740-B40: Introduction to Mechanical Design and Manufacturing
Spring Quarter 1998
LABORATORY #4
Springback in Metal Bending
LOCATION:
Room BG10, Manufacturing Processes Laboratory, Ground Floor,
Technological Institute Building.
OBJECTIVES:
The principal o
MAGNETICS
Magnet
attracts ferromagnetic materials. Also attracts or repels other
magnets.
Iron (Fe), nickel (Ni), cobalt (Co) etc are ferromagnetic materials.
Poles of a magnet
North pole tries to align itself with the earths north pole.
South pole
sout
POWER SYSTEMS
Power System Representation (Modelling)
It is impossible to draw the complete system on a piece
of paper.
Real systems are very, very large.
The portion of interest is usually drawn.
Standard symbols are used for components.
Most often only
INDUCTION MACHINES
Induction Motors
Most widely used motor
Rugged
Cheap
Stator supplied with ac power.
AC voltage is induced in the rotor by transformer action.
Hence the name induction machine.
No separate field voltage required.
Induction generators
Har
TRANSFORMERS
EQUIVALENT CIRCUIT PARAMETERS
What is an equivalent circuit?
How to determine?
Open circuit test
Determines: R'c and X'm.
Short circuit test
Determine: Xl1, X'12 and R1 + R'2.
Directly measure
Winding resistances: R1 and R2.
Open circuit tes
DC Machines
CHAPTER 4
Right Hand Rule for generation
Consider
a conductor of length
moves at a constant speed of
in a magnetic field of
m
v m/sec
B Wb/m2
in such a way that
B, v and are all mutually perpendicular.
A voltage e is induced in the conductor:
SYNCHRONOUS MACHINES
APPLICATIONS
Generating power
Most (or all) ac electricity is generated by using synchronous generators.
Constant speed, High Efficiency (~95%) machines
M-G sets
Air compressors
Centrifugal pumps
Blowers, crushers and continuous proce
TRANSFORMERS
CHAPTER 3
Magnetic flux
Flux linkage
COUPLED CIRCUIT
One circuit (coil) linked by the magnetic field produced by
another circuit (coil) is known as a (magnetically) coupled
circuit.
FARADAYS LAW of electromagnetic induction
TRANSFORMERS
FARAD
PER UNIT QUANTITIES
Practical units
Electrical
Quantity
MKSA
Unit
Short
Form
Other
Units
Voltage
volt
V
kV
Current
ampere amp, A
mA, kA
Impedance
ohm
m, k, M
Real Power
watt
W
kW, MW, GW
Apparent Power
?
?
?
Reactive Power
?
?
?
PER UNIT QUANTITIES
Per un
POWER SYSTEMS
ALTERNATORS
Steady state analysis
Transients analysis (fault conditions)
Constant emf (Ef) behind Zs or Xs.
Transient voltage (E') behind transient reactance (X') or
Sub-transient voltage (E") behind sub-transient reactance (X")
Fault analys
ELECTRIC POWER SYSTEM
Electric
Power
System
ELECTRIC POWER SYSTEM
A formal definition
An electrical power system is a network of interconnected
components designed to convert nonelectrical energy
continuously into electrical form; transport the electrical
A description of the
material
Polyimide resin
MSE 623
Mi Lu
1. Introduction
Polyimide resin was first used in routine production as one of the composition
materials in integrated circuits (ICs) in 1975 and large scale integrated (LSI)
circuits. At that t
DIRECT CURRENT CIRCUITS
DC CIRCUIT CONCEPTS
Voltage and Current
Ohms law and resistance
Voltage source and current source
Ideal and real sources
Independent and dependent sources
V=IR
Voltage drops
DC circuit elements
Resistor, inductor and capacitor
KCL