Gyaan Series

JUNCTION FIELD EFFECT TRANSISTOR The JFET is abbreviated as Junction Field Effect Transistor. JFET is just like a normal FET. The types of JFET are n-channel FET and P-channel FET. A p-type material is added to the n-type substrate in n-channel FET, whereas an n-type material is added to the ptype substrate in p-channel FET. Hence it is enough to discuss one type of FET to understand both. N-Channel FET: The N-channel FET is the mostly used Field Effect Transistor. For the fabrication of Nchannel FET, a narrow bar of N-type semiconductor is taken on which P-type material is formed by diffusion on the opposite sides. These two sides are joined to draw a single connection for gate terminal. This can be understood from the following figure.  These two gate depositions (p-type materials) form two PN diodes. The area between gates is called as a channel. The majority carriers pass through this channel. Hence the cross sectional form of the FET is understood as ...

FIELD EFFECT TRANSISTOR A  FET is a three-terminal unipolar semiconductor device . It is a voltage controlled device unlike a bipolar junction transistor. The main advantage of FET is that it has a very high input impedance, which is in the order of Mega Ohms. It has many advantages like low power consumption, low heat dissipation and FETs are highly efficient devices. The following image shows how a practical FET looks like.  The FET is a unipolar device, which means that it is made using either p-type or n-type material as main substrate. Hence the current conduction of a FET is done by either electrons or holes. Features of FET: The following are the varied features of a Field Effect Transistor. . Unipolar − It is unipolar as either holes or electrons are responsible for conduction. . High input impedance − The input current in a FET flows due to the reverse bias. Hence it has high input impedance. . Voltage controlled device...

BIPOLAR JUNCTION TRASISTOR A Bipolar junction transistor, shortly termed as BJT is called so as it has two PN junctions for its function. This BJT is nothing but a normal transistor. It has got two types of configurations NPN and PNP. Usually NPN transistor is preferred for the sake of convenience. The following image shows how a practical BJT looks like. The types of BJT are NPN and PNP transistors. The NPN transistor is made by placing a ptype material between two n-type materials. The PNP transistor is made by placing an ntype material between two p-type materials. BJT is a current controlled device. A normal transistor which we had discussed in the previous chapters come under this category. The functionality, configurations and applications are all the same.  

Types of Transistors There are many types of transistors in use. Each transistor is specialized in its application. The main classification is as follows.  The primary transistor is the BJT and FET is the modern version of transistor.  

TRANSISTORS   A transistor is a solid-state device made by joining three positive-type and negative-type semiconductors together. In general, all transistors have three pins: base , collector , and emitter . Transistor is a bi-polar device that is a transistor with two junctions namely BE and CE DE EE FE. In theory we take a specified formulae incorporate this with using any type of meter in figuring the mathematical solution.  A Transistor is a three terminal semiconductor device that regulates current or voltage flow and acts as a switch or gate for signals. Why Do We Need Transistors? Suppose that you have a FM receiver which grabs the signal you want. The received signal will obviously be weak due to the disturbances it would face during its journey. Now if this signal is read as it is, you cannot get a fair output. Hence we need to amplify the signal. Amplification means increasing the signal strength. This is just an instance. Amplificat...

INDUCTORS Let me introduce you to another important component in the field of Electronics and Electricals, the Inductor. Inductor is a passive two-terminal component that temporarily stores energy in the form of a magnetic field. It is usually called as a coil. The main property of an inductor is that it opposes any change in current. According to the Faraday’s law of Electromagnet ic induction, When the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor. According to lens law, the direction of induced EMF opposes the change in current that created it. Hence, induced EMF is opposite to the voltage applied across the coil. This is the property of an inductor.  An inductor blocks any AC component present in a DC signal. The inductor is sometimes wrapped upon a core, for example a ferrite core. It then looks as in the figure below. Symbols: The symbols of various types of...

TYPES OF CAPACITORS There are many types of capacitors depending upon their function, the dielectric material used, their shape etc. The main classification is done according to fixed and variable capacitors.  The main classification is just like the above one. The fixed capacitors are the ones whose value is fixed at the time of manufacturing itself and the variable ones provide us with an option to vary the value of capacitance.   Types: There are different types of capacitors available in the market. The key factor in distinguishing different types of capacitors is the Dielectric used in its construction. Some of the common capacitor types are ceramic, electrolytic (which include Aluminium capacitors, Tantalum capacitors and Niobium capacitors), plastic film, paper and mica. Each capacitor type has its own advantages and disadvantages. The characteristics and areas of applications may vary from one capacitor to other. Hence, when choosing a capacitor, follow...