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Electrical Engineering Basics Around the Home. UEET 101. Presented by Donald S. Zinger. Electricity Everywhere. Entertainment Communication Industry Lights Anything dealing with electron flow Electrical engineers involved in all. Brainstorm.
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Electrical EngineeringBasics Around the Home UEET 101 Presented by Donald S. Zinger
Electricity Everywhere • Entertainment • Communication • Industry • Lights • Anything dealing with electron flow • Electrical engineers involved in all
Brainstorm • List activities an electrical engineer might perform
Electrical Engineering Major Areas • Signal and Systems • Communications • Controls • Digital • Computers • Logic Systems • Power • Generation and distribution • Power conversion
Areas Not Distinct Signal and System Digital Power
Household Appliances Contain All Areas • Look at dissected product • Coffee maker
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
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)
Basic Electrical Quantity Relationships • Current flow is directly proportional to the voltage and inversely proportional to the impedance. • Ohm’s Law
AC vs. D C • AC – alternating current • Continuously varying in time • DC – direct current • Constant in long term (steady state)
AC Measurements • Zero average value • Use RMS to measure values • RMS – Root Mean Square
Electrical Power • Power calculation needed for useful work • Instantaneous power • Average power Where pf = power factor
Energy Calculation • Energy calculation relates to work done • Energy is power used over time • Equation for constant power
Comparison of Energy Users Data from: http://www.eia.doe.gov/emeu/aer/elect.html
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
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
Appliance Design • Find a consumer need • Determine technical specifications • Develop system and components • Evaluate design • Repeat as necessary
Example:Electric Glove • Developing an electrically heated glove • Uses resistive heat • Nominal heat 1 W • Not to exceed 2 W • Should last 2 hours.
Battery Choices From: http://www.duracell.com/oem/Pdf/others/alkaline.pdf
Discharge Curves From: http://www.duracell.com/oem/primary/alkaline/alkaline_manganese_data.asp D Cell C Cell AAA Cell AA Cell
+ + Batteries in Series • Voltages add • Total energy increases Pictorial Schematic
+ + Batteries in Parallel • Current capability adds • Total energy increases • Current sharing problems Pictorial Schematic
Challenge: Choose Resistance and Battery • Light weight • Meets original specifications