zen4 labs

iOS and SoC specialists for teaching & research

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FourierSynth - available on the AppStore for iPad

The Fourier Synthesiser allows students, engineers and musicians to study quantitatively the Fourier components of periodic waveforms. Real-time superposition of harmonically related sinusoids upto 15th harmonic can be viewed with the built in Time Domain display or alternatively viewed on an Oscilloscope connected to the audio stereo output. Those musically inclined can choose to listen to any two sinusoids or the sum of all selected sinusoids.

Designed for undergraduate teaching in the Department of Electrical Engineering & Electronics at The University of Liverpool.


  • Select Sine and Cosine from fundamental to the 15th harmonic

    see how convergence to the ideal improves with more components
  • Fundamental frequency adjustable from 50Hz to 1kHz
  • Individually control amplitude and On/Off state of each harmonic
  • DC term available on iPad display
  • Select from a range of 10 preset waveforms

    Square, Triangle, Sawtooth, Amplitude Modulation, Impulse, Half and Full Wave Rectification
  • Monitor waveforms externally on an Oscilloscope or Listen to audio output
  • Choose which sinusoid or ‘sum‘ appear on display or audio output  
  • Listen to musical chords and hear the effects of phase change on their sound

Use the full range of Swipe, Tap, Pinch, Tap&Hold Gestures

  • tap harmonic component to toggle On or Off
  • swipe up or down to set amplitude of each harmonic component
    swipe faster for rapid adjustment, 
swipe slower for fine settting
  • press & hold harmonic component to reset to previous amplitude
  • change fundamental frequency with pinch in or out
  • tap Time Domain display to toggle channel 1 On or Off
  • pinch Time Domain display to change oscilloscope timebase
  • swipe left/right to set horizontal position of oscilloscope display



History - The Original Fourier Synthesiser used at The University of Liverpool - Dept of Elec Eng & Electronics

Designed by the same Engineer some 20 years earlier