Electricity and Power Systems and Electronics, Study notes of Electrical and Electronics Engineering

Download Electricity and Power Systems and Electronics and more Study notes Electrical and Electronics Engineering in PDF only on Docsity! APPLIED ELECTRICITY Electric theory, quantities and circuits elements Atoms, Electrons, Charge • Conductors and Insulators • Current • Voltage Power Magnetism and Electromagnetism • Circuit Components and Resistance Electricity Electricity is the set of physical phenomena associated with the presence and flow of electric charge. Including:  Lightning and Static electricity  Electromagnetic induction  Current  Electromagnetic radiation and radio waves Atom,Electrons,Charge Matter - has weight and occupies space. Matter is composed of atoms. Atoms are composed of: Electrons (-) orbiting around a nucleus of Protons (+) and Neutrons. Electric theory, quantities and circuits elements. Conductors and insulators When it comes to electricity there are generally, two types of material: -Conductors -Insulators Insulator characteristics Resistance - The ability of the insulator to resist current leakage through and over the surface of the insulator material. Dielectric Strength - The ability to withstand a maximum voltage without breakdown damage to the insulator. CURRENT Current (1) is the movement of charge through a conductor. Electrons carry the charge. Unit of measurement: Amperes (A) One ampere (amp) of current is one coulomb of charge passing a point on a conductor in one second This measurement is analogous to "gallons or liters per second" when measuring the flow of water Direct Current (DC) flows in only one direction. Many uses including: Batteries, electronic circuits, LED lights, generator excitation systems and rotors, DC transmission lines -and much more Alternating Current (AC): Alternating Current (AC) continuously changes in magnitude and direction. AC is used by most lights, appliances and motors. It is used in the high voltage transmission system AC enables us of transformers to change voltage from high to low and back Typical current levels: Cell phone battery charger – 5/1000Amps = 5mA = 5milli-Amps Sensation .2-5mA Let-go threshold - 5mA Potentially lethal – 50mA 40 watt incandescent light bulb - .33Amps Toaster – 10 Amps Car Starter Motor – 100+ Amps Transmission line conductor – 1000 Amps Lightning Bolt or Ground Fault – 2000+Amps Voltage Voltage (V) is the force that causes electrons to move. • Voltage is also referred to as potential difference or electromotive force (emf or E) Unit of measurement: Volts (V) • Similar to "pounds per square inch" when measuring water pressure. Alessandro Volta (1745-1827) Sample voltage levels AA Battery – 1.5v Car Battery – 12v