These days, if you want to flash some LEDs, you’d probably grab a microcontroller. Maybe you’d go a little more old-school, and grab a 555. However, [Jacob] is even more hardcore than that, as ...

When you hit your car's turn signal stalk and that little arrow flashes at you on the dash, you always hear a rhythmic clicking sound in sync with that flashing arrow. Here's what that is. That sound ...