Car maintenance - can you do it?

he mobility of citizens. Public transport, by comparison, becomes increasingly uneconomic with lower population densities. Hence cars tend to dominate in rural and suburban environments with public economic gains. The automobil

Dodane: 05-09-2016 16:40
Car maintenance - can you do it? mot fail emissions test

Cars and costs - from Wikipedia

In countries deprived from wide door-to-door public transport and with low density, such as Australia, the automobile plays an important role on the mobility of citizens. Public transport, by comparison, becomes increasingly uneconomic with lower population densities. Hence cars tend to dominate in rural and suburban environments with public economic gains.

The automobile industry, mainly in the beginning of the 20th century when the high motorization rates were not an issue, had also an important public role, which was the creation of jobs. In 1907, 45,000 cars were produced in The United States, but 28 years later in 1935 3,971,000 were produced, nearly 100 times as many. This increase in production required a large, new work force. In 1913 13,623 people worked at Ford Motor Company, but by 1915 18,028 people worked there.10 Bradford DeLong, author of The Roaring Twenties, tells us that, "Many more lined up outside the Ford factory for chances to work at what appeared to them to be (and, for those who did not mind the pace of the assembly line much, was) an incredible boondoggle of a job.10" There was a surge in the need for workers at big, new high-technology companies such as Ford. Employment largely increased.


Historical facts about electric motor

Perhaps the first electric motors were simple electrostatic devices created by the Scottish monk Andrew Gordon in the 1740s.2 The theoretical principle behind production of mechanical force by the interactions of an electric current and a magnetic field, Amp?re's force law, was discovered later by André-Marie Amp?re in 1820. The conversion of electrical energy into mechanical energy by electromagnetic means was demonstrated by the British scientist Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury, on which a permanent magnet (PM) was placed. When a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire.3 This motor is often demonstrated in physics experiments, brine substituting for toxic mercury. Though Barlow's wheel was an early refinement to this Faraday demonstration, these and similar homopolar motors were to remain unsuited to practical application until late in the century.

Jedlik's "electromagnetic self-rotor", 1827 (Museum of Applied Arts, Budapest). The historic motor still works perfectly today.4
In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils. After Jedlik solved the technical problems of the continuous rotation with the invention of the commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for instructional purposes, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator, rotor and commutator. The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings


Gas turbines

Gas turbines
Main article: gas turbine
Turbine Power Plant

A gas turbine compresses air and uses it to turn a turbine. It is essentially a Jet engine which directs it's output to a shaft. There are three stages to a turbine: 1) air is drawn through a compressor where the temperature rises due to compression, 2) fuel is added in the combuster, and 3) hot air is exhausted through turbines blades which rotate a shaft connected to the compressor.

A gas turbine is a rotary machine similar in principle to a steam turbine and it consists of three main components: a compressor, a combustion chamber, and a turbine. The air, after being compressed in the compressor, is heated by burning fuel in it. About ? of the heated air, combined with the products of combustion, expands in a turbine, producing work output that drives the compressor. The rest (about ?) is available as useful work output. 26

Gas Turbines are among the MOST efficient internal combustion engines. The General Electric 7HA and 9HA turbine electrical plants are rated at over 61% efficiency. 27