1. Wally is a slacker, he is always looking for the easy way out of doing anything

5. The $100 computer?

6. AC vs DC Circuits

7. DC and AC devices in everyday life  DC Devices BatteriesBatteries Automotive electronicsAutomotive electronics Portable electronicsPortable electronics  IPod  Cellular Phone  PDA Laptop computersLaptop computers Desktop computersDesktop computers Solar cellsSolar cells Computer and memory chipsComputer and memory chips  AC Devices Electric wall outlets Household appliances High voltage transmission lines Electromagnetic transmissions  Mobile phone signals  Satellite signals  Radio signals

8. AC Frequency  Number of complete cycles per unit time  Units are hertz, Hz  Units are cycles per second  Household electrical outlets operate at 60 hertz or 60 cycles per second  Electromagnetic waves operate at much higher frequencies

9. Heat lamps Sun burn

10. Broadcast Frequencies  Use of frequencies for broadcast are controlled by the Federal Government – the FCC - Federal Communications Commission  License required to use a given frequency  Companies purchase licenses to use these frequencies  Specific bands are setup for all transmissions Police/Fire/EMS radioPolice/Fire/EMS radio Commercial aircraftCommercial aircraft Marine radiosMarine radios Mobile phonesMobile phones Military applicationsMilitary applications Citizen band radioCitizen band radio  One notable exception is the Unlicensed Band (ULB) at 2400 MHz or 2.4 GHz Microwave ovensMicrowave ovens Cordless phonesCordless phones Bluetooth devicesBluetooth devices Wi-Fi devicesWi-Fi devices Any new device can use this frequency provided it follows set specifications on power, range, and data transmission ratesAny new device can use this frequency provided it follows set specifications on power, range, and data transmission rates

11. Some common frequencies  AM Radio 535 to 1605 KHz535 to 1605 KHz  FM Radio 88-108 MHz88-108 MHz  Broadcast TV (not cable TV transmissions which are not broadcast but sent via a wire) Channels 2-4 54-72 MHzChannels 2-4 54-72 MHz Channels 5-6 76-88 MHzChannels 5-6 76-88 MHz Channels 7-13 174-216 MHzChannels 7-13 174-216 MHz Channels 14-36 470-608 MHzChannels 14-36 470-608 MHz Channels 38-69 614-806 MHzChannels 38-69 614-806 MHz  Older “analog” phones - 824-894 MHz  PCS digital phones - 1850-1990 MHz – Current frequency of operation of most mobile phones  Bluetooth and Wi-Fi devices - 2400-2497 MHz  GPS – 1575.42 and 1227.60 MHz  RFID – multiple frequencies – 860 to 960 MHz very common

12. Assignment due next class  HW #2 from the web site Write a one page report on “How a Cellular Phone System Works”Write a one page report on “How a Cellular Phone System Works” Why is it called “cellular”?Why is it called “cellular”? Is it really a phone or something else?Is it really a phone or something else? Be sure to include the frequency of operation on current cellular phonesBe sure to include the frequency of operation on current cellular phones Include at least two referencesInclude at least two references