Quantsuff reminded me of his Hak Light in an email. I haven’t visited his web page in awhile so my memory needed refreshing. I checked it out, and I thought about another use for his circuit. At the dollar store, they sell (when they’re not out of stock) the CR2032 or CR2025 coin cells on
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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 bought some LT-1073 DC to DC converter chips from Digi-key for about $4.00 apiece. I’m going to try to make something small to power 9 volt radios and other devices. It will use a 1.5 volt AA cell for the input battery. The switching transistor is on the chip so the only parts that
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I used an older Joule Thief that I pulled out of the pile to make an adjustable power Joule Thief. I changed the transistor to a SS9018, put a 1 ohm resistor in series with the cathode of the white LED to allow measuring the LED current. I left a 470 Ohm resistor between the
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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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This is a continuation of the 2013 Dec 18 blog. It was getting too long, and so is this blog. Update Dec 24 – I searched for high current pulse gen schematic using Google and I didn’t come up with anything near enough to what I’m looking for. I saw a lot of high tech
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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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I think I wrote about this circuit in my late Watsonseblog. This circuit is essentially a Joule Thief with an added transistor to regulate the output – somewhat. It doesn’t have very good regulation because the 6.8k is a resistor (see Note). If this resistor is changed to a Zener diode then it regulates much
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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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