Chapter 1: Mechanical and Electromagnetic Fundamentals
1-1.
A motors shaft is spinning at a speed of 1800 r/min. What is the shaft speed in radians per second?
SOLUTION The speed in radians per second is
= (1800 r/min)
1-2.
1 min
60 s
2 rad
= 188.5 rad/s
ECE3040 Midterm I Review Autumn 2013
The mid-term exam will have three parts:
1. Short questions and fill in blanks; 60%
2. Calculation problem 1; 20%
3. Calculation problem 2; 20%
Short questions and fill in blanks (60 points total) will include 6 small
ECE 3040
Homework #5
Autumn 2013
Problem 1: A linear machine has a magnetic flux density of 0.5 T directed into the page,
a resistance of 0.25 ohm, a bar length l = 1.0 m, and a battery voltage of 100 V.
(a) What is the initial force on the bar at startin
ECE 3040
Homework #5
Due: Oct. 18 2013
Autumn 2013
Problem 1: A linear machine has a magnetic flux density of 0.5 T directed into the page,
a resistance of 0.25 ohm, a bar length l = 1.0 m, and a battery voltage of 100 V.
(a) What is the initial force on
ECE 3040
Homework #4
Due: Oct. 11 2013
Au. 2013
(Total: 20 points)
Problem 1: Given the balanced positive-sequence three-phase system in the following
figure, find v1(t ) and i2 (t )
(4 pts.)
Note: All the needed circuit parameters have already been ident
ECE 3040
Homework #3
Due: Oct. 4 2013
Au. 2013
(Total: 20 points)
Problem 1:
For the circuit shown in the following picture,
1) find the magnitudes and angles of each line and phase voltage and current on the
load;
(3 pts.)
After solving the problem,
2) d
ECE 3040
Homework #2
Due: Mon. 16 Sep., in class
Autumn 2013
(Total: 20 points)
Problem 1: A test of basic concepts.
For an inductor, the impedance is Z = jL , if the current goes through the inductor is
i (t ) = 2 I cos(t + ) .
1. Calculate the Q of the
ECE 3040
Homework #1
Due: Mon. 09 Sep., in class
Au. 2013
(Total: 20 points)
Problem 1:
a) Instantaneous ac power is defined as
p(t ) = v(t ) i (t ) = 2VRMS cos(t + V ) 2 I RMS cos(t + I ) ,
1. Use simple trigonometric identities to demonstrate that
p(t )
MOS Field-Effect
Transistors (MOSFETs)
1
5.1 Physical Structure & Physical Operation
The Enhancement-type NMOS Transistor
(a) perspective view
(b) cross-section
Typically L = 0.1 to 3 mm, W = 0.2 to 100 mm, and the
thickness of the oxide layer (tox) is in
Diodes
1
The First Diodes
2
Intrinsic Si at 0K
Intrinsic Si at 300K
Silicon
Acceptors
Donors
N-type Si
P-type Si
neutral
neutral
holes
electrons
PN Junction
v
i = I S exp
nV
T
4
1
4.1 The Ideal Diode
diode circuit symbol
equivalent circuit in
the rever