This is a continuation of my previous blog. I drew up a circuit (see the photo) and then built it, and I’ve been experimenting with it a little, and have some encouraging results. Time for another blog. As can be seen, the blue LED is glowing dimly. I originally used an alligator clip for the
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I was watching this Youtube video of a Joule Thief that is used as an EMF detector. Actually it is detecting the electrostatic field, not the electromagnetic field. If it had a pickup coil instead of an antenna, then it would be detecting the electromagnetic field. Anyway, it looks like he is trying to trace
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This, I believe, is the first Joule Thief I’ve built using a European style connector, I call them EuroConns, but Paul calls them chocolate blocks (I’ve never seen one chocolate color, though). I’ve built other things with them. If you’ve ever watched the Youtube videos of Xee2 AKA Xee2vids, you’ll know how handy these can
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I have often seen the conventional Joule Thief circuit used in situations where it is a poor choice – there could be better choices that would do the job. The Joule Thief or blocking oscillator circuit transfers a low voltage, high current input to a higher voltage, lower current output, with a low efficiency and
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An earlier blog about very lowpower Joule Thiefs is here. I experimented with a very low power Joule Thief using a SS9014 high gain, low noise NPN transistor, a red high brightness LED, a T231212T toroid with two 12 inch (300mm) lengths of 30 AWG (.25mm) solid enameled wire, and a 1k resistor in series
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I had a Joule Thief already assembled, using point-to-point wiring. The transistor was a BC338. The coil was a 3/8″ (9mm) toroid core with a primary winding of about 20 turns of 26 AWG and 666 uH, and a feedback winding of 190 uH. The resistor was 1000 ohms. Modifications I disconnected the feedback (base)
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I have built a few dozen of my Supercharged Joule Thief Flashers using the PC boards that I designed and had made with ExpressPCB (schematic is in the link above and PCB picture is below). The circuit works okay with a fresh battery but when the battery gets low the light comes on solid, and
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Paul got me thinking about the Joule Thief with low battery current. In his nineteenth JT he used the very high performance Fairchild KSD5041, same as the 2SD5041 (Japanese pinout – the center pin is the collector). He thought it was his brightest, and that could very well be. His theory is that the coil
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