ELECTRONIC/COMPUTER AGE. Electronic/Computer Age Electronics –Electrical signals can carry information quickly over wires or through the air by radio.
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Presentation on theme: "ELECTRONIC/COMPUTER AGE. Electronic/Computer Age Electronics –Electrical signals can carry information quickly over wires or through the air by radio."— Presentation transcript:
Electronic/Computer Age Electronics –Electrical signals can carry information quickly over wires or through the air by radio –Light, Appliances and Entertainment Atoms –An atom is the tiniest part of a material –There are only 109 elements known to exist –Compounds --- different kinds of atoms combined together, e.g. table salt, water etc –A compound has properties all its own –Atoms are made of smaller particles with their own properties –Protons and neutrons in the nucleus and electrons in the orbits circling the nucleus --- protons and electrons have diff. charges
Electronic/Computer Age Electric Current –Materials whose atoms give up some electrons easily are conductors –Materials that hold tightly to their electrons are insulators –The flow of electrons is current --- Amperes –1 amp = 6 billion billion electrons flowing past a point in 1 sec –Electromotive force makes a current flow --- Volts –A battery provides electromotive force –Resistance is the opposition to a flow of current --- Ohm’s law –V = IR or I = V/R
Electronic Components & Circuits –Electronic components or parts control the flow of electricity --- each component has its own symbol –Circuits --- different forms in which components are connected –Schematics --- drawings that show plans for circuits –A resistor is used to control the flow of current --- 0.1 – 10 6 –Color coded bands indicate the resistance in ohms –Semiconductors are neither good insulators or good conductors, e.g silicon –A diode is made using a semiconductor, it lets current flow in only one direction
Electronic Components & Circuits Transistor –A resistor that lets a small amount of current control the flow of a much larger amount of current, e.g. motors, computers –It is a square wafer a few thousandths of an inch on a side –A thermistor has a resistance that changes with temperature –A photoresistor has a resistance that changes with the amount of light hitting it Printed Circuits –Solder is a method of joining two wires together –Wires’ contact causes an unintended flow of current --- short circuit --- use of insulation –A printed circuit board is a thin board of an insulating material like fiberglass –The conducting paths are photographically placed over it
Electronic Components & Circuits –Once components are mounted on the board, they can be soldered by an automatic soldering machine Integrated Circuits –It provides a complete circuit on a tiny bit of semiconductor –They are often less than 1/10 th of an inch in length and width –The drawing of a chip is photographically reduced to form a mask –Chips have replaced large bulky circuits and are quite less in volume and price –Computers are built using large ICs Analog and Digital Circuits –An analog circuit works with analog signals –In digital circuits, a voltage above a certain value is coded as a 1 and a voltage below that value is coded as a 0.