An analysis of a joule thief circuit

A joule thief circuit is known mostly as a widely popular solution for driving 5mm white LED from a single alkaline cell. Really, I think that nearly everyone interested in electronics have seen this circuit at least once. It’s simple and cheap (can even be assembled using parts from old CFL) and incredibly easy to build. But is it easy to understand? And how do we calculate it? In fact, I’ve never seen any attempts at quantitative analysis of this circuit.

You know, if you want something to be done good, do it yourself. So I did this theoretical analysis.

Some words on AVR’s INT0

A while ago I was asked a question about external interrupts on AVR. Trying to find the answer I’ve learned rather interesting things, which, I think, worth sharing.

Breaking News

Товарищи! Имею сообщить, что со вчерашнего дня аз есмь бакалавр техники и технологии по направлению «телекоммуникации»!

Ага, я таки защитил свою мега-эпичную бакалаврскую работу про RFID-считыватели, и сдал ее на «отлично».

And now the same for my english-speaking readers. 🙂 I’m proud to announce that I have succesfully graduated from my alma mater as a bachelor of engineering and technology in telecommunications! And, of course, I’m also going to pass a master’s degree program (in the same field). So I’m very happy today. 🙂

Dummy load, now truly resistive

This article was inspired by this Hack a Day post, which is about building a dummy load using a FET and op. amp. No doubt, this build is good, but according to the schematic it turns out that it is a constant current load. In some cases it can be useful, but one can also be in need of a constant resistance load. So in this article I’ll show such design.

Current sense resistor hack

This story began when I bought a power RGBW LED to experiment with.

Fuse bits aren’t that scary

I often find that lock and fuse bits of AVR MCUs are somewhat scary to newbies and even rather skilled ones. So this article is aimed to clarify the mist around this mysterious memory area once for all.