Title: Wally is a slacker, he is always looking for the easy way out of doing anything
1Wally is a slacker, he is always looking for the
easy way out of doing anything
2Pointy Haired Boss saves a million
3Various electronic devices similar to a watch
4Mobile internet access via satellite using pedal
powered electric generator
Where there is a need, an engineer will come up
with a solution
5(No Transcript)
6Transistors are the building block of all
electronics. As the manufacturing cost comes
down, electronics become very cheap.
7AC vs. DC Circuits
8DC and AC devices in everyday life
- DC Devices
- Batteries
- Automotive electronics
- Portable electronics
- IPod
- Cellular Phone
- PDA
- Laptop computers
- Desktop computers
- Solar cells
- Computer and memory chips
- AC Devices
- Electric wall outlets
- Household appliances
- High voltage transmission lines
- Electromagnetic transmissions
- Mobile phone signals
- Satellite signals
- Radio signals
9AC 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
10Sun burn
11Frequency Allocations
12Broadcast 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 radio
- Commercial aircraft
- Marine radios
- Mobile phones
- Military applications
- Citizen band radio
13Typical large broadcast antenna
Very tall, often on mountains, to transmit over
long distances
14Some common frequencies
- AM Radio
- 535 to 1605 KHz
- FM Radio
- 88-108 MHz
- Broadcast TV (old)- requires external antenna
- Channels 2-4 54-72 MHz
- Channels 5-6 76-88 MHz
- Channels 7-13 174-216 MHz
- Channels 14-36 470-608 MHz
- Channels 38-69 614-806 MHz
- Today, most TV transmissions are digitized and
sent via cable, fiber optics, or satellite
15Broadcast Frequencies
- One notable exception is the Unlicensed Band
(ULB) at 2400 MHz or 2.4 GHz, also known as the
Industrial, Scientific, and Medical band - Microwave ovens
- Cordless phones
- Bluetooth devices
- Wi-Fi devices
- Any new device can use this frequency without a
FCC license provided it follows set
specifications on power, range, and data
transmission rates - A second band at 5.0 GHZ is also available but
has limited use due to a lack of inexpensive
chips that operate at 5.0 GHz
16Wireless frequencies for the EE project
- 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 (2.4
2.497 GHz) - GPS 1575.42 and 1227.60 MHz
- RFID multiple frequencies 860 to 960 MHz very
common
17Assignment due next class
- HW 3 from the web site
- Write a one page report on How a Cellular Phone
System Works - Why is it called cellular?
- Is it really a phone or something else?
- Be sure to include the frequency of operation on
current cellular phones - Include at least two references