Transcript Intro & Circuit Review I - University of Delaware Dept. of Physics

Phys 645/445 Electronics for
Scientists
Dr. Jamie Holder
[email protected]
http://www.physics.udel.edu/~jholder
Lecture 1 Overview
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Introductions
Syllabus
Course description
Review of simple DC circuits
Who am I?
• Course Instructor: Dr. Jamie Holder
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University of Leeds, UK: Physics with Astrophysics
University of Durham, UK: Gamma-Ray Astronomy
University of Tokyo, Japan: CANGAROO project
University of Paris, France: CELESTE project
University of Leeds, UK: VERITAS project
University of Delaware, USA: VERITAS project
VERITAS
• Situated at 1250m altitude at the Whipple Observatory near Tucson
• All four telescopes operational since March 2007
VERITAS
• Use 12 meter diameter reflectors to detect gamma-rays (very high
energy photons) from astrophysical sources (Supernova remnants,
active galaxies, black holes, neutron stars)
Stereoscopy:
Telescope Arrays
Gamma-ray Astronomy
What does any of this have to
do with electronics?
Who are you?
6 Grad students, 2 seniors, 1 sophomore
Majors: half Physics, half Mechanical Engineering …
What similar courses have you taken?
Syllabus: Analog
• DC circuit review
– DC components: Sources and loads
– Kirchoff’s Laws: Current Law, Voltage Law
– DC circuit analysis: Element combination, mesh and loop analysis
• AC circuit review
– AC components: Capacitors and inductors in AC circuits
– AC circuit analysis: Complex numbers/ phasors
• Filter circuits
– L,R,C Circuits with a frequency dependent response
• Transient circuit analysis
– Circuits with a time-dependent response
• Semiconductor components: non-linear elements
– Diodes
– Transistors
• Operational Amplifiers
– Applications: ideal amps, mathematical operations, comparators
– Limitations: real world considerations
Syllabus: Digital
• Digital Circuits
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Why digital?
Logic and Boolean algebra
CMOS gates
Digital Circuit design and analysis: Karnaugh Maps
• Combinational Logic
– output depends on present inputs
• Sequential Logic
– output depends on present and past inputs
– Finite state machines: Mealy and Moore
• Wave Shaping
– Producing, cleaning and modifying Digital pulses
• Analog – Digital conversion
• Programmable logic devices and FPGAs
Reference materials
• No one book covers the whole course
• Textbooks are not required, but recommended
useful texts include
– D. Barnaal, “Analog Electronics for Scientific
Application”
– R.E. Simpson, “Introductory Electronics for Scientists
and Engineers”
– Horowitz and Hill “The Art of Electronics”
• Reference copies available in the electronics lab
• Lecture notes available on the web after the
lecture
• http://www.physics.udel.edu/~jholder/
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Lab – 30%
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Course Structure
Work in pairs
Lab reports due one week after the lab
Pair reports acceptable (your choice)
Labs must be written up on a computer and include
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Introduction: Briefly describe why you are doing this lab, and what objectives are.
Experiment: Describe how you do the experiment.
Results: Present measured results
Analyses: Analyze the results and research the conclusions. Have you achieved your
objectives? How accurate are your results, what are the error sources, how would you
improve the experiment, etc. This is the most important part. Bad experimental data or
results do not mean you will get very bad grade. If you successfully point out where you
went wrong, you may still get a good grade.
• Summary: Tell the readers a few (maybe just one) important findings from this experiment.
Try to write in such a way that the reader will still learn a few things even he just reads this
section of the report.
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Weekly assignments – 20%
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Available from my web page (usually on Thursday)
Due in class on the day indicated (usually on Thursday)
Legible handwritten solutions OK
Draw circuits neatly. Show your working!
Lab project – 20%
Mid-term Exam – 10%
Final Exam - 20%
Preliminary Grade scale
Grade scale
85% A
80% A-
75% B+
70% B
65% B60% C+
55% C
50% C45% D+
40% D
Good Lab Practice
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KEEP THE LAB TIDY.
Return components to their boxes.
Make circuits neat
Check circuit before turning power on
Remove power before changing circuit
elements
• Do not touch circuit with bare hands when the
power is on
• Make sure the grounding is good
• Do not short voltage sources or open current
sources
Good Lab Practice
BAD!
GOOD!
Simulate First
Simulation Software:
Electronic Work Bench (EWB)
Next week's lab.
Lab Organisation
• Lab Hours are Tuesday & Wednesday 1:30pm to 4:30pm,
SHL016
• First Lab on Tuesday 6th Sept
• TA support available (Sajan Kumar)
• The labs are difficult, and time consuming! I expect:
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Prep work – read the labs in advance.
Independent problem solving
Time management (and overtime when necessary)
Labs will be open outside of usual hours by request, but no TA
Lab Organisation
• Need even numbers, and equal attendance…
Tuesday:
Wednesday:
Matthew Bihler
Gaurav Pandey
Philip Zandona
Jingliang Zhang
Trisha
Eric
Joseph Brosch
Erin Grace
Ali Jafri
Lei Chen
Halise Celik
Fatih
Projects
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Final 4 weeks of lab to be spent on a project of your choice
Links to project resources from my web page
Many other possibilities on the internet
Kits acceptable (<$50), but must be constructed on a breadboard
Project ideas due by mid-November
Require a Report, Presentation and Demonstration
Examples from previous years:
– laser transmission of sound
– Levitation
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Colour Sensor and indicator
Solar panel charger
Anemometer
Fuel regulator
Review of Simple Circuits: Definitions
• Sources and Loads
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Source + load = simplest description of any electrical system
Voltage sources and current sources
provide prescribed voltages / currents
Ideal sources: can provide an arbitrary amount of energy
Voltage / Current values are not affected by load
Ideal voltage source:
• Output voltage does not change with current drawn
• Current drawn determined by load resistance (V=IR)
• Zero internal resistance
– Ideal current source:
• Output current does not change with voltage generated
• Voltage generated determined by load resistance (V=IR)
• Infinite internal resistance
Branch: Any portion of a circuit with two terminals
Node: a junction of two or more branches
Loop: Any closed connection of branches
Mesh: A loop that does not contain other loops
How many loops
in this 4-mesh circuit?
Answer: 14
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Kirchoff’s Current Law
The sum of the current at
any node must equal
zero: i.e., the current
flowing into a node must
equal the current flowing
out of the node
Conservation of Charge
(Current = rate of change of charge)
At Node 1:
-i+i1+i2+i3=0
i=i1+i2+i3
Note convention: current flows from positive terminal
In order for current to flow, there must exist a closed circuit
Kirchoff’s Voltage Law
The sum of the voltages
around a closed loop is
zero
Conservation of Energy
Voltage=energy required to move charge from
one point to another
Potential: at a=va
b=vb
Potential difference:
v2=va-vb
Around the loop:
-v1+v2=0
v1=v2
Note: potential measured relative to ground: true ground (earth)
or chassis ground (enclosure)