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Electrical generator

July 22nd, 2009 Grace No comments

In electricity generation, an electrical generator is a device that converts mechanical energy to electrical energy, generally using electromagnetic induction.800px-modern_steam_turbine_generator

The reverse conversion of electrical energy into mechanical energy is done by a motor; motors and generators have many similarities. A generator forces electric charges to move through an external electrical circuit, but it does not create electricity or charge, which is already present in the wire of its windings. It is somewhat analogous to a water pump, which creates a flow of water but does not create the water inside. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air or any other source of mechanical energy.

Today, the technology of electrical generator is to come to maturity, but its historic developments are complicated.

Before the connection between magnetism and electricity was discovered, electrostatic generators were invented that used electrostatic principles. These generated very high voltages and low currents. They operated by using moving electrically charged belts, plates and disks to carry charge to a high potential electrode. The charge was generated using either of two mechanisms:

Electrostatic induction

The turboelectric effect, where the contact between two insulators leaves them charged.

Because of their inefficiency and the difficulty of insulating machines producing very high voltages, electrostatic generators had low power ratings and were never used for generation of commercially-significant quantities of electric power. The Wimshurst machine and Van de Graff generator are examples of these machines that have survived.

In 1827, Hungarian Anyos Jedlik started experimenting with electromagnetic rotating devices which he called electromagnetic self-rotors. In the prototype of the single-pole electric starter (finished between 1852 and 1854) both the stationary and the revolving parts were electromagnetic. He formulated the concept of the dynamo at least 6 years before Siemens and Wheatstone but didn’t patent it as he thought he wasn’t the first to realize this. In essence the concept is that instead of permanent magnets, two electromagnets opposite to each other induce the magnetic field around the rotor. Jedlik’s invention was decades ahead of its time.

In 1831-1832 Michael Faraday discovered the operating principle of electromagnetic generators. The principle, later called Faraday’s law, is that a potential difference is generated between the ends of an electrical conductor that moves perpendicular to a magnetic field. He also built the first electromagnetic generator, called the ‘Faraday disc’, a type of homopolar generator, using a copper disc rotating between the poles of a horseshoe magnet. It produced a small DC voltage, and large amounts of current.

The Dynamo was the first electrical generator capable of delivering power for industry. The dynamo uses electromagnetic principles to convert mechanical rotation into a pulsing direct electric current through the use of a commutator. The first dynamo was built by Hippolyte Pixii in 1832.

A dynamo machine consists of a stationary structure, which provides a constant magnetic field, and a set of rotating windings which turn within that field. On small machines the constant magnetic field may be provided by one or more permanent magnets; larger machines have the constant magnetic field provided by one or more electromagnets, which are usually called field coils.

Trash-powered generator is ready?

July 22nd, 2009 Grace No comments
Last year, we heard news that scientists at Purdue University have developed a portable generator that uses trash as its primary fuel source. The device was designed at the behest of the U.S. Army. And the generators could also be used in civilian situations, such as emergencies that require portable generators.

About the size of a small moving van, the diesel generator can process several types of refuse, including paper, plastic, Styrofoam, cardboard, woodchips and food waste.

The biorefinery uses two different processes to create fuel.

The machine separates food material into a bioreactor that uses the yeast ferments to create ethanol.

Other materials go to a gasifier and are converted into propane gas and methane, which then fuel the diesel engine that creates electricity.

The system is designed to run on diesel oil for several hours until the gasifier and the bioreactor begin to produce fuel, researchers said.

The Army commissioned completion of a prototype and is considering it for future use. According to its builders, the system lowers the potential danger and expense of transporting fuel and waste and helps cover the tracks of mobile military units because it destroys trash–the evidence of their presence.

The generator is also an environmentally friendly alternative to traditional diesel generators, they say. Using biomass as a fuel is less polluting than oil because plants absorb carbon dioxide, according to scientists at Indiana-based Purdue.

Also, they note that the system is efficient, with the first prototype producing about 90 percent more energy than it consumes.

Maybe the deployment of these “gizmos” might just help turn the tide on the bad guys in the “war” zones: imagine a “Portable, trash-powered generator” to provide combat units with unlimited power for medical equipment usage in cases where the choppers can come under heavy fire and risk being shot down - they can be treated in-house - less travel risks, less risk to supply lines/routes…

sounds a perfect productwhen is it built? Maybe in the future….

 

 

Introduction to Wind Generator

June 4th, 2009 Grace 13 comments

 A wind power generator is a machine that uses wind energy to produce electrical energy. It captures the winds power and converts it into mechanical energy that rotates the blades of a motor to produce electrical energy. Wind generators help produce thousands of megawatts of electricity. They are also a very popular power solution for individual farms. They are perfect for large areas with good wind speed.f0pe5sktqqep27tq3m_medium

 

Wind generators have been in use for a long time in the form of windmills or wind turbines. Years ago, when electricity was not invented, wind turbines were used to pull boats and pump out water.Surprisingly the first use of the wind machines was for grinding grains as early as 200 B.C in Persia. It was also introduced in the prosperous and powerful Roman Empire in 250 A.D. The year 1900 saw the maximum number of windmills being used in Denmark. Almost 2500 windmills were installed to provide the much needed mechanical load to pumps and gave a peak power of 30MW.

 

Even now, the terms, wind generator, windmill, and wind turbine are used to refer to the same device.

 

What are the advantages of using a wind generator? The advantages of a wind generator are many. Let’s look at a few of them.

 

Environment-friendly: Wind power generators prove to be environment-friendly in two ways:

 

They do not emit harmful gases in the atmosphere nor do they leave any harmful residual component.

 

They do not use any fuel to produce electricity, hence helping the cause of the environment.

 

Power-saver: Wind generators are an alternative power solution. They do not use any non-renewable sources of energy, thus helping in times of energy crisis.

 

Economical: Though the initial cost of setting up a wind generator seems high, the cost of generating electricity in the long run becomes nil. So basically, you will be getting electricity absolutely free after a few years.

 

Independent option: Wind generators do away with the dependence on power plants and the government for electricity. With a wind generator in your land, you have your own power plant for life.

 

24/7 power: With wind generators, you can say bye to power outages forever. You will get continuous, uninterrupted power supply for your entire house and land.

 

Power storage: A wind generator also allows you to store power for use later. This feature makes it an amazingly lucrative power solution.

 

With more and more fuels getting wasted and used, there are very few options remaining. Bio-fuel is one of the options and to add to it is the use of solar panels for driving motors and making electricity. The third option is harnessing the wind power. So build a wind generator today and do something good for your home and for our environment.