FM

ECE 113 FRU

12 February 2016

Design Experiment 1: Design of an Audio Ampifier !it" #igna Conditioning $oni%%a Rosianna &usto' 2012(3)2*0 +o"n Caro Caranguian' 2012(3)))3  ,yine Coigado' Coigado' 2011(22162011(2216 Electrical and Electronics Electronics Engineering Engineering Institute University of the Philippines, Diliman  Abstract  . /n t"is experiment' !e !ere tas%ed to design and buid t"e first fe! stages of an F$ transmitter  namey' t"e pre(emp"asis fiter' t"e ariabe oume ontro and t"e imiter' !"i" form t"e audio onditioning iruit for  t"e said transmitter  Data "is is t"e data !e gat"ered during t"e experiment !"ie

f (Hz)

Vin

V0

Actual Gain (dB)

Theoretical Gain (dB)

200

011

22

2*63)27

23760)11

500

011

2*

2*11)30

2-302066

800

011

2-2

2*7-*03

2*2170-62

1000

011

3

2*17)1

2*)63--6

1500

006

12

2-17)77

2-77*1*-22

1800

006

1**

2--20132

3003*2)-6

2000

006*

2

2-30722

30771661

2120

006*

212

2-*6)3-

306*7-*32*

2200

006

20*

30-*272

30*7111

2500

006

227

31771-3)

317)136672

2800

006

236

31*-)21)

320731120

3000

006

277

321*72

3272-21*-

3500

006

27

331-1-*6

3337-)*211

10000

006

627

7037066

70-02-))1

20000

0027

216

3-0*7*)

7)67116)7

25000

0027

277

70173)2

76*6-27)21

30000

0027

26

706-)272

7233)*1

50000

0027

2*

7133*-36

7-3*773671

100000

0027

2

3*7163)

)033-1171

250000

0027

07

2-*071

)06)0277*2

500000

0027

032

227-*)

)06-67-67*

100000000

0027

016

130602-

)012027)7

 Figure 1 Plot Plot of theoretical theoretical vs. actual data data

 Figure 2 [o! [o! Fre"uency Fre"uency #esponse$ %&&m'(div 1.%2'pp) *+1- %&m'(div) /m'pp *+2- %&&0 

operating t"e design from 200 45 to 1 $45

 Figure  [d point$ %&&m'(div 2.&3'pp) *+1- %&m'(div) 3m'pp *+2- 2.1450

ECE 113 FRU Simetri !ata

 Figure / [#esponse at &50$ 1'(div 2.'pp) *+1- 2&m'(div) 21.m'pp *+2- &.150

 Figure 4 9udio +onditioning +ircuit Design

 Figure %[#esponse at 61&&50$ %&&m'(div 2.'pp) *+1- 1&m'(div) 21.m'pp *+2- 73.&50

 Figure 3 :agnitude *d- vs. Fre"uency Plot 

 Required Discussion

 Figure  [igh Fre"uency #esponse$ %&&m'(div84&m'pp *+1-) 1&m'(div81.3m'pp *+22%&50

 Design 9pproach: 8e buit t"e audio onditioning iruit by separatey anay5ing and "arateri5ing t"e stages #o !e started by omputing t"e gain for t"e pre(emp"asis fiter su" t"at t"e 3d& point !i be at 212 %45 Using t"e transfer funtion t"at !e deried for t"e gien iruit' !e "ae set one of t"e omponents 9t"e apaitor for  a aue t"at !as aaiabe to us' and omputed for t"e resistor  aues sine !e %no! !e; enounter ess probems obtaining standard aues ose to !"ateer resut !e get from t"e omputations &eo! are in(dept" anaysis of t"e stages 8e used t"e ueny to 2 %45 for t"e RC fiter

1 =2 kHz 2 πRC  #et

C =0.01 uF 

 R=

1 2 π ( 2 × 1 0

3

) ( 0.01 × 1 0 6 ) −

 Figure 7 Pre8Emphasis Filter 

 R=7957 Ω =8 k Ω

 R  R B + R

=

f 9%45 f  212 %45 212 %45 20 %45 30 %45 f  30 %45

1 5

 RB =4 R  RB =31830 Ω=32 k Ω

Design of t"e ?EF: V  0

2 Pre8emphasis Filter  "e ?EF is basiay a fiter designed to ao! a onsiderabe magnitude 9!it" gain' inear to be exat of a signa !it"in a fre>ueny band' and in t"e ase of t"is design experiment' it ao!s to pass fre>uenies aboe around 212 %45 93d& gain ie attenuation beo! t"is fre>ueny and gain fatness aboe 30 %45 "is fiter' in genera' sets up a fre>ueny response' !"i" !e an ary and design depending on !"at fre>uenies !e may !is" t"e signa to be attenuated'  passed !it" or !it"out gain

V  i

¿

RB

= H =1 +

 R  A +

1 s C  A

s C  A R A + s C  A R B + 1 s C  A R A + 1

From gien ransfer Funtion: C  A  R  A=

1 2 π  ( 30,000 )

C  A  R  A + C  A  R B=

Set

1 2 π  ( 2120 )

C  A =390 pF 

 R A =13,603 Ω→ 13 kΩ

@4@ 1 90 d& 1711 9B3d& *-7 91-) d& 10031 92003 d& 17 12) 9B23d&

ECE 113 FRU

 RB =178,892 Ω → 180 kΩ

 R  pot  Gain=23.93 =1 +  Ri

3 'aria;le