Ece 203 electrical circuit (9)

YILDIRIM BEYAZIT UNIVERSITY

Week5

ECE 204 - ELECTRICAL CIRCUITS II PRELIMINARY MANUAL – 2 – Miscellaneous OPAMP Circuits Preliminary Work: 1) Derive and sketch the driving point (Vout vs. Iout) characteristics for the one-port circuit given in figure1.

Figure 1: Independent Current Source Then connect a load resistor RL across the one-port (across Vout), and find the maximum value of the resistance for which the one-port still functions as an independent current source.

2) The below circuit is a gyrator circuit.

Figure 2: Grounded Inductor (Gyrator) This circuit can be considered as if there is an inductor connected in series with the load RL, just like in figure3.

YILDIRIM BEYAZIT UNIVERSITY

Week5

Figure 3: Grounded Inductor (Gyrator) Derive a formula for L in terms of R1, R2, R3, R4, and C such that v( t )  L

di( t ) . dt

Then for R1=1.8K, R2=18K, R3=6.8K, R4=1.5K, C1=100nF find the value of L. Construct the circuit in 5spice and plot v(t) and I(t). Add print-outs of the plots to your report.

3) Consider the circuit in figure4. Derive the second order differential equation for Vout in terms of R1, R2, R3, R4, R5, C1 and C2. Then find the maximum value for R5 that which makes Vout pure sinusoid. (Hint: differential equations of type pure sinusoid solutions)

Figure 4: Sinusoidal Oscillator

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