Section III. NONSINUSOIDAL WAVEFORM COMPOSITION
NONSINUSOIDAL WAVEFORMS IN COMMON USE.
a. Composition of a square wave. A waveform commonly employed in
electronic circuits is the square wave which has equal time durations
during its periods of maximum and minimum amplitudes. Figure 2a
illustrates a square wave in which voltage is plotted against time.
This wave is called symmetrical because it varies equally, in time
and amplitude, above and below the zero volt axis.
Figure 2. Square wave composition