History and Fundamentals of Electricity: Edison, Tesla, Volta, and Watt

-Thomas Edison worked for the Western Union (the NY and Mississippi Valley Printing Telegraph Company). In 1860, it had a wide coverage of telegraph lines in the USA. In 1861, it made the 1st transcontinental telegraph line. The Pony Express was made obsolete. He was the inventor of photographs, electric bulb, and motion picture camera.

Edison Electric Illuminating Company (1878) and Edison Illuminating Company (1880) created an electric utility to compete with light gas utilities.

Lighting competition: arc lamp and AC is in competition with DC and incandescent bulb.

Nicola Tesla was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist who is best known for his contributions to the design of the modern alternating current (AC) electricity supply system. In 1893, he spoke about the possibility of wireless communication with his devices.

Alessandro Volta was an Italian physicist, chemist, and pioneer of electricity and power who is credited as the inventor of the electric battery and the discoverer of methane.

James Watt was a Scottish mechanical engineer, inventor, and chemist. The improvements he made in the Newcomen machine resulted in the one known as the steam engine, which was fundamental in the development of the 1st Industrial Revolution.

-Electric current is the movement of electrons through the atoms of a conducting material.

-Intensity of current is the number of electrons that flow through a conductor every second. Its unit of measurement is the ampere or amp.

-Tension or voltage is the force that makes the electrons flow through a circuit, it is the difference between the electrical energy at 2 points of a circuit. Its unit of measurement is the volt.

-Electric resistance is the opposition that a material offers to the movement of electrons. Low resistance means the material conducts electricity well, it is a conductor, and high resistance means the material does not conduct electricity well, it is an insulator. Its unit of measurement is the ohm.

-Electric power (P) is a measure of how much energy is produced or consumed by an electric device every second. Its unit of measurement is the watt. In electricity power is calculated by the product of current and voltage. ----> P=V·I

-Electrical energy (E) is the ability to do work, where work is defined when a force moves an object. In electricity, it is the product of power and time. It is usually measured in kilowatt per hour (kW·h). ----> E=P·t

Ohm's Law is the relationship between voltage, current, and resistance. In 1826, the German scientist Georg Ohm discovered this relationship and he expressed it mathematically as: I=V/R V=I·R R=V/I

-Direct current. Electrons are moved in the same direction. This current is given by batteries, dynamos, and photovoltaic panels and it is used in electronic devices (mobile phones, calculators, laptops...).

-Alternating current. The direction of electrons changes several times every second. It is produced in large power stations and distributed to our houses through long power lines. It is used in home appliances (fridges, ovens, dishwashers...).

-Generators: elements that give energy to the circuit. Ex: dynamos, alternators, batteries.

-Conducting wires: elements where electrons circulate. They are made of copper and covered in plastic.

-Load devices. Elements that receive the electrical energy and transform it into other types of energy such as light, heat, motion, sound (light bulbs, motors, resistors, buzzers).

-Control elements. Elements that allow us to control the flow of current (simple/changeover/push switches).

-Protection elements. Elements that stop the current when it is too strong to prevent damage to other components (fuses, circuit breakers).

SERIES CIRCUIT. All components are connected one after the other along the conductor.

Characteristics: the electrons flow along only one path / we cannot switch the elements on independently / the sum of all voltage drops is equal to the total applied voltage / the current flowing through every component is equal / the total resistance is equal to the sum of all resistances Itotal=I1=I2=I3 Rtotal=R1+R2+R3 Vtotal=V1+V2+V3

PARALLEL CIRCUITS. All components are connected on separated branches.

Characteristics: the electrons flow along different paths / we can switch the elements on and off independently / the voltage across every parallel component is equal / the reciprocal of the Rtotal is equal to the sum of the reciprocal of all resistances / the sum of all the currents in each branch is equal to the total current. Vtotal=V1=V2=V3=V4 1/Rtotal=1/R1+1/R2+1/R3 Itotal=I1+I2+I3