Easy Electronics

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Electronics

• Electronics is the science and technology
  of electronic phenomena. It is a branch of
  physics that deals with the emission, behaviour,
  and effects of electrons and with electronic
  devices
• Electronics, pronounced as elec.tron.ics

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History of Electronics

• The beginnings of electronics can be traced to
  experiments with electricity. In the 1880s Thomas
  Alva Edison and others observed the flow of
  current between the elements in an evacuated
  glass tube.
• By 1920, the development of vacuum tubes and
  circuits employing them had advanced to the point
  where their superiority over all other devices
  used in radio transmitters and receivers was
  apparent.

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Evolution of Electronics
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• In 1948 William Shockley, John Bardeen, and
  Walter H. Brattain of Bell Telephone Laboratories
  developed the First transistor and during the
  early 1950's the technology was developed to
  mass-produce transistors.
• The invention of the transistor initiated a
  progressive miniaturization of electronic
  components . By the mid 1980s,high-density
  microprocessors were developed that led to
  tremendous advancement in Computer technology.

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• During the 1970's and 1980's the size of the
  components of integrated circuits continued to be
  reduced and the number of components that could
  be produced on each chip grew rapidly.
• With increasing miniaturization, the
  capabilities of the electronic circuits and the
  speed at which they could perform their functions
  greatly increased.

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• By 1990's, introduction of Microelectronics
  led to the development of new technologies, such
  as digital audio recording to the introduction
  of new products, such as personal computers and
  to the reduction in the size of portable
  telephones and many other electronic products.

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Easy Electronics

• Hobby electronics combines creativity and
  tinkering as part of the fun process of creating
  devices that are born out of passion, learning,
  dedication, curiosity and, most importantly, play.

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• Before building a circuit, it is necessary to
  understand some basics of electronics.
  Electronics involves current and voltage.
• Current
• Current is the flows of electrons through a
  wire. Current flows from points of high voltage
  to points of low voltage.
• The unit of measurement for current is the
  Ampere (Amp) and is abbreviated as A

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• Voltage
• Voltage indicates the power level of a point
  and is measured in Volts.
• If one point is at 5 volts and another point
  is at 0 volts then when a wire is connected
  between them, current will flow from the point at
  5 volts to the point at 0 volts.

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Semiconductor

• Semiconductor is a substance that releases
  'free electrons' from its outermost orbit when
  exposed to energy such as heat or light.
• The space from which electrons are released is
  called a 'hole.' Semiconductors carry electrical
  current when they release 'free electrons.' 

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• Typical Semiconductor materials are Silicon
  and Germanium. By adding impurities, it is easy
  to create p-type semiconductors with many 'holes'
  and n-type semiconductors with many 'free
  electrons
• When these two types of semiconductors are
  joined, they form an element called a diode.
  Transistors and IC's are formed by combining
  large numbers of these diodes.

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Electrons and Holes
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PN Junction When P-type
and N-type silicon are placed in contact with one
another it forms a PN junction
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Biasing of PN Junction A basic PN junction
creates a diode that allows electricity to flow
in one direction but not the other Near the PN
junction the electrons diffuse into the vacant
holes in the P material causing a depletion zone.
This depletion zone acts like an insulator
preventing other free electrons in the N-type
silicon and holes in the P-type silicon from
combining
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Ohms law

• There is a simple relationship between current,
• voltage and resistance. This relationship is
  called
• Ohms Law.
• Difference in Voltage Current x Resistance
• VIx R
• Current Difference in Voltage / Resistance
• I V / R
• Resistance Difference in Voltage / Current
• R V / I

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Ohms Law Triangle
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Resistors

• Resistors are components that have a
  predetermined resistance. Resistance determines
  how much current will flow through a component.
  Resistors are used to control voltages and
  currents. Resistance is given in units of ohms

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Resistor Colour code Value of a
resistor is determined using the color coded
stripes on the resistor .
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• Let us the a Resistor. Its colour stripes are
  brown, black, orange and gold.
• Value of brown is 1 and that of black is 0.
  Combining these two gives 10.
• The third colour is orange which means x
  1,000.
• The value of the resistance is found as 10 x
  1000 10,000 ohms or 10 Kilo Ohms or 10K.
• The gold stripe is the tolerance that means
  the actual value of the resistor mar vary by 5

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• Series Connection
• When two resistors are connected in series,
• their resistance will add together
• For example if R1 is 500 ohms and R2 250 ohms,
• then R1 R2 500 250 750 ohms
• Parallel Connection
• When two resistors are connected in parallel,
• their resistance will decrease. For example if
• R1 is 500 and R2 250 then the resistance is
• 500 x 250) / (500 250) (125,000) / (750)
  167 ohms.

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Variable ResistorsResistance of Variable
resistor can be increased or decreased. They have
a dial or a knob that allows you to change the
resistance .In higher resistance, less current
flow and in lower resistance ,more current will
flow
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Capacitor

• Capacitors store current and allow AC to pass
  through it. Capacitor has two electrodes and
  between them there is a dielectric material.
• Electrolytic capacitors have value printed on
  its body. Pins can be easily identified. Large
  pin is positive. Moreover a black / white band is
  printed near the negative terminal to identify
  the polarity.

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• In Disc capacitors, only a number is printed
  on its body. One or two numbers on the capacitor
  represents value in PF. E.g. 8 8PF
• Some have 3 numbers and if the third number is
  zero, then the value is in P E.g. 100 100PF
• If the capacitor has 3 numbers and the third
  number is not a zero, it represents the number of
  zeros after the first and second digits E.g. 104
  10 0000 PF
• Disc capacitor is non polarized and can be
  connected either way round

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Capacitors
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Variable Capacitors
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Diodes

• Diodes allow current to flow in only one
• direction. They have a positive side leg and a
  negative leg. When the voltage on the positive
  leg is higher than on the negative leg then
  current flows through the diode
• The negative leg of a diode is the Cathode
  and positive end is Anode

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• Types of Diodes

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Light Emitting Diode
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Light Emitting Diode

• LEDs use a special material which emits light
  when current flows through it. A current of 0.02
  Amps (20 mA) to 0.04 Amps (40 mA) is a good range
  for LEDs.
• LED Requires a series resistor to restrict
  the current through it. The resistor value can be
  determined using Ohms law

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Integrated Circuit
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IC Socket
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Transistors

• Transistor act as a simple switch to turn a
  part of circuit on and off.
• The transistor has three pins namely
  Collector (C) Base (B) and Emitter (E).
• The Base (B) is the On/Off switch for the
  transistor. If a current is flowing to the Base,
  current flows from the Collector (C) to Emitter
  in NPN transistor and Emitter to Collector in PNP
  transistor

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Transistor
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Transistor coding

• Transistor has codes to identify them.
  Usually the code has two letters followed by the
  part number
• First letter
• A Germanium B Silicon C Gallium
  Arsenide
• D Indium Antimide
• Second letter
• C Audio frequency Amplifier D Audio
  frequency power amplifier F Low power Radio
  frequency amplifier P High power Radio
  frequency amplifier
• E.g. BC 548 is B Silicon C - Audio
  frequency amplifier

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Transistors
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Buzzer and Speaker
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Switch

• Switches are devices that create a short
  circuit or an open circuit depending on the
  position of the switch. For a switch, ON means
  short circuit. When the switch is OFF, that means
  there is an open circuit

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Switches
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Power supply - Battery
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Transformer Power supply
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Printed Circuit Board
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Tools
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Circuit Design
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Components to construct Timer
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How to Identify
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Soldering