Page 111 - Schaum's Outline of Theory and Problems of Electric Circuits

AMPLIFIERS AND OPERATIONAL AMPLIFIER CIRCUITS
100
[CHAP. 5
1V t > 0
5.45 Find v 2 in the leaky integrator of Fig. 5-24 with R 1 ¼ R f ¼ 1k
, C ¼ 1 mF, and v 1 ¼ .
0 t < 0
(
1 þ e 1000t ðVÞ t > 0
Ans: v 2 ðtÞ¼
0 t < 0

1V t < 0 e 1000t ðVÞ t > 0
5.46 Repeat Problem 5.45 for v 1 ¼ . Ans: v 2 ðtÞ¼
0 t > 0 1V t < 0
2
5.47 In the differential equation 10 dv 2 =dt þ v 2 ¼ v s , v s is the forcing function and v 2 is the response. Design
2
an op amp circuit to obtain v 2 from v s . Ans: See Fig. 5-24, with R 1 ¼ R f ; RC ¼ 10 , and v 1 ¼ v s .

5.48 Design a circuit containing op amps to solve the following set of equations:
0
y þ x ¼ v s1
0
2y þ x þ 3x ¼ v s2
1
1
Ans. See Fig. 5-55, with R 1 C ¼ R 4 C ¼ 1s, R 2 C ¼ s, R 3 C ¼ s.
3 2

Fig. 5-55