BASIC ELEC

• Electronics


  A branch of Science that deals with the study of flow and control of electrons
• Electronics


  • Derived from the word electrons that are a tiny invisible quantity of electricity present in all materials
  • Includes all the effect of electricity where the action of the individual electrons determines the applications
• Main electronic devices


  • Transistors
  • Diode
  • Resistors
  • Capacitors
  • Coils
  • Transformers
  • Integrated circuits (IC)
• Electronics is essential for many devices application such as computers, radio, television, cellphone, and many others
• Electronics is used in communication, medical apparatus and electronic industries
• Electronic components


  Have a number of electrical terminals or leads<|>Connect to other electrical components, often over wire, to create an electronic circuit with a particular function
• Types of electronic component packaging

  • Discretely packaged
  • Arrays or networks of like components
  • Integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices
• Heinrich Hertz demonstrated the process of electromagnetic radiation through space


  1887
• Guglielmo Marconi developed practical radio system for long distance communication


  1895
• Dr. Lee de Forest invented the vacuum tube that can amplify signals


  1906
• Regular scheduled radio programs were broadcast by station KDKA in the AM (Amplitude Modulation) radio band

  1920
• The commercial FM (Frequency Modulation) broadcast service for sound programs was started

  1939
• Televisions broadcasting was adopted, and color television adopted in 1953


  1941
• Invention of transistors at Bell Telephone Laboratories


  1948
• Applications of electronics


  • Communication and entertainment applications (telephony, telegraphy, optical communication, wireless communication, television communication)
  • Instrumentation applications (CROs, frequency counters, pulse and signal generators, digital multimeters, power supplies, pH meters, strain gauges)
  • Industrial applications
  • Defense applications (RADAR)
  • Medical applications (X ray equipment, ECG, EEG, CRO, short wave diathermy units, ultrasound scanner)
  • Computer aided design of electronic circuits

  
• Components can be classified as passive, active, or electro mechanic
• Passive components


  Can't introduce net energy into the circuit<|>Can't rely on a source of power, except for what is available from the (AC) circuit they are connected to<|>Can't amplify (increase the power of a signal), although they may increase a voltage or current<|>Include two-terminal components such as resistors, capacitors, inductors, and transformers
• Active components


  Rely on a source of energy (usually from the DC circuit)<|>Usually can inject power into a circuit<|>Include amplifying components such as transistors, triode vacuum tubes (valves), and tunnel diodes
• Resistor


  An electronic component used to oppose and limit the current in a circuit<|>Resistance is the opposition to the flow of the current<|>Unit of measurement is ohms (Ω)
• Fixed resistors


  • Have resistances that only change slightly with temperature, time or operating voltage
• Types of fixed resistors

  • Wire wound
  • Carbon composition
  • Carbon film
• Carbon film resistors


  • Feature low noise, precise distribution of pure graphite without binding
  • Power rating range of 0.125 W to 5 W at 70 °C
  • Resistance range of 1 ohm to 10 megohm
  • Operating temperature range of −55 °C to 155 °C
  • Maximum working voltage range of 200 to 600 volts
• Types of variable resistors

  • Rheostat (two terminal)
  • Potentiometer (three terminal)
  • Trimpot (small potentiometer for internal adjustments)
  • Thermistor (thermally sensitive resistor)
  • Humistor (humidity varied resistor)
  • Varistor (passes current when excessive voltage is present)
  • Photoresistor (light dependent resistor)
• Resistor color coding


  4 band resistor: two bands for resistance value, one multiplier, one tolerance

  5 band resistor: three significant digits, one multiplier, one tolerance

  6 band resistor: additional band for temperature coefficient
• Measuring resistance value using multitester


  1. Set Analog multitester to resistance (Ω) range

  2. Connect multitester leads to resistor terminals

  3. Read resistance value on multitester display
• Resistor color code


  The first four bands represent the resistance value, the fourth band is the multiply factor and the fifth band represents the tolerance
• There are exceptions to the resistor color code
• Exceptions to the resistor color code

  • The extra band indicates failure rate (military specification) or temperature coefficient (older or specialized resistors)
• For more information on color code exceptions, read the "Color code exceptions" section
• Six band resistor


  Usually for high precision resistors that have an additional band to specify the temperature coefficient (ppm/K)
• Measuring resistance value using a multitester

  1. Set multitester to Ohmmeter range Rx1, short the two test probes and calibrate to zero ohms

  2. Range multitester based on the color code value of the resistor

  3. Place the test probes across the terminal leads of the resistor
• Evaluating resistor condition


  1. If the resistance is between the minimum and maximum tolerance, the resistor is good

  2. If the resistance is below the minimum, the resistor is leaky

  3. If the resistance is zero ohms, the resistor is shorted

  4. If the resistance is infinite, the resistor is open
• A capacitor is a dielectric component that can store electric charge
• Capacitance unit


  Farad, named after Michael Faraday
• Types of capacitors


  • Air, paper, mica, ceramic, electrolytic
• Capacitors


  • They store and release electrical charge
  • They are used for filtering power supply lines, tuning resonant circuits, and blocking DC voltage while passing AC signals
• Capacitor


  A passive two-terminal electrical component used to store energy electrostatically in an electric field
• Types of fixed capacitors

  • Ceramic
  • Film
  • Electrolytic
  • Aluminum electrolytic
  • Tantalum electrolytic
  • Niobium electrolytic
  • Polymer
  • Super
  • Nano ionic super
  • Lithium-ion
  • Mica
• Types of variable capacitors

  • Tuning
  • Trim
  • Vacuum variable
• Capacitance units


  Farads to Microfarads (F to μF): 1F = 1,000,000 μF<|>Microfarads to Farads (μF to F): 1 μF = 1.0E-6 F<|>Microfarads to Picofarads (μF to pF): 1 μF = 1,000,000 pF<|>Picofarads to Microfarads (pF to μF): 1 pF = 1.0E-6 μF