Page 173 - Servo Motors and Industrial Control Theory -

Appendix A 169

25. Using OP-AMP sketch, an amplifier to give a gain of 100. You should remem-
ber that to get the sign of the signal correct you should use two OP-AMPs in
cascade. Select the input resistance in the range of kilo ohms to minimize the
current drawn through the amplifier. It is not required to design the system cir-
cuits just determine the input and feedback resistors.
26. Using OP-AMP, define a proportional controller to have a gain of 100. The
system equation must be as,

V := 100 ( V − V )
1
2
o
27. Using OP-AMP, design a system to have the following first order lag transfer
function.
θ o := 10
θ 3s 1
+
i
Select the required capacitance in the range of microfarad.
28. Using OP-AMP, design a proportional plus integral controller. Again select the
resistance in the range of kilo-ohms and capacitor in the range of microfarads.
The transfer function must be in the form of,

θ K
=
o :K + i
θ i p s
or
⋅+
θ (K s K )
o := p i
θ s
i
where,
K := 100
p
K := 50
i
29. Again using OP-AMPs, design a system to have a lead-lag network as,

+
V (2 s1)
o :=
+
V i 5s 1
30. Again using OP-AMPs, design a system to have the properties of a PID control-
ler. The system transfer function should be the form of,
θ K
=
o : K + i + K ·S
θ i p s d
⋅+
θ (Ks Ks ⋅ 2 + K )
o := p d i
θ i s