example of PERFECT waves :


sinusoidal wave, square wave & triangle wave are symmetrical
sawtooth wave is non-symmetrical

PERFECT sinusoidal wave produces FIRST harmonic only
all PERFECT symmetrical waves (except sinusoidal wave) produce ODD harmonics only
all DISTORTED symmetrical waves produce ODD & EVEN harmonics

all non-symmetrical waves produce ODD & EVEN harmonics


DISTORTED sinusoidal wave (2nd wave is 3 times faster then 1st wave)


DISTORTED sinusoidal wave (3rd wave is 5 times faster then 1st wave)


DISTORTED sinusoidal wave (4th wave is 7 times faster then 1st wave)


DISTORTED sinusoidal wave (5th wave is 9 times faster then 1st wave)


sinusoidal wave in TIME DOMAIN
(slightly DISTORTED; not enough to produce harmonics)


sinusoidal wave in FREQUENCY DOMAIN
(slightly DISTORTED; not enough to produce harmonics)


square wave in TIME DOMAIN
(slightly DISTORTED; not enough to produce EVEN harmonics)


square wave in FREQUENCY DOMAIN
(slightly DISTORTED; not enough to produce EVEN harmonics)


triangle wave in TIME DOMAIN
(slightly DISTORTED; just enough to produce EVEN harmonics)


triangle wave in FREQUENCY DOMAIN
(slightly DISTORTED; just enough to produce EVEN harmonics)


sawtooth wave in TIME DOMAIN


sawtooth wave in FREQUENCY DOMAIN