A Little History About Ohm

George Simon Ohm was a German physicist born in Erlangen, Bavaria, March 16, 1787. As a high school teacher, Ohm began his research with the cell, newly invented electricity, invented by Alessandro Volta Italian Conte. The use of computer of their own creation, Ohm found that the current flowing in a wire is proportional to its cross section and inversely proportional to its length. Using the results of their experiments, Georg Simon Ohm was able to define the fundamental relationship between voltage, current and resistance. These relationships are of such fundamental importance that represent the true beginning of electrical circuit analysis. Unfortunately, when Ohm published his discovery in 1827, his ideas were rejected by their peers. Ohm was forced to resign from his teaching job in high school and lived in poverty and shame. However, his research award won support outside Germany.

In 1849 Georg Simon Ohm finally recognized for his efforts to be appointed professor at the University of Munich.

Invention Of The Transistor By John Bardeen, Walter Brattain And William Shockley In 1947

Almost every piece of equipment that stores, transmits, displays or manipulates information to his heart full of electronics silicon chip. These chips of each house of thousands, even millions of transistors.

The history of the transistor 1800 begins a dramatic scientific discoveries, scientists such as Maxwell, Hertz, Faraday, Edison and electricity could be harnessed for human use. Inventors such as Braun, Marconi, Fleming and DeForest to apply the information for the development of electrical equipment such as radio.

Their work was created by Bell Labs, whose scientists challenge was to use this information to create practical and useful electronic devices for communication. Teams of Bell Labs scientists, such as Shockley, Brattain, Bardeen, and many others .-- responded to this challenge and came up with the information age. They stood on the shoulders of great inventors, to produce 19 century greatest invention of our time: the transistor.

The transistor was invented in 1947 at Bell Labs by a team led by physicists John Bardeen, Walter Brattain and William Shockley. Initially, the team has not been high on the list of possible applications of this little device. This is not surprising that the first computers were built in 1940 and 1950, some scientists have seen in them the seed of a technology that, in just a few decades to penetrate almost all spheres of human life. Before the digital explosion, the transistors are a vital part of improving the existing analog systems, such as radios and stereos.

When it was put in computers, however, the transistor has become an integral part of the dotcom boom. They are also capable of mass-produced by millions sliver of silicon semiconductor chips. And 'this almost unlimited capacity to integrate on-chip transistors, which has fueled the information age. Today, these chips are not only part of the computer. They are also important in many devices such as cameras, cell phones, copiers, jumbo jets, modern cars, manufacturing equipment, electronic scoreboards, video and games. Without the transistor would not have the Internet and space travel.

Years after its creation, the transistor replaced the large, fragile vacuum tubes that had been used to enhance and change the signals. The transistor became the building block of all modern electronics and the foundation for microchip and computer technology.

Quartz watch

(1927, W.A. Marrison and J.W. Horton)

The original quartz clock, the invention of J.W. Horton and Warren A. Marrison, took up the better part of a small room. Today, quartz clocks are built into calculators and PC, and quartz watches are everywhere. They are far and away the most popular timekeepers. Depending on the size, shape, and vibration frequency of its crystal, a quartz timepiece can keep time accurately to about one second every ten years.

Before the innovation of the quartz clock, a second had been defined as 1 86,400 of a twenty four hour period -- that is, of the average duration of one rotation of the Earth. The quartz clock itself did not provide a new definition of the second, but its precision helped scientists identify irregularities in the Earth's rotation that showed our planet was not a reliable baseline for timekeeping. 

The reasons that quartz clocks did not redefine the second is that the oscillations, or vibrations, of quartz crystals begin to drift over a long period. This drifting can be due to temperature changes, impurities in the quartz, or the cumulative effects of the vibrations. The new second would have to wait for the visual aspect of the atomic clock.

Quartz mechanicses are highly precise because a quartz crystal vibrates thousands or millions of times a second when exposed to alternating electric fields. Inside a quartz watch, electric current from the battery causes the quartz crystal to vibrate. A microprocessor divides down the high frequency to a much slower electric pulse that is transmitted to the coil. The current pulsating through the coil activates a tiny magnet, which switches rapidly backward and forward in time with the pulse. As the magnet switches backward and forward, it turns a small pinion that controls the watch's gear train, completing the conversion of the crystal's vibration to mechanical movement.