Electronics 101

1
Electronics 101

• Overview
• Research Terms
• Series Parallel Circuits
• Resisters
• Ohms Law
• AC/DC

2
Objectives

• Create Glossary of Terms
• Use Formula to Solve Problems
• Create DC Motor Circuit

3
Electronics 101

• An electrical circuit is a network that has a
  closed loop, giving a return path for the
  current.
• Electric current is by definition the flow of
  electric charge. The SI unit of electric current
  is the ampere (A), which is equal to a flow of
  one coulomb of charge per second. One coulomb is
  the amount of electric charge carried by a
  current of 1 ampere flowing for 1 second.
• To design any electrical circuits electrical
  engineers need to be able to predict the voltages
  and currents in the circuit.

4
Glossary Assignment

• Using the internet, create a glossary of
  electronic terms with its definition.
• Round Robin everyone will provide the class
  with at least (5) five terms and definitions.
• Everyone is responsible for the terms discussed
  in class.

5
Series Parallel

• A series circuit is one that has a single path
  for current to flow through all of its elements.
• A parallel circuit is one that requires more than
  one path for current flow in order to reach all
  of the circuit elements.

6
Series Parallel

• Left Series / Right ParallelArrows indicate
  direction of current. The red bars represent the
  voltage as it drops in the series circuit. The
  red bars in the parallel circuit do not drop
  because the voltage across each element in a
  parallel circuit is the same.

7
Closed Loop

• An electrical circuit is a network that has a
  closed loop, giving a return path for the
  current.
• To design circuits electrical engineers need to
  be able to predict the voltage and current in the
  circuit.

8
Resistors

• A resistor is a two-terminal electrical or
  electronic component that resists an electric
  current by producing a voltage drop between its
  terminals in accordance with Ohm's law.
• The electrical resistance is equal to the voltage
  drop across the resistor divided by the current
  through the resistor. Resistors are used as part
  of electrical networks and electronic circuits

9
Resistors

• The Path of Least Resistance
• Resistors are electronic components used
  extensively on the circuit boards of electronic
  equipment. They are color coded with stripes to
  reveal their resistance value (in ohms) as well
  as their manufacturing tolerance. Should you
  encounter a resistor and don't know the color
  codes, use this page to determine its resistance
  value. For 99 of the world, this is of no
  intrinsic value, but to JavaScript scripters, it
  is a solid demonstration of controlling image
  objects on the fly via a script.
• http//www.dannyg.com/examples/res2/resistor.htm

10
AC /DC

• An alternating current (AC) is an electrical
  current whose magnitude and direction vary
  cyclically, as opposed to direct current, whose
  direction remains constant. The usual waveform of
  an AC power circuit is a sine wave, as this
  results in the most efficient transmission of
  energy. However in certain applications different
  waveforms are used, such as triangular or square
  waves.
• Used generically, AC refers to the form in which
  electricity is delivered to businesses and
  residences. However, audio and radio signals
  carried on electrical wire are also examples of
  alternating current. In these applications, an
  important goal is often the recovery of
  information encoded (or modulated) onto the AC
  signal.

11
Ohms Law

• A voltage source, V, drives an electric current,
  I , through resistor, R, the three quantities
  obeying
• Ohm's law V IR

V I R
12
Practice Problem

• voltage drives an current through resistor
  Ohm's law V IR

Power (watts) Current Squared (I2)
Resistance (R) Power IE E2 / R Sample
Problem
Voltage Current Resistance Power 15 x 2 30
15 A 2 ? 15 x 15 250 x 2 450
V I R
13
Practice Problems Use the two given values to
find the two unknown.
14
Practice Problems Use the two given values to
find the two unknown.
15
Ohms Law

• Ohms Law Calculator
• Enter any two known values and press "Calculate"
  to solve for the others. For example, a 100 watt
  light bulb operating on 120 volts AC will have
  144 ohms of resistance and will draw 0.833 Amps.
  Enter 100 in the Watts field and 120 in the
  Voltage field and press Calculate to find the
  resistance and current. Fields should be reset to
  0 before each new calculation.
• Voltage (E) Current (I) Resistance (R)
• Power (watts) Current Squared (I2)
  Resistance (R)
• Power IE E2 / R
• http//ourworld.compuserve.com/homepages/Bill_Bowd
  en/ohmslaw.htm

16
Evaluation

• Glossary with 15 terms 30 points
• Practice Problems 40 points
• Simple Motor Activity 30 points (see web page
  for details)