TH 1501 Stage Lighting I
Electrical Theory



Parts of the Atom



Law of Changes
Protons and electrons attract.
Velocity of electrons keeps electrons in orbit.




Conductors

Electrical Conductors


Copper

 

Other Electrical Conductors
Silver, Brass, Aluminum

Insulators
Glass, Rubber, Fiber



Electrical Systems

Ohm's Law: I = E/R

• As electromotive force increases, current increases.
As resistance increases, current decreases.

I = quantity of electrons moving through circuit measured in amperes.
E = electrical pressure in the circuit measured in voltage.
R = resistance in the circuit measured in ohms.

P = amount of work circuit is capable of providing measured in watts.



West Virginia Law
W = V x A

A = current measured in amperes.
V = electromotive force measured in voltage.
W = energy available measured in wattage.


Types of Circuits
Electrical Circuits Explained

Series

Increasing amounts of resistance to same circuit, current decreases.



Parallel
Increasing amounts of pressure to same circuit, current increases.


Combination Circuits
Some components in series, others in parallel.


Types of Electromotive Force

Direct Current (DC)

Battery University


Carbon Zinc Batteries
General Purpose
Clocks
Flashlights
Calculators
Portable Electronics


Lithium Batteries
Light weight
High energy
Portable computers
Cell phones
Watches

Alkaline Batteries
Excellent storage life
Portable audio systems
Cameras
Toys
High power flashlights
Pagers


Nickel Cadmium (Ni-Cad) Battery
Rechargeable
Recyclable
Built-in charge level indicator


Lead Acid Battery
Wet cell and dry cell
Cars and trucks

Photovolactic



How Alternating Current (AC) Works

Electrical Transformer
Electrical Turbine


Construction of a Sine Wave
Sine Wave

 


Turbine Cross Section
Turbine Cross Section Demonstrating Rotating Magnetic Fields

United States Alternating Current Standard
Three Phase 60 Cycles per Second

Three Phase Sine Wave
Three Phase Sine Wave

 


Electrical Safety

Why a ground wire?



Why electrical breakers?

Types of Wire Conductors
Solid

Stranded wire


American Wire Gauges
16 Gauge Wire: 6 amps x 120 volts = 720 watts
14 Gauge Wire: 15 amps x 120 volts = 1,680 watts

12 Gauge Wire: 20 amps x 120 volts = 2,400 watts