I have built several of the “Single Cell Flasher With Two Year Battery Life” flashers found at Pigeonsnest.co.uk and they flash for what seems like eternity – they’re real misers when it comes to battery current. But the flash is somewhat anemic and I had never tried this type flasher with any color LED other
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I have read the claims of many Joule Thief fanatics who say that the JT will “suck the life out of dead batteries” and that’s how it got its name. But by the time the Joule Thief gets to a battery, isn’t it already mostly used up? During the Xmas holidays and since then, I
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Paul posed a question about the base resistor and how it affects efficiency. This is a point that was apparently addressed by the low Vce(sat), high gain transistors that were made especially for DC to DC converters. Since the BJT (bipolar junction transistor) is a current operated device, the current that it needs to turn
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My “rival” Flagiusz has done some experimenting with a version of a Joule Thief which uses a capacitor similar to my Supercharged Joule thief, but is simpler. He also claimed that it was a bit more efficient than my SJT. This version, which he calls Fast Joule Thief, is the second one after the ‘basic’
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I measured the voltage of an unused Energizer Lithium AA cell, and found that it was 1.806 VDC, and another one measured 1.807V. Wow! Looked like the Energizer Bunny was running on jet fuel! These are very potent batteries. Their voltage is 20 percent higher than the normal AA cell. These lithium cells are supposed
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I left a comment to one Joule Thief experimenter (video is on Youtube) that one should never power a Joule Thief with no LED connected. If the emitter to base voltage exceeds the breakdown voltage the resulting current will permanently damage the transistor by reducing the current gain. He tried running the Joule Thief with
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Paul discussed some points regarding the low voltage joule thief. (I’ll have to get his permission to put the paragraph here.) First I have to admit that I’m not an expert when it comes to electromagnetics and toroid cores and transformers. The reference data books give standard information such as the transformer’s voltage step-up is
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Paul asked a question: If you increase the resistor and the [supply] intake current reduces, what does the efficiency do? Paul has asked several questions about Joule Thiefs that I had not thought about previously, and they’ve brought up some thoughts that may be important and should be examined further. I have calculated the efficiency
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This is a photo of a Joule Thief I built more than a year ago using the core from a dead CFL light bulb. The windings were only 9 turns each of solid insulated telephone wire. That was all I could get on the core. This core is the typical size for the CFLs where
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I’ve been trying to get a stable 5 milliamps of current from this circuit, which is a Supercharged Joule Thief with the LED replaced with a rectifier, filter capacitor and zener shunt regulator. I’m getting about 9V with no load, but when I put a 2.2k load resistor on I get 8.5V which is drawing
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