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S i n e 0 =
.
A
Fig. 28
N o a m p l i t u d e d i s t o r -
t i o n , n o p h a s e s h i f t
N o a m p l i t u d e d i s t o r -
t i o n , 1 8 0 ° p h a s e s h i f t
A m p l i t u d e d i s t o r t i o n ,
p h a s e s h i f t e d
Fig. 29 Typical displays in phaze measurement
FREQUENCY MEASUREMENT
In addition to
phaze measurement, frequency can be
measured from the Lissajous' pattern.
Procedure:
1. Connect a sine wave of known frequency to the channel
2 I N P U T jack of the oscilloscope, and set the M O D E
selector to X - Y .
2 . Connect the C H 1 probe to the unknown frequency.
3 . Adjust the channel 1 and 2 gains.
4 . T h e resulting Lissjous' pattern shows the ratio between
the two frequencies.
w h e r e <t> = p h a s e a n g l e
A m p l i t u d e d i s t o r t i o n ,
p h a s e s h i f t e d
N o a m p l i t u d e d i s t o r -
t i o n b u t p h a s e s h i f t e d
N o a m p l i t u d e d i s t o r -
t i o n , 1 8 0 ° p h a s e s h i f t
U n k n o w n f r e q u e n c y t o
v e r t i c a l I n p u t , s t a n d a r d
f r e q u e n c y t o h o r i z o n t a l I n p u t
Fig. 30 Lissajous' patterns used for frequency
measurement
R a t i o o f u n k n o w n
t o s t a n d a r d
'i : 1
1 : 1
VA
: 1
6 : 1
31
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