Unveiling the Mystery of Transistors: What are the Brain Cells of Computers?

many inventions are conceived simultaneously by several different people because the time is right meaning that a technical and scientific Foundation exists and that there is demand and business potential for the invention the transistor however is an invention that was conceived long before the time was right it was invented in 1947. the inventors themselves believed that the transistor might be used in some special instruments and in military radio equipment yet the transistor is fundamental for all modern technology including telecommunications data Communications Aviation and audio and video recording equipment a transistor is really simple and really complex a transistor is a miniature Electronic Component that can do two different jobs it can work either as an amplifier or a switch amplifier in simple words is a current booster it is useful in things like hearing aids one of the first things people used transistors for how are transistors made transistors are made from silicone a chemical element found in sand which does not normally conduct electricity silicon is a semiconductor which means it's neither really a conductor nor an insulator if we treat silicon with impurities a process known as doping we can make it behave in a different way silicon can be treated into two types n-type negative and p-type positive if atoms lose electrons they become positive ions or cations if atoms gain electrons they become negative ions or anions we now have two different types of silicon if we put them together in layers making sandwiches of p-type and n-type material we can make different kinds of electronic components that work in all kinds of ways if we turn on the circuit we can make electrons flow through the junction from the n-type side to the p-type side and out through the circuit this happens because of the lack of electrons on the p-type side of the junction pulls electrons over from the n-type side and vice versa but if we reverse the current the electrons won't flow at all what we have made here is called a diode or Rectifier it's an electronic component that lets current flow through it in Only One Direction it's useful if you want to turn alternating two-week electric current into direct one-way current diodes can also be made so they give off light when electricity flows through them these are what you call LEDs how a junction transistor works now suppose we use three layers of silicone in our sandwich instead of two we can either make a PNP sandwich with a slice of n-type silicone as the filling between two slices of p-type or an npn sandwich with the p-type in between the two slabs of n-type if we join electrical contacts to all three layers of the sandwich we can make a component that will either amplify a current or switch it on or off in other words a transistor let's see how it works in the case of an npn transistor so we know what we are talking about let's give names to the three electric contacts we'll call the two contacts joined to the two pieces of n-tap silicon the emitter and The Collector the contact joined to the p-type Silicon we'll call the base when no current is flowing in the transistor we know the ptap silicone is short of electrons shown here by little plus signs and the two pieces of n-type silicon have extra electrons shown by little minus signs there the excess electrons from n-type go to the vacant spaces in the p-type there are no more excess electrons in the n-type and this creates a depletion layer this makes the p-tab negative making it to Ripple electrons that come across the n-type and preventing the flow of electric current through the transistor let's connect the transistor up to some power suppose we attach a small positive voltage to the base make the emitter negatively charged and make the collector positively charged the depletion layer shrinks electrons are pulled from the emitter into the base and then from the base into the collector and the transistor switches to its own state the small current that we turn on at the base makes a big current flow between the emitter and The Collector by turning a small input current into a large output current the transistor acts like an amplifier but it also acts like a switch at the same time when there is no current to the base little or no current flows between the collector and the emitter turn on the base current and the big current flows so the base current switches the whole transistor on and off technically this type of transistor is called bipolar because two kinds or polarities of electric charge are involved in making the current flow how does a field affect transistor fet works all transistors work by controlling the movement of electrons but not all of them do it the same way like a junction transistor fet has three different terminals they have the names Source drain and gate in a fet the layers of n-type and p-tap silicon are arranged in a slightly different way and coated with layers of metal and oxide that gives us a device called moveset metal oxide semiconductor Field Effect transistor although there are extra electrons in the n-type source and drain they cannot flow from one to the other because there is no charge in the gate if we attach a positive voltage to the gate an electric field is created there that allows electrons to flow in a thin channel from the source to the drain this Field Effect also allows the current to flow and switches the transistor on how do transistors work in calculators and computers we can put a few transistor switches together to make something called a logic gate which Compares several input currents and gives a different output as a result logic gates let computers make very simple decisions using a mathematical technique called Boolean algebra your brain makes decisions the same way Boolean algebra uses operators like and or nor sore not and nand so that computers can add up or compare binary numbers today transistors are only about 50 atoms wide in the upcoming years they will be made more small

Channel: The Science Builds

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Keywords: brain cells of computers, transistors, transistors explained, transistor as an amplifier, transistor as a switch, transistor class 12 physics, transistors semiconductors, transistors in computer, science, technology, transistors and diodes, electronics, circuit, how transistors work, bipolar junction transistor, what is a transistor, npn transistor, mystery of transistors, transistors explained - how transistors work, Electronics engineering, brain computer interface, neuroscience

Id: zHj2c3SjxH0

Length: 8min 27sec (507 seconds)

Published: Wed Dec 07 2022