
24-6 Electrical Variables
If the two signals have the same frequency, then the Lissajous gure will assume the shape of an
el
lipse
. e el
lipse’s
sh
ape
wi
ll
va
ry
ac
cording
to th
e
ph
ase
di
erence
be
tween
th
e
tw
o
sig
nals
an
d
ac
cording
to th
e
ra
tio
of th
e
am
plitudes
of th
e
tw
o
sig
nals
. Fi
gure
24.6 sh
ows
so
me
g
ures
fo
r
tw
o
sig
-
nals
wi
th
sy
nchronized
fr
equency
an
d
eq
ual
am
plitudes,
bu
t
di
erent
ph
ase
re
lationships
. e fo
rmula
us
ed
f
or
d
etermining
t
he
p
hase
i
s
sin( )
φ
= ±
Y
H
(2
4
.9)
w
here
H is half the maximum vertical height of the ellipse
Y is the intercept on the y-axis
Figure 24.7 shows some gures for two signals that are identical in frequency and ...