Over on YouTube [Andrew Neal] has a Function Generator Build for Beginners. As beginner videos go this one is fairly comprehensive. [Andrew] shows us how to build a square-wave generator on a ...

Here is a 1Hz pulse/frequency generator using the popular timer IC 555 which is wired as an Astable Multivibrator. The output pulses can be indicated visually by the LED. An Astable Multivibrator, ...