Hardware Components

Index of Topics

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Basics

• How electricity works
• Voltage
• Current
• Current
• Types of Electricity

Usages

• How home electricity works

How electricity works

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• Electrons are negatively charged, meaning they flow from negative to positive

Electrons are the building blocks of understanding how electricity works

• Conductors
  • have very few electrons in the valance shell allowing them to move freely
  • example
    • copper
    • silver
      
• Insulators
  • have many electrons in the valence shell not allowing the free electron to move freely
  • Example:
    • glass
    • rubber

Current (not appied/ applied) to copper wire

• With no current supplied to a copper wire, electrons are free and move randomly
  • 
• When current is applied to the copper wire via a battery, the free electrons will move in the a circuit from negative to positive
  • 

(Closed / Open) Circuit

• Closed Circuit
  • 
• Open Circuit
  • 

Voltage (V)

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Water Analogy

• 
• Like pressure in a water pipe. The more voltage means more pressure.
  • More pressure water can flow == More pressure electrons can flow
  • Voltage can exist without current
    • Just like how we can measure pressure in a water tank without it flowing
    • This is just measuring the pressure difference from the outside of the tank compared to inside the tank
    • We can measure the voltage with a multimeter with a closed and open circuit

What is a Volt

• One Volt, is the force required to drive one coulomb through a resistor of one ohm in one second
• Remember 1 coulomb = 6.242 * 10 ^ 18
• 
• Volt = Joules / Coulomb
  • Joule = Work
  • Coulomb = Group of flowing electrons

Voltage and Volts are different

• Voltage is the pressure
• Volts is the units we measure the pressure in

Potential Difference

• You will hear this term used a lot for voltage
• All this is saying is that “how much work can potentially be done by a circuit”

Voltage in Series

• 
  • if we cascade two batteries together in series, then the circuit will thus have more voltage, meaning a brighter light bulb

Voltage in Parallel

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  • If the two batteries are together in a parallel circuit, then the voltage stays the same because the electrons are split up, dividing the work into 2
  • In this example. The lamp is dimmer but powered for longer than if it was in series

Two lamps, One battery

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  • The image shows how the one battery powers both lamps across each at 0.75 splitting the voltage into two between the the two lamps

Current

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What is current

• Current is the flow of electrons measured in Amperes (Amps) past a single point in a circuit within a set amount of time
• Amps is also denoted by an A
• 1 Amp = 1 Coulomb
• 1 Coulomb = 6,242,000,000,000,000,000 electrons per second
• In order test the current we need an Ammeter in series in the circuit to capture the current

Resistance

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What is Resistance

• Resistance is a restriction to the flow of electrons
• Resistance is measured in Ohms

This example shows how size, material and temperature have resistance in a wire

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Resistors protect components by restricting the flow of current

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Types of Electricity

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1. Alternating Current (AC)
   • current moves back and forth with the changing magnetic field
   • used in wall sockets at home
2. Direct Current (DC)
   • Current travels only in one direction
   • used in circuits that contain batteries

Electricity at Homes

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  • Electricity is produced at the power plant
    • Voltage is increased and connected to the grid and transferred over long distances

REFERENCES

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