I’ve read quite a few of the blog posts (here is one) and seen quite a few of the Youtube videos that use a JT for a charger. Basically it’s a regular JT, with a diode from the collector to the charging battery’s positive terminal, and the other negative terminal connected to the positive of
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Peter emailed me with a question about Geiger Counters. With his permission, I’ll quote his questions in the paragraph below and answer them following. it´s Peter again – a few weeks ago I purchased a good, sensitive (and fully functional!!) Geigertube for measuring background radiation – the only problem is that it requires 1000 Volts.
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This is a schematic of the electrical system of a microwave oven that uses a mechanical timer. It is so simple that hesitate to use the term electronic, because there are really only two components that are more than electrical: the magnetron and the high voltage rectifier diode. The capacitor is a high voltage capacitor,
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Quantsuff sent me a link to a Youtube video about Electrofishing. He said “Googling on Electrofishing yielded these numbers: 150-300V, 1-4A @ 16pps (15% duty).” Looks like it might be fun to build one of those gadgets. I got a Google Alert this morning about a Joule Thief, if you want to call it that,
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Here’s a picture that I originally posted to my watsonseblog back in 2009. It shows several ways to scrounge wire, and also a toroid core from a mouse cable. The plastic and cable have to be removed from the core before it can be used. The easiest way that I’ve found to do it is
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I took this pic in Jan 2009, and put it in my watsonseblog at about the same time. It’s just two astable multivibrators suspended in a wire frame for support. Since then I’ve replaced some of the LEDs with more modern high brightness green LEDs.
A picture of some homemade battery holders, once blogged on my old watsonseblog. These have contacts that can survive alkaline corrosion and be replaced.
Quantsuff says he’s getting one of these DC to DC buck converters combined with a meter, from a vendor on eBay named Kuuco (this link may go dead after a time, so do a search for “4.5-24V to 1-20V 2A Voltage Regulator DC Buck Converter Voltmeter Ammeter Blue”. What I think is a stinking shame
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This power supply circuit uses a LM317 or 7805 regulator chip to do the work. The problem is that when the wiper arm of R1 is turned to the position closest to the top, it will short the output to the common or adjust pin. This will cause the R1 pot to overheat and burn
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I came across this column in talkingelectronics.com where the author discusses small signal and medium signal amplifiers. This medium signal term is one that I’ve never heard used before, and I’ve read a lot of literature that uses the small and large signal terms. I’ve heard the small signal term applied when an incremental term
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