Square, Integrator, Triangle, Sine (S.I.T.S) Oscillator [tutorial]

A noisy square produced from the simple oscillator using NE555 timer IC

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.

Integrator wave signal

Part List

C1 10nF   C2 47NF   C3 47nF   C4 1uF   C5 100nF   C6 47nF   C7 47nF   C8 1uF   C9 1uF
D1 1N4007 G1   9V Battery Clips   IC1 NE555N   S1 4 channel switch   Audio mini jack out mono   Q1 BC547   Q2 BC547
R1 1K   R2 15K   R3 4K7   R4 1K   R5 10K   R6 10K   R7 10K   R8 1M   R9 100K   R10 100K   R11 1M   VR1 20K   VR2 50K

Triangle Wave Signal

Sine wave signal

Schematic

PCB Layout

PCB Print (Inverted)

PCB Layout

SITS oscillator 0.3 EagleCad Schematic File download: [>>link<<]

SITS oscillator 0.3 EagleCad Board File download: [>>link<<]