A nine octave synthesizer may be used to demonstrate the decomposition of functions into a Fourier series. Square, triangle, and saw-tooth waveforms may be easily generated by summing sine functions generated by the synthesizer in the correct proportions. The phase of each channel is also fully adjustable. Waveforms are made visible to the class with a projection oscilloscope. A loudspeaker may also be used.

L3, scope near workbench or D3

PIRA DCS 3C50.10