Background: I should explain what I’ve been considering. My door has southern exposure so I would like to put a solar cell on it along with a long-running joule thief. The LED will be pointed at the keyhole in the lock. During the day the solar cell will charge a supercapacitor and run the Joule
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A few months ago I came across a 7 Year Joule Thief video from Xee2vids on YouTube (link below). It’s a conventional Joule Thief except that the resistor has been increased to 2 megohms, and a 100 pF capacitor has been added from the resistor to ground. He calculates that the LED should run for
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A .TXT file I had from 2009, probably from my late great Watsonseblog. If it had a pic attached, I’d like to add it, but I’m unable to determine what picture. Joule Thief using Air Core Inductor – Feb 13, 2009 I saw Quantsuff’s Valentine’s Day Flashing Heart on Instructables and it inspired me to
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I found this picture that I had posted to my late, great watsonseblog.blogspot.com. I have added my new rustybolt.info/wordpress blog address to it. This is a Joule Thief that uses standard parts, including a readily available toroid core. This high permeability core can be wound with various sizes of wire, but about ten turns will
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In late 2000 I bought a digital camera which was demanding of the AA cells, and it used quite a few. I decided to convert to NiMH rechargeable cells. That saved me a good bit of money, but at that time I hadn’t begun experimenting with Joule Thief circuits. This means that I really never
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In a comment, Metis asked: How can I reliably measure and/or control the output voltage of the JT? I’m currently trying to build a small power supply to recharge a Li-ion battery and I’d prefer to be able to keep the output voltage at (or rather below) a known level rather than invest in a
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I answered a Yahoo question: is joule thief fine as grade 12 physics final project? Additional Details Is the joule thief circuit appropriate as 12th class final physics project? I have made a joule thief circuit (http://www.youtube.com/watch?v=gTAqGKt64… as 12th class’s final project. Should my high school add this in my transcript for the Universities? Will
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I got this schematic out of an old book, old enough to still use Germanium transistors. It uses some overvoltage protection diodes on the base. The 9V Zener and capacitor also look like some form of overvoltage protection. This would have to be modified for a silicon transistor. The battery says 5V, so I assume
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In my earlier blog, yesterday I discussed using a 1 Farad capacitor to hold enough charge to run the flasher for several hours, from dusk to midnight or later. I checked Mouser’s parts and found a 1F 2.5V capacitor from Bussman for about 2 dollars in single unit quantities. Kind of expensive but cheaper in
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