From the simple oscillator using NE555 I posted before, we can make different wave signals. The simple oscillator produced a square wave signal in which the changes between 0 to 1 goes in an instant. To produce a different wave signal, we can put a passive filters to ‘shape’ the signal output. Passive filter consists a composition of Resistors and Capacitors in which they shave and cut the square wave output. In this post, I put a together an oscillator based on MK555 schematic which combine Square, Integrator, Triangle, Sine (S I T S – to make it easier :D) in one oscillator with various different passive filter.