Joule Thief

[Cap-Z-ro]

" from what i have read about Pomerlou, the phemomena are closely related to him.
his device does not work without him being there. "


If I am on the right track, that may be only because no one but him knows how it works...and if would follow that no one but him knows how to engage the effect.

Something to consider for sure.

Regards...

[Pirate88179]

Jeanna:

I was using one then I decide to add another since these uv leds are the small kind and not high output.  So, what you saw in the video was simply two separate leds and two pieces of plastic tubing.  I think one is a bit longer than the other.  I was trying to see how far the light would excite the paint....it is not that far.  I still think this idea has some merit as we can excite the materials using the uv bandwidth to get possibly more light than from a standard led as the light would then go out in all directions and not be so confined as our leds now are.  This was the original idea anyway.  I just have not yet found the best "delivery" device for this approach.  Now, if anyone knows of ultrabright 10mm uv leds, then this would get better real fast.  To me, the main problem of leds, as I have said before, is their directional nature of output.  I was hoping to diffuse the light over a larger area using the photons released by the excitement of the material in the black light paint.  There is a lot of experimenting that can be done in this area and I am very sure, someone will come up with something better than I have done.

I like the idea of using glass Jeanna, my plastic tubing is opaque and limits the light output from the start.  If I could find some glass tubing locally, I think it would work better.

Thanks for welcoming my new scope everyone, it will take a while but.......at least it works.

Bill

[dog812]

Well today i picked up some 3904's and didnt notice any difference from the 2n222A i was using before.
I also experimented with the pots.. and found that removing the pot / resistor completely made the LED's the brightest..
Why would that be? What is the point of using the resistor in this schematic? http://www.instructables.com/files/deriv/F2I/ZRXQ/FR0ZHOS5/F2IZRXQFR0ZHOS5.MEDIUM.jpg

I finally picked up a voltmeter..  so hopefully i can get better at testing.. now i just need to figure out how to use it.. so far no readings make sence to me haha.

[WilbyInebriated]

hey bill and jeanna you can get small sections of glass by taking apart a fuse. i use them all the time, for my QHC spark gap, as a roller in my van de graff, etc.
they aren't that big, but then bill said the light doesn't go very far. heck you might be able to just fill the glass tube with paint, glue the led to one end and and seal the other?

maybe a UV laser diode with no collimator instead of a led? i have run IR and red laser diodes off a jt. needs current limiting or you're rolling dice with you laser diode.

[Pirate88179]

Dog:

Excellent that you got a meter, good going.  OK, here is my non-professional opinion of the resistors.  Waaaay back in the beginning of this topic, I asked about resistors as I have always seen them as "wasting" energy. (they get hot, heat takes power)  The answer I received from many of our fellow experiments was that it is there (resistance) to protect the transistor.  OK, I can live with that.  Then, I started using variable resistors and found I could get a very bright light with low power draw and the transistor survived ok.

So, if you get a bright light without ANY resistance, and your transistor does not get hot or blow out, then my unskilled opinion would be not to use one.  Whatever you have done in your circuit due to materials, components and windings may allow this to happen and it is important for us to understand that.

As Jeanna can tell you, you may see, once you use your meter, that your power draw is way, way up with no resistance and, that getting the proper resistance give you almost the same amount of light, and 1/10 the power draw, which leads to better longevity. 


Well, this is all I can contribute I am sure others that know more can help.  Nice job.

Bill