Letter H

Harmonics
The base frequency produced by a circuit is said to be the
fundamental frequency or first harmonic. Additional harmonics
are multiples of the first harmonic. The 3rd harmonic of a 60 Hz
power supply, for example, is 3 x 60 Hz = 180 Hz.

Harmonic Distortion
The effect of harmonics on the fundamental frequency.
Harmonic distortion can interfere with the operation of
electronic devices.

Henry
The basic unit of inductance. The symbol for the henry is “H.”


Hertz
A unit of frequency equal to one cycle per second. Hertz is
abbreviated Hz.