Magluvin:

I actually alluded to another interesting "what's next."

Supposing there is a very common super-bright white LED that most Joule Thief experimenters use and it turns out that the decaying voltage/current waveform from the discharging coil does indeed show that the inductor's energy output is not being used very efficiently.

So that begs the question:  Can you do an improved Joule Thief design where the extra power required to support the presumably increased circuit complexity to improve the efficiency of the inductor's energy output still manages to give you better overall performance?  Heck, even if the performance is not significantly improved it's a new challenge to get your minds out of the same-old-same-old Joule Thief rut and get some juices flowing.

It means that you actually have to apply your knowledge and try to design something new instead of painting by numbers all the time.  That would inject some life into a static subject that has not really changed in years.

MileHigh

[Nink]

https://www.youtube.com/watch?v=Co4WsKOcJk0

200 leds lit from a single "dead" AA battery.  To me, this is what the JT circuit is for.  I have also done 300 and then 400 but, they are not as bright as these 200 leds.  The battery was well below 1 volt at this time.  I am still impressed by this...call me simple but, it is still pretty cool.

Bill

Where were you at Christmas