EET 110 - Survey of Electronics

Chap. 18 - Circuit protection devices

Chap. 19 - Electric Power

Undesirable Circuit Cond.

• Overloads - excessive current for wire size.– Ampacity determined by size of wires used

• Short Circuits– Special case of Overloads - 0 load resistance

• Ohms law says I = V/R = V/0 =

Fuse and Circuit Breakers

• Rated in amps

• Fuse consists of link that melts at a rated current - opening circuit

• Breaker heats a bi-metal strip that opens circuit mechanically

Fuse Packages

• Dependent on application

Testing Fuses

• Using a continuity tester

• Ohmmeter – Good fuse tests ~ 0 ohms– Blown fuse = infinity (OL)

• To replace fuses – use fuse puller

Circuit Breaker operation

Other Circuit protections

• Thermal Overload Protection– Motors, computer power supplies

• Lightening Rods/Arresters– Surge Suppression

• Power conditioning– Eliminate RF noise – Produce sinusoidal voltage

Chapter 19 - Electric Power

• Electrical Generation– Hydroelectric– Thermal Electric

• Coalstrip

Nuclear Power

Alternative Generation

• Wind power

• Solar Power– Photo-voltaic cells

• Magneto Hydrodynamics– Use plasma as part of generation current flow

Fuel Cell

• Converts hydrogen directly to electricity

• Ballard Fuel Cell– Uses PEM technology

• Proton Exchange Membrane (PEM) Fuel Cells

Power Transmission

• Distribution to from the generation facility to the customer.

• Sequence of step-up / step-down transformation

• Calculating power– P = V x I

• I2R

• Look at the Internet for examples of alternate power generation– Alternative generation equipment– Alternative fuels

• Chapter 19: 1-10

• Read Chapter