Introduction to Electrical Engineering

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Introduction to Electrical Engineering week 5

• Electrical Safety

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Course outline we are in week 4
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Electrical Safety

• The rule of thumbElectricity could kill you if
  you are not careful.

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Electrical Safety

• What killsvoltage or current?
• Voltage is needed to produce current
• Basic rule ohms law
• Current Voltage/resistance

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Electrical Safety

• Electricity is produced in power plants in
  3-phases

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Electrical Safety

• Ground is used as a conductor
• The resistivity is not low
• The cross section is very large
• The resistance is smallresistance
  (resistivity) x (length) /(cross sectional area)

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Electrical Safety

• Two lines come to the residences

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Electrical Safety

• Use a voltage sensor (faz kalemi) to identify the
  live wire (the phase line)

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Electrical Safety How does voltage sensor work?
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How much current is dangerous?

• 1 mA or less Not felt
• 1mA to 8 mA
• Sensation of shock, not painfulIndividual can
  let the wire go at will since muscular control
  is not lost.

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How much current is dangerous?

• 8 mA to 15 mA
• Painful shock individual can let go at will
  since muscular control is not lost.
• 15 mA to 20 mA
• Painful shock control of adjacent muscles lost
  victim can not let go.

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How much current is dangerous?

• 50 mA to 100 mA
• Ventricular fibrillation is possible (a heart
  condition that can result in death).
• uncoordinated twitching of the walls of the
  heart's ventricles
• 100 mA to 200 mA
• Ventricular fibrillation occurs.

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How much current is dangerous?

• 200 mA and over
• severe burns, severe muscular contractions so
  severe that chest muscles clamp the heart and
  stop it for the duration of the shock. (This
  prevents ventricular fibrillation).

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For more info
Read the book Electronics for Dummies
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Safety tips
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Safety tips
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Safety tips
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Safety tips
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Safety tips
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Safety tips
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Safety tips
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More safety tips
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More safety tips
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More safety tips
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• The End of Presentation
• Remember to be careful
• and take precautions!