Basic Power and Energy
F1
1
Power = Rate of transfer of energy
Energy is discrete: in common parlance, it comes in lumps. The unit is the joule ( J).
1
1 J of energy will heat 1 g of water by 412 = 0243 K.
1
1 J is needed to lift 1 kg upwards by 981 = 010
J
lSimple LC resonant circuits.
Parallel Resonant Circuit
Series Resonant Circuit
L
IL
I
V
L
ITotal
C
C
V
IC
The impedance
The impedance
1
Z = jL + jC
1
= jC [ 1-2LC ]
Z=
jCV
V
The current , I = Z =
1 2LC
/o
C
1 ( / )2
L
o
I
V
I
V
=
jLI
I/(jC)
Above res
H
1
OPERATIONAL AMPLIFIERS - commonly referred to as op-amps
The operational amplifier is characterised by
Inverting input
terminal
Noninverting input terminal
high gain, typically 104 105
+
Output
terminal
Power supply
terminals not
usually shown
The bas
Basic AC Circuits
F2
1
AC Basic Notes
AC Theory - Sinusoidally varying currents and voltages - Phasors
Vpsin(t+)
Vpsin(t+)
Phasor
t
t
t
Direction of
rotation of
phasor vector
Circle
radius Vp
We can represent a sinusoidal voltage by a vector whose length
G
1
Three phase systems
Instead of having 2 wires with a single voltage between the phase and neutral it is
advantageous to have three live phases and a neutral conductor. Phase is the name
given to the conductors other than the neutral.
The neutral is di
I
Mechanical and Electrical Systems
'
Mechanical
Electrical
Through ' quantities
F, force
i, current
"Across' quantities
dx
dt
velocity difference
v,
voltage or potential
difference
Through variable energy
store
1 F2
2 k
k = spring constant
F=kx
1 2
2Li
L
F3
Mutual Inductance and Transformers
1
Mutual Inductance & Transformers
If a current , i1 , flows in a coil or circuit then it produces a magnetic field. Some of the
magnetic flux may link a second coil of circuit. That flux linkage, 21 , will be
proport
Revision of Circuit analysis
D
1
The Three Things for circuit analysis
Two Kirchoff Laws
KCL Kirchoff Current Law.: the algebraic sum of all
currents into a node in a circuit is zero.
KVL - Kirchoff Voltage Law.: the change in voltage
around a loop in a c
M
Convolution Theorem
1
Convolution Theorem
also called Composition, Superposition, Faltung, Borel's or Duhamel's Theorem
Suppose that the impulse response of a system is h(t): this is the response when an impulse
is applied at time, t = 0. Since we are
C
Bels, decibels and Bode Plots
1
Bels and decibels
Define Normalised Power associated with a voltage V as the power dissipated when the
voltage, V, is applied across a 1 resistor. The power is
V2
P = 1 = V2
Similarly the normalised power associated with
A 1
ASTON UNIVERSITY
MODULE CODE:
MODULE TITLE
SCHOOL OF ENGINEERING AND APPLIED SCIENCE
EE2SAS
Signals and Systems
A Second Level Course for students of Electronics and associated programmes.
Organised and Delivered by Prof Toby Norris with advice from D
B
1
SIGNALS & SYSTEMS
Ziemer, pp. 112
The core of this course is to explore ways of simplifying the understanding and analysis of
systems under dynamic conditions.
This has applications in control systems, electronics, communications, mechanical systems,
L1
1
The Laplace Transform Method
once known as Heaviside's Operational Calculus
(Denbigh , pp 282 299, Howatson, pp 215 - 239: and Maths Texts)
The Laplace transform gives firstly a method of solving ordinary linear differential
equations for values of t