Electricity and Electronics
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Transcript of Electricity and Electronics
Electricity and ElectronicsBase of Modern Technology
Electricity
• Flow of electrons
• Originally conceived of as positive
• Now we know that they are negatively charged
• Flows from - to +
Properties of Electricity
• Voltage
• “Pressure” that moves electrons
• Also called EMF (Electromotive Force)
• Measured in Volts (V)
• Measured between two points
Properties of Electricity
• Current
• Quantity of electrons flowing past a certain point at one time
• Measured in Amperes (A)
• Measured across one point
Properties of Electricity
• Resistance
• Opposition to flow of electrons
• Measured in Ohms (Ω)
• Measured across component(s)
Properties of Electricity
• Relationship of Voltage, Current and Resistance
• Ohm’s Law
• V = I*R
• 1 volt can push 1 amp through 1 ohm
DC Current
• Electrons flow straight through from - to +
• Used in electronics and computers
• “Wall warts” (transformers) change from outlet AC to DC
• AC (Alternating current) is sinusoidal
Sources
• Different types of sources
• Voltage source
• Battery
• Current source
• Ground
Resistors
• Resist flow of electrons
• Measured in Ohms with an Ohmmeter
• Series and Parallel
Capacitors
• Capacitors resist changes in current by storing energy in an electric field and dissipating it
• Measured in farads
• Series and parallel
Transistors
• Used as amplifier
• Changes in Vin change Vout
• 3 pins
• Used by the billions in electronics
555 Timer chip
• IC (Integrated Circuit)
• Large quantity components in one package
•http://ecee.colorado.edu/~mcleod/teaching/Circuits2250/Labs/lab01/index.html
•http://www.play-hookey.com/dc_theory/fundamentals/
•http://en.wikipedia.org/wiki/Resistors
•http://en.wikipedia.org/wiki/Capacitor