Read about 'Learning - Basics of computerescue.info' on elementcom. Learning - Basics of computerescue.info Electricity and. Electronics. Third Edition. Stan Gibilisco. McGraw-Hill. New York Chicago San Francisco Lisbon London Madrid. Mexico City Milan New Delhi. computerescue.info State Approval Listing Link, check to see if your State accepts or has pre- approved this course. Not all States .
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Trademarks: Wiley, the Wiley Publishing logo, For Dummies, the Dummies Man logo, Rest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, . •Flow of electric current through a conductor experiences a certain amount of resistance. •The resistance, expressed in ohms (Ω, named after George ohm). In order to understand even the simplest concepts of electronics, you must first understand what electricity is. After all, the whole purpose of electronics is to get.
Navy Electricity and Electronics Training Series
We also know that electricity can be measured in watts. Incandescent light bulbs are typically 60, 75, or watts. Compact fluorescent lights CFLs have somewhat smaller wattage ratings.
Microwave ovens and hair dryers are 1, or 1, watts. A typical household electrical outlet is 15 amps abbreviated 15 A. But, what is electricity really?
Electrical theory, part 1
Suffice it to say that two of the tiny particles that make up atoms — protons and electrons — are the bearers of electric charge. There are two types of charge: Protons have positive charge, electrons have negative charge. Electric current refers to the flow of the electric charge carried by electrons as they jump from atom to atom.
Electric current is a very familiar concept: When you turn on a light switch, electric current flows from the switch through the wire to the light, and the room is instantly illuminated.
But, what is electricity really? Suffice it to say that two of the tiny particles that make up atoms — protons and electrons — are the bearers of electric charge. There are two types of charge: positive and negative. Protons have positive charge, electrons have negative charge.
Electric current refers to the flow of the electric charge carried by electrons as they jump from atom to atom. Electric current is a very familiar concept: When you turn on a light switch, electric current flows from the switch through the wire to the light, and the room is instantly illuminated.
Electric current flows more easily in some types of atoms than in others.
An electric circuit is a closed loop made of conductors and other electrical elements through which electric current can flow. For example, a very simple electrical circuit consists of three elements: a battery, a lamp, and an electrical wire that connects the two. Circuits can get much more complex, consisting of dozens, hundreds, or even thousands or millions of separate components, all connected with conductors in precisely orchestrated ways so that each component can do its bit to contribute to the overall purpose of the circuit.
But all circuits must obey the basic principle of a closed loop. Transformers, motors and fluorescent ballasts are the most common types of inductors.
The effect of inductance is to oppose a change in current in the circuit. Inductance tends to make the current lag the voltage in the circuit.
Step 2: Circuits
When the voltage begins to rise in the circuit, the current does not begin to rise immediately, but lags behind the voltage. The amount of lag depends upon the amount of inductance in the circuit.
In a purely inductive circuit, this would be a 90 deg. The cosine of the angle between the voltage and current sine waves is the power factor.
The higher the frequency, the greater the inductive reactance. Inductive reactance is much more of a problem at high frequencies than at the 60Hz level. In many ways, capacitive reactance is the opposite of inductive reactance. Inductors resist a change in current, and capacitors resist a change in voltage.
The unit of measure for capacitance is the farad. Technically, one farad is the amount of capacitance that would allow you to store one coulomb 6. Because the storage of one coulomb under a pressure of 1V is a tremendous amount of capacitance, the capacitors commonly used are rated in microfarads millionths of a farad , or picofarads billionths of a farad.
Figure 1 page 34 illustrates current lead and lag. Capacitance tends to make current lead voltage in a circuit, while inductance tends to make current lag. This is why capacitors are use to correct power factor in industrial circuits, which are predominantly inductive.
The center letter is L symbolizing inductance. In an inductive circuit, E leads I.It travels from the power plants to our houses in big cables hung high in the air or buried in the ground.
Inductors are coils of wire, especially those that are wound on an iron core. In these articles, we will go through all of the basic electrical concepts.
Module 3 Circuit Protection, Control, and Measurement NAVEDTRA A edition , encompasses circuit breakers, fuses, and current limiters used in circuit protection, as well as the theory and use of meters as electrical measuring devices. This is why capacitors are use to correct power factor in industrial circuits, which are predominantly inductive. Electric current flows more easily in some types of atoms than in others.
Electronics Basics: Impedance is the total opposition to the flow of electricity.