giới thiệu về các loại động cơ điện một chiều thường sử dụng trong cơ điện tử....1 Nguyên tắc hoạt động 2 Cơ chế sinh lực quay của động cơ điện một chiều 3 Điều khiển tốc độ 4 Điều khiển số động cơ một chiều có chổi than 4.1 1. Bộ điều khiển PID số
Trang 1Lecture 18
Trang 2• Op-Amps is a low-cost and
versatile IC consisting of many
internal transistors, resistors,
and capacitors
• Amplifiers
• Integrators
• Summers
• Differentiators
Trang 3SMART Funded by The National Science Foundation
Two Rules for Op-Amp Circuits
• There is no current
flow through the
op-amps input terminal
(Ioa= 0 )
• The voltage drop
across the input
terminals is zero
(Voa= 0 )
output
-+
Inverting Input
Non-Inverting Input
Ioa = 0
Voa= 0
Trang 4• Inverting Amplifier
• Non-Inverting Amplifier
• Summing Amplifier
• Integrator Amplifier
• Differentiator Amplifier
Trang 5SMART Funded by The National Science Foundation
Inverting Amplifier
• Gain =
i
o V V
=
-i
f
R R
Ri
Rf
Vo
-+
Trang 6Non-Inverting Amplifier
• Gain =
i
o V V
= 1+
i
f
R
Rf
Vo
-+
Trang 7SMART Funded by The National Science Foundation
Summing Amplifier
2 2
1 1
V R
R V
R
R
1
Rf
Vo
-+
R2
V2
Trang 8Integrator Amplifier
R
Cf
Vo
-+
∫
−
t
i
V
0
R C
1
f
τ
Trang 9SMART Funded by The National Science Foundation
Differentiator Amplifier
-+
Rf
Ci
Vo
Vi
dt
dV
o = − C i R f
Trang 10Active Filters
• First-Order Low-Pass Filter
• Second-Order Low-Pass Filter
• First-Order High-Pass Filter
• Second-Order High-Pass Filter
• Notch Filter
Trang 11SMART Funded by The National Science Foundation
Active First-Order Filter
-+
Ri
Rf
Vo
Vi
Cf
-+
Ci
Rf
Vo
Vi
Cf
Low-Pass Filter High-Pass Filter
Trang 12Active Second-Order Filters
-+
R1
C1
Vo
Vi
R2
C2
-+
R1
C1
Vo
Vi
R2
C2
Trang 13SMART Funded by The National Science Foundation
Notch Filter
• Notch (or band-stop) filters
are useful in measurement
systems containing
undesirable signal of fixed
frequency It can reduce the
undesirable frequency to a
tolerance level.
-+
R
R
Vo
Vi
R
R/2
R/2
C
C
-+
RC
s )
s ( V
) s (
V )
s
(
A
0
2 0 0
2
2 0 2
i
o n
=
ω
ω + ω +
ω
+
=
=
An(s) is transfer function
ω0is notch frequency
Trang 14Bode Plot of Active Notch Filter
Trang 15SMART Funded by The National Science Foundation
Band-Pass Filter
• Band-Pass filters
are used when
certain frequencies
of a signal need to
be emphasized
while the rest be
attenuated.
) s ( A
1 ) s ( V
) s (
V )
s
(
i
o = −
=
An(s) is the transfer function
of notch filter
Band-Pass Filter
-+
Notch Filter
-+
R
R
R
R
R
Vi
Trang 16Bode Plot of Band-Pass Filter