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Electronics is an engineering discipline that involves the design and analysis of electronic circuits. Originally, this subject was referred to as radio engineering. An electronic circuit is a collection of components through which electrical current can flow or which use electromagnetic fields in their operation.

The electronic circuit design and analysis rests primarily on two Kirchoff's laws in conjunction with Ohm's law modified for AC circuits and power relationships. There are also a number of network theorems and methods (such as Thevenin, Norton, Superposition, Y-Delta transform) that are consequences of these three laws.

In order to simplify calculations in AC circuits, sinusoidal voltage and current are usually represented as complex-valued functions called phasors. Practical circuit design and analysis also requires a comprehensive understanding of semiconductor devices, integrated circuits and magnetics. Read more...



I = current(amps.), V = voltage(volts), R = resistance(ohms), P = power(watts)
CURRENT:
I = V/R or I = P/V
VOLTAGE:
V= P/I or V = IR
POWER:
I2R or VI
RESISTANCE:
R = V/I
ALTERNATING CURRENT(AC):
Il = line current(amps.), Ip = phase current(amps.), Vp = phase voltage(volts), Vl = line voltage(volts), Z = impedance(ohms), P = power(watts), f = power factor(angle), VA = volt ampers

CURRENT(single phase):
I = P/(Vp cos(f) Read more...


Common electrical units used in formulas and equations are:

Volt - unit of electrical potential or motive force - potential is required to send one ampere of current through one ohm of resistance
Ohm - unit of resistance - one ohm is the resistance offered to the passage of one ampere when impelled by one volt
Ampere - units of current - one ampere is the current which one volt can send through a resistance of one ohm
Watt - unit of electrical energy or power - one watt is the product of one ampere and one volt - one ampere of current flowing under the force of one volt gives one watt of energy
Volt Ampere - product of volts and amperes as shown by a voltmeter and ammeter - in direct current systems the volt ampere is the same as watts or the energy delivered - in alternating current systems - the volts and amperes may or may not be 100% synchronous - when synchronous the volt amperes equals the watts on a wattmeter - when not synchronous volt amperes exceed watts - reactive power
Kilovolt Ampere - one kilovolt ampere - KVA - is equal to 1,000 volt amperes
Power Factor - ratio of watts to volt amperes
Electric Power Formulas
W = E I (1a)

W = R I2 (1b)

W = E2/ R (1c)

where

W = power (Watts)

E = voltage (Volts)

I = current (Amperes)

R = resistance (Ohms)

Electric Current Formulas
I = E / R (2a)

I = W / E (2b)

I = (W / R)1/2 (2c)

Electric Resistance Formulas
R = E / I (3a)

R = E2/ W (3b)

R = W / I2 (3c)

Electrical Potential Formulas - Ohms Law
Ohms law can be expressed as:

E = R I (4a)

E = W / I (4b)

E = (W R)1/2 (4c)

Example - Ohm's law
A 12 volt battery supplies power to a resistance of 18 ohms.

I = (12 Volts) / (18 ohms)

= 0.67 Ampere

Electrical Motor Formulas
Electrical Motor Efficiency

μ = 746 Php / Winput (5)

where

μ = efficiency

Php = output horsepower (hp)

Winput = input electrical power (Watts)

or alternatively

μ = 746 Php / (1.732 E I PF) (5b)

Electrical Motor - Power

W3-phase = (E I PF 1.732) / 1,000 (6)

where

W3-phase = electrical power 3-phase motor (kW)

PF = power factor electrical motor

3 Famous Engineers From Aerospace, Chemical And Electrical Engineering Backgrounds

Aeronautical Engineering is focused only on Aircrafts that do not leave the Earth's atmosphere whereas Astronautical Engineering is focused on Aircrafts that are able to leave the Earth's atmosphere. Initially this industry was focused on Aeroplanes and flight technology but it has expanded to also run the operation of outer space aircrafts. Some of the issues that Aerospace Engineers have to deal with include temperature change and control, atmospheric pressure and flight planning. They deal with these issues by using technologies such as aerodynamics, avionics, propulsion and material science.

Wernher von Braun

Wernher von Braun made a significant impact in the development and advancement of rocket technology in America and Germany. However, some found his work very controversial because he did some work on a Nazi rocket programme and there was even a song written about him! Wernher had an interest in space and astronomy from a very early age and his mother supported his interest by buying him a telescope.

Wernher went to the Berlin Institute of Technology where he became a prominent member of the Spaceflight Society. A few years later he earned a doctorate in physics and received a research grant to work on a rocket test site.

Chemical Engineering

Chemical Engineers work to combine both Chemistry and Engineering in an intelligent way in order to closely study the production of chemicals.

Henry Bessemer

Bessemer was an English Engineer born in 1813. He is best known for his division of the Bessemer process which was used in the manufacture of steel. This was a very well known process that was implemented worldwide and was very important to the industry at the time. It resulted in steel dropping significantly in price and being used for a huge variety of things for the first time. Bessemer invented another very important process, the decarbonisation of cast iron. He also invented a great deal of other things and coming up with revolutionary ideas was his passion.

Electrical Engineering

Electrical engineering is centred around the study of electricity. However, what many people don't realise is that it covers a variety of subjects and industries such as electromagnetism, control systems, telecommunications and power.

Thomas Edison

Thomas Edison was an American businessman who also spent a great deal of his time attempting to come up with new inventions. Consequently he invented a wide range of useful ideas and devices. He was most famous for using the principles of mass production to enhance the process of invention. Thomas Edison came up with so many ideas that he ended up obtaining 1,093 patents for his vast array of inventions.

Career Options in Electrical Engineering

Electrical engineering or electronic engineering is a professional engineering discipline which involves the study of electricity, as well as the application of electricity, electronics and related topics. Being a one of the oldest and basic branch of engineering, consists of concepts of electricity transmission and distribution with theoretical and practical knowledge of subjects like wireless systems, quantum electronics, modern optics, solid state materials and devices, power electronics, control theory, data compression and communications etc. The area first started to be noticed as a concrete profession towards the end of the 19th century with the advent of the electric telegraph and power supply. Today the field has advanced to a great extent, spanning diverse areas within the field like digital electronics, artificial intelligence, signal processing etc.

Electrical engineers are in charge of a diverse array of technological applications, such as the designing, development, execution and supervision of the operation of electrical structures and gadgets.

Electrical engineers may be involved in the functioning of electric power stations, the development of telecommunication structures etc. Careers in electrical engineering are as diverse as the area itself, they may be found in a laboratory of a fabrication plant, or even on site in a mining area. A person who chooses Electrical Engineering as a career can work as Project Engineer, Supervisor, Consultant, Purchase Electrical Engineer in various Domestic and International Companies. Because of developing power & real estate sector there are numerous opportunities in Electrical Engineering field.

Career Options in Electrical Engineering

Electrical engineering or electronic engineering is a professional engineering discipline which involves the study of electricity, as well as the application of electricity, electronics and related topics. Being a one of the oldest and basic branch of engineering, consists of concepts of electricity transmission and distribution with theoretical and practical knowledge of subjects like wireless systems, quantum electronics, modern optics, solid state materials and devices, power electronics, control theory, data compression and communications etc. The area first started to be noticed as a concrete profession towards the end of the 19th century with the advent of the electric telegraph and power supply. Today the field has advanced to a great extent, spanning diverse areas within the field like digital electronics, artificial intelligence, signal processing etc.

Electrical engineers are in charge of a diverse array of technological applications, such as the designing, development, execution and supervision of the operation of electrical structures and gadgets.

Electrical engineers may be involved in the functioning of electric power stations, the development of telecommunication structures etc. Careers in electrical engineering are as diverse as the area itself, they may be found in a laboratory of a fabrication plant, or even on site in a mining area. A person who chooses Electrical Engineering as a career can work as Project Engineer, Supervisor, Consultant, Purchase Electrical Engineer in various Domestic and International Companies. Because of developing power & real estate sector there are numerous opportunities in Electrical Engineering field.

What does an electrical engineer do?

An electrical engineer is a specific type of engineer. Electrical engineers work with a variety of different electrical components. Most electrical engineers have a specific field of expertise – such as computer components or automotive engineering – and this is where they really get to create remarkable new technology.

When an electrical engineer works on a project, he'll usually be given a brief by a client, or be presented with a problem and asked to come up with a solution. The electrical engineer will then create a plan – maybe even a 3D map – of the component they're creating. This will include all the circuitry and wiring.

The next step is to build a prototype of the component, and test that prototype in all kinds of different situations. There will be stringent safety tests to pass, as well as making sure all the components work together the way they should. Only once all the tests have been completed and the design modified and re-tested can the electrical engineer put a component into construction. But his/her job is still not over – for he/she may be required to perform maintenance or repair on the components over the years.

An electrical engineer is often part of a team of engineers, so they have to understand not just electronics, but other types of engineering as well. It's important that an electrical engineer can work well alongside other colleagues to produce the most efficient, cost effective and quality product.

Many electrical engineers will specialise in a particular type of technology, for example switch mode power supplies engineers. In order to become an electrical engineer, you'll need to go to university and obtain a Bachelor's degree in engineering with an electrical engineering speciality. Many engineers who wish to specialise further than that will go on to postgraduate study or choose a particular course of study. To be a good electrical engineer, you'll need to have a decent background in physics, mathematics, design (computer-aided), processing and production.

Above all, electrical engineers need to be quick thinkers with a real attention to detail and the ability to think laterally about any problem.

Getting a job as an electrical engineer

You're just out of grad school and looking for a job. Perhaps you're a general electrical engineer, or maybe you've specialised as a transformer engineer, but either way, there are too few jobs for so many graduates. What are your chances of landing a job as an electrical engineer in this economy?

Despite what you may think when you're not getting any results from sending out your resume, there are a shortage of electrical engineers in New Zealand, according to Department of Labour estimates. "Electrical Engineer" appears on New Zealand's "long-term skill shortage" list at Immigration, which means immigrants with electrical engineering degrees are being encouraged to come here. Instead, you should be applying for those jobs.

The NZ Government is spending more than ever on infrastructure, and with that comes increasing opportunities for qualified electrical engineers. The government has confirmed in the 2011 Budget it will be spending a further $3.8 billion updating the national grid, so you'll be seeing more and more opportunities for electrical engineers as this project progresses.

And, don't forget, the new sustainable energy market is creating more jobs for specialised electrical engineers. The increased use of wind power, solar power and hydro-electrical schemes demand specialist skills, and would be a fascinating area for any electrical engineer interested in specializing.

As an electrical or transformer engineer, you'll either be working for a major power company, or for an engineering consulting firm as part of a team of specialised engineers. The work will vary between designing new systems, implementing new electrical technology, and maintaining and troubleshooting the current systems.

If you want to stand out amongst the other engineering candidates, the first thing you should do is approach major companies and power suppliers about internship programmes and work experience opportunities. Each year these companies take on a certain number of graduates as part of these programmes and it is to the standout graduates in this pool that they offer jobs at the end of the internship period. If you can land an internship and prove yourself a competent and efficient employee, then you can find yourself with a job offer as an electrical engineer.

Electrical Engineering, Jobs, Careers, Salaries, education, degrees

An Introduction to Electrical Engineering

It became an identifiable occupation after commercialization of electrical power supply and the electric telegraph late in the nineteenth century. Currently it covers subtopics such as control systems, telecommunications, power electronics, signal processing and more.

Electrical Engineering Education

An electrical engineer will have an academic degree combined with an electrical engineering major. The study period for the degree range from four to five years and usually include subjects such as computer science, mathematics, physics, project management as well as several specific topics specializing in electrical engineering.

Electrical Engineering Degrees

A completed degree in electrical engineering is usually designated as Bachelor of Applied Science, Bachelor of Technology, Bachelor of Science and Bachelor of Engineering, depending on the various institutions and universities. Student will often choose a specialized field within the course in one or even more than one sub-disciplines.

An electrical engineer can also pursue a postgraduate degree such as Master of Science, Master of Engineering, Master of Engineering Management, Engineering Doctorate or a Doctor of Philosophy in Engineering.

Career Industries in Electrical Engineering

The career fields where an electrical engineer can find a great job in development of solutions and research technical problems and apply the principles and theories of mathematics and science include:

Agricultural, Aerospace, Biomedical, Civil, Chemical, Environmental, Industrial, Mining and Geological, Petroleum, Nuclear and more.

Jobs and Salaries for Electrical Engineers

An electrical engineer earns a much higher entry-level salary than his counterpart with other degrees does. Salaries vary by the different branches of the engineering field as well as the level of education. The lowest entry-level salary is in the range of $80,000 and with a five-year experience behind him, an electrical engineer will find a high salary jump of over $20,000 more.

An electrical engineer in maintenance for a mining company, which involves reduction in operating costs, increasing of safety, investigation, implementation and design of technical solutions as well as improvements to maximize production. This position also requires interaction with maintenance staff, negotiating with contractors and consultants with a salary of $145,000 for the right candidate.

Engineering salaries differ in the different industries and degree level. An Engineer with a Master of Science degree will for example earn as an Electrical engineer at entry level an average of $87,295 and a senior Electrical engineer will earn an average of $117,656 in the same field. An Electrical design engineer earns an average of $83,783 and an Analog and mixed signal Design engineer will earn an average of $128,906.

An engineer with a Bachelor of Science degree can expect an average starting salary of $80,137 and the senior electrical engineer can expect an average of $104,377 per annum. The different career industries also plays a major role in the salaries of engineers as Aerospace and Defense pays an average of $81-592 per annum to their entry level engineers. Engineering consulting pays average of $73,311 and Semiconductors pays average $92,836. Military and Space Systems pays Electrical engineers from $56,227 - $80,772.

What is Electrical Engineering Today and What is it Likely to Become?

So what is Electrical engineering, as distinct from computer engineering, and what is its future? We address this question by examining it from the perspective of university Electrical engineering programs and the needs of industry and society. As a result of our investigation, we also develop a definitional set of broad areas and specialties that define Electrical engineering, both now and in the future. We conclude with a recommendation to give Electrical engineering more curb appeal for prospective students. The perception of service to society is important in attracting students. Electrical engineering has historically been critically important to society. If whatever form Electrical engineering takes in the future continues to be of critical importance, we need to be able to convey this to prospective students and attract them to the field.

A DEFINITION OF ELECTRICAL ENGINEERING

There are certain broad areas that are important to Electrical engineering across the board. In addition, there are prominent specialties that many may consider a subset of one or more of the broad areas, but they are notable in that they are distinctively Electrical engineering. We propose the four following broad areas that are fundamental to Electrical engineering (in no particular order):

• Electromagnetics and Optics: The entire field of controlling electromagnetic phenomena,

electromagnetic waves of all frequencies, including optical, are clearly the domain of the electrical engineer.

• Signals Engineering: The processing of signals that historically have been generated by electrical or

electronic devices and electromagnetics remains a critical domain of the electrical engineer. Where once

the signals were processed by analog devices and continuous time mathematics, today digital signal

processing dominates. Many signals today are important in bioengineering.

• Systems Engineering: By this we mean solving complex problems that can be modeled by, in general, complex calculus based matrix mathematics. Historically, this included such things as state space equations, convolution, mathematical transforms, minimization/maximization problems, etc. whether analog or digital. In particular linear system theory has been a cornerstone of advanced electrical engineering work, and we should retain the ownership of it. The interdisciplinary nature of the world today makes systems engineering indispensable.

• Electronics, Microelectronics, and Circuits: This allen compassing field has long been the domain of the electrical engineer. The understanding of this area remains important, and competent electrical engineers, even if they are not designing circuits, still need to know how circuits work. The semiconductor area still needs competent electrical engineers, and there are predictions of a bright future for engineers in this area . Power electronics is important to the electric power industry. Photonics is here to stay. There is demand for consumer electronics, avionics, navigation, vehicular electronic systems, and computer components. The four specialties we propose are listed below. Again, some may contend that they are subsets of the above broad areas, but that is fine. These specialties in particular help characterize Electrical engineering

• Telecommunications and Radar: This is the specialty that has evolved from traditional radio engineering, and includes wireless communications, radar, remote sensing, networks, wired communications, information theory, error correction coding, detection and estimation theory, etc. Today, telecommunications is playing a larger and larger role in medicine and radar is helping us understand climate change. Where once all radio devices were constructed with analog electronic components, today much of the signal processing is done with software. However, it doesn't matter how the systems are constructed; it is still telecommunications and radar and the domain of Electrical engineering.

• Electric Power Systems: The generation and transmission of electric energy including alternative sources of energy and the impact on society and the planet is an important part of Electrical engineering. Although not many Electrical engineering programs offer power emphases anymore, we propose that at a minimum a set of power electives should be available. This is clearly an area where future Electrical engineering's can help make a difference in the world, and it is also an area where an interdisciplinary approach is crucial, e.g. economics, network theory, political science, law, etc.

• Instrumentation and Control: Both instrumentation and control systems are classic domains of Electrical engineering. Much of classic control theory is an integral part of what we have labeled systems engineering, so the heavy mathematics may more appropriately belong there. With instrumentation, we deal with transducers. The signals today may be represented digitally, but we feel that transducers, the building of these devices, and the processing of the signals remain the domain of EE. This specialty also includes robotics. And one notable Electrical engineering contribution, among a number, to the biological revolution is in the area of medical instrumentation.

Future Trends in Electrical Engineering

The future of electrical engineering looks very bright. This is a profession that's exploded over the last several years. With the popularity of computers and the future of computers, electrical engineering careers will probably be in even more demand. Just about every industry needs computers and that means that electrical engineers will always be needed. So this is a great career to go into and it will continue to be for many, many years to come.

When staying in an electrical engineering career there are many different jobs that can be held. And there are many different job titles that go along with all the different jobs. The job titles include electrical engineer, development engineer, field engineer, project engineer, design engineer, systems design engineer, and test engineer. Most of these job titles explain basically what each job entails. Though there is obviously much more to each job than you'd know at first glance.

The jobs will require the electrical engineer to do things such as design, develop, and implement products or services. The electrical engineer may also be expected to research and come-up with new ideas. Some of the tasks can and will be very challenging but with the proper education and the proper training an electrical engineer will be able to perfectly complete every task and solve every problem.

Electric Generator - Types and Usage

Electric Generator is commonly used as backup systems in several residential and commercial areas. These types of generators work on the principle of converting mechanical energy into electrical energy with the help of a motor. Separate electrical circuit provides the flow of electrons into the windings of the generator. Conversion of mechanical energy into electrical energy is done with the assistance of a turbine steam engine, wind turbine; hand crank compressed air, internal combustion engine or energy of falling water is tapped through a water wheel or turbine.

Today power cuts are frequent. You cannot afford to lose business because of a power cut. Hospitals particularly may face life threatening situations as many life saving medical equipments work on electricity. Hence, in recent years the demand for standby and portable generators has increased manifold.

Size and voltage is an important factor to consider before buying emergency equipments. Electric generator can be divided into four categories, recreational, standby, portable and commercial.

The recreational generators are usually used for RV's that is recreational vehicles particularly used for camping. Camping is mostly done in remote places and apart from the battery backup of the vehicle additional power is required to light up some basic appliances and devices that the modern RV's are equipped with.

Two types of recreational generators are available, 1000 watts and 2000 watts. The 1000 watts equipment will aid in running only about one or two appliances like coffee maker or toaster and 2000 watts should ideally help in running multiple appliances.

Recreational generators cannot be used at home due to limited capacity. Portable generator that comes in medium, large and extra large sizes is a good option. These are for purely emergency backups. They vary from 3000 watts to 10,000 watts in power. A 3000 watts medium sized generator will only supply power to tube lights, fans, furnace fans, refrigerator and some more small appliances but not to air conditioners. Principally for central air conditioning, you would require 9000 to 10,000 watts electric generator.

Standby generators are constantly plugged in with main utility supply line, consist of an automatic on and off switch, which keeps you tension free from keeping a check on fuel or gas levels unlike portable generators. While buying standby generators it is imperative to check the number of circuits and wattage required for various types.

Three kinds of standby devices are available in the market with varying potency like powering whole house, essential circuits and smart circuits. The wattage requirement varies from 8 KVA to 48 KVA and starts from utilizing 8 to 16 circuits to complete circuit board respectively. Standby electric generators are considered to be the best today for residential use.

For commercial employment, large sized generators are used that are usually tailor made as per requirement. Large offices and commercial centers typically use this type of generators. These generators work on three phases and exploit diesel or natural gas. Natural gas is a better source as it produces less exhaust waste and is less noisy. Electric generator that best suits your needs is the one that is compatible with your incoming utility voltage.

Work, Energy and Power

Work:

A man pushing a car along a level road is said to be doing work. The amount of work done depends on the force exerted and the distance through which the force acts.

UNIT OF WORK: Since W = F x s, Unit of work = (unit of F) x (unit of s) = newton x metre (N m) = Joule

This unit is called the joule in honour of James Joule (1818—89) who did much early research in the area of work and the related of energy.

One Joule is the work done when a force of 1 Newton acts over a distance of 1 metre in the direction of the force: 1J = 1Nxm

Energy:

Energy is the ability to do work. The amount of energy something has is the amount of work it can do.

The unit of energy is the Joule.

Power:

A bulb in a desk lamp can convert electrical energy into heat and light at the rate of 40 joules per second; a bulb in a floodlight can convert electrical ener

gy into heat and light at the rate of 500 joules per second. The second bulb is more powerful than the first.

A builder brings 1000 blocks each of mass 20 kg from the ground, up a ladder, to the top of a house. It takes him 5 hours to do so. A crane lifts all the blocks

together from the ground to the top in a time of 10 seconds. Even though the man and the crane do the same work the crane does it

in a much shorter time. The cra

ne is much more powerful than the man.

Power is defined as the rate at which work is done. That is Power = Energy/time

UNIT OF POWER Since the U nit of Energy = joule and the Unit of time is the Second;

P = 1J / 1s

This unit is called the W

att (W) in honour of the English s

cientist James Watt.

DIFFERENT FORMS OF ENERGY

Since a body can do work for different reasons it can have energy for different reasons. It is useful to classify energy a ccording to the reasons that bodies have it.

KINETIC ENERGY: All moving objects have energy due to their motion. The energy a body has due to its motion is called kinetic energy.

POTENTIAL ENERGY: Potential energy is the energy a body

has due to its position in a force field.

In the picture shown on the right, a cyclist with Kinetic energy is moving up the hill and transforming the en

ergy into Potential energy

ELECTROMAGNETIC ENERGY: This i

s the energy transmitted from one point to another in the form of electromagnetic waves that travel at the speed of light. Example of a electromagnetic energy producer i

s a microwave.

INTERNAL ENERGY or heat energy: The molecules of every substance, whether solid, liquid or gas are in perpetual motion. If heat is supplied to a substance, the motion (the vibration) of its molecules increases as its temperature

rises. The kinetic energy of the molecules therefore increases. Thus heat is

a form of energy.

SOUND ENERGY: Any source of sound is always some object vibrating. As sound travels through a substance, the vibration from the source is passed on from molecule to molecule in that substance. Each molecule acquires energy in kinetic and potential form as the sound wave passes.

CHEMICAL ENERGY: The energy given out (or sometimes taken in) in the form of heat, light or kinetic energy during a chemical reaction is called chemical energy. For example, when something is burned, some of the chemical energy stored in it is changed into heat and light energy.

ELECTRICAL ENERGY When an electric current flows in a metal wire subatomic particles called electrons move in the wire. As they move, they lose energy called electric potential energy. This potential energy appears as

heat and other forms of energy in the wire.

NUCLEAR ENERGY The energy given out from the nuclei of certain atoms during nuclear reactions (fission or f

usion for example) is called nuclear energy

. This energy is used practically in the nuclear reactor

THE PRINCIPLE OF THE CONSERVATION OF ENERGY

Energy cannot be created or destroyed but can only be transferred from one body to another or changed from one for m to another. In every chemical or physical reaction, there is no net gain or loss of energy; any loss is always accompanied by an equal gain.

RENEWAB

LE AND NON-RENEWABLE SOURCES OF ENERGY

Every day we use energy for many purposes, e.g. transport and heating. The sources of this energy are many, e.g. oil, coal and hydroelectricity.

Sources of energy are classified as renewable or non-renewable. Examples of renewable energy sources are wind energy and solar energy, hydroelectric energy, wave energy and biomass. Non-renewable s

ources include oil, coal, peat and natural gas.

Energy is said to be renewable if the source of the energy is still there after energy is taken from it, and non-renewable if the source of the energy is gone after energy is taken from it.

Renewable energy sources will not run out. A problem with renewable energy sources is generating enough reliable energy to meet all our requirements. A lot of research is being done to find practical ways of using these ‘altemative

’ sources for the future.

Non-renewable ener

gy sources are fossil fuels, oil, gas, coal, peat or nuclear. They are usually easier to get energy from and store, but have a bigger environmental impact.

Energy pl

ant.

We need electrical energy to run all our appliances at home. We know that energy is everywhere around us, but how can we get it? There are several ways to transform energy into electrical energy. Energy plants have all these components to produce energy. Let's see a very simple one.

HYDROELECTRIC ENERGY

The store water behind an enormous dam flows through the intake and into a pipe called a penstock. The intake remains closed when no energy is asked for, for example, at night, as everybody is in bed. The water pushes against blades (the arms of the rotary mechanism), causing them to turn. The turbine spins and its shaft is connected to a generator that changes the mechanical spinning energy into electrical energy ( electricity ).

Advantage: Water power is reasonably easy to store ( in a reservoir ). Renewable energy.

Disadvantages: A lot of water is needed

P = V x I

If we want to transfer high power from the electric plant to the town where it can be used, we need high Voltage and Current ( Amps )values.

Remember that Amps mean electrons moving through conductors which, because of their collisions with atoms, produce heat.

The cables of transmission lines are made of aluminium ( cheaper ) or copper ( more expansive )

because they have a low resistance. So the higher the current, the higher the energy lost in the wires.

It is not good. All this work just to warm the bird's foot.

By the way, do you know how birds can sit safely on electric power lines?.

The answer is simple. Because the bird only touches one line, so electrons flow through the path of least resistance, the wire, and not its body.

So, the trick is to reduce the Current and increase the voltage. There is an electrical device that does just this. Its name is the transformer.

Electrical transformers are widely used to "transform" voltage from a lower voltage to a higher voltage or vice versa ( normally in appliances ). The principle of magnetic induction between coils makes it possible.

A transformer basically consists of a ferromagnetic core and two coils called "windings".

A changing current in the primary winding generates an alternating magnetic field in the ferromagnetic material.

The alternating magnetic field "goes and comes back" through the magnetic core ( the green line).

There is a relationship between voltage and electric field, so if a voltage is applied in the primary winding with 10 turns it generates a Magnetic field of value X , the same magnetic field generates a voltage in the secondary winding.

The voltage in the Secondary winding will be the same if N2 = 10

The voltage will be less if the secondary winding has less turns than the primary winding

In general, the simple formula that relates both voltages is:

V1 X N1 = V2 X N2

Example: If the output voltage in an alternator is 20000 volts and we want 200000 for the transmission lines, in a transformer with 100 turns in its primary winding:

20.000 X 100 = 20000 X N2 .....N2 = 2.000.000 / 20.000 = 1000 turns.

As Power is a constant, the current in the secondary winding will be less.

Now, everything is ready for the electricity to travels long distances to a substation. Substations are situated near factories and homes. Here transformers do their work in a inversely. I mean, they change the very high voltage electricity back into lower voltage electricity. In this case, the secondary winding will have less turns than the Primary Winding.

The next image illustrates the different elements of a transmission power system.

1º Step, The power plant, in this case a Hydroelectric plant.2º The transmission substation where the transformer increases the voltage 3º High voltage transmission, using long thick cables made of copper or aluminium with voltages from 200.000 v to 400.000 v4º The power substation, which will decrease the voltage from 400.000 to 20.000 5º Power poles take electricity to the Transformer Drum and from this element to homes with tension of 220 v

floodlight: light that is a source of artificial illumination having a broad beam; used in photography.

Crane: a device for lifting and moving heavy weights in suspension.

Blade: the arm of a propeller or other similar rotary mechanism, such as an electric fan or turbine.

shaft: a rotating, straight bar for transmitting motion, usually supported on bearings and carrying gears, wheels, such as a propeller shaft on a ship

Core: The piece of iron, or other ferrous material forming the central portion in an transformer .

Solar power. How to use the sun's energy

What are Electrical Transformers?

Electrical transformers are used to transform electrical energy. How electrical transformers do so is by altering voltage, generally from high to low. Voltage is simply the measurement of electrons, how many or how strong, in the flow. Electricity can then be transported more easily and efficiently over long distances.

While power line electrical transformers are commonly recognized, there are other various types and sizes as well. They range from huge, multi-ton units like those at power plants, to intermediate, such as the type used on electric poles, and others can be quite small. Those used in equipment or appliances in your home or place of business are smaller electrical transformers and there are also tiny ones used in items like microphones and other electronics.

Probably the most common and perhaps the most necessary use of various electrical transformers is the transportation of electricity from power plants to homes and businesses. Because power often has to travel long distances, it is transformed first into a more manageable state. It is then transformed again and again, or “stepped down,” repeatedly as it gets closer to its destination.

When the power leaves the plant, it is usually of high voltage. When it reaches the substation the voltage is lowered. When it reaches a smaller transformer, the type found on top of electric poles, it is stepped down again. It is a continuous process, which repeats until the power is at a usable level.

You have likely seen the type of electrical transformers that sit on top of electric poles. These, like most electrical transformers, contain coils or “windings” that are wrapped around a core. The power travels through the coils. The more coils, the higher the voltage. On the other hand, fewer coils mean lower voltage.

Electrical transformers have changed industry. Electric power distribution is now more efficient than ever. Transformers have made it possible to transfer power near and far, in a timely, efficient, and more economical manner. Since many people do not wish to live in close proximity to a power plant, there is the added benefit of making it possible for homes and businesses that are quite a distance from power plants to obtain dependable, affordable electricity. Much of the electricity used today will have passed through many electrical transformers before it reaches users.

Electrical transformers are used to "transform" voltage from one level to another, usually from a higher voltage to a lower voltage. They do this by applying the principle of magnetic induction between coils to convert voltage and/or current levels.

Electrical transformers are used to "transform" voltage from one level to another, usually from a higher voltage to a lower voltage. They do this by applying the principle of magnetic induction between coils to convert voltage and/or current levels.

Electrical transformers can be configured as either a single-phase or a three-phase configuration. There are several important specifications to specify when searching for electrical transformers. These include: maximum secondary voltage rating, maximum secondary current rating, maximum power rating, and output type. An electrical transformer may provide more than one secondary voltage value. The Rated Power is the sum of the VA (Volts x Amps) for all of the secondary windings. Output choices include AC or DC. For Alternating Current waveform output, voltage the values are typically given in RMS values. Consult manufacturer for waveform options. For direct current secondary voltage output, consult manufacturer for type of rectification.

Cores can be constructed as either a toroidal or laminated. Toroidal units typically have copper wire wrapped around a cylindrical core so the magnetic flux, which occurs within the coil, doesn't leak out, the coil efficiency is good, and the magnetic flux has little influence on other components. Laminated refers to the laminated-steel cores. These steel laminations are insulated with a nonconducting material, such as varnish, and then formed into a core that reduce electrical losses. There are many types. These include autotransformer, control, current, distribution, general-purpose, instrument, isolation, potential (voltage), power, step-up, and step-down. Mountings include chassis mount, dish or disk mount, enclosure or free standing, h frame, and PCB mount.