Chapter 1 ECE

• Voltage


  The difference in electrical potential between two points in space
• Potential


  The possibility of doing work
• Charge


  Has the potential to do the work of attracting a similar charge or repulsing an opposite charge
• Potential difference


  Symbol is E (for electromotive force)
• Volt


  The practical unit of potential difference, a measure of the amount of work required to move 1C of charge
• Current (I)


  The charge passing through a given cross section of wire per unit time
• Conductors


  Free electrons can be forced to move with relative ease, since they require little work to be moved
• Current


  Charge in motion, the more electrons in motion the greater the current
• Amperes


  Current indicates the intensity of the electricity in motion, symbol I (for intensity), measured in amperes
• Charge (Q)


  Symbol for quantity, practical unit is the coulomb (C), 1C is equal to 6.24X1018 electrons or protons
• Resistance (R)


  The capacity of a material to resist or prevent the flow of current or the flow of electric charge within a circuit, measured in Ohms (Ω)

  
• Conductors


  Have very little resistance
• Insulators


  Have large amounts of resistance
• Kirchoff's Voltage Law (KVL)


  The sum of the voltage changes around any closed loop is zero
• Kirchoff's Current Law (KCL)


  The currents flowing out of any closed region of a circuit sum to zero
• Grounding


  One side of the voltage source is connected to a metal cold water pipe or metal chassis for safety
• Power


  The unit is the watt, equal to the work done in one second by one volt moving one coulomb of charge, P = E x I, P = I2 x R, P = E2 / R
• The technology in electronics field changes over time, systems are smaller, current speeds are faster, and new gadgets surface everyday
• Majority of the devices in use were invented decade ago, what we see is a steady improvement in construction techniques and application of those devices rather than the development of new elements
• John Ambrose Fleming invented the Diode


  1904
• Triode Amplifier invented


  1906
• Edwin H. Armstrong invented the Superheterodyne receiver


  1912
• William Shockley, Walter Brittain, John Bardeen invented the transistor


  1947
• Jack Kilby invented Integrated Circuits


  1959
• Electronics


  The science dealing with the development and application of devices and systems involving the flow of electron in gaseous media, semiconductor
• The integrated circuit or IC was put forth by Jack Kilby at Texas Instruments, his first working IC contained a single transistor and supporting components on a slice of germanium
• Fairchild Semiconductor produced the 1st commercial ICs in 1961, consisting of only 4 transistors sold for USD 150 a piece, with NASA as the main customer
• In 1968, Robert Noyce cofounded Intel Corp. with Andrew Groove and Gordon Moore
• Moore's Law


  Prediction that transistors would continue to shrink, allowing doubled transistors density and performance every 18-24 months
• Types of Electronic devices

  • Diode
  • Transistor
  • Thyristor
  • Integrated circuit (IC)

  
• Matter


  Occupies space and has weight
• Elements


  Basic building block of nature, cannot be reduced to a simpler substance by chemical means, over 100 known elements
• Atomic Structure


  Made up of electrons, protons, and neutrons
• Atomic number


  The number of protons in the nucleus of the atom
• Atomic weight


  The mass of an atom, determined by the total number of protons and neutrons in the nucleus
• Shell


  Electrons orbit here, concentric circles around nucleus, filled in sequence
• Valence Shell


  The outermost shell
• Valence


  The number of electrons contained in the valence shell
• Valence band


  The band of energy levels in the valence shell
• Conduction band


  The band of energy levels where valence electrons can escape to when they gain enough energy