See Note at bottom. Years ago I bought a shake flashlight and it was nearly worthless. I shook it for quite awhile, and as soon as I stopped, the LED went dim. So how am I supposed to shake the light and try to aim it as something that needs light? And if it wasn’t
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I added a 1 Farad capacitor to the Xee2 flasher circuit I blogged. I left the 10000 microfarad capacitor connected, but this is only 1 percent of the 1 Farad capacitor so it really doesn’t make any difference. I used my LED task light to illuminate the 4 LEDs and charge the capacitors. I connected
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My recent two blogs on powering a flasher with four red LEDs used a flasher made by modifying a Joule Thief. It works fine, but it requires a toroid core and wire; the flasher I blogged earlier does not require any inductor. It is a switched capacitor or charge pump,. and it works okay with
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A lady at work brought in a solar garden light for me to look at. The problem was that it wasn’t working. It consisted of a string of LEDs, all colored orange, just like a Xmas tree light string. On the end was a small box that fit in the palm of my hand. The
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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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I’ve seen a lot of Xee2’s xee2vids on Youtube, but I don’t remember seeing this one before. It’s dated Sept 2011, so it’s more than 2 years old. The Joule Thief flasher obtains its power from four red LEDs connected in parallel, which are used as solar cells and charge a 10 thousand uF capacitor.
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I got a Google Alert that pointed to a facebook page for a Joule Thief. In that page I found a link to this UK blog about using a Joule Thief as a battery charger (click on the link to the .PDF schematic). The Joule Thief circuit is a typical example of a conventional JT.
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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 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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Fellow JT experimenter Quantsuff has been experimenting with a Joule Thief using the 2SK170 JFET, and it runs at 131 millivolts (0.131V), powered by a solar PV cell lit by a table lamp. This is a very good JFET for low voltages; I made a similar circuit a while back and it ran at several
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