When the winding gets tough, double up the number of toroid cores, I say. This JT uses toroid cores that are less than 1/4 inch (6.4mm) outside diameter. The wire has to be fine to get several inches wound on a core. So I wound one core with the wire, and then coupled it to
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Paul suggested this Wikipedia article. I quote: I remembered these, having seen one in action, and always wanted one. I think you might be interested. Perhaps that is why I am interested in JTs. There is more than a simple parallel. http://en.wikipedia.org/wiki/Hydraulic_ram When I was a kid, one of my dad’s customers died and his
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The conventional Joule Thief uses a single cell at 1.5V for power. It also typically uses a coil that has both windings the same number of turns. This means that the voltage across the primary, which is also the voltage across the LED, is the same as the voltage across the feedback winding. Almost all
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A question a Youtuber brought up made me think about going to the opposite extreme from the one I normally pursue: trying to get a Joule Thief to run at very low power. Normally I would try to maximize both the light output and efficiency. I started out with a run-of-the-mill Joule Thief having a
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One of my email correspondents and botmaker, Bill Sherman, had made some Joule Thiefs inside of a jar, but this Instructible uses diluted fluorescent ink from a Highlighter pen to diffuse the light into various colors. That’s quite a nice idea, and gives the light a very dispersed and colorful look. What I would like
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Here’s a picture of one of my flashlights, taken on the last day of 2006. I most likely had this posted on my late great watsonseblog. Maybe even here, too.
I drew this schematic up a few years ago (2009, IIRC) when I first made the Supercharged Joule Thief. It was supposed to help me keep track of the several SJTs that I built, and continued to build to validate the design. I suppose I should delete all of the text in the schematic, and
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I bought some ‘high current’ chokes from Jameco, P/N 642855, which are 390 uH. They’re bigger than average, and mount axially; in other words the leads are at opposite ends of the cylindrical package. They are made by winding relatively heavy copper wire onto a ferrite bobbin. The bobbin is then covered by a piece
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I built this up to see how well the blue LEDs I got recently would work on the DC output of a JT. I put three pairs of two in series on a perf board and soldered them to the air wired JT. I knew that the Vf of two blue LEDs was going to
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I went on a Joule Thief building binge for a few hours last night, making up some germanium Joule Thiefs after I found a small box of old unidentified germanium transistors that I had forgotten about. I used a small piece of the “Woodsies Squares” thin birch plywood about 1/2″ by 1″ (12.5 by 25
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