ECET 102/CPET 101 Electric Circuits

Spring 2012

January 9, 2012

Paul I. Lin, Professor of Electrical and Computer Engineering Technology

Indiana University Purdue University Fort Wayne

Introduction

1. Electric Power/Energy Conversion

Electric Power Generation

Energy conversion (to Electricity through electric generator)

Water fall – Hydroelectric power

Hydroelectric Power, Tennessee Valley Authority http://www.tva.gov/power/hydro.htm
Pump-Storage Plant, http://www.tva.gov/power/pumpstorart.htm

Burning coal – Fossil power

Coal-Fired Power Plant, http://www.tva.gov/power/coalart.htm

Burning oil – Fossil Fuel Power
Burning gas – Nature Gas Fire
Nuclear power

Pressurized Water Reactor, http://www.tva.gov/power/wbndiag.htm
Boiling Water Reactor System, http://www.tva.gov/power/bfndiag.htm

Biomass energy
Geothermal energy
Renewable energy: solar cell, wind energy, ocean wave

Power plants, turbines, generators, transformers
Can be used conveniently

Electric Power Transmission (electric circuits)

Step-up transformer
Switches
Transmission lines
Transmission lines supporting towers and carrying infrastructure

Electric Power Distribution (electric circuits)

Business customers
Residential customers

2. Residential Electrical Circuits

120V/240V, 60 Hz, single phase system
KWH Meter:

I&M
Monthly Service Charge
KWH billing fee @ per KWH
Fuel Adj @ per KWH

Power Panel (100A)
Insulated Circuit Conductors: electrical materials

Wire/Cables installation
Rated Amperage, Voltage, Operating Temperature
Conductor Resistance, Voltage Drops, and Wasted Wattage
AWG (American Wire Gage)
Equipment Grounding Conductors

Outlet, Junction boxes
Switches, indicators, over current protection
Lighting Circuit
Motor Powering (Mechanical) Circuits

Refrigerator
Dish Washer
Cloth Washer
Dryer
Water Pump
Fans
A/C

Heating Circuits

Toaster oven
Microwave oven
Electric (gas) Range
Water heater (electric)

Computer/Multimedia Entertainment

Plasma TV
Computer
Tablet
Smartphone
Plug-in Hybrid Electric Vehicle Charger

Electrical Circuit Theory and Calculations, Symbols and Diagrams
Needed Math and Tools

3. Business Users (Industrial/Healthcare/Manufacturing/Office Buildings - Electric Circuits (single/three Phase)

Lighting circuits
Environment Comfort Systems
Mechanical/ Motion Control
Monitoring and Protection of Electrical Systems
Motors

Current rating, Voltage rating, Horse power rating
Motor controllers
PLCs
Motor drives

Actuators
Vacuum gripper
Solenoid, for valve control
Relays, power electronic devices
Electrical/Mechanical Power Conversion

A/C and Heating
Elevators
Escalators
Material Handling (Conveyor: horizontal, spiral; slider, robots)
Robots: pick and place, assembly
Welding
Hydraulic power and technology
Pneumatic power, air technology
Vacuum pump
Automatic feeding system
Product distribution system
Wire drawing
Packaging, wrapping, bottling machines and systems
Filling, sealing, vibrating, shacking, marking
Winder, Cutter
Labeling Machines & Systems

Electrical/ Heating Conversion

Heating: (plastic injection machine)
Dryer
Soldering
Blow/Molding
Extrusion

Process Monitoring, Inspection, Safety, Quality

Position
Speed
Temperature
Weigh/Fill
ID
Vision inspection
Photo sensor

Industrial Informatics
Electrical Symbols and Diagrams
Electrical Circuit Theory and Calculations, Symbols and Diagrams
Needed Math and Tools

4. Electrical Materials

Electrical Conductors (metallic):

Copper
Aluminum
Zinc
Silver
Gold

Electrical Insulators or Nonconductors (nonmetallic)

Glass
Mica
Porcelain
Slate
Wood
Ceramic
Insulation tape

Semiconductors

Silicon
Germanium
Compound Semiconductors: gallium arsenide, indium phosphide
Alloys: silicon germanium, aluminium gallium arsenide

5. Electric Current and Units

Electrical Charge - Charles Augustin de Coulomb (1736-1806), France

· Unit: Coulomb

· 1 Electron = 1.6 x 10-19 Coulombs

· 1 C = 6.24 x 10¹⁸ electrons

· 1 C = 1 Amp-second

Coulomb’s Law describes forces between two charged particles

F = k(Q_a Q_b/r)

Attractive force (negative sign) or repulsive force (positive sign)

r is distance between two particles

k = 8.99 x 10⁹ Nm²/C²

Electrical Current – the movement of electrons or negative charges through a conductor

· 1 Amp = 1 Coulomb of electrons per second

= 6.24 x 10¹⁸ electrons per second

· Symbol: I or i

· Unit: Ampere, A

· Instrument: Ammeter

· Types: AC, DC

Example: 100 Watt lamp used on a house lighting circuit takes

a current of about 0.83 Amperes
0.83 C per second

6. Electrical Resistance – opposition offered by a material to the flow of an electric current

Conductor: low resistance
Insulator: high resistance
Practical unit of measurement: Ohms
Symbol: Ω (Omega)

Example 1: 100-watt electric lamp used on 120-volt circuit has a resistance of 144 Ω

Example 2: A 1000-ft length of No. 10 AWG (American Wire Gauge) copper wire (0.1 in diameter) has a resistance of about 1 Ω.

Example 3: A round copper wire with a cross-sectional area of 2 square millimeters (mm²) and a length of 1 kilometer (km) has a resistance of about 6.8Ω.

Example 4: A 240-volt, 2500-watt electric heater has a resistance of about 23 Ω.

7. Potential Difference and Electromotive Force

Potential Difference – the difference in electric pressure between two points that cause an electric current to flow
Measure in Volts (Voltage)
Symbol: V
Examples:

Potential difference between a dry cell – 1.5 V
Between two terminals of an automobile storage battery – 12 V
Potential differences applied to the terminals of electric motors are 115, 230, 460, etc
Potential difference between long-transmission lines are 354 KV, 765 KV

Electromotive Force (emf)

Developed by devices through chemical, mechanical means

Examples

Thermocouple

o A junction of two dissimilar metals

Heated -> generate a small emf

Photo Electric Cell

8. Measurement of Current, Voltage, and Resistance

Ohm Meter – off line measurement
Ammeter – in series
Voltmeter – in parallel
DMM – Digital Multimeter

9. Basic SI Units

Quantity	Name	Symbol
Length	meter	m
Mass	kilogram	kg
Time	second	s
Electric Current	ampere	A
Luminous intensity	candela	cd
Amount of substance	mole	mol

10. Unit Conversions

Mass

Kilogram (kg)
1 kg = 2.205 pounds
1 pound (lb) = 0.4536 kg
1 oz = 0.02835 kg = 28.35 g

Length

Meter (m)
1 m = 100 cm = 1000 mm = 39.27 inches
1 inch = 25.4 cm

Temperature (Three temperature scales)

o Celsius

o Fahrenheit, and

o Kelvin

· Electric current

o ampere: A

· Thermodynamic temperature

o Kelvin: K

· Amount of substance

o Mole: mol

· Luminous intensity

Candela: cd

Temperature	Kelvin	degrees Celsius	degrees Fahrenheit
Symbol	K	°C	°F
Boiling point of water	373.15	100.	212.
Freezing / melting point of water / ice	273.15	0.	32.
Absolute zero	0.	-273.15	-459.67

Temperature Conversion Formulas

Kelvin = C + 273.15
degree F = C (9/5) + 32
degree C = (F – 32)/1.8

Number Prefix Used with Electrical/Electronic Units

Prefix Symbol Factor

Yotta Y 10²⁴ or E24

Zetta Z 10²¹ or E21

Exa E 10¹⁸ or E18

Peta P 10¹⁵ or E15

Tera T 10¹² or E12

Giga G 10⁹ or E9

Mega M 10⁶ or E6

Kilo k 10³ or E3

hecto h 10² or E2

deca da 10¹ or E1

deci d 10^-1 or E-1

centi c 10^-2 or E-2

milli m 10^-3 or E-3

micro m 10^-6 or E-6

nano n 10^-9 or E-9

pico p 10^-12 or E-12

femto f 10^-15 or E-15

atto a 10^-18 or E-18

zepto z 10^-21 or E-21

yocto y 10^-24 or E-24

Electrical Units

Quantity and Symbol	Unit and Symbol	Measuement Device
Current I	ampere (A)	Ammeter
Electromotive force E	volt (V)	Voltmeter
Potential difference V	volt (V)	Voltmeter
Resistance R	ohm (Ω)	Wheatstone bridge, Ohmmeter, Voltmeter-ammeter

11. Electrical Safety Issues and safety Codes

Safety issues

Human safety related: wet hands, long hair, long sleeves, etc
Rating: electric wires, fuse, NFB (No Fuse Breaker), insulation
Equipment protection: voltage rating, electronics and semiconductor related

National Electrical Safety Code

IEEE Standards Association - http://standards.ieee.org/nesc/

Electrical Safety: safety and Health for Electrical Trades Student Manual, National Institute for Occupational Safety and Health,

http://www.cdc.gov/niosh/docs/2009-113/
Section 8: Safety Model Stage 3- Controlling Hazards: safe Work Practice, http://www.cdc.gov/niosh/docs/2002-123/2002-123e.html

12. SI Derived Units

Frequency

Hertz: Hz = 1/s ; s - second

Force

Newton: N = m kg/s²

Pressure, stress

Pascal: Pa = N/m² = kg/m s²

Energy, work, quantity of heat

joule: J = N m = m² kg/s²

Power, radiant flux

watt: W = J/s = m² kg/s³

Quantity of electricity, electric charge

coulomb: C = s A

Electric potential

volt: V = W/A = m² kg/s³ A

Capacitance

farad: F = C/V = s⁴ A²/m² kg

Electric resistance

ohm: Omega = V/A = m² kg/s³ A²

Conductance

siemens: S = A/V = s³ A²/m² kg

Magnetic flux

weber: Wb = V s = m² kg/s² A

Magnetic flux density, magnetic induction

tesla: T = Wb/m² = kg/s² A

Inductance

henry: H = Wb/A = m² kg/s² A²

Luminous flux

lumen: lm = cd sr

Illuminance

lux: lx = lm/m² = cd sr/m²

Activity (ionizing radiations)

becquerel: Bq = 1/s

Absorbed dose

gray: Gy = J/kg = m²/s²

Dynamic viscosity

pascal second: Pa s = kg/m s

Moment of force

meter newton: N m = m² kg/s²

Surface tension

newton per meter: N/m = kg/s²

Heat flux density, irradiance

watt per square meter: W/m² = kg/s³

Heat capacity, entropy

joule per kelvin: J/K = m² kg/s² K

Specific heat capacity, specific entropy

joule per kilogram kelvin: J/kg K = m²/s² K

Specific energy

joule per kilogram: J/kg = m²/s²

Thermal conductivity

watt per meter kelvin: W/m K = m kg/s³ K

Energy density

joule per cubic meter: J/m³ = kg/m s²

Electric field strength

volt per meter: V/m = m kg/s³ A

Electric charge density

coulomb per cubic meter: C/m³ = s A/m³

Electric displacement, electric flux density

coulomb per square meter: C/m² = s A/m²

Permittivity

farad per meter: F/m = s⁴ A²/m³ kg

Permeability

henry per meter: H/m = m kg/s² A²

Molar energy

joule per mole: J/mol = m² kg/s² mol

Molar entropy, molar heat capacity

joule per mole kelvin: J/mol K = m² kg/s² K mol

Exposure (ionizing radiations)

coulomb per kilogram: C/kg = s A/kg

Absorbed dose rate

gray per second: Gy/s = m²/s³

Reference

Electrical Conductor – from Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Electrical_conductor
Semiconductor – from Wikipedia, the free encyclopedia, http://en.wikipedia.org/wiki/Semiconductor