BENZAROUR date :1/11/2023
NOUZHA
4eme annee u_electronique
Practical work 1 : pspice simulation of fundamental
circuit
1/the netlist describing the circuit :
.R1 1 0 800
.R2 1 2 500
.R3 1 3 1K
.C1 3 0 33n
.I1 0 1 DC 4mA
.V1 2 0 DC 30V
2/The value of voltages V(1) and V(3) :
.R1 1 0 800
.R2 1 2 500
.R3 1 3 1K
.C1 3 0 33n
.I1 0 1 DC 4mA
.V1 2 0 DC 30V
.op
.end
V(1)=19.620v
V(2)= 19.620v
3/perform a continuous simulation :
.R1 1 0 800
.R2 1 2 500
.R3 1 3 1K
.C1 3 0 33n
.I1 0 1 DC 4mA
.V1 2 0 DC 30V
.DC V1 0 30 0.5
.probe
.op
.end
4/the forms of the voltages v(1) and v(3) as a function of v1:
V(1) = V(3) = ax + b (x=V1)
a= (5.84 - 3.84 )/(7.51 - 3.59) = 0.51 b= 1.23
V(1)=V(3)=0.51V1+1.23
5/ by using the command .TF :
.R1 1 0 800
.R2 1 2 500
.R3 1 3 1K
.C1 3 0 33n
.I1 0 1 DC 4mA
.V1 2 0 DC 30V
.TF V(3) v1
.op
.end
Req: 1.300E+03
Veq: 19.6920
6/perform a transient similation using .TRAN
.R1 1 0 800
.R2 1 2 500
.R3 1 3 1K
.C1 3 0 33n IC=0
.I1 0 1 DC 4mA
.V1 2 0 DC 30V
.op
.tran 1u 0.8m
.probe
.end
7/plot the simulated curve and find the voltageans the constant of capacity charge :
Final voltage: Vs=19.692V
. 0.63*Vs= 12.4V
by viewing the corresponding time for Vs= 12.4, we find that τ=43.22us
8/PULSE:
For Frequence= 1KHz
Vth= 1 0 PULSE (0 5 1f 1f 0.5m 1m)
C1 0 2 1300
Rth 2 1 1300
.tran 50u 4m
.probe
.end
Frequence= 10KHz
Vth= 1 0 PULSE (0 5 1f 1f 0.05m 0.1m)
C1 0 2 33n IC=0
Rth 2 1 1300
.tran 1u 0.4m
.probe
.end
Frequence =20KHz
Vth= 1 0 PULSE (0 5 1f 1f 25u 50u)
C1 0 2 33n IC=0
Rth 2 1 1300
.tran 0.5u 200m
.probe
.end
9/
10/plot the transfer function curves en DB and phase .AC :
11/The cutoff frequency:
The cutoff frequency is the frequency corresponding to G(dB)=-3dB and also Δfi(°)=-45° which is:
f=3.7kHz
12/the conclusion:
we observe, we identified that the implemented circuit functions as a low-pass filter. This means it
allows low frequencies to pass through unchanged while attenuating or cutting off higher
frequencies. The specific cutoff frequency for this filter was determined to be 3.7kHz. Consequently,
any signal with a frequency below 3.7kHz remains intact, while frequencies exceeding this value are
effectively filtered out or removed.
