The Wien Bridge Oscillator (sometimes mistakenly misspelled Wein) uses negative feedback to generate a very pure sine wave. The circuit can generate a sine with distortion so low it is difficult to measure. The schematic I´ve attached does not necessarily have such very low distortion, but it is simple – three transistors – and generates
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Leonard Meeks posted a schematic of Mk.7 Mod 2 AGC amplifier to the Regenrx Yahoo group. I’ll include it here. The amp uses a FET for the input stage, a 2N3904 for the second stage of amplification and two high voltage transistors for the third and fourth stage. For now I will talk about the
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Q Multiplier experiment in Yahoo group Regenrx2. You heve to join the newsgroup.
Here’s a screenshot of my DSO with the scope probes across the LED. The pic on the bottom is the actual Joule Thief. The capacitor that is half hidden at the bottom is a 10 uF bypass capacitor.
I was watching JonnyDavro’s Joule Thief driving a power transformer, which is used in reverse to step up the voltage to drive a CFL tube. He shows the schematic, and later says that the unlabeled transistor is a BD139. I added a comment, saying “What amazes me is that you’re getting these high voltages at
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The first thing that comes to mind when the experimenter wants to find out how much current is flowing through the LED is to measure it with a DMM set to read milliamps. This works okay if the LED is connected in series with a current limiting resistor. The DMM will add maybe 10 ohms
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Most silicon transistors have an emitter to base reverse voltage rated at 5 volts maximum, with some transistors rated as high as 6 volts. Old germanium transistors were higher than this, but when the manufacturers began to make silicon transistors, they apparently gave up having a higher emitter to base reverse breakdown voltage so they
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My watsonseblog dated 2007 Jul 14 Back in the early days of electronics, they would assemble several neon lamps with 1 meg resistors and 1 uf caps in a box, along with a 90V B battery. The lamps would flash in random patterns. These were called a “Do Nothing Box”. I guess this is
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My watsonseblog dated 2011 Apr 12 2012 Apr 12 JT Toroid Turns, Inductance I have some answers to the questions I read here. What are the inductance ranges that work in the Joule Thief? What are the limits to the choice of turns? What is the maximum number of turns and the minimum number
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Well, Happy Santa’s Day to you, and I hope you got more than an lump of coal in your stocking. 🙂 Measure With a Cheap Meter When you wind the Joule Thief core, there are a few things that you should try to avoid. The most important is to keep the resistance of the coil
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