Circuit 6.2: Ri = 1.2k, R1 = R2 = 1KQ, C1 = C2 = C3 = 10 nF and Rf = 50 kn (at least) potentiometer. VCC = 15V and VEE = -15V Circuit 6.3: R1 = R2 = R4 = 100KQ, R3 = 1 MQ, R5 = 1k 2, C1 = 100 nF and D1 = LED. VCC = 9V and VEE = Ground Circuit 6.4: R1 = R2 = 10KQ, Rf = 100k 2, C1 = 10 nF. VCC = 15V and VEE = -15V Circuit 6.6: R1 = R2 = Ri = 1KQ, Rf = 4.7k potentiometer, C1 = C2 = 10 nF. VCC = 15V and VEE- 15V PRE-CALCULATIONS 1. According to circuit fig. 6.2 calculate the oscillation frequency f1. 2. According to circuit fig. 6.3 calculate the oscillation frequency f2. 3. According to circuit fig. 6.4 calculate the oscillation frequency f3. 4. According to circuit fig. 6.6 calculate the oscillation frequency f4. =- 5. What will the value of potentiometer be to start oscillate and to give undistorted output for circuit 6.2? 6. What will the value of potentiometer be to start oscillate and to give undistorted output for circuit 6.6? 7. Why we need to connect extra 2 resistors to use same circuit with only one supply voltage? 8. Can you redraw circuits shown in figure 6.2 and figure 6.6 with single supply? 9. Can you redraw circuit shown in figure 6.3 with double supply? ww Rf 50 k pot VEE-15V LM741 45 Ri 2 6 1.2k 3 VCC +15V U1 31 10 nF 10 nF 10 nF 1k 1k Figure 6.2 Circuit Diagram for Phase Shift Oscillator Vcc = 9V R1 100k C1 R2 100k 100n +A 5 1M R3 U1 6 LM741 1k R5 XX 100k D1 R4 Figure 6.3 Circuit Diagram for a Common Oscillator C1 R1 R2 Rf B لیسا ww ww R R Figure 6.4 Circuit Diagram for Relaxation Oscillator with Double Source Figure 6.5 Circuit Diagram for Relaxation Oscillator with Single Source Ri 1k 2 3 Rf 4.7 k pot VEE -15V 5 6 LM741 U1 C1 R1 10 nF 1k VCC +15V C2 R2 1k 10 nF ure 6.6 Circuit Diagram for a Wien-Bridge Oscillator