Electricity
Electricity is all around us. We have electric lights, electric clocks, we have mobilephones, calculators, television, V-recorders, CD-players, MP3-players, radio, computers. Light it self is an electromagnetic phenomenon, as radio waves are. The colors of the ribbon on the blue sky are they because of electricity.
Walter Lewin
Technology Defined
Webster’s dictionary defines technology as “the practical application of knowledge especially in a particular area” and “a manner of accomplishing a task, especially using technical processes or methods”. The etymology of both words, technology and technical, is the Greek word techne meaning art or skill, maybe even craftsmanship.
The basics of synchronous machines
Synchronous machines can be used as generators or motors. They are of 3-phase construction, even though some special exceptions can be found. A bulk of the applications are within power ranges roughly varying from a megawatt level to several tenths (or even hundreds) of megawatts with rated voltages from 3 kV to 15 kV.
History of Electric Christmas Tree Lights
Like so many things electrical, the history of electric Christmas lights begins with Thomas Edison.
During the Christmas season of 1880, Edison, who had invented the incandescent bulb the previous year, hung strings of electric lights outside his laboratory in Menlo Park, New Jersey.
Interactive animation to learn electric cicuitFundamental characteristics of circuit breaker
Apart from small circuit breakers which are very easily replaced, industrial circuit breakers are equipped with removable, i.e. exchangeable, overcurrent-trip relays. Moreover, in order to adapt a circuit breaker to the requirements of the circuit it controls, and to avoid the need to install over-sized cables, the trip relays are generally adjustable.
