I’ve taken apart many disk drives, CD drives and floppy drives. The magnets are awesome! Another fun part is the motor. In the case of floppies and CDs, the head stepper motor is small, relatively powerful for its size, and can be used as a generator to drive a red LED connected directly to it
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Two years ago I decided that I wanted to get a light meter. I had two old light meters for setting a camera, one was a Weston and the other a G.E. Both were not sensitive enought to give an accurate reading of a LED. I had some other choices, one was to use a
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I received a Google Alert and watched Jonny Davro’s Diode Oscillator running from a AA cell and putting out light when connected to, among other coils, a Slinky spring. I thought that I should have a go at this odd circuit. I assembled it as he showed in the schematic. I used the same BC560C
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I downloaded Stiffler’s SEC (Spatial Energy Coherence) .PDF and I found this schematic on P.47. It’s supposed to be for testing how bright LEDs are with a very short pulse. I found the circuit to be designed for danger; the same high voltage that appears across the primary (collector connected) winding also appears across the
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There’s no law that says that you have to have a ferrite toroid or any core material. Air core works, but the coil has to have many more turns, which makes it bigger and bulkier. But if the space is available, there’s nothing wrong with using a reasonably thick wire for the coils to keep
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Andrew asked a question about a DC-DC converter: I need your advise on the following challenge I have an 8 volt 0.3amp solar panel which I would like to use to charge a small lead acid battery 12 volt no more than 10 AH. Could you suggest a simple JT circuit that could be used
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I blogged this for a neophyte on Energetic forum. If you’re going to use an existing lantern, then you may have a lot of modifications, since a lantern usually has several cells in a battery pack, which gives you a long battery life. If you reduce the number of cells, the battery life will be
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Many experimenters have this “brilliant idea” of using a Joule Thief to boost the voltage of a low voltage, low power device such as a solar cell or Peltier TEG, to a higher voltage. I’ll go over what I’ve learned in my experiments with Joule Thiefs. Conventional JT performance See a photo of a conventional
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Clear Silicone seal does wonders when it comes to weatherproofing and sealing against moisture. I used it to cover up and protect the Joule Thief parts on this nearly disposable flashlight. Components I wound two six inch lengths of 20 AWG (0.25mm) solid enameled magnet wire (bifilar wound) onto a 0.25 inch outside diameter ferrite
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Note (from yesterday’s blog): I have seen many good Joule Thief projects mistakenly use the 1N4003 series rectifier, which is made for 50 or 60 Hz, and has a slow recovery time. I have put a 1N4003 in parallel with a 1N4148, and found that the Joule Thief’s performance often drops. This is because it
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