What would you say if I told you that I could make a Joule Thief without a transistor or other electronic parts, just a single mechanical part? Would you believe me? I have seem this method used many times in old radios and old equipment made before transistors were born. It’s not magic! You may
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One Joule Thief I have not built (at least not in the same JT) is the low power JT with the CdS photocell. Almost all of my JTs with daylight shutoff used a LED as a light sensing diode, and then most were flashers. I have a bunch of CdS photocells but I haven’t really
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I was reading this article and saw that it said that when the voltage of a 1.5V cell drops to 0.9V, it still has 10 percent of its capacity left. I have read in the past that the battery is considered used up when its voltage drops to 1 volt. I don’t know what the
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I came across this .PDF a while back and I had one thing I wanted to show about it. The circuit is okay, but the 2 ohm current sensing resistor in series with the LED wastes about 25 percent of the power of the 1W LED. There is a simple way to reduce this, and
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I came across a schematic of a “Joule Thief” circuit, actually a two transistor LED V boost circuit, on OverUnity.com. This is part of a garden light, and has a solar cell to recharge the battery, and the battery to store the electricity until after dark. The schematic, dated 10/16/2013, was drawn partially upside down
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I was reading some of the thread over at OU about transistor behavior. The discussion was about the BC337-25 and the 13003, which is often found in CFL bulbs. One poster said the 13003 was rated at 1 amp, and the BC337-25 was rated at 0.8 amps. But in the Joule Thief the BC337-25 drew
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I received a request for a pictorial that shows the wiring of a Supercharged Joule Thief. I redrew the one here to show the wiring of the SJT.
Paul sent me an email with some questions about making a generic Joule Thief PC board and getting it made into some PC boards. I advised him about using the free ExpressPCB software to design the schematic and PC board, and their service to fabricate the PC board. They charge 66 dollars U.S. for a
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I blogged my experiments with this very low power JT back in April, and I connected it to a cheap ‘heavy duty’ AA cell and left it running for a month or two. I added updates to the end of that blog I made one mistake: I should have taped a post it note to
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I came across this guy’s EMP blog describing his experiments with various Joule Thiefs, and the results he got. I couldn’t find an email address or how to contact him, so right now I just have to say it in my blog. He has been methodical and taken measurements while he has experimented and he
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