The 2N2222 and BC549 transistors are two old components that are still universally used in the vast majority of electrical circuits today. Their applications include amplifiers, filters, impedance ...

I was looking at a schematic in a recently published advanced-hobbyist article, and there it was, again: the venerable 2N2222 transistor, this time in a role as a relay driver. It's not a ...

You can salvage some nice motors out of optical drives but they can be tricky to control. That’s because brushless DC motors require carefully timed signals used in a process called Electronic Speed ...