In the classical oscilloscopic representation, a physical quantity is represented in a time reference. It is different with the Lissajous figures. Here the X-axis of the oscilloscope is deflected by a sinusoidal voltage
. In Lissajous figures, the vertical and horizontal deflections are controlled by synchronous sinusoidal signals. The resulting displays show intertwined figures from which phase shifts
and harmonic relationships can be determined.phase position
, a diagonal line appears on thescreen
as a Lissajous figure.
As the phase between the two frequencies changes, the line opens and an ellipse appears, which becomes a circle at a phase difference of 90°.
The Lissajous figures are named after their discoverer, the French mathematician Jules Antoine Lissajous (1822 to 1180).