38 Unit 6: Electrical Basics

Basics

Atoms are the extremely tiny building blocks of our universe. An atom gets its characteristics by how many protons, neutrons and electrons it contains. They bond together to create elements

• Protons are positively charged
• Neutrons are neutral charged
• Electrons are negatively charged

Electrical Current is the movement of electrons

• Current is measured in Amps (A)

Voltage is the amount of pressure required to move those electrons from their source

• Voltage is measured in Volts (V)

The opposition to the flow of electrons is called Resistance

• Resistance is measured in Ohms (Ω)

Electrical Power

Electrical power is voltage x current and is measured in Watts. It is the rate which electrical energy is transferred to the circuit.

P = I * V

AC/DC

There are two types of current

Alternating current (AC) and Direct Current (DC). The type that comes out of your wall is AC and the type that comes off a battery is DC.

AC is the most common type in most facilities. It is considered to be more dangerous than DC because of the way the electricity is produced. It alternates sides of the power source which can disrupt heart rhythm more effectively than DC.

Ground

Ground is a term used to describe a low-resistance path to earth. It is not a requirement for a circuit to work but it is a safety feature

Insulators vs Conductors

Insulators are materials that don’t allow the flow of electrons or have a high resistance to the flow of electrons. Things like rubber or cement are good insulators

Conductors are the opposite. They freely allow the flow of electrons like most metals