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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I’ve thought about this a number of times in the recent past. There used to be a .ZIP file on the ‘netcalled Xanadu Zapper which consisted of plans and code to implement an IR xmit/recv interface for the PC along with code for learning and sending the IR codes. Many years ago I built the
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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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In this Youtube video comment, he asks the question [A] Joule Thief is a concept or it defines a device that uses a toroid? About your Q: The original Joule Thief was a simple one transistor device that used the inductive kick or Counter EMF of a coil to boost a low voltage up
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This is a reply to Paul’s question. After all the experimenting you have done since this was first designed, do you still favour a SJT over a conventional JT routinely, or can the extra components be circumvented by a different coil design or optimised transistor specification. The SJT has the feedback winding connected to the
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I needed a bright light over my workbench to see my work better, and this project was born out of necessity. The Electronics I bought a Bivar high power white LED Mouser P/N 749-L2PGN1-F, which uses a Cree XP-G mounted on a star board along with a reflector. The cost was $10.10 US. I have
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At Xmas, I had more than a dozen of the Blue Blinkies under the eaves. Last year a guy at work gave me a bag full of used AA cells, more than 5 pounds, must’ve been well over a hundred. Some measured 1.3V, some measured less than a volt, and some leaked juice and I
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