Exp 8

Electric lab

: Objective familiarization with the low-pass, high-pass,-1 . band-pass and band-stop filters find the frequency and phase response of a -2 .series RC circuit plot the magnitude and phase response of a-3 . series RC circuit .design, build and test a low pass filter -4 . design, build and test a high pass filter-5

: Theory (Xc=1/(2πfC ( Very high frequency =Xc =ф

(open circuit

( Very high frequency =Xc =0

(short circuit

Filter : function is to permit certain frequency to pass and not permit other frequency .(first order ( filters ,second filter order and active filter :Type of filters (low pass filter (LPF-1

(high pass filter (HPF-2

(Band pass filter (BPF-3

Electric lab

band reject (stop)filter -4 /V0=Vin (At fc(cut off frequency

Second – order filter

Active filter

Gain =V0/Vin

First – order

Electric lab

:(result and digrams(data of table Input frquncy (K) 1 2 5 10 20 50 100 200 500 1000 2000

Input amplitude (voltage (V 2 2 2 2 2 2 2 2 2 2 2

Out put amplitude (voltage (v 1.5 1 0.5 1.04 0.2 0.1 0.1 0.08 0.07 0.07 0.12

:Table 2

Phase shift 28.8 10-5*4.32 10-5*5.76 10-5*3.6 10-5*1.44 10-6*7.2 0 0 0

Gain 0.75 0.5 0.25 0.52 0.1 0.05 0.05 0.04 0.035 0.035 0.06

Electric lab

Input frquncy (K) 1 2 5 10 20 50 100 200 500 1000 2000

Input amplitude (voltage (V 2 2 2 2 2 2 2 2 2 2 2

: Calculation

Out put amplitude (voltage (v 1 1.2 1.4 2 2 2 2 2 2 2 2

Phase shift 28.8 10-5*2.88 10-5*1.8 10-6*7.5 0 0 0 0 0 0 0

Gain 0.5 0.6 0.7 1 1 1 1 1 1 1 1

Electric lab

Phase angle Ф=(t/T)*360 T=1/f=1/1K=1*10-3 Ф=(8*10-5/1*10-3)*360=28.8º Gain =V0/Vin =1.5/2=0.75

: Calculation on the fc point the frequency of power equal half-1 .it maxpower at 3dB /V0=Vin-2 At the fc frequency