Data Sheet
-86-
162. Sine Wave
Build the circuit shown on the left and turn on the switch (62). Press
the press switch (61) and you will hear the alarm (78) sound. Release
the press switch (61) and the alarm (78) will sound briey and then go
off. The sound you hear from the alarm (78) is a tone. A pure tone is
produced by a sinusoidal wave (called a sine wave), which is shown in
the gure below.
163. Formula for a Sine Wave
Replace the 1kW resistor (42) in project #162 with the 5.1kW resistor
(43) and turn on the switch (62). Press the press switch (61) and you
will hear the alarm (78) sound. Release the press switch (61) and the
alarm (78) will sound for a little while and then go off. The sine wave
producing the tone you hear from the alarm (78) can be dened as
A*sin(2pf
c
t+q), where f
c
is the frequency of the sine wave, A is the
amplitude of the sine wave, q (the Greek letter theta) is the phase of the
sine wave, and t is time.
164. Amplitude of a Sine Wave
Replace the 1kW resistor (42) in project #162 with the 10kW resistor
(44) and then turn on the switch (62). Press the press switch (61) and
you will hear the alarm (78) sound. Release the press switch (61) and
the alarm (78) will sound for a while and then go off. A was dened as
the amplitude of a sine wave in project #163. The below gure shows
various sine waves with different amplitudes. The green sine wave
has the largest amplitude and the black sine wave has the smallest
amplitude.