Engr. Maria Romina P. Angustia-Professor-

What is Electronics?• Electronics deals with electrical circuitsthat

involve active electrical components such as vacuumtubes, transistors, diodes, integrated circuits, associated passive electrical components, and interconnection technologies.

• The science of Electronics is also considered to be a branch of Physics and Electrical Engineering

History of Electronics• Vacuum tubes (Thermionic valves) were among

the earliest electronic components. They were almost solely responsible for the electronics revolution of the first half of the Twentieth Century. They took electronics from parlor tricks and gave us radio, television, phonographs, radar, long distance telephony and much more. They played a leading role in the field of microwave and high power transmission as well as television receivers until the middle of the 1980s.

Vacuum Tube• an electron tube containing a near-vacuum

that allows the free passage of electric current.

• Since that time, solid state devices have all but completely taken over. Vacuum tubes are still used in some specialist applications such as high power RF amplifiers, cathode ray tubes, specialist audio equipment, guitar amplifiers and some microwave devices.

• In April 1955 the IBM 608 was the first IBM product to use transistor circuits without any vacuum tubes and is believed to be the world's first all-transistorized calculator to be manufactured for the commercial market.

By 1958, new, small, solid-state transistors, accompanied by printed circuit techniques, permitted

greater speed and better reliability. Ferrite core technology replaced vacuum tubes for stored programs. That advance meant that two 10-digit numbers could be

multiplied 100,000 times per second.

• Thomas J. Watson Jr. ordered all future IBM products to use transistors in their design. From that time on transistors were almost exclusively used for computer logic and peripherals.

Branches of Electronics• Digital electronics• Analogue electronics• Microelectronics• Circuit design• Integrated circuits• Optoelectronics• Semiconductor devices• Embedded systems

• Digital electronics or digital (electronic) circuits are electronics that handle digital signals.

• Analogue electronics (also spelled analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term "analogue" describes the proportional relationship between a signal and a voltage or current that represents the signal. The word analogue is derived from the Greek word ανάλογος (analogos) meaning "proportional".

• Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture (or microfabrication) of very small electronic designs and components. Usually, but not always, this means micrometre-scale or smaller.

• The process of circuit design can cover systems ranging from complex electronic systems all the way down to the individual transistors within an integrated circuit.

• An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, normally silicon. This can be made much smaller than a discrete circuit made from independent electronic components - a modern chip may have several billion transistors in an area the size of a human fingernail.

• Optoelectronics is the study and application of electronic devices and systems that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light.

• Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide, as well as organic semiconductors.

• An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computingconstraints.It is embedded as part of a complete device often including hardware and mechanical parts. Embedded systems control many devices in common use today.Ninety-eight percent of all microprocessors are manufactured as components of embedded systems.

Application of Electronics• Entertainment and Communication:Availability of economical and fast means of communication paves the way for progress of a country. Few decades ago, the main application of electronics was in the field of telephony and telegraphy. Now, with the aid of radio waves we can transmit any message from one place to another, with out the use of wires. Radio and TV broadcasting offers a means of both entertainment as well as communication. Today, Electronics gadgets are widely used for entertainment

• Defence Applications:Defence applications are completely controlled by electronic circuits. RADAR that is Radio Detection and Ranging is the most important development in electronics field. With the help of radar it is possible to detect and find the exact location of enemy aircraft. Radar and anti craft guns can be linked by an automatic control system to make a complete unit

• Industrial Application:Electronics circuits are widely being used in industrial applications such as control of thickness, quality, weight and moisture content of a material. Electronic amplifier circuits are used to amplify signals and thus control the operations of automatic door openers, power systems and safety devices. Electronically controlled systems are used for heating and welding in the industry. The most important industrial application is that the power stations which generate thousands of megawatts of electricity are controlled by tiny electronic devices and circuits.

• Medical Services:Electronics systems are being used by Doctors and scientists in the diagnosis and treatment of various diseases. X-rays, ECG, Short eave diathermy units and oscillographs are some instruments which have been used so far in medical science. The use of electronics in medical science has grown so extremely and is useful in saving the life of mankind from a lot of sufferings.

• Instrumentation:Electronics instruments such as cathode-ray oscilloscopes, frequency counters, signal generators, strain gauges are of great help in for precise measurement of various quantities. Without these electronic instruments no research laboratory is complete.