Joule Thief

[SeaMonkey]

I believe that 3D TVs are also going to croak but I am not following that in detail.  I see somewhat of an analogy to the famous Tesla bifilar coil.

I would have to agree with that sentiment.

In Tesla's day his specially wound "coil" was a
novelty in a technology which didn't have many
options.

Today we have numerous options which
will get the job done equally well and/or
better.

The true bifilar wound coil takes on some
very interesting resonant properties at the
higher frequencies.

.

[gnino]

Don't worry about your English, it is fine. I understand you better than I understand many speakers of English as first language! You are getting your thoughts and ideas across very well, at least I think so.

You aren't seeing the benefit of Tesla bifilar windings because the true Tesla design depends on carefully winding the coil so that the turns are closely parallel, evenly and tightly spaced, and carry large voltage differences between the closely spaced turns. You are winding multi-strand coils but they don't qualify as Tesla bi- or multi- filar because they don't have the increased inter-turn capacitance of the Tesla system.

If you take a ferrite rod and a double-wire, wind a single careful layer with the doubled wire, then connect the far end of one of the wires to the near end of the other, you will then have a true "tesla bifilar" winding (although he used air cores). Each turn of one wire is between two turns of the other wire, and the voltage difference between the adjacent windings will be higher than between the turns of a single wire winding. This means increased capacitance between the windings and more energy storage in the coil during its oscillations. You should notice a difference then. (Ignore the green wire in the image below, it is a "primary" and is not bifilar-wound.)

Ok
I try to compare bifilar vs normal wound coil with my Circuit to see difference
First comparison i charge capacitor (with 220 lightbulb across it)with back-emf
And i look the Voltage ,no difference
Second i look i look the Voltage on a pick-up coil no difference
Here the photo of the coil they are both wound on the top of a coil
Like the one on the top of the photo wich i use for trigger coil

Later i will make a video
Why i dont see bigger voltage on the pick-up coil Whit the bifilar?
Maybe 25 volt isn't enough to see benefits?

[xee2]

@ gnino


Here is a test I did comparing bi-filar and solenoid coils: http://www.youtube.com/watch?v=GNtH9bp7QVo

[gnino]

The video
http://www.youtube.com/watch?v=huKivwkvpoY

http://youtu.be/oSXVKaHm4mc

But i'm not satisfied i wanna redo the test with magnet wire, this is with
Salvage litz wire and maybe there is some broke wire or i don't clean the ends properly

Ciao Luca

[Pirate88179]

Bill:

I like the high/low options you get with your switches.  If you don't mind I can mention an interesting project that simply popped into my head after watching your clip.  Let's call it the "supercap lamp."

Imagine a large supercap, about size of a standard coke can or perhaps larger.  Sitting on top of the cap you have two JT circuits.  Then on top of that you have your gutted LED light bulb.  With some effort you can imagine a "torch" that you can put on a table as a light.  Naturally you have the option to put on a small lampshade.  Two tiny switches are at the "neck" of you supercapacitor powered table lamp to select high/low for the light.

Someone with good build skills could make it look quite nice.  Of you could go insane with hot glue.  Or design a proper chassis to hold everything and print it out on a 3D printer.  The big cap makes for a nice stable base for the lamp.  How long will it run off the big cap?  I am sure there are JT/LED veterans out there that can comment.

Now here is the hopefully cool thing that makes the project that much more fun.  You get double-duty from the JT circuits.  On the shaft of the big cap you mount some solar cells.  Imagine long thin rectangular strips.  Black cap - dark blue solar cells - shouldn't look too bad.  So in the daytime you simply put your supercap lamp outside.  You use the JT circuits to charge up the supercap from the solar cells.  So that implies that you need another switch.  Power is all low here so you could use very tiny switches.  I would even consider using DIP switches in this application.

A little pop quiz question:  You absolutely cannot have the JT circuits over-voltage the supercap.  How can you do that automatically on the cheap and dumb?  There is a smart easy solution for that.

This can be breadboarded to check if it makes sense.  If it's a go, I think that you end up with a pretty elegant solution.   Your set your supercap lamp outside or in a window during the daytime, and then at night you have a table lamp with two brightness levels that hopefully lasts quite a while.  It's "solid" and practical.  You just move it from point A to point B and flip a few switches and you have a self-charging supercap lamp with two brightness settings that you can put on your table.

MileHigh

MH:

Sorry, I don't know how I missed your post.

That sounds like a nice project idea but, for me, not worth doing as I can not get decent sunlight where I live due to the trees and the way the buildings are positioned.  I have tried several solar devices and they work, but not well as they might get about 1 hour of decent sunlight on a good day.

I like the idea of using the JT circuits to charge the supercaps but, will the 350 volts output from the JT's hurt the 2.7 volt supercaps?  I wish I had purchased some of those used 3,000 Farad caps when they were in the surplus stores a few years ago...they were cheap like $15.00 ea. and now, to get one (New) is like $100.00 or more.

What I am trying to figure out with this current project is how/why the light gets brighter when I have been told by several folks that you can't put ac circuits in parallel and get any increased output?  If I can, I will add more circuits this weekend and get some tests done on amp draw vs the multiple circuits.  I also have a way to compare the light output on each setting.

Maybe these flash circuits output pulsed dc and not ac?  I am not sure if that issue was ever settled one way or the other.

Thanks,

Bill