ELECTRONIC PRINCIPLES - OD1647 - LESSON 1/TASK 1
alternating current or voltage completed each second is referred
to as the FREQUENCY. Frequency is always measured and expressed
in Hertz.
Alternatingcurrent frequency is an important term to understand
since most ac electrical equipment requires a specific frequency
for proper operation.
(3) Period. An individual cycle of any sine wave represents a
definite amount of time. Notice that figure 61 shows 2 cycles
of a sine wave which has a frequency of 2 Hertz (Hz). Since 2
cycles occur each second, 1 cycle must require onehalf second
of time. The time required to complete one cycle of a waveform
is called the PERIOD of the wave. In the example in figure 61,
the period is onehalf second. The relationship between time
(t) and frequency (f) is indicated by the formulas
1 1
t = and f =
f t
where t = period of time in seconds and
f = frequency in Hertz
FIGURE 61. PERIOD OF SINE WAVE.
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