I came across this forum thread where the person asks how to find and equivalent transistor. First off I would like to say that if you substitute another transistor and it burns up in a few seconds, like it did in this case, then you should certainly consider that the circuit is bad in some
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I was observing this video, and I saw that the 2N3904’s collector was connected to the negative and LED cathode, and the emitter was connected to the coil winding and LED anode. But I was surprised that when he connected it up, the LED lit up. Weird. But when he tried it with the 2n2222A
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Here is my latest germanium Joule Thief, shown squeezing the last few hundred millivolts out of the Energizer Bunny (“It just keep going and going…”). This is a real Zombie Battery Killer – that last half volt left after the regular silicon JT has given up is now sucked out, down to less than0.2V.
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Reasons to not use a 2N3904 in a Joule Thief or other high current circuit I’ve said this more than just a few times before: when used in a Joule Thief circuit, the 2N3904 is pushed beyond its ratings and gives below standard performance. The maximum ratings for the 2N3904 are 200 milliamps collector current,
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I blogged Anton’s HV JT and noticed that it uses a 2SC945. I googled for 2SC945 datasheet and found a .PDF of the datasheet from NEC. It showed that the absolute maximum collector current is 100 mA, which is way too low for a Joule Thief, which needs several hundred mA. I scrolled down to
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Peter asked me why the Joule Thief transistor’s Vce(sat) is important. I will try to make an analogy of the current in a transistor to the flow of water in a pipe. In a JT, the transistor is supposed to be like a switch: it’s on (like a short) or off (like an open). But
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