Recently, [Solder Hub] put together a brief video that demonstrates the basics of a Hall Effect sensor — in this case, one salvaged from an old CPU fan. Two LEDs, a 100 ohm resistor, and a 3.7 volt ...

Pantographs were once used as simple mechanical devices for a range of tasks, including duplicating simple line drawings. [Tim] decided to make a modern electronic version that spits out G-Code ...