Electrical Engineering Basics Around the Home

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Electrical EngineeringBasics Around the Home
UEET 101

• Presented by
• Donald S. Zinger

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Electricity Everywhere

• Entertainment
• Communication
• Industry
• Lights
• Anything dealing with electron flow
• Electrical engineers involved in all

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Brainstorm

• List activities an electrical engineer might
  perform

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Electrical Engineering Major Areas

• Signal and Systems
• Communications
• Controls
• Digital
• Computers
• Logic Systems
• Power
• Generation and distribution
• Power conversion

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Areas Not Distinct
Signal and System
Digital
Power
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Household Appliances Contain All Areas

• Look at dissected product
• Coffee maker

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Coffee MakerBottom Panel Removed
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Coffee MakerElectronic Module Removed
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All Related to Electricity

• A fundamental property of matter, associated with
  atomic particles whose movements , free or
  controlled, lead to the development of fields of
  force and the generation of kinetic or potential
  energy.
• Funk and Wagnall New International Dictionary of
  the English Language, Ferguson Publishing
  Company, Chicago, 1997, pp. 406

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Quantifying Electricity

• Current
• Flow of positive electrical charge
• Measured in Amperes
• Voltage
• Pressure that causes current to flow
• Measured in volts
• Impedance
• Circuit opposition to current flow
• Resistance in many circuits
• Measured in ohms (W)

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Basic Electrical Quantity Relationships

• Current flow is directly proportional to the
  voltage and inversely proportional to the
  impedance.
• Ohms Law

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AC vs. D C

• AC alternating current
• Continuously varying in time
• DC direct current
• Constant in long term (steady state)

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AC Measurements

• Zero average value
• Use RMS to measure values
• RMS Root Mean Square

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Electrical Power

• Power calculation needed for useful work
• Instantaneous power

• Average power

Where pf power factor
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Energy Calculation

• Energy calculation relates to work done
• Energy is power used over time
• Equation for constant power

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Comparison of Energy Users
Data from http//www.eia.doe.gov/emeu/aer/elect.h
tml
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Single Residence Energy Use Calculation

• Sum last digits of your groups ZIDs
• Use last digit of sum to choose appliance
• Estimate hours of use in a year
• Estimate total energy

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US Average Residential Energy Used

• Total residential electrical energy use 2005
  1,201,147,845 kWh
• Source http//www.eia.doe.gov/emeu/aer/elect.html
  
• Number of households 2001 107 Million
• Source http//www.eia.doe.gov/emeu/reps/appli/us_
  table.html
• Energy per household 11.2 MWh

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Appliance Design

• Find a consumer need
• Determine technical specifications
• Develop system and components
• Evaluate design
• Repeat as necessary

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ExampleElectric Glove

• Developing an electrically heated glove
• Uses resistive heat
• Nominal heat 1 W
• Not to exceed 2 W
• Should last 2 hours.

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Battery Choices
From http//www.duracell.com/oem/Pdf/others/alkal
ine.pdf
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Discharge Curves
From http//www.duracell.com/oem/primary/alkaline
/alkaline_manganese_data.asp
D Cell
C Cell
AAA Cell
AA Cell
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Batteries in Series

• Voltages add
• Total energy increases

Pictorial
Schematic
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Batteries in Parallel

• Current capability adds
• Total energy increases
• Current sharing problems

Pictorial
Schematic
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Challenge Choose Resistance and Battery

• Light weight
• Meets original specifications