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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This is one of those Joule Thiefs that uses an old germanium 2N404. But I got them from a German seller on eBay, and I have a suspicion that they were made within the last decade or so, probably by one of the makers in the former soviet bloc countries. I’ve measured true 2N404s and
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I did a search of my blog and I couldn’t find this topic, so I think that I blogged this ‘way back in my late, great watsonseblog. So I’ll go over this again. Sometimes it’s necessary to use a Zener diode for overvoltage protection. It can also be used as a shunt regulator, but nowadays
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The photo is of a 2N256 germanium power transistor made by Electronics Transistors. The “314” date code means that it was made during the 14th week of 1963. So this transistor turned 50 years old sometime during early April. I haven’t tried to hook it up, but it’s just cool to think that if it
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These 2N560 transistors are the only ones I’ve seen with plastic for the standard TO-5 case, which is usually metal. The size and shape is identical, even down to the little tab that sticks out. According to the Motorola Semiconductor Data Book (1969), the specifications are: 2N560 Silicon NPN Pd@25 deg. C (ambient): 500 mW
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I went on a Joule Thief building binge for a few hours last night, making up some germanium Joule Thiefs after I found a small box of old unidentified germanium transistors that I had forgotten about. I used a small piece of the “Woodsies Squares” thin birch plywood about 1/2″ by 1″ (12.5 by 25
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I took this picture by holding a two lens pocket magnifier in front of my point-n-shoot camera. I came out good considering that the magnifying lenses had no color correction. That’s why there’s a slight color fringe at some dark and light points. This is an old germanium transistor from the late ’50s or early
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I left a comment to one Joule Thief experimenter (video is on Youtube) that one should never power a Joule Thief with no LED connected. If the emitter to base voltage exceeds the breakdown voltage the resulting current will permanently damage the transistor by reducing the current gain. He tried running the Joule Thief with
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I received an email from Paul, with some good questions about the Joule Thief, particularly about the coil. He’s given me permission to use them in this blog. Here is his intro and first question: Imagine 1st an average JT circuit just as frequently made. 1 transistor, 1 white LED, 1 resistor, 1 battery at
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I continued on with my experiments using the BD433 by building a Light Flasher. This flasher is a very old design which originally used germanium transistors. It also predates LEDs, so it used a standard #1850 miniature lamp or incandescent light bulb. Instead I used LEDs, so I had to allow a small current to
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