Exp 7

Electric lab

: Objective familiarization with the parameter that -1 characterize an AC signal ,and the method of .measuring them to learn using the oscilloscope whine we show -2 . tow signal measurement of phase different by means of -3 . the oscilloscopes .familiarization with lissajous patterns -4

: Theory Exist two method to measure the phase angle ( :(experimental The first Ф =(t/T) *360º Ф : is the phase angle in .degree t: the time period of signal . one .T: the time period of signal two (The second

Ф= sin-1(a/b

.Ф : is the phase angle in degree b : is the peak value of the ellipse in .the horizontal direction ,in centimeters a : is the value at the intersection of the .ellipse and the horizontal axis, in centimeters

1

Electric lab

( Theoretical) (Ф =tan-1 (Xc/R) Xc=1/(2πfc) C:capacitor

or ,

Ф=tan-1(XL/R

XL=2πfL

L: inductor

,

:(result and digrams(data of table

(table

1:(RC

circuit

Measured quantity (input frequency(Hz

500

(t (cm

(T(cm

Phase angle Ф

*4.7 0.2m=0.94

76.59

*2.3 0.2m=0.46

62.6

2000

50µ*4.8 =240µ

37.5

3000 20µ =14 µ*0.7

µ =180 µ 20*9

28

4000 µ =8 µ 20*0.4

20µ=118µ*5.9

24.4

5000 µ =4 µ 20*0.2

µ=96 µ 20*4.8

15

0.2m=0.2*1

*0.4 1000 0.2m=0.08 50µ=25µ*0.5

Table at pspice

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Electric lab

Measured quantity

(t (cm

(T(cm

Phase angle Ф

Input (frequency(Hz 500

1m.*0.4

1m.*2

1000

*0.16 0.003m

0.003m*1 57.6

2000

*0.53 0.001m

0.001m*5 38.16

Measured quantity

a

b

a/b

72

Phase angle Ф

Input frequency(Hz (

500

*2.25 0.2m

*2.5 0.2m

0.9

64.158

1000

*1.9 0.2m

*2.4 0.2m

0.791

52.34

2000

µ 50*1.4

50*2.4

0.5833

35.68

0.4583

27.28

0.391

23.035

0.28

16.26

µ

3000

µ 20*1.1

20*2.4 µ

4000

µ 20*0.9

20*2.3 µ

5000

µ 20*0.7

20*2.5 µ

(Table 2: (RL circuit

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Electric lab

Measured quantity (input frequency(Hz

(t (cm

500 µ =5 50*0.1 µ

(T(cm

Phase angle Ф

0.5m=1m*2

1.8

µ =4 20*0.2 1000 µ

*2.4 0.2m=0.48m

3

20µ=4µ*0.2

*2.3 0.1m=0.23m

6.26

20µ*0.19 3000 =3.8 µ

µ =170 µ 50*3.4

8.047

µ =4 20*0.2 4000 µ

50µ=125µ*2.5

11.52

µ =4 20*0.2 5000 µ

µ=90 µ 50*1.8

16

2000

Table at pspice Measured quantity

(t (cm

(T(cm

Phase angle Ф

500

*0.1 0.001m

*20 0.001m

1.8

1000

*0.1 0.001m

*10 0.001m

3.6

2000

*1. 0.001m

0.001m*5 7.2

Input (frequency(Hz

1

Electric lab

Measured quantity

a

b

a/b

Phase angle Ф

Input frequency(Hz (

500

*0.1 0.2m

*2.1 0.2m

0.0476

2.729

1000

*0.15 0.1m

*1.9 0.1m

0.0789

4.528

2000

0.1*0.25 0.1*2.1

0.119

6.837

0.1578

9.08

3000

m

m

50µ*0.3

50*1.9 µ

4000

µ 50*0.4

µ 50*2

0.2

11.536

5000

µ 50*0.4

50*1.8

0.2222

12.84

µ

: Calculation Xc at f=500Hz

,Xc=1/(2*3.14*500*0.1*10-6)=3184.71 Ω

XL at f=500Hz

,XL=2*3.14*500*10*10-3 =31.4 Ω

In the table 1 at f=500Hz

Ф=(t/T)*360 =(0.2/0.94)*360º=76.59º Ф=sin-1(a/b)=sin-1(2.25/2.5)=64.158º the percentage error is large because the reading) ( on the oscilloscope not exact =(The phase angle exact Ф=tan-1(Xc/R

1

Electric lab

tan-1(3184.71/1000)=72.56º in the table 2 at f=500Hz Ф=(5*10-6)/(1*10-3)*360=1.8º Ф=sin-1(0.1/2.1)=2.729º the percentage error is large because the reading) ( on the oscilloscope not exact The phase angle exact Ф=tan-1(XL/R)=tan1 (31.4/1000)=1.798º ( In the table pspice (RC circuit At f=500Hz

At f=1000Hz

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Electric lab

At f =2000Hz

I n t h :(e table pspice (RL circuit at f=500Hz

at f=1000Hz a t f = 2 0 0 0Hz

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Electric lab

: Conclusions . exist two method to measure the phase angle-1 the percentage error is large because the reading-2 . on the oscilloscope ont exact using two channel on oscilloscope in the same-3 .time .we can using the pspic to find the phase angle-4

1