Goals: Design of a with frequency of 9 kHz and test of Barkhausen condition.

Components to be used: 1 TL081; 2 C=6.8 nF; R1=10k R and R2 with value to be defined.

Setup: Assemble on breadboard the circuit shown in the figure, paying particular attention to the biasing of the integrated circuit (Vcc = 15V).

R2 Measure to be done 1) Apply at the input and output of the op-amp the R1 +VCC - oscilloscope probes. Measure the frequency of the Vout obtained signal and compare the measured frequency + C with the value assumed in the synthesis step. Vin 2) Connect, between the output of the op-amp and R ground, a resistor R3 = 1K   and observe what -VCC Vf happens. 3) Remove R3, remove the wire from Vf to Vin and A apply to the + terminal a sinusoidal signal with suitable C R amplitude and frequency equal to the measured frequency in point 1). Using the two probes evaluate  the open-loop gain.

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Goals: Design of a with oscillation frequency equal to 58 kHz and test of Barkhausen condition.

Components to be used 1 TL081; 1 with value equal to 2 mH, 2 Capacitors with value to be defined; 3 Resistors, R1, R2 with value to be defined, and R3=1K. A R2 Setup: Assemble on breadboard the Vin +VCC  circuit shown in the figure, - Vout paying particular attention to R1 the biasing of the integrated + C1 IL circuit (Vcc = 15V). -Vcc

L C2 Vf

Measure to be done 1) Apply at the input and output of the op-amp the oscilloscope probes. Measure the frequency of the obtained signal and compare the measured frequency with the value assumed in the synthesis step. 2) Connect, between the output of the op-amp and ground, a resistor R3 = 1K   and observe what happens. 3) Remove R3, remove the wire from the A amplifier output and the network input. Apply to the network input a sinusoidal signal with suitable amplitude and frequency equal to the measured frequency in point 1). Using the two probes evaluate the open-loop gain.

################################################################################ Goals: Design of a Clapp oscillator with oscillation frequency equal to 25 kHz and the amplifier gain between 2 and 3. Test of Barkhausen condition.

Components to be used 1 TL081; 1 inductor with value equal to 2 mH, C1, C2, C3, R1 and R2 with value to be defined.

Setup: Assemble on breadboard the circuit shown in the figure, paying particular attention to the biasing of the integrated circuit (Vcc = 15V).

Measure to be done 1) Apply at the input and output of the op-amp the oscilloscope probes. Measure the frequency of the obtained signal and compare the measured frequency with the value assumed in the synthesis step.

2) Remove the wire from the A amplifier output and the network input. Apply to the network input a sinusoidal signal with suitable amplitude and frequency equal to the measured frequency in point 1). Using the two probes evaluate the open-loop gain.